Exploring meteorite mysteries - USRA Houston Repository

Exploring Meteorite MysteriesA Teacher�s Guide with Activities for

Earth and Space Sciences

Educational ProductTeachers Grades 5-12National Aeronautics and

Space Administration

Exploring Meteorite MysteriesA Teacher�s Guide with Activities for

Earth and Space Sciences

EG-1997-08-104-HQNational Aeronautics andSpace Administration

Office of Space ScienceSolar System Exploration Division

Office of Human Resources and Education

Education Division

August 1997

This publication is in the Public Domain and is not copyrighted.Permission is not required for duplication.

i NASA EG-1997-08-104-HQ

Acknowledgements

This teacher’s guide was developed in a partnership betweenscientists in the Planetary Materials Office, at NASA’s Johnson SpaceCenter in Houston, Texas, and teachers from local school districts.

On the Cover—

Several aspects of a meteoritefall are depicted on the cover.The background is a paintingcreated by an eyewitness ofthe Sikhote-Alin fireball. Atthe top is the asteroid Ida, apossible source of meteorites.At the bottom is MeteorCrater in Arizona—the firstidentified meteorite impactcrater.

*Now at the Lunar & Planetary Institute, Houston, Texas. **Now at Antarctic Support Services, Denver, Colorado.

NASA and Contractor Staff

Marilyn LindstromProject Coordinator and Meteorite CuratorNASA Johnson Space CenterHouston, Texas

Jaclyn AllenScientist and Science Education SpecialistLockheed Martin Engineering & Sciences Co.Houston, Texas

Allan Treiman* and Carl AllenPlanetary ScientistsLockheed Martin Engineering & Sciences Co.Houston, Texas

Anita DodsonGraphic DesignerLockheed Martin Engineering & Sciences Co.Houston, Texas

Teachers

JoAnne BurchPearland ISD,ElementaryPearland, Texas

Karen CrowellPasadena ISD,ElementaryPasadena, Texas

Roy LukschAlvin ISD,High SchoolAlvin, Texas

Karen StoccoPasadena ISD,High SchoolPasadena, Texas

Bobbie SwabyPasadena ISD,Middle SchoolPasadena, Texas

Kay TobolaAlvin ISD,Middle SchoolAlvin, Texas

We would also like to thank the following for reviews and meteorite samples:

NASA - Don Bogard, Mark Cintala, Everett Gibson, Kathleen McBride, Dave Mittlefehldt, Larry Nyquist, CeciliaSatterwhite, Carol Schwarz, Roberta Score,** Faith Vilas, and Mike Zolensky.

NASA/OSU - Richard Adams, Jim Fitzgerald, Larry Gilbert, Les Gold, Tibisay Marin, Debbie Shearer, Greg Vogt,and Ralph Winrich.

Teachers - Gregg Baumgartner, Stephanie McNeel, and Susan Ross (Alvin ISD); Jean Groover and John Ristvey(Clear Creek ISD); Cathy Corley and Jeanie Thuneman (Friendswood ISD) and John Beasley (Stafford MSD).

Organizations - U.S. Antarctic Program (NSF), NNMH Smithsonian Institution, NASA, and the Field Museum ofNatural History.

National Aeronautics andSpace AdministrationLyndon B. Johnson Space CenterEarth Science and Solar SystemExploration Divison

ii NASA EG-1997-08-104-HQ

Contents

About Exploring Meteorite Mysteries ........................................................................................................................... iiiAbout the Meteorite Disk ................................................................................................................................................ ivAbout the Slide Set .......................................................................................................................................................... ivScience Process Skills ...................................................................................................................................................... vScience and Mathematics Standards ..............................................................................................................................viiLesson Topic Planner ...................................................................................................................................................... ixLesson Sequence Suggestions ......................................................................................................................................... x

Teacher’s GuideMeteorites, Clues to Solar System History ............................................................................................................... 1Meteorite ABC’s Fact Sheet .................................................................................................................................... 29Solar System ABC’s Fact Sheet .............................................................................................................................. 31

Mysterious MeteoritesLesson 1: Noblesville Fall ..................................................................................................................................... 1.1

Where Do They Come From?Lesson 2: Follow the Falling Meteorite ................................................................................................................. 2.1Lesson 3: Searching for Meteorites ....................................................................................................................... 3.1Lesson 4: The Meteorite-Asteroid Connection ..................................................................................................... 4.1Lesson 5: Looking at Asteroids ............................................................................................................................. 5.1Lesson 6: Impact Craters — Holes In the Ground! ................................................................................................ 6.1Lesson 7: Crater Hunters ........................................................................................................................................ 7.1

What Are They?Lesson 8: Edible Rocks ......................................................................................................................................... 8.1Lesson 9: Meteorite Sleuths! ................................................................................................................................. 9.1

How Did They Form?Lesson 10: Building Blocks of Planets ............................................................................................................... 10.1Lesson 11: Changes Inside Planets ...................................................................................................................... 11.1Lesson 12: Building Blocks of Life ..................................................................................................................... 12.1Lesson 13: Solving a Mystery ............................................................................................................................. 13.1

What Effect Do They Have?Lesson 14: Direct Hit at the K-T Boundary ......................................................................................................... 14.1Lesson 15: Historical Meteorite Falls .................................................................................................................. 15.1Lesson 16: Near Miss ........................................................................................................................................... 16.1

How Can I Use Them?Lesson 17: Asteroid Resources ............................................................................................................................ 17.1

Is There a Career for Me?Lesson 18: Antarctic Meteorite Teams ................................................................................................................. 18.1

What Can We Believe?Lesson 19: The Daily Shooting Star .................................................................................................................... 19.1

Glossary ........................................................................................................................................................................ A.1Education Resources .................................................................................................................................................... B.1

iii NASA EG-1997-08-104-HQ

About Exploring Meteorite Mysteries

Teachers and scientists designed this book to engage students in inquiry science and to extend science withinterdisciplinary connections. The study of meteorites provides a unifying theme that links almost everyaspect of Earth and planetary science with mathematics, physics, chemistry and even biology. The effects ofmeteorite impacts have serious implications for social science. The activities in this book are designed forupper elementary to high school levels. Many of the lessons begin with a simple activity and build to morecomplex ones. The Curriculum Content Matrix, Lesson Topic Planner and Lesson Sequence Suggestionsmay assist teachers in integrating the meteorite activities with their existing Earth science curricula andstandards requirements.

The Teacher’s Guide, Meteorites, Clues to Solar System History, gives a broad introduction to manyaspects of meteorite science. It tells the story of solar system history from the formation of the planets tocatastrophic impacts on Earth. It helps the students learn how scientists use studies of these rocks fromspace to decipher that history. The Meteorite ABC’s and Solar System ABC’s Fact Sheets containimportant information about meteorites and bodies in the solar system in convenient table format.

The Activities are divided into units based on key questionsstudents may ask about meteorites. For example, the unitentitled “Where do they come from?” contains six lessons withmany activities that explore that question. The activities rangefrom introductory impact experiments to rather complex orbitconstructions that use beginning geometry. Some lessons aredesigned to use the Meteorite Sample Disk, although mostlessons do not require the disk. All the lessons could betaught in the science classroom, but many lessons couldbe used in other areas. The lessons include both teacherand student pages, both of which may be copied asneeded. Measurements are given in metric units withsome English units in parentheses for commonhousehold items.

The book concludes with a Glossary and anEducation Resources section. Key words thatappear in bold in the Teachers’ Guide or asvocabulary in the Activities are defined in theglossary. The Education Resources section listsspecific books and supporting materials formeteorites. It also provides a guide to accessing thebroad range of NASA resources for educators.

iv NASA EG-1997-08-104-HQ

About the Slide Set

About the Meteorite Sample Disk

The Meteorite Sample Disk contains six labeled meteorites embedded ina 15 cm plastic disk. These pieces of asteroids represent the products ofbasic planetary processes: accretion, differentiation, volcanism andimpact. Educators may borrow the Meteorite Sample Disk containingthese rocks from space to help students learn about the early history ofthe solar system. The Meteorite Sample Disk package contains the disk,a copy of this activity guide, and the Exploring Meteorite Mysteriesslide set described below.

To borrow the Meteorite Sample Disk educators must first attend a shortcertification briefing on security requirements and handling procedures.

This is the same certification as for borrowing the Lunar Sample Disk. These briefings are given by NASAstaff at locations around the country. Following certification educators may request the loan of the disks forperiods of one to two weeks. Written requests should be sent to the NASA Educator Resource Center inyour geographic area at least one month before the requested loan date. For more information onscheduling certification and request procedures, educators should contact their Educator Resource Centerat the locations given on page B.2 at the end of this book.

A set of forty-eight 35 mm slides has been prepared to supplement theactivities in this Exploring Meteorite Mysteries book. The slides andnarrative descriptions are divided into four parts. The first 25 slidespresent a general introduction to meteorites and what they tell us about thehistory of the solar system. It begins with observations of meteorite falls,depicts meteorites and their formation processes, and concludes with theirimpact on life and future exploration of the solar system. The remaining threeparts are more detailed sections for use with various lessons in the activity guide. These sections reusesome of the slides from the introduction. One section on impact craters illustrates craters on Earth, theMoon and other planets. The next section on classification and formation depicts various meteorite typesand the processes of accretion, differentiation, volcanism, and impact. The final section shows collection,curation, and research on Antarctic meteorites.

The slide set is distributed to educators with the Meteorite Sample Disk. Anyone desiring a permanentcopy of the slide set may order it at cost from NASA Central Operation of Resources for Educators(CORE). The address and various contacts for CORE are listed on page B.2 at the back of this book.

T his c h art is d esi g n e d t o assist t e a c h ers i n i nt e gr ati n g t h e a cti viti es c o nt ai n e d i n t h e g ui d e wit h e xisti n g c urri c ul a.

Obs

ervi

ng

Clas

sifyi

ng

Co

mmuni

cati

ng

Meas

uring

Inf

erri

ng

Predi

cting

Experi

ment

al Des

ign

Gat

hering

and

Organi

zing

Dat

a

Cont

roll

ing

Vari

abl

es

Dev

elopi

ng

a Hy

pot

hes

is

Extendi

ng

Sens

es

Res

ear

chi

ng

Tea

m Wor

k

Mat

he

mati

cs

Int

erdi

scipli

nar

y

Introduc

tor

y Ac

tivit

y

Adv

anc

ed

Acti

vity

U nit L e s s o n

M y st eri o u s L e s s o n 1 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔M et e orit e s N o bl e s vill e F all

“ W h er e D o L e s s o n 2 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔T h e y C o m e F oll o w t h eFr o m ?” F alli n g M et e orit e

L e s s o n 3 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔S e ar c hi n gf or M et e orit e s

L e s s o n 4 ✔ ✔ ✔ ✔ ✔ ✔ ✔T h e M et e orit e-A st er oi dC o n n e cti o n

L e s s o n 5 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔L o o ki n g atA st er oi d s

L e s s o n 6 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔I m p a ct Cr at er s —H ol e s i n t h eGr o u n d!

L e s s o n 7 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔Cr at er H u nt er s

“ W h at Ar e L e s s o n 8 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔T h e y ?” E di bl e R o c k s

Obs

ervi

ng

Clas

sifyi

ng

Co

mmuni

cati

ng

Meas

uring

Inf

erri

ng

Predi

cting

Experi

ment

al Des

ign

Gat

hering

and

Organi

zing

Dat

a

Cont

roll

ing

Vari

abl

es

Dev

elopi

ng

a Hy

pot

hes

is

Extendi

ng

Sens

es

Res

ear

chi

ng

Tea

m Wor

k

Mat

he

mati

cs

Int

erdi

scipli

nar

y

Introduc

tor

y Ac

tivit

y

Adv

anc

ed

Acti

vity

U nit L e s s o n

“ W h at Ar e L e s s o n 9 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔T h e y ?” M et e orit e Sl e ut h s!

“ H o w Di d L e s s o n 1 0 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔T h e y B uil di n g Bl o c k sF or m ?” of Pl a n et s

L e s s o n 1 1 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔C h a n g e s I n si d ePl a n et s

L e s s o n 1 2 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔B uil di n g Bl o c k sof Lif e

L e s s o n 1 3 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔S ol vi n g aM y st er y

“ W h at L e s s o n 1 4 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔Eff e ct D o Dir e ct Hit at t h eT h e y K- T B o u n d ar yH a v e ?”

L e s s o n 1 5 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔Hi st ori c alM et e orit e F all s

L e s s o n 1 6 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔N e ar Mi s s

“ H o w C a n I L e s s o n 1 7 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔U s e T h e m ? A st er oi d R e s o ur c e s

“I s T h er e L e s s o n 1 8 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔a C ar e er A nt ar cti c M et e orit ef or M e ?” T e a m s

“ W h at C a n L e s s o n 1 9 ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔W e T h e D ail y S h o oti n gB eli e v e ?” St ar

L e s s o n 1N o bl e s vill e F all ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔

L e s s o n 2F oll o w t h e ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔F alli n g M et e orit e

L e s s o n 3S e ar c hi n g ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔f or M et e orit e s

L e s s o n 4T h e M et e orit e-A st er oi d ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔C o n n e cti o n

L e s s o n 5L o o ki n g at ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔A st er oi d s

L e s s o n 6I m p a ct Cr at er s —H ol e s i n t h e ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔Gr o u n d!

L e s s o n 7Cr at er H u nt er s ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔

L e s s o n 8E di bl e R o c k s ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔

Scienc

e as

Inquiry

Struc

tur

e and

Ener

gy o

f the

Earth

Syst

em

Origi

n and

Hist

ory

of t

he

Earth

Earth i

n the

Sol

ar

Syst

em

Geoc

he

mical

Cycl

es

Phy

sical

Scienc

e

Popul

ations

and

Ecos

yste

ms

Under

standi

ng

about Sc

ienc

e and

Technol

ogy

Scienc

e in

Per

sonal

and

Soc

ial

Per

spec

tives

Hist

ory

and

Nat

ure

of Sc

ienc

e

Probl

em

Sol

ving

Meas

ure

ment

Co

mput

ation

and

Esti

mati

on

Co

mmuni

cati

on

Geo

metry

and

Adv

anc

ed

Mat

he

mati

cs

Stati

stics

and

Probabil

ity

Nu

mber a

nd

Nu

mber

Rel

ations

hips

Patter

ns a

nd

Func

tions

L e s s o n 9M et e orit e Sl e ut h s ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔

L e s s o n 1 0B uil di n g Bl o c k s of ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔Pl a n et s

L e s s o n 1 1C h a n g e s I n si d e ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔Pl a n et s

L e s s o n 1 2B uil di n g Bl o c k s ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔of Lif e

L e s s o n 1 3S ol vi n g a M y st er y ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔

L e s s o n 1 4Dir e ct Hit at t h e K- T ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔B o u n d ar y

L e s s o n 1 5Hi st ori c al M et e orit e ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔F all s

L e s s o n 1 6N e ar Mi s s ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔

L e s s o n 1 7A st er oi d R e s o ur c e s ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔

L e s s o n 1 8A nt ar cti c M et e orit e ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔T e a m s

L e s s o n 1 9T h e D ail y S h o oti n g ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔ ✔✔✔✔✔St ar

Scienc

e as

Inquiry

Struc

tur

e and

Ener

gy o

f the

Earth

Syst

em

Origi

n and

Hist

ory

of t

he

Earth

Earth i

n the

Sol

ar

Syst

em

Geoc

he

mical

Cycl

es

Phy

sical

Scienc

e

Popul

ations

and

Ecos

yste

ms

Under

standi

ng

about Sc

ienc

e and

Technol

ogy

Scienc

e in

Per

sonal

and

Soc

ial

Per

spec

tives

Hist

ory

and

Nat

ure

of Sc

ienc

e

Probl

em

Sol

ving

Meas

ure

ment

Co

mput

ation

and

Esti

mati

on

Co

mmuni

cati

on

Geo

metry

and

Adv

anc

ed

Mat

he

mati

cs

Stati

stics

and

Probabil

ity

Nu

mber a

nd

Nu

mber

Rel

ations

hips

Patter

ns a

nd

Func

tions

ix NASA EG-1997-08-104-HQ

Lesson Topic Plannerfor Exploring Meteorite Mysteries

This matrix indicates some of the lessons in Exploring Meteorite Mysteries that could be used to enhanceselected science topic themes frequently used in Earth/Space Science curricula.

Natural Resources/National ParksLesson 3 Searching for MeteoritesLesson 10 Building Blocks of PlanetsLesson 11 Changes Inside PlanetsLesson 12 Building Blocks of PlanetsLesson 17 Asteroid Resources

Historical Connections/ People/CareersLesson 1 Noblesville FallLesson 7 Crater HuntersLesson 14 Direct Hit at the K-T BoundaryLesson 15 Historical Meteorite FallsLesson 16 Near MissLesson 18 Antarctic Meteorite TeamsLesson 19 The Daily Shooting Star

Space (Stars and Solar System)Lesson 1 Noblesville FallLesson 2 Follow the Falling MeteoriteLesson 3 Searching for MeteoritesLesson 4 The Meteorite-Asteroid ConnectionLesson 5 Looking at AsteroidsLesson 10 Building Blocks of PlanetsLesson 11 Changes Inside PlanetsLesson 17 Asteroid Resources

Metric and Scientific Method (students use metricmeasurements in activities)

Lesson 2 Follow the Falling MeteoriteLesson 4 The Meteorite-Asteroid ConnectionLesson 6 Impact Craters — Holes in the Ground!Lesson 9 Meteorite Sleuths

Water (fresh and oceans)Lesson 12 Building Blocks of LifeLesson 14 Direct Hit at the K-T BoundaryLesson 16 Near MissLesson 17 Asteroid Resources

Atmosphere/Climate/WeatherLesson 14 Direct Hit at the K-T BoundaryLesson 16 Near Miss

Rocks/Minerals/Geologic TimeLesson 1 Noblesville FallLesson 6 Impact Craters — Holes in the Ground!Lesson 7 Crater HuntersLesson 8 Edible RocksLesson 9 Meteorite SleuthsLesson 10 Building Block of PlanetsLesson 11 Changes Inside PlanetsLesson 12 Building Blocks of LifeLesson 13 Solving a MysteryLesson 14 Direct Hit at the K-T Boundary

Planet DynamicsEarthquakes

Lesson 14 Direct Hit at the K-T BoundaryLesson 16 Near MissLesson 6 Impact Craters — Holes in the Ground!

Plate Tectonics and VolcanismLesson 7 Crater HuntersLesson 10 Building Blocks of PlanetsLesson 11 Changes Inside PlanetsLesson 14 Direct Hit at the K-T Boundary

Weathering and ErosionLesson 6 Impact Craters — Holes in the Ground!Lesson 7 Crater Hunters

x NASA EG-1997-08-104-HQ

Lesson Groups are suggested for one or a combination of several of the following criteria: time available inthe classroom, theme or topic of existing curricula, Meteorite Sample Disk availability, and interdisciplinaryconnections. More than one lesson could be accomplished in a 90-minute class. Some lessons may beinserted directly into existing Earth/Space Science curricula as enrichment activities without a more extensivemeteorite focus.

Lesson Sequence Suggestionsfor Exploring Meteorite Mysteries

Activities Without Meteorite Sample Disk

Stand alone activities for one or two class periodswithout Meteorite Sample Disk.

Lesson 1 Noblesville FallLesson 2 Follow the Falling MeteoriteLesson 4 The Meteorite-Asteroid Connection:

Orbits in the inner Solar SystemLesson 6 Impact Craters —Holes in the Ground!Lesson 7 Crater HuntersLesson 8 Edible RocksLesson 10 Building Blocks of Planets (non-

Meteorite Sample Disk activities only)Lesson 11 Changes Inside Planets (non-Meteorite

Sample Disk activities only)Lesson 12 Building Blocks of LifeLesson 14 Direct Hit at the K-T BoundaryLesson 15 Historical Meteorite FallsLesson 16 Near MissLesson 18 Antarctic Meteorite Teams

One week without Meteorite Sample Disk. (Emphasizingbasic meteorite background and hands-on activities on impactcratering.)

Lesson 1 Noblesville FallLesson 2 Follow the Falling MeteoriteLesson 3 Searching for MeteoritesLesson 6 Impact Craters —Holes in the Ground!

One or two weeks without Meteorite Sample Disk.(Emphasizing basic meteorite background and hands-onactivities about the origin and physical characteristics ofmeteorites.)

Lesson 1 Noblesville FallLesson 8 Edible RocksLesson 10 Building Blocks of PlanetsLesson 11 Changes Inside PlanetsLesson 12 Building Blocks of LifeLesson 13 Solving a Mystery

Activities With Meteorite Sample Disk

One or two class periods with Meteorite Sample Disk.(other lessons do not need the Disk)

Sequence of :

Lesson 1 Noblesville FallLesson 10 Building Blocks of PlanetsLesson 11 Changes inside Planets

or

Lesson 8 Edible RocksLesson 10 Building Blocks of PlanetsLesson 11 Changes Inside Planets

or

Lesson 8 Edible RocksLesson 9 Meteorite Sleuths!

One week with a Meteorite Sample Disk.

Sequence of :

Lesson 1 Noblesville FallLesson 8 Edible RocksLesson 10 Building Blocks of PlanetsLesson 11 Changes Inside Planets

or

Lesson 1 Noblesville FallLesson 8 Edible RocksLesson 9 Meteorite Sleuths!

Teacher�s Guide 1NASA EG-1997-08-104-HQ

A family on a camping trip watches a bright light streak across the sky and disappear.

An explorer comes upon a circular crater with rocks scattered around its rim.

Two boys watch a rock fall from the sky and land near them.

A farmer picks up an unusually heavy rock while plowing his field.

A scientist discovers the rare element iridium in a soil layer that marksthe end of the age of dinosaurs.

All of these people have discovered possible evidence of rocksfrom space that passed through the atmosphere and landed onEarth. Sometimes there is little or no evidence of the rock itself;it burned up in the atmosphere or broke up on impact. Othertimes the rock is all there is, with little evidence of its fiery entryor crash landing. These events all involve the mysteries ofmeteorites: what they are, where they come from, how they gothere, how they affect people, and what they tell us about thesolar system. These are some of the questions that areinvestigated in Exploring Meteorite Mysteries.

Meteorites are rocks from space that have survived theirpassage through the atmosphere to land on Earth’s surface. Somemeteorites are seen or heard to fall and are picked up soonafterward, while most are found much later. Some meteorites arelarge enough to produce impact craters or showers of fragments,but others are small enough to hold in one hand, and still othersare so small that you need to use a microscope to see them.Some meteorites are like igneous rocks on Earth, others arepieces of metal, and others are different from all known Earthrocks. Yet, despite their variety in size, appearance, and mannerof discovery, all meteorites are pieces of other bodies in spacethat give us clues to the origin and history of the solar system.

Brodie Spaulding (age 13) and BrianKinzie (age 9). The boys are standing onthe lawn where they observed theNoblesville, Indiana meteorite fall onAugust 31, 1991. (Photo by M. Lipschutz)

Noblesville meteorite. The 0.5 kg (fist-sized)meteorite found by the boys. Inside Noblesvilleis a gray stony meteorite, but outside it iscovered by a dark brown glassy crust.

Meteorites, Clues toSolar System History

Teacher�s Guide2 NASA EG-1997-08-104-HQ

Meteorite Falland Recovery

Meteors, Falls and FindsMeteors, bright streaks of light moving rapidly across the sky, arefairly common. On a clear night outside the city you could see anaverage of three or four an hour. Sometimes many more meteors arevisible. These times are called meteor showers and many showersreturn year after year on the same dates. These showers are associated withcomet dust left by long-passed comets. However, very few meteors, and none of theyearly meteor showers, yield meteorites on Earth’s surface. Most of the dust and ice particles burn upcompletely as they pass through the atmosphere.

Only a few people each year actually see a meteorite fall. Meteorites that are recovered soon after theyland on Earth are called falls. About 900 meteorite falls have been recovered around the world, mostly inthe last 200 years. The fall of a relatively small meteorite is exciting, but not dramatic unless it injures aperson or damages property. When young Brodie Spaulding and Brian Kenzie observed the fall of thesmall Noblesville meteorite in August 1991 (see Lesson 1), they saw no bright light and heard only awhistling sound. The meteorite was slightly warm to touch and made a small hole in the ground where itlanded.

Falls of large meteorites are rare, occurring only once every few decades, but are dramatic, beginning withthe bright streak of light and thunderous noise of a fireball. The falls of the Allende stony meteorite in ruralMexico and the Sikhote-Alin iron meteorite in Siberia, Russia, were two recent large falls (see Lesson 15).Both meteorite falls began with bright light and explosions that were seen, heard and felt for great distances.The cover of this booklet shows the Sikhote-Alin fireball as depicted in an eyewitness painting. The fallsites for the two meteorites were soon found. Allende was scattered over a 150 square kilometer area

Allende meteorite. This is a fragment from the Allende shower that fellin Mexico in February 1969. It is a dark gray stony meteorite withblack glassy fusion crust. The Allende stones weighed a total of 2,000kg, with the largest piece weighing 100 kg.

Sikhote-Alin meteorite. This is a fragmentfrom the Sikhote-Alin shower that fell inRussia in February, 1947. It is an ironmeteorite that is covered by black fusioncrust and indentations like thumbprintsfrom melting during flight through theatmosphere. The Sikhote-Alin ironsweighed a total of 23,000 kg, with thelargest piece weighing 300 kg.


around the town of Pueblito del Allende. The Sikhote-Alin site was located from the air by its devastationof a forested area. On the ground scientists found over 100 craters of varying sizes. Both meteorites fell asthousands of fragments covering wide areas. The breakup and fall of a large meteorite like Allende orSikhote-Alin before impact is called a meteorite shower. (See Lessons 2 and 3)

The impact of a huge meteorite has never been observed and recorded by people; however, many havebeen recorded as craters in the surfaces where they landed on the Earth or other planetary bodies. Me-teor Crater in Arizona is the best known meteorite impact crater on Earth. It is about 50,000 years oldand well preserved in the arid desert. Many small fragments of the Canyon Diablo meteorite have beenfound around the crater, but their total mass is only a tiny fraction of the total mass of the incomingmeteorite. The force of the impact is thought to have vaporized most of the meteorite. Imagine howpowerful that explosion must have been if anyone were nearby to see and feel it!

Studies of numerous observed falls, combined with field and experimental studies of impact craters, give usa general picture of the fall process. Meteorites approaching Earth come in all sizes from microscopic togigantic. The larger the size, the fewer the number of meteorites there are. Most meteorites approachEarth at speeds of about 20-30 km/sec. They are slowed down by friction with the air as they pass throughthe atmosphere. The heat produced causes their outsides to melt to glass creating the fusion crust. Thetiniest rocks and dust burn up as meteors without landing on Earth. Small meteorites like Noblesville areslowed to below the speed of sound. Larger meteorites like Allende and Sikhote-Alin don’t slow downmuch and make sonic booms as they approach Earth at speeds greater than the speed of sound. Evenlarger meteorites, like Canyon Diablo that formed Meteor Crater, are hardly slowed at all by the Earth’satmosphere and hit the Earth at very high speeds, making large impact craters. No meteorite this large hasfallen in recorded history. Most small to medium falls are stony meteorites and most of the larger showersand impact craters are produced by iron meteorites. Iron meteorites are stronger than stony meteorites;therefore, they don’t break up as easily in space or as they pass through the atmosphere.

Many meteorites fall to Earth each year, but are not observed. Few of these meteorites are ever found.From photographic records of fireballs and smaller meteors, scientists have calculated that about 30,000meteorites larger than 100 g fall on the Earth’s surface each year. Although this sounds like a huge number,there is very little chance of a meteorite falling on you. Most of these meteorites just go unnoticed becausethey fall quietly during the night, in unpopulated areas, or in the ocean . However, some meteorites surviveexposure at the Earth’s surface and are picked up hundreds or thousands of years after they fall.

Meteor Crater in Arizona. This 1.2 kmwide, 150 m deep, crater was made by a 30m iron meteorite weighing about1,000,000,000 kg. Thousands of fragmentstotaling 30,000 kg of the Canyon Diabloiron meteorite have been found, but most ofthe meteorite was vaporized by the heat ofthe impact.


Meteorites that are collected with no visual evidence at the timeof their fall are called finds and make up the bulk of the world’smeteorite collections. Prior to 1970, about 1500 meteorite findshad been collected around the world. The discoveries ofnumerous meteorites in desert regions in North America, Africaand especially Australia have added hundreds of new meteoritesto the collections in the last few years. But the best area in theworld for collecting meteorites is the icy desert of Antarctica. In1969, nine meteorites were found on Antarctic ice by a Japanesefield team. Since then about 17,000 meteorite fragments havebeen found by Japanese, European, and U.S. meteoritecollection teams.

Antarctic MeteoritesAntarctica is a special place for collecting meteorites. Moremeteorite fragments have been recovered there than from the restof the world combined. Yet because the continent is frozen,remote and uninhabited, not a single Antarctic meteorite fall hasbeen observed. Several factors combine to make Antarcticaideal for finding previously-fallen meteorites. The first is the easeof finding dark meteorites on ice. This aids in recovery of smalland sometimes rare meteorites. The ice also helps to preservethe meteorites because they rust and weather away more slowlyin cold Antarctic temperatures than in warmer climates. The nextfactor is the movement of the ice which concentrates meteoritesthat fell in different places at different times. The meteorites areenclosed in ice and move with a glacier until it comes to a rockbarrier and stalls. The meteorites are later exposed at thesurface as the ice gradually erodes away. This concentrationmakes it difficult to tell which meteorites are parts of a meteoriteshower, and which are individual falls. All Antarctic meteoritesare given separate names although some are later grouped aspaired meteorites if data suggest that they came from a singleshower. It is estimated that the 17,000Antarctic meteorite fragments representabout 3,000 separate meteorites, or about thesame as the total for the rest of the world’scollection. (See Lesson 18)

The concentration process and ease offinding meteorites in Antarctica led tonational and international meteoriteprograms organized by the Japanese,Americans and Europeans, and toyearly expeditions to collect meteor-ites. The Japanese JARE (JapaneseAntarctic Research Expedition)

IdentifyingMeteorites

Finding a meteorite on Antarcticice when there are no other rocksaround is easy (if you can standthe cold!). Finding a meteoriteon sand, a plowed field, or a pathor road isn’t hard. But finding ameteorite in a thick forest, orpicking one out of a pile of Earthrocks is challenging, even forexperts. There are many types ofmeteorites and they are found inall sizes and shapes, but mostmeteorites have two things incommon: Outside they have darkbrown or black glassy crusts andinside they contain enough ironmetal to attract a magnet. Theouter glassy crust, of themeteorite, called its fusion crust,is produced as the rock is heatedby friction when it comesthrough the atmosphere. Theouter part of the rock melts andforms fusion crust that often hasflow marks or indentations likethumbprints. The inside stayscool and is usually light gray toblack in color, but some may betan or, if weathered and rusted,brown.

The three major types of meteor-ites are stony, iron, and stony-iron meteorites. These are easilydistinguished by their amounts ofiron metal. Stony meteorites aremostly silicate minerals with lessthan 25% metal, iron meteoritesare essentially all metal, andstony-iron meteorites are abouthalf silicate minerals and halfmetal. Iron-rich meteorites canbe easily identified by theirdensity; they feel much heavierthan Earth rocks. Most stonymeteorites have shiny or rusty

continued on next page


continued from previous page

metal flecks visible inside: almostno Earth rocks have iron metal.A few stony meteorites have nometal and are very similar toEarth rocks; these can berecognized by their glassy fusioncrust. Stony meteorites are themost abundant (94%) among fallsand irons are uncommon (5%).However, irons make up abouthalf of all finds, except inAntarctica. Stony-irons are rare(1%) among both falls and finds.

The only way to be sure if a rockis a meteorite is to have itexamined and analyzed by anexpert. If you have a sample thatmight be a meteorite, you shouldcontact a meteoriticist, geologistor astronomer at a local sciencemuseum or university.Alternatively, you could contact anational meteorite curation centerat NASA Johnson Space Center inHouston or the SmithsonianNational Museum of NaturalHistory in Washington, DC.

program is run by the National Institute of Polar Research (NIPR)in Tokyo. The EUROMET (European Meteorite) consortium isa cooperative program among many European countries with itsheadquarters at the Open University, Milton Keynes, England.The American ANSMET (Antarctic Search for Meteorites)program is a collaboration among three government agencies:the National Science Foundation (NSF), NASA, and theSmithsonian Institution.

In Antarctica, meteorites are concentrated on ice fields nearmountains, especially the Transantarctic Mountains. The sites arefar from the few coastal research stations or from the South Polestation. The weather is extreme, with sub-zero temperatures andhigh winds to make life hazardous. Teams of scientists spendone to two months in this frigid environment collecting meteorites.They travel to these sites by helicopters or cargo planes, drivearound in snowmobiles, and live in special polar tents. Theymust take almost everything they need to survive becauseAntarctica provides only air, frozen water and refrigeration.Despite these hazardous conditions, the teams have been highlysuccessful in collecting meteorites. During approximately twentyyears of collection, American expeditions have returned over

Collecting Antarctic meteorites. This scientist is collecting a meteorite onthe ice in Antarctica. The Antarctic ice aids meteorite collection byconcentrating many meteorites in some areas, weathering them slowly,and making them easy to see. Scientists live and work in remote, hazard-ous conditions in order to recover hundreds of meteorites per year.

Antarctic ice cave. A member of the U.S.meteorite collection team is standingoutside an ice cave in Antarctica.


NamingMeteoritesNoblesville, Allende

Sikhote-AlinCanyon Diablo

Gibeon, BrenhamALH90411, EET83227

Meteorites are named after thenearest town (Noblesville, IN) orpost office so their names areoften picturesque. Becausemeteorites have been found theworld over, the list of meteoritenames looks like a geographylesson. When meteorites are foundfar from towns, they may benamed after their county of origin(Sioux County, NB), or after anearby river (Calkalong Creek,Aus.), lake (Carlisle Lakes, Aus.)or other geographic feature(Canyon Diablo, AZ). In desertswhere many meteorites are foundin areas with few towns orgeographic names, meteoritenames include both a geographicarea and sample number. Forexample, Acfer 287 is from theSahara Desert in Algeria andCamel Donga 005 is from theNullarbor region in Australia. InAntarctica, where thousands ofmeteorites have been collected inyearly expeditions, the namesinclude the geographic area, yearof collection and sample number.Geographic areas are oftenabbreviated using one to fourletters. Thus ALH90411 standsfor sample 411 collected in 1990in the Allan Hills area ofAntarctica. The names, locationsand find dates of meteorites in thedisks are given in the MeteoriteABC’s Fact Sheet on page 29.

8,000 meteorite fragments, and Japanese over 9,000. In onlythree expeditions Europeans found 530 meteorites.

Meteorite CurationScientists in museums and universities around the world areresponsible for the curation of non-Antarctic meteorites.Curation includes classifying new meteorites, storing them, anddistributing them to scientists for study. When the three Antarcticmeteorite collection programs began bringing back hundreds tothousands of meteorite fragments per year, each program set upits own facilities to do curation. Each of these facilities hasspecial clean labs because Antarctic meteorites are less contami-nated by Earth’s environment and pollution than other meteoritefinds. Meteorites are stored in clean cabinets, sometimes in adry nitrogen gas, and handled and examined in glove box cabi-nets or lab benches with filtered air. The first task of the curatorsis to classify new meteorites and announce them to researchscientists. Scientists then send requests for samples to study. Inresponse, the curators take small pieces of each requestedmeteorite and distribute them to the scientists. Finally, thecurators store the meteorites in clean environments to preservethem for future studies.

Antarctic meteorite locations. Meteorites are found mostly along the3,000 km Transantarctic Mountains that diagonally cut the continent.These sites are remote from the U.S. research stations South Pole andMcMurdo (indicated with stars).


Meteorite curation. This is the meteoritecuration facility at NASA‘s Johnson SpaceCenter in Houston, Texas. It is operated bythe same group which curates the Apollolunar samples. A companion facility is atthe Smithsonian National Museum ofNatural History in Washington, DC.

MicrometeoritesThe smallest objects approaching Earth are cosmic spherulesand interplanetary dust particles (IDP). They are calledmicrometeorites because they are so small that a microscope isneeded to see them. Because micrometeorites are small andhave very large surface areas compared to their masses, theyradiate heat rapidly and are not melted as they pass through theatmosphere. Cosmic spherules are droplets less than a millimeterin size that are found in deep sea sediments and Antarctic andGreenland ice. EUROMET has an active micrometeoritecollection program with a curation facility in Orsay, France.IDPs are micrometer-sized irregular aggregates that vary widelyin composition, mineralogy and structure. NASA collects IDP’sin the upper atmosphere using military airplanes with collectorsattached under their wings. The collectors are opened uponreaching high altitudes and closed before returning to the ground.This ensures that only high altitude particles are collected. Someof these particles are man-made space debris, others are ashfrom Earth’s volcanoes, but many are interplanetary dust. TheseIDP’s are curated at NASA Johnson Space Center in a labadjacent to the Antarctic meteorite curation lab. NASA curatorsdescribe, announce and distribute the IDP’s which are studied byscientists around the world.

Interplanetary dust particle. This fluffyaggregate of grains was collected by NASAhigh in the atmosphere. It consists of avariety of minerals loosely held together. Itis sitting on a metal surface with holes in it.

Cosmic dust collection. NASA collectscosmic dust in collectors mounted onaircraft that fly in the stratosphere.


Impacts and CratersImpact as a Planetary ProcessOne of the most significant discoveries from NASA’s exploration of the solar system is the importance ofmeteorite impact as a planetary process. Images of the Moon, Mercury, Mars, asteroids, and the moons ofthe outer planets show surfaces covered with impact craters. The recent Magellan radar images of Venusrevealed both craters and volcanism on that cloud-covered planet. The view of the whole Earth from spaceshows little effect of impact. However, from photos taken in orbits closer to Earth, scientists have identifieda number of circular impact features. Meteor Crater in Arizona is the most familiar example of an impactcrater. It is relatively small, young, and well preserved compared to most impact craters. Many of thesecraters are old; some craters are partly-filled circular lakes; others are heavily eroded. Various types ofcraters are illustrated in the companion slide set. A map of terrestrial impact crater locations shows thatthey are scattered around the Earth.

Terrestrial impact craters. This map shows locations of 140 impact craters which have been identified on Earth. Thecraters range in size from under 1 km to over 200 km across and in age from recent to 2 billion years old. The clustersof craters in eastern North America, Europe, and Australia are due to both stable geologic environments and activecrater search programs.

Field and Laboratory Studies of ImpactsRecognizing impact craters and understanding how they form require a combination of field geology andimpact experiments. The experiments define the speeds of impacting objects, structures of craters, andtypes of rocks formed in the impact process. Field studies of well-exposed craters provide “ground truth”for experiments and help define crater structure and the nature of rocks modified by impact. The speed ofthe impacting object (about 20-30 km/sec) is greater than the speed of sound in air. The object produces asonic boom as it passes through the atmosphere and an explosion crater when it impacts. The diameter ofthe crater is about 10 times larger than that of the impacting object while the crater depth is about 1/10 the


crater diameter. These numbers vary with the speed, size, mass, and angle of approach of the impactingobject, and with the nature of the target rocks.

Finding a circular crater is not sufficient to identify it as an impact crater because there are also volcaniccraters. Although their size ranges overlap, impact craters tend to be larger than volcanic craters. Theirstructures also differ. A volcanic crater’s floor is often above the surrounding surface, while an impactcrater’s floor is below the surrounding terrain. Thus a fresh impact crater is circular, with a raised rim and alowered floor. Impact craters are also surrounded by rocky material thrown from the crater, ejecta. Thebest proof of an impact crater is associated meteorite fragments; after that, the next best indicator is thenature of its rocks. They are broken, distorted or even melted by the shock of the explosive impact. Muchof the ejecta outside the crater is broken pieces of various rocks mixed together to form a breccia. Therocks inside the crater are also breccias which are highly shocked and sometimes melted. The originalbedrock below the crater is shocked and fractured. (See Lessons 6 and 7)

Catastrophic ImpactsLooking at the surface of the Moon we see craters ranging in sizefrom tiny to gigantic. The largest basins are the dark, roughlycircular mare that are filled with solidified basalt. Such largeimpacts must have had a major affect on the whole Moon.Studies of lunar rocks returned by the Apollo missions showedthat the giant impacts happened about 3.9 billion years ago (seecompanion volume Exploring the Moon). Studies also showedthat the breccias formed by impact on the Moon are rich in somemetals that are abundant in meteorites, but rare in rocks on thesurfaces of the Moon and Earth. Iridium is one such metal that iscommon in meteorites. Its discovery in the K/T boundary soiloffers an explanation of a catastrophic Earth event.

The K/T boundary is the layer of soil that marks the end of the Cretaceous (K) period and beginning of theTertiary (T) period of geologic time. It occurred 65 million years ago when three-fourths of all species oflife on Earth became extinct. Other time boundaries in earlier periods also mark extinctions of manyspecies. Geologists have tried to understand the causes of these mass extinctions, suggesting perhaps

Crater cross sections. This diagram shows two views of a typical impact crater. The left view shows the circularcrater with its rim and scattered ejecta. The right view shows that the rim is above and the crater floor is below theoriginal surface. The ejecta are thickest closest to the rim.

Aristarchus. The lunar crater Aristarchusis about 40 km in diameter. It is one of themost studied craters on the Moon.


major changes in climate. In 1980 geologists discovered that this layer is surprisingly rich in iridium. Theysuggested that the iridium was from a giant meteorite that impacted the Earth throwing a tremendous volumeof dust into the atmosphere. While the immediate effects of the impact would have been regional, the effectof the dust in the atmosphere could have been global. The climate might have been changed drastically forsome time after the impact. For years the impact hypothesis seemed plausible, but there were no terrestrialcraters with the right age and size to have caused these changes. Recently, geologists found a 65 millionyear old buried crater that is over 200 km across on the Yucatan Peninsula in Mexico. It, possibly incombination with other craters the same age, might be the “smoking gun” of the K/T mass extinctions (seeLesson 14).

It is only natural to ask when the last large impact occurred on Earthand whether another one could occur soon. Meteor Crater wasmade by the impact of a large meteorite 50,000 years ago.Although it is a relatively small crater, it would have caused majordestruction in a city, had there been any in existence at the time.Two medium-sized impacts occurred this century in Russia,Tunguska in 1908 and Sikhote-Alin in 1947 (see Lesson 15). TheTunguska explosion was large enough to have caused significantdestruction if it had happened near a city.

The threat of global devastation froma major impact led the U.S. govern-ment and NASA to propose theSpaceguard Survey. It would have

been an international network of automated telescopes that would scan the sky in search ofall Earth-approaching asteroids or comets large enough (1 km) to cause severe destruction.Once their orbits were determined, calculations would be done to predict whether any body wouldimpact Earth. Although the full international program was not approved, there are at least twosmaller programs which search the sky for incoming asteroids and comets. A means of deflectingthe asteroid or comet out of its orbit would then be needed to avoid a catastrophe. Although theprobability of a devastating impact is very low, the potential destruction of such an impact is sogreat that precautions are warranted.

The impact of Comet Shoemaker-Levy 9 onJupiter in July 1994 was the first timescientists predicted the impact of a smallbody on a planet. The comet was discov-ered in March 1993 after it broke apart into22 fragments as it passed close to Jupiter.The orbit of this “string of pearls” wasdetermined by continued telescopicobservation. Calculations predicted that onits next pass through Jupiter’s orbit thefragments would impact the planet.Because of the predictions, thewhole world watched andwaited, while thousands of

The Tunguska Impact. In 1908 the biggestmeteor in recorded history shot across theTunguska River in Russia and exploded.(Credit: Smithsonian Institution)


telescopes were aimed at Jupiter as the fragments of the comet impacted the planet on schedule. The views fromthe Hubble Space Telescope and from the Galileo spacecraft were even better than from large Earth-basedtelescopes. The successful identification of the comet and prediction of its impact allude to the potential capabili-ties of the Spaceguard Survey.

Meteorite Classificationand FormationClassification

Meteorites are rocks that are made upof a variety of minerals. Minerals arenaturally occurring crystalline materialscomposed of elements in definedproportions and structures. The mostcommon minerals in meteorites arelisted in the Meteorite ABC’s FactSheet on page 29. Most meteoriteminerals are similar to those occurringin Earth rocks, but a few of the rarerminerals are found only in meteorites.Different types of meteorites havedifferent types and proportions ofminerals and different compositions.Therefore, meteorites are classified bytheir mineralogy and composition. As

Comet Shoemaker-Levy 9 approachingJupiter. This picture is a composite ofphotographs taken by the Hubble SpaceTelescope. The “string of pearls” is thebroken pieces of comet Shoemaker-Levy 9which were photographed during theapproach to Jupiter. The collisions in July1994 were the first predicted impacts of anasteroid or comet on a planet. (Credit:Space Telescope Science Institute.)

Meteorite Sample Disk. The meteoritesample disk contains six different meteoritesamples. See page iv for more informationon using this disk in the classroom.


discussed in the section on identifying meteorites, the simplest classification of meteorites into stony, iron,and stony-iron types is based on the amount of iron metal and silicate minerals in the meteorite. It isrelatively easy to tell whether a sample has little metal, is mostly metal, or is about half metal and half silicateminerals. This can be determined by looking at the amount of metal and silicate minerals in the sample’sinterior and by hefting it to feel its density because iron metal is about twice as dense as silicate minerals.

Each of the three major types of meteorites shows considerable variability and is further subdivided basedon mineralogy and composition. Meteorite classification is complex because of the diverse possibilities.Meteorites represent many different rock types and probably come from different bodies in the solarsystem. However, after detailed studies, some meteorites of different types appear to be related to eachother and possibly come from the same solar system body. A simplified listing of meteorite types is given inthe Meteorite ABC’s Fact Sheet.

Stony meteorites are divided into chondrites and achondrites based on whether they contain smallround balls of silicate minerals called chondrules. Chondrites contain chondrules and achondrites do not.Chondrites are the most abundant type of meteorites, making up nearly 90% of both falls and Antarcticmeteorites. Chondrites are divided into several classes, including ordinary chondrites, the most common,and carbonaceous chondrites, perhaps the most interesting because of their potential to tell the earliesthistory of the solar system.

ALH90411 chondrite. This stony meteoriteis chondrite A in the meteorite sample diskand accompanying lithographs. This sawnsurface shows an irregular texture withround chondrules, broken fragments, and alittle dark rusted metal. ALH90411 is a lowiron chondrite and is not metamorphic.

LEW87030 chondrite. This stony meteoriteis chondrite B in the meteorite sample disk.It has a more uniform texture thanALH90411 and indistinct chondrules(vertical streaks are saw marks). It also haslots of shiny metal. LEW87030, likeNoblesville, is a high iron,metamorphic chondrite.


Ordinary chondrites consist of variable amounts of metal and chondrules in a matrix of mostly silicateminerals. The silicates are mostly olivine and pyroxene, with minor feldspar. Further subdivisions ofordinary chondrites are based on the amount of iron metal and the variability in composition and texture.Some are high iron chondrites, others are low or very low iron types. Chondrites which have distinctchondrules and variable mineral compositions have not been heated since they formed and are non-meta-morphic chondrites. Metamorphic chondrites have indistinct chondrules and constant mineral compositionsand have been changed since their initial formation.

Carbonaceous chondrites are a very special meteorite class because they are the most primitive meteoritesand they contain water and carbon compounds. These chondrites consist mostly of the silicate mineralsolivine and pyroxene or clay minerals that formed from them by weathering. Carbonaceous chondritescontain very little metal, but contain unusual inclusions, and 2-20% water in their clay minerals. The carbonoccurs in elemental form as graphite and occasionally diamond, and in organic molecules which rangefrom simple molecules to amino acids, the building blocks of DNA and life. Carbonaceous chondritesshow variations in composition and degree of metamorphism and weathering.

Achondrites are the second most abundant type of meteorites (8%) and many are similar to igneous rockson Earth. Achondrites are divided into several classes, of which the most abundant is basaltic achondrites,and the most unusual is planetary meteorites. The basaltic achondrites are actually a family of threedistinct subclasses that are grouped together because they appear to be related to each other. The mostcommon are pyroxene-feldspar igneous rocks similar to basalts on Earth. Many of these basalts werebroken up by impacts so that the meteorites are breccias made up of basalt fragments. Another typeconsists mostly of pyroxene and may have formed by accumulation of minerals sinking in a magma. The

ALH84028 carbonaceous chondrite. Thisstony meteorite has a highly irregulartexture with distinct round chondrules,white inclusions, and little metal in a darkcarbon-bearing matrix (vertical streaks aresaw marks). It is a carbonaceous chondritesimilar to Allende, the carbonaceouschondrite in the meteorite sample disk.

RKPA80224 basaltic achondrite. Thisstony meteorite contains no chondrules ormetal and is an achondrite. Basalticachondrites consist of feldspar (whitemineral) and pyroxene (dark mineral) andare similar to basalts that formed from lavason Earth and the Moon. This sample has anigneous texture showing that it crystallizedfrom a melt. Other basaltic achondriteshave the same mineralogy and composition,but are breccias containing broken rockfragments. The achondrite in the meteoritesample disk, EET83227, is a basalticachondrite breccia.


third type are complex breccias made up of fragments of the other two types. These meteorites formed byimpact mixing on the surface of a parent body.

Planetary meteorites are a recently recognized class of achondrites which include both lunar and martianmeteorites. They are igneous rocks and breccias that formed from igneous rocks. Their compositions andmineral proportions range widely. Some are basalts that crystallized as lavas. Others are cumulates, rocksthat formed by accumulation of minerals floating or sinking in magmas. These include lunar anorthositebreccias which formed by feldspar floating (see companion volume Exploring the Moon) or martiancumulates which formed by pyroxene and olivine sinking. More lunar and martian meteorites have beenfound in Antarctica than in the rest of the world.

Iron meteorites, which make up only 5% of meteorite falls, consist almost entirely of iron-nickel metal withvariable amounts of sulfides and occasional inclusions of silicate minerals. Iron meteorites usually consist oftwo distinct iron-nickel minerals, kamacite (high iron) and taenite (high nickel) which are intergrown to forma criss-cross Widmanstatten pattern which can be seen when the sample is etched lightly with acid. Ironsare subdivided both by the texture of this intergrowth and by the composition of trace elements in the metal.However, the textural and compositional subdivisions do not correlate well. Some groups of iron meteoritesmay be related to basaltic achondrites.

Gibeon iron meteorite. This photo shows asawed surface which has been etched withacid to reveal the criss-cross Widmanstattenpattern. The Gibeon iron meteorite in thesample disk and the Sikhote-Alin meteoritehave fine intergrowths of iron-nickel metals.

Brenham stony-iron meteorite. This stony-iron meteorite consists of yellow-greenolivine crystals surrounded by iron-nickelmetal. It is a cumulate stony-iron and isused in the meteorite sample disk.


Meteorite research. This scientist isworking at a scanning electron microscope.With this instrument the scientist can lookin detail at the mineralogy, composition,and physical structure of meteorites.

Stony-irons, which are the least abundant major type of meteorites (1%), include both cumulate andbreccia varieties. The cumulates consist of metal and the silicate mineral olivine, where the olivine grains arelarge and surrounded by metal grains. The metal and silicates formed by slow cooling of heavy phases froma melted body. The metal and silicate grains in the stony-iron breccias are usually much smaller than in thecumulates, and the texture is a complex mixture of broken fragments imbedded in matrix. The silicatefragments are similar to those in basaltic achondrites. Both cumulate and breccia stony-irons may comefrom the same bodies as basaltic achondrites.

Meteorite ResearchMany different types of science are involved in the study of meteorites, their formation and their sources.Meteorite research bridges the gap between geology, the study of Earth’s rocks and landforms, andastronomy, the study of the Sun, planets, moons, and stars in space. Planetary geology is a new sciencewhich began when we were first able to study the Moon and other planets up close. Planetary scientistsstudy the planets and other bodies in the solar system using photographs and chemical or physical datacollected from flyby and orbiting spacecraft or robotic landers: Voyager, a flyby craft, explored the outerplanets; the orbiter Magellan focused on Venus; Viking studied Mars with both orbiters and robotic landers.The Apollo missions to the Moon provided the only chance so far for humans to walk on another planetarybody, to study the landforms, and to bring rocks back to Earth for detailed analyses (see companion volumeExploring the Moon).

Meteoriticists are scientists who study meteorites. They may be trained in geology, chemistry, physics, orastronomy because all these fields are needed to understand meteorites and their relationships to bodies inthe solar system. Meteoriticists often work in teams so that specialists in several different fields contribute tothe research. Mineralogists study the mineralogy and textures of thin slices of rock; chemists analyze rocksfor their elemental and isotopic compositions and determine ages; physicists measure physical propertiessuch as magnetism.

To learn about the relationship of meteorites to planetary bodies, astronomers try to match meteorites withpossible sources. Planetary geologists study impact craters on Earth, the Moon and planets to understand the

impact process. Other scientists do notstudy meteorites or planetary bodiesdirectly, but do experiments in laboratoriesto simulate the processes of meteoriteformation or impact. NASA funds mostof the research on meteorites that is donein the U.S. through grants to investigatorsat universities, industry, and governmentlaboratories.


Processes of meteorite formation. Thisdiagram illustrates several meteorite

formation processes. The first processes arecondensation from a gas to a solid (not

illustrated) followed by accretion of smallparticles to form an asteroid or planet.When the accreted body is heated, it is

modified by metamorphism or differentia-tion. Even if heating is not enough to melt

the body, it may undergo metamorphicprocesses which make the texture and

mineral compositions more uniform. Ifheating melts the body, it may undergo

differentiation: Metal separates from thesilicate melt and sinks under the influence

of gravity to form the core. Silicateminerals crystallize and heavy minerals,

like olivine and pyroxene, sink to form themantle, while light ones, like feldspar and

some pyroxene, float to form the crust.Volcanism (not illustrated) brings basalts

to the surface to add to the crust. Weather-ing (not illustrated) alters the surface rocks

through chemical or physical changes.Finally, impacts on a variety of bodies

break off fragments that may fall to Earthas meteorites.

Formation ProcessesThe processes of meteorite formation have been identified by comparing studies of meteorite mineralogy,composition and ages with those of Earth and Moon rocks, and experimental results. On Earth, rocks formby igneous, metamorphic and sedimentary processes, but the continued action of these processes haserased all evidence of Earth’s initial formation. Meteorites bear evidence of the history of the solar systemfrom its initial formation to recent volcanism and impacts on Mars. Chondrites are primitive objects formedat the beginning of the solar system and changed by metamorphic and sedimentary processes. Achondrites,irons, and stony-irons are differentiated objects formed by igneous processes and changed by impacts andmetamorphism. Evidence for these processes is listed on the Solar System ABC’s Fact Sheet on page 31.Many of the details of the processes are not fully understood — hence meteorite research continues — butenough is known to present a general story of meteorite formation.

The evidence for the primitive nature of chondrites is found in their ancient ages, Sun-like compositions, andunusual minerals and textures. All chondrites are 4.5-4.6 billion years old. They are the oldest rocks in thesolar system and are used to date the beginning of the solar system. Chondrite compositions are verysimilar to that of the condensable part of the Sun without the gaseous elements, H and He. Carbonaceouschondrites are most similar to the Sun’s composition because they contain volatile components such aswater and carbon compounds. Chondrites tell us about formation of solid bodies from the cloud of gas anddust called the solar nebula. Carbonaceous chondrites contain stardust and white inclusions. Stardust iscomposed of minerals such as diamond and silicon carbide which are thought to have formed in a red giantstar before our Sun was formed. The white inclusions consist of unusual minerals which were the firstminerals to condense from a gas in the formation of the solar system. This condensation is the first stage insolar system formation. The gases in the solar nebula gradually condense as it cools to produce the minerals


found in meteorites, first the white inclusions, then silicate minerals. Chondrules are melted and crystallizedspheres of silicate minerals which are thought to have formed by flashheating as the solid matter in the solar system condensed.

Accretion is the physical process of building up chondritesand planetary bodies by collecting together smaller pieces ofunrelated materials such as chondrules, white inclusions,stardust, and volatile components. The variations in chondritemineralogy and composition show that there were areas in theearly solar system with different compositions or temperatureand pressure conditions. Inverse variations in the amount ofiron in metal versus iron in silicate minerals suggest thatthere were variations in oxidation state for different chondritetypes. Variations in volatile contents suggest that the volatile-rich carbonaceous chondrites accreted at lower temperaturesthan volatile-poor ordinary chondrites. (See Lesson 10)

The organic compounds in carbonaceous chondrites are believed tohave formed very early in solar system history. There is considerable varietyin organic compounds in carbonaceous chondrites, from simple molecules to amino acids, butapparently none were formed by living organisms. The evidence for this is in the symmetry of the organiccompounds which are found in both right- and left-handed forms in meteorites, while similar compoundsformed by living organisms on Earth are found only in one form. (See Lesson 12)

After condensation and accretion, most chondrites were changed by metamorphism and weathering. Heatingof originally heterogeneous chondrites to temperatures below their melting points caused the mineral compositionsto homogenize and chondrules to fade into the matrix. Heating of carbonaceous chondrites allowed their water toweather the olivine and pyroxene silicates to clay minerals. This was the first weathering in the solar system, anEarth-like sedimentary process that took place near the beginning of the solar system.

Differentiated meteorites (achondrites, irons, stony-irons) have compositions very different from those ofthe chondrites or the condensable part of the Sun. However, if their compositions are recombined in therelative proportions in which they fall to Earth, the average differentiated meteorite composition is a lotcloser to chondrite composition. Most differentiated meteorites are also ancient rocks 4.4-4.5 billion yearsold, nearly as old as the primitive chondrites. The only exceptions are planetary meteorites which have agesranging from 180 million years through 4.5 billion years. Although many differentiated meteorites arebreccias broken and mixed by impacts, it is apparent that most are rocks that originally crystallized frommelts and formed by igneous processes.

The suite of differentiated meteorites is evidence of early differentiation on asteroids (and planets) into core,mantle and crust. Heating of the body to above the melting temperature allowed separation of iron and silicatemelts and later separation of crystallized minerals. Iron meteorites represent the core of the asteroid whichformed by slow cooling from an iron melt to produce the intergrown iron-nickel minerals. Stony-iron cumulatescome from the core-mantle boundary where iron melt surrounded olivine silicate minerals. Basaltic achondritesare mostly from the crust of the asteroid, with cumulates possibly from the upper part of the mantle. Basalticachondrites flowed as lava onto the surface, just like basaltic lavas produced by volcanism on the Earth, Moon,and Mars. Finally, breccias of basaltic achondrites and stony-irons represent the soil and rocks at the surface ofan asteroid where various rock types are broken and mixed by impacts. (See Lesson 11)


Meteorite Sources

Meteorites fromAsteroidsMeteorites are “rocks from space,” butthere’s a vast area of space out there.Our Sun is just one of billions of stars inthe Milky Way galaxy, which is one ofbillions of galaxies in the universe. Luck-ily, we don’t have to search all of outerspace for the sources of meteoritesbecause scientists think that meteoritescome from our own “backyard,” from theasteroids, comets, moons and planets inour solar system (see Solar SystemABC’s Fact Sheet).

Most meteorites appear to come from asteroids, the small (diameter less than 1000 km) rocky bodies thatorbit the Sun in the region between Mars and Jupiter, but are mostly concentrated in the asteroid beltbetween 2.2-3.2 AU (astronomical unit, the mean distance between the Earth and Sun). The evidence thatmost meteorites come from asteroids is based on comparison of meteorite and asteroid orbits andmineralogies. Three meteorites have been observed photographically as they approached Earth. It waspossible to calculate the orbits of the Innisfree, Lost City, and Pribram meteorites from a series of timedphotographs. These are all elliptical orbits that extend from Earth back to the asteroid belt. (See Lesson 4)

Asteroids are so small and far away that telescopes on Earth see them only as points of light. Astronomers findasteroids by studying telescopic images and looking for the objects that move compared to the stationary starfield. Long exposure photographs show a background of stars as bright spots with a streak of light from anasteroid caused by its movement across the sky. To calculate the orbit of an asteroid, one must measure itsposition at several different places and times, but it is not necessary to follow it through an entire orbit. Asteroidalorbits are ellipses rather than circles (see Lesson 4), but most orbits are not too far from circular and thereforestay within the asteroid belt and do not cross the orbits of the planets. A few asteroids, such as Aten, Apollo, andAmor, have highly elliptical orbits that cross the orbits of Earth or Mars, while others like Hector are in the orbitsof Jupiter or beyond. Gravitational interactions with Jupiter, and impacts between asteroids in the belt may breakthem up and send the resulting fragments into planet-crossing orbits.

Ceres, the largest asteroid (almost 1,000 km) was the first asteroid found in 1801. Since then over 6,000asteroids have been catalogued. Most asteroids are very small, only three are larger than 500 km, and onlyabout 25 are larger than 250 km. All of the Earth- and Mars-crossing asteroids are smaller than 30 km.Our first close up look at asteroids was provided by the Galileo spacecraft that flew by and photographedasteroids Gaspra in 1991 and Ida in 1993. Both are irregular masses of rock, seemingly broken andcovered with impact craters. Phobos and Deimos, the moons of Mars, look very much like asteroids in sizeand shape. The next planned asteroid encounters are part of the NEAR mission. It will fly by asteroidMathilde in summer 1997 and orbit and map asteroid Eros in 1999. The Solar System ABC’s Fact Sheetgives information for twenty asteroids in order of distance from the Sun. It gives examples from each of thegroups of planet-crossers and several of the larger asteroids that populate the asteroid belt.

Asteroid Ida. This photograph of 52 km asteroid 243 Ida was taken in1993 by the Galileo mission. The asteroid is a rocky body that isirregular in shape and covered with impact craters.


Meteorite and asteroid orbits. Orbits ofmeteorites and asteroids compared to thoseof Earth, Mars and Jupiter. (Top) The orbitsof three meteorites, Innisfree, Lost City andPribram, were calculated from series oftimed photographs taken as each meteoritefell to Earth. (Bottom) Orbits of sevenasteroids are shown. The three closest tothe sun, Aten, Apollo and Amor, are ellipti-cal and cross the orbits of Earth or Mars.The next three, Vesta, Ceres and Hygeia, arein the asteroid belt where most asteroids arefound. The last one, Hector, is in Jupiter’sorbit, but spaced far enough from the planetthat it does not impact Jupiter.

Astronomers study different types of asteroids using the brightness and color of light they reflect. This iscalled reflectance spectroscopy. Asteroids are divided into several classes (indicated by letters) basedon their overall brightness and reflectance spectrum. E asteroids are very bright, S and M asteroids aremoderately bright, and C and D asteroids are dark. U asteroids are unusual and varied. E, M, and Uasteroids are rare, while S and C asteroids are common. The asteroid belt appears to be zoned, with mostof the S asteroids in the inner part of the belt, C asteroids in the central to outer belt, and D asteroids only inthe outer belt. (See Lesson 5)

The spectrum of reflected light at different wavelengths is caused by the mineralogy on the surface of theasteroid. If we have reflectance measurements of appropriate mineral and rock standards, we can deter-mine the mineralogy of an asteroid by matching it to that of the standards. In this way we find that E aster-oids are rich in iron-free pyroxene, M asteroids are rich in metal, C and D asteroids are rich in carbon, Sasteroids are mixtures of metal and silicates, and Vesta, one of the U asteroids, is made of basaltic rock.When compared to meteorites, fairly good matches between asteroid and meteorite classes are found. Easteroids match a special class of achondrites, M asteroids match irons and stony-irons, Vesta matchesbasaltic achondrites, C and D asteroids match carbonaceous chondrites. However, S asteroids are not avery good match for ordinary chondrites. Also, there is a problem that the most abundant type of asteroidin the inner asteroid belt does not match the most common type of meteorites. Our knowledge of the


relationships between asteroids and meteorites is still incomplete. Nevertheless, there is a general relation-ship between meteorites and asteroids, and a zoning in asteroid types in the asteroid belt This suggests thatasteroids represent the transition in formation from rocky inner planets to volatile-rich, outer planets.

Meteorites from CometsComets are small (1-10 km) balls of ice and dust that spend most of their time in the frigid outer solarsystem, but make spectacular displays when their highly elliptical orbits bring them into the warmer innersolar system. The Sun’s heat produces a gaseous coma around the solid nucleus and long tails of gas anddust that can be seen by the naked eye. Periodic comets, like Halley which appears every 76 years, haveelliptical orbits centered near Jupiter and Saturn and periods of less than 200 years. Most comets have verylong periods (>10,000 y) and have visited the inner solar system only once in recorded history. They havenearly parabolic orbits and spend most of their time in the Oort cloud far beyond the orbit of Pluto. CometsHyakutake and Hale-Bopp that visited the inner solar system in 1996-97 have periods of 65,000 years and4,200 years, respectively.

Comets are considered to be the most primitive bodies in the solar system. They are “dirty snowballs”consisting of water, methane and ammonia ices mixed with silicates and a little metal dust. They are thoughtto have formed in the region around Uranus and Neptune, but were moved to new orbits by gravitationalinteraction with the planets: Periodic comets we see today were moved inward toward Jupiter and Saturn.Most comets, however, were thrown outward beyond the planets to form the Oort cloud.

Comets are clearly related to periodic meteor showers. Almost all periodic showers occur when Earthcrosses the orbit of a periodic comet. Meteors are produced as cometary particles of dust and gas areburned up in the Earth’s atmosphere. The Solar System ABC’s Fact Sheet lists several comets and theirassociated meteor showers. The relationship between comets and meteorites is less certain. Since thecompositions of comets and interplanetary dust particles are quite similar, comets are thought to be thesources of IDP’s. Comet composition is also somewhat similar to that of some carbonaceous chondrites; arelationship with them is possible, although much less certain. Until we have more detailed information onthe nature and composition of comets, either from robotic landers or comet sample return missions such asthe Stardust mission to comet Wild 2, we will not know with certainty whether comets are the sources ofcarbonaceous chondrites.

Comet Halley. This photograph of CometHalley and a meteor, which appears as astreak, was taken on January 7, 1986 at theMount Palomar Observatory. The inset isan image of the nucleus of Comet Halleytaken by the European Space Agency’sGiotto spacecraft shortly before closestapproach.


Meteorites from the Moon and Mars

The surfaces of the Moon and the rocky inner planets showmany craters caused by meteorite impact. Could some of theseimpacts have ejected material into space that might later fall toEarth as meteorites? Before the Apollo lunar landings a fewscientists thought that meteorites might come from the Moon.But none of the lunar rocks returned by six Apollo missions in1969-1972 resembled meteorites. It was ten years later whenthe first lunar meteorite, ALHA81005, was identified in Antarc-tica. Although not identical to any specific Apollo sample, thisachondrite is an anorthosite breccia that is very similar to manysamples collected in the lunar highlands (see companionvolume Exploring the Moon). Since 1982, a total of fifteenlunar meteorites have been identified. These meteorites includeanorthosite breccias from the highlands and basalts and brecciasfrom the lunar mare.

The identification of martian meteorites is a space detective story.Because we have not yet returned samples from Mars we haveto rely on what we learned from robotic exploration and ourunderstanding of rocks from the Earth, Moon and asteroids. In 1976 the Viking mission provided our firstdetailed look at Mars using two orbiters which photographed the whole surface and two landers whichanalyzed the atmosphere and soil.

The intensive studies of lunar samples and meteorites in the 1970s led to general models for planetarydifferentiation and evolution. Small bodies like asteroids differentiated early, if at all, and their heat enginesdied shortly after solar system formation. Hence asteroidal meteorites, including basaltic achondrites, areclose to 4.5 billion years old. Larger bodies like the Moon and planets stayed active longer and have

Moon. This photograph of the Moon wastaken during the Apollo 17 mission. Thelight areas are highlands that are coveredmainly with breccias rich in anorthosites.The dark areas are maria that are coveredwith basalt lavas.

Lunar meteorite ALHA81005. This 31 g(ping pong ball-sized) meteorite is abreccia rich in light colored anorthositefragments melted and mixed together byimpacts in the lunar highlands. Other lunarmeteorites are dark colored basalts from themare. The scale is 1 cm across.


younger rocks on their surfaces, such as lunar basalts which are3-4 billion years old. The Earth is obviously still producingigneous rocks today.

When geochemists discovered the SNC family, a group ofachondrites which were 1.3 billion years old or less, they arguedthat they must be from a body larger than the Moon, perhapsMars. The absence of lunar meteorites was used to argue that itwas not possible to get meteorites off the surfaces of planets.The argument was if you couldn’t get meteorites from the Moonwith its lower gravity and closer distance, you couldn’t get themfrom Mars. The discovery of first one, and then several, lunarmeteorites refuted that argument. The definitive clues to amartian origin were found by comparing the meteorites to theViking lander measurements. The martian soil had the composi-tion of weathered basaltic rocks similar to the basaltic SNCmeteorites. But the real clincher was the discovery that gases inone meteorite, EETA79001, had compositions identical to thoseViking measured in the martian atmosphere. The rock actuallyhad martian atmosphere trapped inside. In all there are twelvemartian meteorites and all of them are igneous rocks, eitherbasalts or olivine and/or pyroxene cumulates.

Mars. This picture of Mars is a compositemade from many photos taken during theViking mission. The crack across the middleis a canyon as long as the United States.The dark circles at the left are hugevolcanoes that are the largest in the solarsystem.

Martian meteorite EETA79001. This 8 kg (soccer ball-sized) meteoriteis a basalt similar to, but distinct from, basalts on Earth, the Moon, andthe basaltic achondrite asteroid. It has dark glass-lined holes whichcontain gases with compositions the same as those measured in themartian atmosphere by the Viking lander.

Martian meteorite EETA79001. Remainsof dark fusion crust, created during highspeed entry through Earth’s atmosphere arevisible.


Brief History of the Solar System

Our geological understanding of the history of the solarsystem has been pieced together by geologists andastronomers based on numerous studies of the largebodies and rocks in the solar system. Many differentscientists participated in the study of the Earth, Sun, Moon,planets, asteroids, and comets. Some studied the astro-nomical bodies with telescopes; others did geology withorbital data and photographs; and still others studied themineralogy, composition, and ages of Earth and Moonrocks and meteorites. These studies haverevealed a series of processes in solar systemhistory: condensation, accretion, differentia-tion, volcanism, metamorphism, weathering, and impact.These processes have taken place throughout the rocky inner solar system, but the duration and extent ofthe last four processes depend on the solar system body. Therefore, different bodies and their rocksprovide evidence for different processes in solar system history. This evidence is tabulated in the SolarSystem ABC’s Fact Sheet, page 31.

The Earth, Moon and Mars have no evidence remaining of initial planet formation by condensation andaccretion. Primitive chondrite meteorites provide the evidence for the beginning of solar system history.Iron, stony-iron meteorites, lunar anorthosites, and seismic studies of Earth’s interior structure provideevidence of early differentiation into core, mantle, and crust. Basalts are products of volcanism on all typesof rocky bodies. Changes in the original mineralogy and composition of rocks were produced by metamor-

phism, weathering and impact on various bodies to different degrees.

Dating these events can be done in both relative and absolute ways. Relativedating on Earth is done in layers of rock where the rock on the bottom ispresumed to be older than the rock on the top (unless there is evidence thatthe whole unit is turned over). However, when comparing meteorites orrocks from various planets these relationships are not available so absolute

dating must be used. Absolute dating of rocks is based on radioactive decayof some elements with very long half-lives. The process that is dated depends

on whether the rock was changed by later processes and how extensive thosechanges were. For example, if we want to date the initial formation of a meteorite

(accretion of a chondrite or crystallization of a basaltic achondrite) the sample should be one that has notbeen extensively changed by metamorphism or weathering.

A solar system timeline based on dating of many meteorites and rocks from both Earth and Moon is given inthe Solar System ABC’s Fact Sheet. Like layers in rocks on Earth, the youngest events are at the top, theoldest are at the bottom. Although scientists don’t fully understand all of these formation processes, they doknow generally what happened and when. Some of these processes took place at about the same time ondifferent bodies in the solar system. Some processes took place once and were finished. Sun and planetformation and initial differentiation are good examples of this. Other processes such as volcanism, meta-morphism, and weathering continued over different periods of time on different bodies.


Billions of years ago, the elements which would eventually make up our solar system were produced inother stars. Around 4.6 billion years ago a rotating disk of gas and dust called the nebula formed from theseelements. The center of the nebula collapsed under gravity to form the Sun. Slightly later, about 4.55 billionyears ago, continued condensation and accretion led to the formation of the planets, moons and asteroids ofthe solar system. Very soon after their formation the inner planets, Moon and some of the larger asteroidsmelted and differentiated to produce core-mantle-crust. Basaltic volcanism, metamorphism and weatheringtook place shortly after the surfaces of these bodies formed. Thereafter the asteroids were geologicallyinactive except for impacts and the evidence of their early history was preserved.

The Moon and inner planets continued to evolve geologically for various periods of time which appear todepend on the size of the body. The record of their earliest geologic history is obscured by this subsequentactivity. The oldest Moon rocks, anorthosites, norites and troctolites, date the initial differentiation and firstmagmas production at 4.4-4.5 and 4.2-4.5 billion years, respectively. The lunar cataclysmic bombardment(discussed in the companion volume Exploring the Moon) occurred about 3.9 billion years ago. Marebasaltic volcanism began before 4 billion years and continued until around 2-3 billion years. Geologicactivity (other than impact) on the Moon ended long ago.

Our knowledge of the geologic histories of Mars and Venus is extremely limited. The Viking mission to Marsrevealed ancient highlands, giant “young” volcanoes, and extensive surface weathering. The samples analyzed bythe Viking lander were weathered rocks and soils. The martian meteorites are all igneous rocks most of whichhave ages of 180 million years (My) to 1.3 billion years. Thus martian basaltic volcanism continued at least to 180My ago. One martian meteorite is an ancient rock 4.5 billion years old. The Magellan mission remote observa-tions suggest that there may still be active volcanoes on Venus today. We have only very limited analyses ofsurface samples and no known meteorites from Venus so our information about the geologic history of Venus iswoefully inadequate.

Earth is clearly the planet about which we have the most information. However, Earth’s current geologic pro-cesses (plate tectonics, volcanism, metamorphism and weathering) have hidden the early history by changing thesurface rocks. The earliest known Earth rocks are about 4.0 billion years old, although geologists think that Earthhistory began at 4.5 billion years along with the Moon and asteroids. Earth is clearly still geologically active today.

Earth is the only body in the solar system where we know for certain that life began and evolved. Theconditions necessary for life as we know it (water, carbon, nitrogen and moderate temperature) are notcurrently available on any other body; however, there is evidence that Mars was wetter and may have been

warmer in the past. The ancient martian meteorite may containevidence of fossil life from an earlier era. The debate about life inthe martian meteorite continues and may not be resolved withoutmartian returned samples. The earliest evidence of life on Earthis dated around 3.7 billion years ago. Life evolved through upsand downs to the present. Periodic mass extinctions changed thedirection of evolution. For example, at 65 million years ago75% of all species died and small mammals took over domi-nance from the giant reptiles called dinosaurs. Whether thecause of these mass extinctions is a biologic process or thegeologic process of meteorite impact is still hotly debated.Nevertheless, meteorite impacts, both small and medium-sized,continue on Earth and other planets at the present.

Martian meteorite ALH84001. This 4.5billion year old rock may contain fossilevidence that primitive life may haveexisted on Mars as much as 3.6 billionyears ago.


The history of our solar system is long and complex. Our knowledge has been gained through various studies ingeology and astronomy and related fields. Scientists are still trying to understand the physical and chemicalprocesses in solar system history so the story is not complete. However, the history as we see it involves similarprocesses occurring at varied times on different bodies. Taken as a whole, it is a fascinating story.

Future ExplorationFurther understanding of the history of the solar system is closelylinked to the future exploration of space by robotic and humanmissions. There is still much that we can learn about solar systemprocesses from studies of meteorites and Apollo lunar samplesand from telescopic studies of the planets. But think how muchmore we can learn about planetary bodies with new samples andclose-up geologic exploration! The six Apollo lunar landingsdemonstrated the value of human observation and ingenuity inexploration and returned many documented samples for contin-ued studies. The spectacular results of the Voyager and Vikingmissions showed how much we can learn about distant planets from robotic missions. Future missions suchas the Mars Surveyor orbiter and lander series and the Discovery class missions to the Moon (Prospector),an asteroid (NEAR) and a comet (Stardust) promise exciting discoveries in the next ten years.

Exploration of space has other benefits besides knowledge. It creates new technologies and, perhaps moreimportantly, it inspires people to excel and to work together. However, space exploration, especially humanexploration, is a very expensive business. Not only must the benefits of knowledge, technology, inspiration,and cooperation be high, but the costs must be reduced as much as possible. One of the most effectivemeans of reducing costs comes from using space resources and reusing everything possible.

Asteroidal ResourcesNASA has worked on a number of plans for future robotic exploration of the planets, asteroids, and cometsand on human missions to the Moon and Mars. The most important expendables for space exploration areenergy for transportation and operations and consumables for life support. It takes lots of expensive energyto move a mass of consumables against Earth’s gravity. It takes much less energy to move the same mass inlower gravity environments like the Moon and especially asteroids. There is a big advantage in energy, and

Near Earth Asteroid Rendezvouz (NEAR)spacecraft. The NEAR mission willrendezvouz with Asteroid 433 Eros inFebruary 1999.

Mining an Asteroid. This is an artist’s ideaof mining an asteroid to support spaceexploration. Depending on the type ofasteroid, the products might be oxygen,metal, glass, water, organic compounds orseveral of these resources at once. (Credit:Dennis Davidson)


thereby cost, in using space resources as compared to carrying them from Earth. It may even be advanta-geous to get resources from one place in space for use in other places.

The closest planetary targets, the Moon, Mars, and asteroids, have little or no atmosphere and surfacewater, and no known plants for food, but there is abundant energy for operations from solar radiation.Moreover, the rocks and soils can provide many of the elements necessary for space exploration. Therocks themselves are nearly half oxygen, and some also contain water and organic compounds. NASA hasdeveloped technologies to extract oxygen from rocks, producing metals or glass as by-products. Thisoxygen will be used mostly for spacecraft propulsion, but also for astronaut life support. The metals andglass, as well as surface rocks and soil, can be used for building materials and radiation shielding. NASAhas also developed methods of growing plants in closed environments, reusing scarce consumables.

The first targets for extended space exploration and resource utilization are likely to be the Moon andasteroids. The Moon is close and relatively easy to get to. Although it doesn’t have air, water, or food, weknow what it is like, and we could produce oxygen, water, and even food in lunar factories and green-houses. Ideas for a Moon base are discussed in the companion volume Exploring the Moon. Asteroidsare such small bodies that their minimal gravity makes it easy to get materials off the surface and into space.In fact it takes less energy to get materials to and from some near-Earth asteroids than from the Moon. TheMoon and asteroids could provide test-beds for proving technology to sustain life on Mars or extendedspace flight.

Asteroids are particularly promising for using space resources because they offer a variety of differentresources. Asteroids similar to stony meteorites could provide oxygen for fuel and metal or glass forconstruction. Asteroids similar to ironmeteorites could provide metal, evensome precious metals, with very littleprocessing. Perhaps most promising,asteroids similar to carbonaceouschondrites could provide water andorganic compounds essential for lifesupport. Mining asteroid resourcescould become a stepping stone tohuman exploration of the outer solarsystem. (See Lesson 17)

Mars ExplorationMars is the ultimate near-term goal forhuman space exploration. It is theclosest planet that may be habitable bypeople. Venus, although closer toEarth, has a highly toxic atmosphere

Future mission to Mars. In the year 2020Mars exploration will be returning samplesfrom the red planet. (Credit: Pat Rawlings)


and extremely high temperatures which make it uninhabitable. Mars has a less toxic atmosphere andmoderate temperatures. Mars has always intrigued people because some astronomers thought they sawchannels suggesting the possibility of intelligent life. Recent geologic studies have shown that all surfacefeatures are natural formations, but also confirmed that Mars is the only other planet in our solar system thatcould once have harbored life of some kind. Although the Viking landers did not detect life in the martiansoil, we can’t be certain that life doesn’t or did not exist elsewhere on the planet. Mars is now cold and dry,but it was not always so. There is evidence that water flowed on the surface in the past. Mars was oncewetter and may have been warmer, and more hospitable for life. Several martian meteorites show interac-tion with martian water. The oldest one, ALH84001, may even have evidence of past life on Mars. Thepossibility of life and the more habitable conditions make Mars an important target for exploration.

Most of our information about Mars was collected during the Mariner and Viking missions. They wereflybys and orbiters that photographed the planet and made geophysical and geochemical measurements,and landers that analyzed the atmosphere and soil composition. Mars’ weather is always changing. Windand dust storms are common and sometimes global. The polar ice caps change with seasonal temperaturechanges. Major changes occurred some time in the past which made the surface water disappear and theatmosphere decrease. We do not yet understand the causes of these changes.

Mars’ geology is also fascinating. Although the planet is much smaller than Earth, the scale of its majorgeologic features is much larger. Mars’ volcanoes are the largest in the solar system, ten times greater thanthe largest on Earth. Mars’ huge canyon, Valles Marineris, is as long as North America is wide! Mars isdivided by a global cliff into old cratered southern highlands and young volcanic northern plains. Both thehighlands and the plains have been eroded by water and wind. The two Viking landing sites in the plainshad soil compositions similar to basalts altered by water. The martian meteorites are all igneous rocks,mostly from the young northern plains, but they contain some minor minerals in cracks and bubbles that areproducts of alteration by water. There are many questions left unanswered about the geology and climate

Exploring Mars. This painting shows astronauts exploring Mars using a rover for transportation. The astronauts areat the top cliff of a large canyon which is shrouded in mist. (Credit: Pat Rawlings)


of Mars. How has the planet changed with time? Why are the northern and southern hemispheres sodifferent? What caused the climate to change drastically so that the surface water and atmosphere disap-peared? Is water or ice present at the poles or as permafrost? Is there convincing evidence of life, eitherliving organisms or fossils? These are some of the questions to be addressed by future exploration.

The exploration of Mars is a complicated and expensive endeavor. The trip to Mars takes at least sixmonths when the two planets are closest, which happens every two years. Ideally, Mars exploration willinclude a combination of robotic and human missions. Robotic exploration is necessary in the early stagesto conduct global surveys and investigate potential sites for human exploration. Robotic missions will alsotest technologies, deliver cargo, and return the first documented Mars samples. Human missions are desir-able for detailed exploration of selected sites because people are best at observation, interpretation andproblem solving.

Preparation for a human mission to Mars is extensive. The mission would last about three years, includingthe long trip each way and plenty of time for exploration while waiting for the planets to return to closestapproach. This extended mission requires a huge amount of consumables, both for fuel and for life support. The amounts can be reduced to about one third by using Mars’ resources. The selected siteshould be one where water or ice is available for human use. NASA is developing technologies to produceoxygen from the carbon dioxide in Mars’ atmosphere. This would be used for breathing, but also to powerrovers for exploration and the spacecraft for the return trip to Earth. Astronauts could grow plants for foodin greenhouses that recycle CO2 and other waste components. With habitats for shelter and rovers fortransportation, the first Mars outpost could be nearly self-sufficient. It would also be the first step in apermanent human presence on Mars.

Once their basic needs are met the astronauts will spend part of their time on exploration and sampleanalysis. They will observe geologic formations, collect rocks and soils, and look for any signs of life. Inthe habitat labs they will do geochemical and biological analyses. Together with their scientific colleaguesback on Earth they will attempt to answer some of the questions about the evolution of Mars and its part inthe history of the solar system. By exploring the asteroids and planets we may be able to solve some of themysteries revealed by meteorites.

Mars Habitats. The joined habitats providethe crew with multiple pressurized volumesfor conducting greenhouse experiments,biological research, geochemical analysisof samples, and general crewaccomodations. (Credit: Jack Frassanito)

Meteorite Fact Sheet 29NASA EG-1997-08-104-HQ

Exploring Meteorite Mysteries

Meteorite ABC�s Fact Sheet

Major Minerals in MeteoritesListed are the major minerals in meteorites, their composition and occurrence. Minerals are listed by group:silicates, metal, sulfides, oxides, phosphates, and carbon compounds. Many other minerals occur in smallabundances but are not listed. Mineral compositions in meteorites and other rocks are variable, with similarelements substituting for each other in the crystal structure (for example Mg, Fe, Ca in silicates or Mg, Fe, Cr, Al inoxides). Variations in these mineral compositions are important in meteorite classification.

Mineral Formula or Composition Occurrence in MeteoritesSilicates stony and stony-irons olivine (Mg,Fe)Si2O4 chondrites, stony-irons pyroxene (Mg,Fe,Ca)SiO3 chondrites, achondrites, stony-irons feldspar CaAl2Si2O8-NaAlSi3O8 most abundant in achondrites clay minerals (Mg,Fe,Ca)3-6 Si4O10 (OH)2 *H2O mostly in carbonaceous chondritesMetal abundant in irons, stony irons kamacite, taenite Fe (low and high Ni) common in most chondritesSulfides abundant in irons, stony irons troilite, pyrrotite FeS, Fe7S8 minor in stony meteoritesOxides minor in most meteorites spinel, magnetite, chromite (Mg,Fe,Cr,Al)3 O4 composition depends on typePhosphates apatite, whitlockite Ca5 (F,Cl,OH)(PO4)3, Ca2PO4 minor in stony meteoritesCarbon compounds diamond, graphite C (elemental carbon) carbonaceous chondrites organic molecules, amino acids C,H,O,N compounds carbonaceous chondrites

Meteorite ClassificationsListed are the major types and classes of meteorites, with examples of each. Major types are in bold and mostabundant classes are in italics. Minor classes are in normal font and only those discussed in text are listed. Othersometimes more abundant classes are omitted for simplicity.

Type / Class Mineralogy / Rock Types ExamplesStony - chondrites silicate minerals, chondrules ordinary chondrites varied iron, metamorphism Noblesville, LEW87030,

ALH90411 carbonaceous chondrites varied metamorphism, weathering Allende, ALH83100Stony - achondrites silicate minerals, no chondrules basaltic achondrites basalt, breccia, pyroxene cumulate Juvinas, Johnstown, EET83227 planetary- lunar - martian

basalt, anorthosite, brecciabasalt, pyroxene-olivine cumulate

ALHA81005, EET87521EETA79001, Shergotty

Stony-irons metal-silicate cumulate, breccia Brenham, EsthervilleIrons iron-nickel metal intergrowths Sikhote Alin, Gibeon

Meteorite Fact Sheet30 NASA EG-1997-08-104-HQ

Meteorites in Meteorite Sample DiskName Location Find date mass (kg) classificationALH90411 Allan Hills, Antarctica 1990 5.8 chondrite L3LEW87030 Lewis Cliff, Antarctica 1987 8.0 chondrite H5Allende Allende, Mexico 1969 1,000 carbonaceous chondriteEET83227 Elephant Moraine, Ant. 1983 2.0 basaltic achondriteGibeon Namibia, Africa 1836 21,000 Iron - octahedriteBrenham Kansas, USA 1882 4400 Stony-iron - pallastite

Descriptions of Meteorites in Meteorite Sample Disk

ALH90411 (Chondrite A) This ordinary chondrite has numerous clasts and chondrulesin a light gray matrix. It is a low-iron, non-metamorphic chondrite made up mostly ofolivine and pyroxene silicate minerals, with a little iron-nickel metal.

LEW87030 (Chondrite B) This ordinary chondrite has abundant metal and few clasts orchondrules in a dark gray matrix. It is a high-iron, metamorphic chondrite made up ofolivine and pyroxene silicate minerals and iron-nickel metal.

Allende (Carbonaceous Chondrite) This carbonaceous chondrite is a dull black samplewith visible clasts and chondrules in hand specimen. A thin slice shows numerous smallwhite inclusions and chondrules in a dark carbonaceous matrix.

EET83227 (Achondrite) This basaltic achondrite is a rock made up of fragments ofvarious types of basaltic materials in a fine-grained matrix. A thin slice shows fragmentsof different types of pyroxene-feldspar basalts and mineral fragments in a matrix of thesame minerals.

Gibeon (Iron) This iron meteorite has a fine-grained intergrown of kamacite and taeniteiron-nickel minerals. This criss-crossed intergrowth is called Widmanstatten texture andis visible on the sawn surface that has been etched with acid.

Brenham (Stony-iron) This stony-iron meteorite is a cumulate consisting of yellowolivine silicate crystals surrounded by iron-nickel metal. The metal has been polished andwould show a Widmanstatten texture if it were etched with acid.

We would like to thank the following organizations for providing meteorite samples for the disks:

U.S. Antarctic Meteorite Program (NSF), for ALH90411, EET83227, and LEW87030National Museum of Natural History, Smithsonian Institution, for Allende and GibeonField Museum of Natural History, for Brenham

Solar System Fact Sheet 31NASA EG-1997-08-104-HQ


Solar System ABC�s Fact Sheet

Bodies in the Solar System

Listed are the Sun and bodies in the solar system that may be sources of meteorites. These include major bodies(planets) and minor bodies (Moon, asteroids and comets). Given are the body name, diameter, orbit, and surface andatmosphere composition. Orbital data include distance from the Sun (AU, semi-major axis), and eccentricity(e: 0 for circular, 1.0 for parabolic, and values between are elliptical).

Body Diameterkm

OrbitAU

Orbit e

SurfaceComposition

Atmosphere Composition

Sun 1,400,000 -- -- none H2, He, C, NMercury 4,880 0.4 0.20 silicates noneVenus 12,100 0.7 0.01 silicates thick CO2Earth 12,800 1.0 0.02 silicates, H2O medium N2, O2, H2OMoon 3,480 1.0 silicates noneMars 6,800 1.5 0.09 silicates, H2O,CO2 ices thin CO2Asteroids <1,000 2.2-3.8 vary silicates, iron noneJupiter 143,200 5.2 0.05 liquid H, silicate core thick H2, HeSaturn 120,000 9.5 0.06 liquid H, silicate core thick H2, HeUranus 51,800 19.2 0.05 liquid H, silicate core thick H2, He, methaneNeptune 49,500 30.0 0.01 liquid H, silicate core thick H2, He, methanePluto 2,300 39.4 0.25 silicates very thin methaneComets 1-10 per: 4-7

40,0000.4-0.9

1.0H2O, ices of methane,ammonia, silicates

H2O, H,C,O,N compounds

AsteroidsTwenty asteroids are listed in order of distance from the Sun. Given are the asteroid number and name, yeardiscovered, diameter, semi-major axis of orbit, and asteroid type. The first four asteroids are Earth or Mars-crossingand have elliptical orbits. The next 13 asteroids are all in the asteroid belt and have nearly circular orbits. Thesewere chosen to include the largest of the common S and C type asteroids and examples of the rarer types U, E, M.The last three asteroids have orbits outside the asteroid belt. Hector is within the orbit of Jupiter.

Number Name Year Size km Orbit AU Type2062 Aten 1976 0.9 0.97 S433 Eros 1898 23 1.46 S1862 Apollo 932 1.4 1.47 U1221 Amor 1932 1.0 1.92 S

4 Vesta 1807 549 2.36 U7 Iris 1847 210 2.39 S44 Nysa 1857 73 2.42 E6 Hebe 1847 201 2.43 S21 Lutetia 1852 115 2.43 M19 Fortuna 1852 215 2.44 C3 Juno 1804 265 2.67 S1 Ceres 1801 940 2.77 C2 Pallas 1802 540 2.77 C45 Eugenia 1857 228 2.72 C16 Psyche 1852 265 2.92 M10 Hygeia 1849 410 3.14 C65 Cybele 1861 280 3.43 C

279 Thule 1888 60 4.26 D624 Hector 1907 150x300 5.15 D944 Hildago 1920 39 5.80 D

Comets and Meteor ShowersListed are ten periodic meteor showers, their dates ofpeak annual activity, and the comet associated witheach shower. Meteors are produced when the Earthpasses through the orbit of the comet and its residualgas and dust particles burn up in the atmosphere.

Comet Shower Date1491I Quadrantids January 3Thatcher Lyrids April 23Halley Aquarids May 4Encke Taurids June 30Swift-Tuttle Perseids August 12Giacobini-Zinner Draconids October 9Halley Orionids October 21Encke Taurids November 4Temple Leonids November 16Phaeton Geminids December 13

Solar System Fact Sheet32 NASA EG-1997-08-104-HQ

Evidence for Processes in the Solar SystemListed is the geologic evidence for rock-forming processes on various bodies in the solar system. Many of theprocesses occurred on all planetary bodies and some asteroids. However, the geologic evidence is not alwaysavailable because it is masked by later processes.

Process Earth Moon / Mars Asteroids (meteorites)condensation no evidence no evidence carbonaceous chondritesaccretion no evidence no evidence chondritesdifferentiation core/mantle/crust anorthosites, meteorites irons, stony-ironsvolcanism basalts, volcanoes mare basalts, meteorites basaltic achondritesmetamorphism metamorphic rocks lunar metamorphic rocks chondritesweathering sedimentary rocks Mars geology, meteorites carbonaceous chondritesimpact meteorite falls, craters breccias, craters meteorites, breccias

Solar System TimelineListed are major events or processes in the history of the solar system as determined from the geologic orastronomical evidence. Time is in years (y) before the present (K=thousand; M=million; B=billion). Some of theevents on the Moon are not discussed in this book, but are explained in the companion volume Exploring the Moon.

Time Where Event or Process Evidence0 y - 4.0 By Earth volcanism, metamorphism, weathering Earth rocks, geology3, 25, 47 y Earth falls-Noblesville, Allende, Sikhote-Alin meteorites50 Ky Earth fall of Canyon Diablo, Meteor Crater crater, meteorite0.1-11 My Moon impacts sent lunar meteorites to Earth lunar meteorites0.5-16 My Mars impacts sent Mars meteorites to Earth Mars meteorites65 My Earth K/T impact and death of dinosaurs Ir in soils, fossils0.2-4.5 By Mars basaltic volcanism, intrusions Mars meteorites3.2-4.3 By Moon mare basaltic volcanism lunar basalts, meteorites3.7 By Earth first evidence of life on Earth fossils3.9 By Moon cataclysmic bombardment breccias, craters4.0 By Earth oldest known Earth rock Earth rocks4.2-4.4 By Moon igneous intrusions troctolite, norite4.2-4.55 By Asteroids metamorphism, weathering chondrites4.4-4.5 By Moon differentiation, magma ocean anorthosites, meteorites4.55 By Asteroids differentiation, core, mantle, crust achondrite, iron, stony-iron4.55 By nebula solar system forms by condensation, accretion chondrites, astronomy4.6 By nebula Sun forms from nebula astronomy, physics>4.6 By Stars elements form in other stars astronomy, physics~10 By Universe H, He formed by "Big Bang" astronomy, physics

M yst eri o usM et e orit es

O bj e cti v e sSt u d e nts will:

• p arti ci p at e i n a br ai nst or m s essi o n t h at will h el p f o c us t h eiri nt er est o n a n d ar o us e t h eir c uri osit y a b o ut m et e orit es.

• vi e w a sli d e s h o w t h at pr o vi d es b a c k gr o u n d i nf or m ati o n.

B a c k g r o u n dT hr o u g h o ut t h e w orl d m et e orit e f alls ar e r ar e e v e nts t h at ar eo bs er v e d j ust a f e w ti m es a y e ar. T h e f all of t h e N o bl es vill em et e orit e i n 1 9 9 1 w as o bs er v e d b y t w o b o ys. T h e st or y of t h e b o ysa n d t h e m et e orit e m a k es a n e x c ell e nt f o c us f or t h e u nit.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. R e vi e w st or y a n d b e r e a d y t o t ell it li k e a st or yt ell er.2. Pr e vi e w sli d e s et a n d n arr ati v e.

A b o ut T his L ess o nSt u d e nts will list e n t o t h est or y of a n a ct u al m et e orit ef all a n d br ai nst or m o n w h att h e y w a nt t o k n o w a n d h o wt h e y w o ul d r e a ct. T h eq u esti o ns st u d e nts g e n er at ewill r el at e dir e ctl y t o t h eu nits c o nt ai n e d i n E x pl ori n gM et e orit e M yst eri es a n d willh el p t e a c h ers f o c us st u d e nts’att e nti o n o n m et e orit ei n v esti g ati o ns. Aft er m a ki n g alist of w h at t h e y w a nt t ok n o w, t h e y will vi e w a sli d es h o w i ntr o d u cti o n t om et e orit es.

M at e ri als❑ N o bl es vill e F all N arr ati v e

( p g. 1. 2)❑ Sli d e S et, I ntr o d u cti o n❑ pr oj e ct or❑ s cr e e n❑ c h al k b o ar d or o v er h e a d

pr oj e ct or

V o c a b ul a r ym et e orit e, f all, fi n d, cr at er

P h ot o of b o ys c o urt es y ofM. Li ps h utz.

Lesson 1 � Noblesville Fall1.2 NASA EG-1997-08-104-HQ

Classroom Procedure1. Tell the Noblesville Fall Narrative, Part 1 with as much animation and sound effects as

possible.

2. Ask the class to put themselves in the boys’ place and tell how they would feel, what theywould want to know, and what they would do next? Brainstorm on these questions, making arandom list of responses on the board. The class could then organize the responses intogroups such as Feelings, Actions, and Questions. Some of the questions students mayexpress are: What is it? Where did it come from? How did it get here? What is it made of?How did it form? What good is it? Is it dangerous?

3. Conclude the NoblesvilleFall Narrative, Part 2about what the boys did.

4. Show slides as anintroduction tometeorites.

Noblesville Fall Narrative

Part 1: Observation of the fall

It was 7:00 PM and early dusk on the summer evening of August 31, 1991, in the small townof Noblesville, Indiana. Two boys, 13 year old Brodie Spaulding and 9 year old Brian Kinzie, hadjust finished riding bikes and were standing talking on Brodie’s lawn. Suddenly they heard a low-pitched whistling sound. Then Brian saw an object spinning through the air past Brodie. Theobject landed with a thud on the ground 4 meters from them and rocked as it landed. The boyspicked up the object, which appeared to be a stone, and found that it was slightly warm. It hadmade a hole 5 centimeters deep in the lawn where it landed. They looked around and couldn’t findanyone who might have thrown the stone.

Stop for class brainstorm session.

Part 2: What the boys did

What Brodie and Brian did was take the stone inside to Brodie’s parents. They decided tocall nearby Purdue University. The mystery was solved a few days later when a Purdueprofessor confirmed that the rock was a meteorite. The boys let the scientists have a smallportion of the meteorite for scientific studies. Today, although meteorite dealers have offeredthem several thousand dollars to buy the meteorite, the boys still own it.

The boys learned that meteorites are very special rocks that have fallen to Earth aftertraveling through the solar system. They provide clues for scientific detectives to solve themysteries of our early solar system, the origin of the planets, and the beginning of life itself.

Noblesville Meteorite

Lesson 2 � Follow the Falling MeteoriteNASA EG-1997-08-104-HQ 2.1


Lesson 2 � Follow the Falling Meteorite

ObjectivesStudents will:

• apply geometric properties and relationships to meteoritehunting.

• demonstrate and experience the way remote objects or sitescan be accurately located by triangulation.

• use triangulation on a map, both in a directed activity and in agroup-challenge activity.

BackgroundTriangulation is a basic geometric technique for locating distantobjects or events by measuring the directions to an object from twoknown locations. The basic premise behind triangulation is thatmany of our senses can accurately determine the direction to anobject but cannot always accurately determine its distance.However, two observers in different locations will see the object indifferent directions. The two known locations of the observers formthe base of a triangle. The angles to the distant object define wherethat object is located, as seen in Figure 2-1.

Triangulation is used extensively in astronomy to determinedistances or sizes of objects we cannot visit (like stars and planets).Triangulation is a useful map and survival skill often taught in scout-ing and orienteering. This technique is used in surveying and indetermining the epicenter of an earthquake. It is also a good intro-duction to the geometry and mathematics of triangles.

About This LessonIn the activities in this lessonstudents use sound to easilydemonstrate basic triangula-tion techniques. They alsotriangulate using a meteor’spath to predict wheremeteorites might be found.Extended math applicationsmay be added. Students alsodevelop a treasure hunt mapin the final activity.

“Wheredo theycomefrom?”

Vocabularymeteor, meteorite,triangulation

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. G at h er m at eri als.

Cl assr o o m Pr o c e d ur e1. C h o os e a st u d e nt t o b e t h e list e n er ( n ot h e ari n g-i m p air e d i n

eit h er e ar), a n d a n ot h er t o m a k e n ois e ( b ell, b u z z er, p e n cilt a p pi n g et c.). M a k e s ur e t h at t h e list e n er c a n n ot ( or will n ot)s e e d uri n g t h e pr o c e d ur e, as b y bli n df ol di n g. H a v e t h e n ois em a k er g o t o a f ar p oi nt i n t h e r o o m, m o vi n g q ui etl y or m as k e db y n ois es m a d e b y t h e ot h er st u d e nts. W h e n t h e r o o m is q ui eta g ai n, h a v e t h e n ois e m a k er m a k e a s o u n d. R e p e at if n e c es-s ar y u ntil t h e list e n er p oi nts at t h e n ois e m a k er. Al m ost allst u d e nts will b e a bl e t o p oi nt v er y cl os e t o t h e dir e cti o n of t h en ois e m a k er. [ M a n y st u d e nts h a v e pr o b a bl y pl a y e d t h es wi m mi n g p o ol g a m e “ M ar c o P ol o,” w hi c h is t his s a m e i d e a.]As k bli n df ol d e d list e n er t o d et er mi n e dist a n c e t o t h e n ois em a k er. S h o w t h e st u d e nts t h at a si n gl e list e n er c a n t ell t h edir e cti o n t o t h e n ois e, b ut n ot al w a ys t h e a c c ur at e dist a n c e.

2. C h os e t w o st u d e nts t o b e list e n ers a n d r e p e at as i n st e p 1,k e e pi n g as m u c h dist a n c e b et w e e n t h e m as p ossi bl e. B ot hlist e n er s s h o ul d b e p oi nti n g f airl y cl os e t o t h e n ois e m a k er.S h o w h o w t h e l o c ati o n a c c ur a c y is i m pr o v e d. T o m a k e ite asi er f or st u d e nts t o s e e t h e tri a n gl e, tr y usi n g y ar n t o tr a c et h e vis u al li n es of si g ht.

3. R e p e at wit h m or e t h a n t w o list e n ers if d esir e d. A s m all“t ar g et ar e a ” will us u all y b e f or m e d.

M a t e ri als fo r A cti vit y A❑ bli n df ol ds f or t w o

( o pti o n al)❑ n ois e m a k er ( a n yt hi n g t h at

m a k es a n ois e)❑ y ar n ( e n o u g h t o “tr a c e ”

t h e tri a n gl e i n A cti vit y A-St e p 2, or ~ 5 0 m)

A b o ut T his A cti vit ySt u d e nts will d e m o nstr at eh o w t o l o c at e dist a nt o bj e ctsor sit es b y tri a n g ul ati o n.T h e y will us e s o u n d t o s h o wt h e b asi c pri n ci pl es oftri a n g ul ati o n. T his a cti vit yc a n b e d o n e i n d o ors oro utsi d e.

Fi g u r e 2- 1

A b o ut T his A cti vit ySt u d e nts will tr a c k a m et e or’sp at h usi n g tri a n g ul ati o n a n dpr e di ct w h er e its m et e orit esmi g ht b e f o u n d. T h e e x er cis ec a n b e e xt e n d e d t oc al c ul ati n g t h e v el o cit y of am et e or a n d u n d erst a n di n gh o w s ci e ntists c a n d et er mi n e am et e or’s ori gi n al or bit i ns p a c e.

M a t e ri als fo r A cti vit y B❑ pr otr a ct ors❑ r ul ers❑ St u d e nt Pr o c e d ur e

( p gs. 2. 5- 2. 6, o n e p erst u d e nt)

❑ c ol or e d p e n cils❑ p e n cils

Q u esti o n K e y

S e cti o n 1W h er e d o t h e t w o li n es cr oss ?

4 0- 4 3 k m E ast- N o rt h e ast of D r y g ul c h Fl ats.W h er e di d t h e m et e or e x pl o d e ?

I n t h e ai r n e a r w h e r e t h e li n es c r oss e d, o r s a m e a ns w e r asfi rst q u esti o n.

S e cti o n 2W h er e w as t h e m et e or w h e n t h e s p ar k fl e w ?

5 0- 5 2 k m n o rt h e ast of B u b bli n g B a y o u, o r n e a r t h ec o astli n e b y t h e p e ni ns ul a.

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. R e vi e w st u d e nt pr o c e d ur e.2. Ass e m bl e m at eri als.

Cl assr o o m Pr o c e d ur e1. R e vi e w us e of pr otr a ct ors, m a p c o or di n at es, m a p s c al e a n d

u nits.2. Pr a cti c e s e v er al pr otr a ct or r e a di n gs (s e e e x a m pl e b el o w).3. Distri b ut e “ St u d e nt Pr o c e d ur e: A cti vit y B.”4. If d esir e d, w or k t h e first o bs er v ati o n m e as ur e m e nt as a cl ass

or o n t h e o v er h e a d.5. All o w st u d e nts t o c o nti n u e w or ki n g o n t h e w or ks h e et.6. Dis c uss.

M a p T e a c h e r K e y

E x a m pl e

Lesson 2 � Follow the Falling Meteorite2.4 NASA EG-1997-08-104-HQ

Using the positions of the spark and the explosion, which direction was themeteorite traveling?

North-Northwest

How far was it from where the meteorite sparked to where it exploded?(measure with ruler)?

23-25 km

Where would you first look for meteorites that might havefallen from the explosion?

Northeast of Drygulch Flats, near where the lines cross.

Section 3 (optional)If both observers counted twoseconds between the spark andthe explosion, how fast was themeteor going?

Approximately 43,200 kmper hour.

Extra Thinking Questions1. Why might a meteor not produce meteorites?

The meteorite might burn up before landing.

2. Could a meteorite fall without anyone seeing a meteor? Explain.Yes. Meteors can be small enough and slow enough that they do not make big meteorstreaks in the sky; no one saw a meteor when Noblesville fell. Also, it might fall at a time orremote location where no one is looking.

3. How could you determine the elevations of the meteor’s sparking and its explosion?You can calculate the height using the determined distance and the measured observedangle above the horizon h = d Tan angle.

4. What information would you need to determine the orbit a meteorite was in before it hit theEarth?

You would need several accurately located photo observations of the meteor with exacttime records, and data charts of Earth’s positions. (See also Lesson 4.)

Extensions1. Try depicting this activity in 3 dimensions by providing altitude angles. Challenge students to

come up with a way of representing the true meteor location.2. For students with a background in algebra and trigonometry, the location of the meteor spark and

explosion in Activity B can be determined mathematically using the cosine rule.3. If possible have students observe and or photograph a meteor shower.

M at e ri al s❑ r ul er ❑ pr otr a ct or ❑ p e n cil ❑ c ol or e d p e n cils

P at h a n d S p e e d of a M et e o rUsi n g t h e m a p pr o vi d e d, y o u will b e l e d t hr o u g h t h e pr o c e d ur es of tri a n g ul ati n g t h ep at h a n d e x pl osi o n of a m et e or a n d d et er mi ni n g a li k el y ar e a t o l o o k f or m et e orit es.R e vi e w t h e us e of a pr otr a ct or if n e c ess ar y.

S e cti o n 1. T h e att a c h e d m a p s h o ws t h e l o c ati o n of t w o p e o pl e w h e n t h e y s a wt h e m et e or. T h e o bs er v er i n Dr y g ul c h Fl ats w as l o o ki n g 8 0° E ast of N ort hw h e n s h e s a w t h e m et e or e x pl o d e.

— Fr o m Dr y g ul c h Fl ats, m e as ur e a n a n gl e 8 0 ° E f r o m t h e d as h e d N- Sr ef e r e n c e li n e, m ar k t h e a n gl e, a n d wit h a c ol or e d p e n cil dr a w a l o n g li n efr o m Dr y g ul c h Fl ats t hr o u g h t h e m ar k y o u m a d e.

T h e o bs er v er i n B u b bli n g B a y o u w as l o o ki n g i n a dir e cti o n 4 0 ° E ast of N ort hw h e n h e s a w t h e m et e or e x pl o d e.

— Fr o m B u b bli n g B a y o u m e as ur e a n a n gl e 4 0 ° E fr o m t h e d as h e d N- Sr ef e r e n c e li n e, m ar k t h e a n gl e. Usi n g t h e s a m e c ol or p e n cils dr a w a l o n gli n e fr o m B u b bli n g B a y o u t hr o u g h t h e m ar k y o u m a d e.

Lesson 2 � Follow the Falling Meteorite2.6 NASA EG-1997-08-104-HQ

QuestionsWhere do the two lines cross?

Where did the meteor explode?

Section 2. Both observers also saw the meteor shed a spark some time before itexploded (assume the meteor’s path was horizontal). The observer inDrygulch Flats was looking in a direction 110° East of North when she sawthe spark fly.

— Using the same technique as in step 1 and a different color pencil,draw a long line from Drygulch Flats in that direction.

The observer in Bubbling Bayou was looking in a direction 60° East of Northwhen he saw the spark fly.

— Draw a long line from Bubbling Bayou in that direction.

QuestionsWhere was the meteor when the spark flew?

Using the positions of the spark and the explosion, which direction was themeteorite traveling?

How far was it from where the meteor sparked to where it exploded?(measure with ruler)

Where would you first look for meteorites that might have fallen from theexplosion?

Section 3. Determine how fast the meteor was going. If both observers counted2 seconds between the spark and the explosion, how fast was the meteor going(in km/hr)?

A b o ut T his A cti vit yT his tri a n g ul ati o n a cti vit y c a nb e d o n e as a tr e as ur e h u ntg a m e usi n g a m a p of y o url o c al c o m m u nit y, c o u nt y, orst at e. E a c h t e a m cr e at esdir e cti o ns t h at all o w a n ot h ert e a m t o d et er mi n e t h e f all sit e.

M a t e ri als fo r A cti vit y C❑ c o pi es of l o c al or r e gi o n al

m a p (t w o p er t e a m)❑ c ol or e d p e n cils❑ p a p er❑ pr otr a ct or ( p er t e a m)

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. H a v e c o pi es of l o c al or r e gi o n al m a ps f or e a c h t e a m.

Cl assr o o m Pr o c e d ur e1. D e ci d e w h er e o n t h e m a p t h e t w o o bs er v ers w o ul d b e.

Di vi d e t h e cl ass i nt o t e a ms a n d gi v e e a c h t e a m t w o c o pi es oft h e m a p.

2. E a c h t e a m c h o os es a m et e orit e f all s p ot, a n d m ar ks it wit h ad ot o n o n e m a p. D et er mi n e w h at dir e cti o n t h e o bs er v ersw o ul d h a v e h a d t o l o o k t o s e e t h e m et e orit e f all p oi nt. Dr a wli n es fr o m t h e f all p oi nt t o w h er e e a c h o bs er v er is st ati o n e d.M e as ur e t h e a n gl e t h os e li n es m a k e wit h N ort h. At t h eb ott o m of t h e s e c o n d m a p or a pi e c e of p a p er, r e c or d t h es ea n gl es f or us e b y a n ot h er t e a m.

3. E a c h t e a m p ass es t h eir list of a n gl es t o a n ot h er t e a m s o t h att h e y h a v e “l o o k dir e cti o ns ” f or a n e w m et e orit e f all. T h e nus e tri a n g ul ati o n as i n A cti vit y B t o d et er mi n e w h er e t h em et e orit e f ell. T his c o ul d b e d o n e as a r a c e or as a na c c ur a c y c o nt est. Aft er t e a ms ar e fi nis h e d, t h e y c a nc o m p ar e t h eir f all l o c ati o n wit h t h e ori gi n al m a ps.

E xt e nsi o ns1. O utsi d e, s et u p tr e as ur e h u nt s o t h at st u d e nts l e ar n t o us e a

m a g n eti c c o m p ass.

2. Pl a c e a b all b e ari n g i n a fi el d t o r e pr es e nt a m et e orit e.Pr o vi d e a m a p of t h e fi el d a n d tri a n g ul ati o n o bs er v ati o n a n gl es.H a v e st u d e nts att e m pt t o fi n d t h e “ m et e orit e.”

Lesson 3 � Searching for MeteoritesNASA EG-1997-08-104-HQ 3.1

Exploring Meteorite Mysteries Lesson 3 � Searching for Meteorites “Where

do theycomefrom?”

About This LessonWater balloons filled withflour and pebbles helpstudents model the distributionof materials after meteoriteimpacts. The flour simulatesthe ejected crater material andthe pebbles represent themeteorite fragments.Students will use the model todraw conclusions about whereit would be easiest to findmeteorites.

Vocabularymeteorite, ejecta, terrain,velocity, impact


• perform a demonstration of meteorite impacts with waterballoons.

• assess various terrains for meteorite recovery usinggeography skills.

• attempt to recover simulated meteorite fragments.

• make experimental predictions.

• graph experimental results and draw conclusions.

BackgroundFinding meteorites is quite difficult because most meteorites look likeEarth rocks to the casual or untrained eye. Even to the trained eye,recognizing meteorites can be difficult. In many casesmeteorites break apart into many fragments as they pass through theatmosphere or impact the Earth. These smaller fragments are harderto find than one large meteorite. Meteorites are rarely found in forestsor fields, where they become lost or buried among the plants. Inrocky areas, meteorites are hard to find because they tend to be dullblack, gray or white, and do not stand out among the much morecommon Earth rocks (see Meteorite Sample Disk if available). Ironmeteorites are the exception. There are few natural sources of metalexcept meteorites. Old iron implements can be (and often are) mis-taken for meteorites. In many cases, a chemical analysis is requiredto distinguish a meteorite from an Earth rock.

In their experiments, students will likely discover thatgood places to retrieve meteorites aresurfaces that have no similar rocks, are veryflat, have a contrasting background, and donot have thick vegetation. These conditionsare best met on Earth by the polar ice cap inAntarctica, where in fact, thousands ofmeteorites have been found since 1969.Lots of meteorites are also found in deserts,especially in the Sahara and in southernAustralia, where there are flat areas with fewother rocks.

M at e ri alsP e r St u d e nt❑ St u d e nt Pr o c e d ur e a n d

D at a Ta bl e ( p gs. 3. 3- 3. 5)❑ 1 b all o o n (r o u n d b all o o ns

w or k b est)❑ 0. 1 lit er fl o ur ( 1/ 2 c u p)❑ 1 0 t o 2 0 s m all p e b bl es

( c ol or e d a q u ari u m r o c k sw or k w ell)

❑ gr a p h p a p er

P e r G r o u p o rCl ass r o o m❑ w at er f a u c et t o fill b all o o n❑ f u n n el ( o n e p er gr o u p)❑ m e as uri n g c u p❑ t hi n sti c k or s k e w er E xt e nsi o ns

1. Var y t h e e x er cis e b y usi n g a v ari et y of m at eri als, c h art all d at a,a n d r e writ e t h e a cti vit y, m a ki n g it m or e eff e cti v e.

2. Dr a m ati z e t h e i m p a ct a n d s c att er p att er n of p e b bl es, usi n gst u d e nts as p e b bl es a n d d oi n g t h e dr a m ati z ati o n i n sl o w m oti o n.

3. O n a w orl d m a p h a v e st u d e nts pr e di ct w h er e m et e orit es mi g hte asil y b e f o u n d.

4. L ess o n 1 8 c o ul d b e us e d t o e xt e n d t h e A nt ar cti c m et e orit e t e a mi nf or m ati o n.

5. S h o w A nt ar cti c sli d es ( a v ail a bl e fr o m N A S A, s e e p a g e i v).

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. Ass e m bl e m at eri als.2. Pr a cti c e filli n g b all o o n wit h fl o ur a n d c h e c k f or a p pr o pri at e

l o c ati o ns t o c o n d u ct i m p a cts.

Cl assr o o m Pr o c e d ur e1. Distri b ut e St u d e nt Pr o c e d ur e a n d D at a Ta bl e.2. Dis c uss b a c k gr o u n d a n d i nt e nt f or a cti vit y ( w h y a n d h o w).3. L o o k at ( or dis c uss) s el e ct e d i m p a ct sit es pri or t o pr e di cti n g

o n St u d e nt Pr o c e d ur e.4. H a v e st u d e nts c oll e ct m at eri als.5. F oll o w St u d e nt Pr o c e d ur e.6. Dis c uss r es ults a n d l e a d t o c o n cl usi o ns t h at A nt ar cti c a a n d

d es erts ar e li k el y t h e e asi est pl a c es t o fi n d m et e orit es.

P r o c e d u r eD esi g n at e Gr o u psT his a cti vit y is d esi g n e d t o b e d o n e i n gr o u ps of 3- 4 st u d e nts. Alt h o u g h e a c hst u d e nt l a u n c h es (t hr o ws) a b all o o n fill e d wit h w at er a n d p e b bl es, st u d e ntss h o ul d w or k as a gr o u p t o c h o os e ar e as, m a k e pr e di cti o ns, r e c or d o bs er v ati o ns,a n d dr a w c o n cl usi o ns.

D esi g n a t e T ar g et Ar e asW or ki n g wit h y o ur t e a c h er, fi n d 3- 4 l o c ati o ns of v ari o us s urf a c es w h er e b all o o nsfill e d wit h w at er a n d p e b bl es c a n b e e x pl o d e d. S urf a c es c o m m o nl y f o u n d at as c h o ol sit e ar e c o n cr et e p a v e m e nt, l o n g j u m p pit or ot h er s a n d pit, gr ass y ar e a,gr a v el, p e b bl e, or s h ell s urf a c e, as p h alt p a v e m e nt, s n o w, i c e, a n d w at er. B e s ur et o g et p er missi o n t o us e all ar e as.

Cl assr o o m Pr o c e d ur e

1. G at h er all e q ui p m e nt.

2. C h o os e or assi g n t err ai n t ar g ets f or e a c h st u d e nt.

3. R e c or d i nf or m ati o n o n D at a Ta bl e.

4. M a k e pr e di cti o ns a n d r e c or d o n D at a Ta bl e.

P e r G r o u p o r Cl ass r o o m❑ w at er f a u c et❑ f u n n el❑ m e as uri n g c u p❑ t hi n sti c k or s k e w er

M at e ri al sP e r St u d e nt❑ St u d e nt Pr o c e d ur e a n d D at a Ta bl e❑ 1 b all o o n❑ 0. 1 lit er fl o ur ( 1/ 2 c u p)❑ 1 0 t o 2 0 s m all p e b bl es❑ gr a p h p a p er

Lesson 3 � Searching for Meteorites3.4 NASA EG-1997-08-104-HQ

5. Place a funnel in the neck of a balloon. Fill balloon with approximately0.1 liter (1/2 cup) of flour. Flour tends to pack, so it should be poured intothe funnel slowly. A thin stick may be used to keep the flour flowing, but donot puncture the balloon.

6. Add pebbles one at a time, noting number of pebbles and color.

7. Fill balloon 3/4 full with water. Do not shake the balloon. Be sure to tiethe balloon securely. This step must be done just before going outside tolaunch the balloons.

8. Launch balloons one at a time in designated areas. You may throw theballoon at an angle, lob them or throw them straight up so that they impactvertically. Remember to work as a group. Record observations at your launchsite quickly then move to the next launch. When the group launches arecomplete, individuals return to their impact site to finish the sketch of theirscatter pattern.

9. Clean up all balloon fragments and leave impact areas as clean as possible.

Lesson 3 � Searching for MeteoritesNASA EG-1997-08-104-HQ 3.5

Name: Other Team members:Date:

Individual Launch InformationBalloon Fillingpebbles (note number and color)water volume (estimate)flour volume

predict number and colors of pebblesthat you will recover

Launch Site Description(note terrain, estimate wind direction, and wind speed)

Launch Specificsimpact angle (estimate)impact directionimpact velocity (fast-slow)

sketch impact site in the space at right

number(s) and colors of pebbles recovered

Team Launch Datalist different terrains below pebbles pebbles pebbles explainother variables(predict if you think it will be # launched # recovered % recovered (wind or height, etc.)easy or hard to find the pebbles) and colors and colorsexample: ice easy 8 6 75% building blocked wind

Searching for Meteorites: Data Table

2 red, 1 blue,5 green

2 red, 1 blue,3 green

Lesson 3 � Searching for Meteorites3.6 NASA EG-1997-08-104-HQ

GraphMake a graph of the percentage of pebbles recovered from each impact surface.Note how the data compares to your predictions. Include data from different colorsof pebbles if available.

QuestionsBased on your data, which surface was the easiest for pebble recovery? Why?

Did this match your predictions?

What kind of land surface might be most productive for searching for meteorites?Why?

How is the scatter pattern affected: by the ground surface? by the angle of impact?

How might a scientist use this type of information to help locate meteorites?

Lesson 4 � The Meteorite-Asteroid ConnectionNASA EG-1997-08-104-HQ 4.1


Exploring Meteorite MysteriesLesson 4 � The Meteorite-AsteroidConnection: Orbits in the Inner

Solar System

ObjectivesIn Activity A students will:

• draw circles and ellipses to illustrate basic shapes of orbitsin the solar system.

• define an elliptical orbit from three of its points (optional).

In Activity B students will:

• construct a scale model of the inner solar system including:the Sun, the inner planets, the asteroid belt, and the orbits ofa few selected asteroids.

• observe relative distances and sizes within the inner solarsystem.

• plot the paths meteoroids might take in traveling from theasteroid belt to the Earth.

• manipulate models to demonstrate the concept of the eclipticplane, and discover that some asteroids do not orbit in theecliptic plane (upper grades).

(For Advanced Students)In Activity C students will:

• graph the locations of the Earth and a near-Earth asteroid.

• observe from the graph that both time and location in spaceare important.

• estimate when an asteroid would cross the Earth’s orbit.

About This LessonThis lesson allows students tounderstand how meteorites getfrom the asteroid belt to Earthand how rare it is for the Earthto be hit by a large asteroid.The students will build anexact-scale model of the innersolar system; the scale allowsthe model to fit within anormal classroom and alsoallows the representation ofEarth to be visible withoutmagnification. Students willchart where most asteroidsare, compared to the Earth,and see that a few asteroidscome close to the Earth.Students will see that the solarsystem is mostly empty spaceunlike the way it appears onmost charts and maps.Higher grade students canextend the activities as atransition to astronomy.

Vocabularyellipse, orbit, astronomer,asteroid, asteroid belt, eclipticplane, retrograde

Not to Scale!

Lesson 4 � The Meteorite-Asteroid Connection4.2 NASA EG-1997-08-104-HQ

BackgroundTo appreciate the Earth in respect to meteorites and asteroids in the solar system, it is

important to know the configuration of the inner solar system, including the proper relative sizes anddistances of objects. Most charts of the solar system show the planets’ orbits at a different scale fromthe planets, so that the solar system appears as large planets close together. The student gets anincorrect impression of how far it is to other planets, how small planets are compared to thedistances between them, and how small the Earth is as a target for meteorite impacts. The exact scalemodel of the inner solar system, from the Sun through the asteroid belt, will allow the student toappreciate the sizes and distances pertinent to these exercises (information in Tables 2 and 4).

Most meteorites are thought to be broken fragments of asteroids — small “planets” or bodies ofrock or ice orbiting around the Sun. The largest asteroid is Ceres, 940 km in diameter, much smallerthan our Moon (3,500 km diameter). Ceres was the first asteroid discovered (in 1801), and about6,000 have been discovered since then. Asteroids are so small that telescopes on Earth can see them

only as points of light. Recently the Galileo spacecraft passed closeto the asteroids Gaspra and Ida and sent us pictures of them. Bothare irregular masses of rock, seemingly broken and covered withimpact craters. As indicated by their colors(reflectance spectra), most asteroids are mixtures of metal and silicateminerals, possibly like chondrite meteorites. A few are made ofbasalt rock, just like the basalt meteorites (example: 1983RD in thislesson).

Most asteroids orbit in the asteroid belt between 2.2 and 3.2times the Earth’s distance from the Sun; their orbits are ellipses,oval-shaped curves that carry them nearer and farther from the Sun.Only a few asteroids follow orbits that get near the Earth, and theseasteroids are probably the sources of some meteorites.

An asteroid that crosses the Earth’s orbit could collide with theEarth and cause a devastating impact explosion. About 200 of theseEarth crossing asteroids are known, and it is estimated that 20-40percent of them will collide with the Earth over the next millionyears. No known asteroid will hit the Earth for at least 200 years.We will likely have many years of warning before an asteroidcollision like this, and the students will see from the solar systemmodel that the Earth is really a very small target. But when thereare a million shots, over a long time, one is likely to hit.

To hunt for asteroids, astronomers photograph the night sky, andlook for “stars” that move compared to real stars. A long exposurephotograph would show a background of stars as spots, with astreak from an asteroid, due to theasteroid’s motion across the sky. Todiscover the orbit of an asteroid, it isnot necessary to observe the asteroid asit follows its whole orbit; knowing itslocation a few times, over severalweeks or months, is sufficient.

Asteroids Can HaveThree Names!

When one is found, it is givena temporary name, like1983RD, showing what yearit was found. After theasteroid’s orbit is known well,it gets a number and can begiven a ‘real’ name by theperson who found it. Thenames of the asteroids in thislesson are “1 Ceres,” “1566Icarus,” and “3551 1983RD.”The last doesn’t have a ‘real’name yet. Asteroid namescome mostly from mythol-ogy, but also include famouspeople, including: “3352McAuliffe” (after ChristaMcAuliffe, the teacher/astronaut who was killedwhen the Space ShuttleChallenger exploded), “2266Tschaikovsky” (after theRussian composer), “1744Paavo Nurmi” (after aFinnish marathon runner),“1569 Evita” (after EvitaPerón, wife of ex-presidentJuan Perón of Argentina), and“2578 Saint-Exupéry” (afterthe author of “The LittlePrince”).

Cl assr o o m Pr o c e d ur eP a rt 1. D r a wi n g a Ci r cl e . H a v e e a c h gr o u p of st u d e nts sti c k

o n e p us h pi n i nt o t h e c e nt er of t h eir c ar d b o ar d s h e et. P ut t h el o o p of stri n g ar o u n d t h e p us h pi n, p ut t h e p oi nt of t h e p e n cilwit hi n t h e l o o p, a n d dr a w t h e l o o p ti g ht wit h t h e p e n cil ti p( n ot s o ti g ht as t o p ull o ut t h e pi n!). Dr a w a li n e wit h t h ep e n cil, k e e pi n g t h e st ri n g ti g ht . T h e p e n cil li n e will b e acir cl e ar o u n d t h e p us h pi n.

P a rt 2. D r a wi n g Elli ps es . H a v e e a c h gr o u p of st u d e nts sti c kt w o p us h pi ns i nt o t h eir c ar d b o ar d s h e et n e ar its c e nt er, pl a ci n gt h e pi ns 1 0- 1 5 c m a p art. P ut t h e l o o p of stri n g ar o u n d b ot hp us h pi ns, a n d c ar ef ull y dr a w t h e l o o p ti g ht wit h t h e p e n cil ti pf or mi n g a tri a n gl e. Dr a w wit h t h e p e n cil, k e e pi n g t h e stri n gti g ht ar o u n d b ot h pi ns. T h e p e n cil li n e will b e a n o v al, orelli ps e . St u d e nts m a y e x p eri m e nt wit h diff er e nt dist a n c esb et w e e n pi ns a n d diff er e nt l e n gt hs of stri n g. O pti o n al: p a p erm a y b e t a p e d t o t h e c ar d b o ar d if d esir e d.

O bj e cti v esSt u d e nts will:

• dr a w cir cl es a n d elli ps es t o ill ustr at e b asi c s h a p es of or bitsi n t h e s ol ar s yst e m.

• d efi n e a n elli pti c al or bit fr o m t hr e e of its p oi nts ( o pti o n al).

P r o c e d u r esA d v a n c e d Pr e p ar ati o n1. T h e i nstr u ct or s h o ul d pr e p ar e a l o o p of stri n g, a p pr o xi m at el y

4 0 c m i n cir c u mf er e n c e, f or e a c h gr o u p. A d diti o n all o o ps of stri n g of diff er e nt si z es m a y b e us e df or e x p eri m e nt ati o n. S e e fi g ur e b el o w.

2. Pr a cti c e dr a wi n g elli ps es.

A b o ut T his A cti vit yI n t his a cti vit y, st u d e nts willl e ar n h o w t o dr a w cir cl es a n delli ps es usi n g a p e n cil,p us h pi ns a n d stri n g. T h e ywill l e ar n w h at a n elli ps e is,h o w it is diff er e nt fr o m acir cl e, a n d h o w a n astr o n o m erc a n d et er mi n e t h e elli pti c alor bit of a n ast er oi d.

M a t e ri als fo r A cti vit y A❑ p ost er b o ar d or c ar d b o ar d,

a b o ut 6 0 c m x 6 0 c m,t hi c k e n o u g h t o h ol d ap us h pi n ( ol d s ci e n c e f airtrif ol ds w or k), o n e f ore a c h gr o u p

❑ tr a ci n g p a p er, a b o ut 6 0 c mx 6 0 c m, o n e or m or e f ore a c h gr o u p

❑ p us h pi ns, 6 p er gr o u p❑ p e n cil/ p e n❑ stri n g❑ s ciss ors

p u s h pi n = f o ci

stri n g


Part 3. Find the Asteroid Orbits. The orbits of asteroids are ellipses, not circles, around the Sun.Astronomers can figure out the whole elliptical orbit of an asteroid by knowing just three pointsin the orbit. In this activity, a team will draw an ellipse, and another team will work likeastronomers to try to reconstruct that ellipse knowing only the locations of three points and the“Sun.” It is important that all the teams have strings of the same length.

Have each team draw an orbit for an asteroid on their cardboard by drawing an ellipse(Part 2), and designating one pushpin as the “Sun.” Have each team remove the pushpins,place the tracing paper over the orbit drawing, tack the tracing paper to the cardboard at thecorners, and using a pen, mark on the tracing paper the “Sun” position and three points on theorbit ellipse (do not draw the entire ellipse). These three “data points” represent observationsmade by astronomers which are used to plot the orbit of an asteroid. See figures below.

Teams label their ellipses, trade tracing papers, tack their new paper down at thecorners, and put a pushpin in at the “Sun” position. Each team of “astronomers” then tries tofind a placement for the second pushpin, so that an ellipse drawn with their loop passes throughthe three points on the tracing paper. When complete, compare with the original group’s ellipsethat includes the three data points.

Questions1. How are ellipses different from circles?2. What shape is drawn when the pushpins are right next to each other?

Extensions1. If you wanted to describe an ellipse to another person, what would you say? (length of string,

length of ellipse, breadth of ellipse, orientation) What more would you need if the ellipse could bein the air oriented in any way?

2. Part 3 can be extended by having the asteroid orbits drawn with different lengths of string, andhaving each “astronomer” team determine the string length in addition to the location of the secondpin.

A b o ut T his A cti vit yI n t his a cti vit y, t h e cl ass willl e ar n h o w m et e orit es a n dast er oi ds tr a v el fr o m t h east er oi d b elt t o t h e E art h. T h ef o c us h er e is o nc o nstr u cti o n of a n e x a ct s c al em o d el of t h e i n n er s ol ars yst e m ( S u n t o ast er oi d b elt),i n cl u di n g s o m e ast er oi ds t h atmi g ht hit t h e E art h. At t h egi v e n s c al e ( w hi c h c a n b ee x p a n d e d or r e d u c e d), t h em o d el will fit o n a 1. 2 m x 1. 2m pi e c e of c ar d b o ar d or p ost erb o ar d, a n d t h e E art h will b ej ust l ar g e e n o u g h t o b e s e e n.

M a t e ri als fo r A cti vit y B❑ 1. 2 m s q u ar e or l ar g er pi e c e

of c orr u g at e d c ar d b o ar d(r efri g er at or b o x ?) or v er ystiff p ost er b o ar d

❑ 6 0 c m x 3 0 c m pi e c e ofc orr u g at e d c ar d b o ar d orv er y stiff p ost er b o ar d( u p p er gr a d es)

❑ p us h pi ns, t w o p er gr o u p❑ c ol or e d a n d r e g ul ar p e n cils❑ stri n g, or l o o ps of stri n g i n

t h e l e n gt hs i n di c at e d i nTa bl e 1

❑ s ciss ors, r ul er, a n dpr otr a ct or

❑ cl a y- d o u g h ( or si mil ars u bst a n c e) i n y ell o wor w hit e

❑ m a g a zi n es wit h c ol or e dpi ct ur es

❑ Ta bl e 1 ( p g. 4. 6) a n d Ta bl e 2( p g. 4. 7) fr o m t his l ess o n

O pti o n al f o r u p p e r g r a d es❑ r a z or k nif e or ot h er k nif e

(t o b e us e d o nl y wit hs u p er visi o n)


• c o nstr u ct a s c al e m o d el of t h e i n n er s ol ar s yst e m i n cl u di n g:t h e S u n, t h e i n n er pl a n ets, t h e ast er oi d b elt, a n d t h e or bits of af e w s el e ct e d ast er oi ds.

• c o nstr u ct cir c ul ar a n d elli pti c al pl a n et ar y or bits.

• c o n cl u d e t h at t h e r el ati v e si z es of t h e S u n a n d t h e i n n erpl a n ets ar e oft e n misr e pr es e nt e d.

• o bs er v e r el ati v e dist a n c es a n d si z es wit hi n t h e i n n er s ol ars yst e m.

• pl ot t h e p at hs m et e or oi ds mi g ht t a k e i n tr a v eli n g fr o m t h east er oi d b elt t o t h e E art h.

• o bs er v e t h at t h e E art h is a v er y s m all t ar g et.

• m a ni p ul at e m o d els t o d e m o nstr at e t h e c o n c e pt of t h e e cli pti cpl a n e a n d dis c o v er t h at s o m e ast er oi ds d o n ot or bit i n t h ee cli pti c pl a n e ( u p p er gr a d es).

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. G at h er m at eri als, pr e p ar e stri n g l o o ps a h e a d if d esir e d.2. Pr a cti c e pr o c e d ur e.

Cl assr o o m Pr o c e d ur e1. P r e p a r ati o n of t h e B o a r d .

M ar k t h e c e nt er of t h e l ar g e s h e et of c ar d b o ar d; t his will b et h e S u n’s l o c ati o n. Dr a w a cir cl e 1. 8- 2 m m di a m et er ar o u n dt h e p oi nt; t his is t h e s c al e d di a m et er of t h e S u n. If t h e e x a ctori e nt ati o ns of or bits ar e d esir e d f or u p p er gr a d es, dr a w a li g htr ef er e n c e p e n cil li n e fr o m t h e S u n’s c e nt er t o w ar d a si d e;a n gl es f or ori e nt ati o ns of elli pti c al or bits will b em e as ur e d fr o m t his li n e.

2. P r e p a r e St ri n gs .A l o o p of stri n g is n e e d e d f or e a c h or bit. T h e i nstr u ct or m a ypr e p ar e t h e l o o ps a h e a d of ti m e; or st u d e nt t e a ms m a ym e as ur e, c ut, a n d k n ot a l o o p f or t h eir o w n or bit. T o k e e p


the proper scale, use the string lengths in Table 1. If the loop turns out too long, it can beshortened with an overhand knot.

3. Draw the Orbits.Each student team should draw their orbit on the cardboard, using the pin(s) and string tech-nique in Activity A, Part 2 and the data of Table 1; lower grades include the asteroid Icarushere, upper grades may do Icarus separately (See optional section below—Asteroid Icarus inthe Third Dimension.).

Circular orbits require one pin at the Sun position. Elliptical orbits require two pins each: one at theSun and the other at the distance from the Sun shown in Table 1. The ellipses may be oriented atany convenient angle on the board; to make the model exact, the second pins should be oriented atthe angles in Table 1 from the pencil line drawn in Part 1 (exact orientations are not used later). Seeillustration on page 19 in the Teacher’s Guide. To draw the orbit of the Earth’s moon, pick a pointon the Earth’s orbit to be the Earth’s position. Around that point, draw a circle of 5 mm radius (10mm or 1 cm diameter) to represent the Moon’s orbit.

Table 1. Drawing Orbits in Scale Model

4. Adding the Sun and Planets.To complete the model, add the Sun and planets at the same scale as their orbits. Real and to-scale diameters are given in Table 2. At this scale the Sun should be a ball just under2 mm diameter, about the size of a BB or a ball bearing from a bicycle.

The Earth and Venus should be 1/50 mm across, which is almost invisible; smaller than a grainof salt or a pin-prick in paper (~1/5 mm), and about the thickness of standard copier paper. Asingle dot out of a half-tone print (as in a magazine) is about 3 times too large, but gives the


right idea of scale. The individual dots in a half-tone print can be seen with a 5 or 10Xmagnifying glass. The Moon, Mercury, Mars and the asteroids are too small to be visible atthis scale!

5. Discussion.Encourage students to share their observations about size and scale as they construct and viewthe scale model. Help students to observe that there is mostly open space in the solar system.Lead students to the observation that Earth is a small moving target and is not frequently hit bylarge impacting asteroids or comets.

Table 2. Real and Scaled Diameters of Solar System Objects

6. Optional - Upper GradesAsteroid Icarus in the Third Dimension. The orbits of all the planets (except Pluto) and mostof the asteroids are nearly in the same plane, the ecliptic plane. In the model, the ecliptic planeis the main cardboard. The asteroid Icarus orbits outside the ecliptic, and so provides anexercise in three-dimensional geometry.

On a separate piece of cardboard, draw an ellipse following the method of Activity A with thestring length and pin distance for Icarus from Table 1. Cut out the ellipse. Draw a straightpencil line through the pin holes from one end of the ellipse to the other. Select one pin hole tobe the Sun’s location. Draw a straight pencil line through the Sun pin hole at a 30° angle to theend-to-end line; this last line is at the intersection of Icarus’s ellipse and the ecliptic plane.Measure and write down the lengths of this intersection line on both sides of the Sun hole; thedistances will not be the same. In the ellipse, cut out a hole about 1 cm diameter around theSun point.

On the main solar system board, cut a slit through the Sun position as long as the intersectionline, so that the Sun point on the main board and the Sun hole in the Icarus ellipse cancoincide. The slit may be at any convenient orientation; to make the model exact, cut the slit atan angle of 87° clockwise from the reference line, with the shorter part of the slit pointing to87° and the longer part pointing to 273°.


To attach the Icarus ellipse to the main board, insert the Sun end of the ellipse into the slit frombelow the main board. Adjust the ellipse so that the intersection line is at the main board, andthe Sun point of the main board and the Sun hole on the ellipse coincide. Tape in place alongthe intersection line.

Finally, tilt the Icarus ellipse (flexing the tape along the intersection line) so that its plane makesa 25° angle to the main board (ecliptic plane). Tape or wire in place. Reinforce as needed tocorrect possible sagging.

Extensions1. Who was Icarus? Why name this particular asteroid after him? Another asteroid with a similar

orbit is named Phaethon. Who was Phaethon, and why might an asteroid be named after him?2. At the scale of this model, a light year (the distance light travels in a year) is about 12.1 km. In this

model, how far from the Sun would it be to the nearest star, Proxima Centauri at 4.3 light yearsdistance? (52 km) How far to the nearest star visible in the Northern Hemisphere, Sirius at 8 lightyears distance? (96.8 km) At this scale, how far away is the center of our Milky Way galaxy at30,000 light years distance? (363,000 km) How is this image of the distances between starsdifferent from the images shown in TV shows or movies about space? (Space is more empty andmuch larger than it is usually depicted.) (See Table 3 for additional information.)

3. View the video “Powers of 10.”

Table 3. Solar System and Nearest Star at this ScaleDistances are averages from Sun, except for Earth’s Moon* which is from Earth.


• gr a p h t h e l o c ati o ns of t h e E art h a n d a n e ar- E art h ast er oi d.

• o bs er v e fr o m t h e gr a p h t h at b ot h ti m e a n d l o c ati o n i n s p a c ear e i m p ort a nt.

• esti m at e w h e n a n ast er oi d w o ul d cr oss t h e E art h’s or bit.

• d et er mi n e if a c ollisi o n w o ul d t a k e pl a c e.

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. H a v e m at eri als r e a d y. I nstr u ct or m a y pr e p ar e t h e p a p ers a n d

t h e cir c ul ar E art h or bit as i n P art 1. Us e a stri n g, 3 0 c m k n ott o k n ot. T h e i nstr u ct or m a y c h o os e t o dr a w t h e E art h or bitwit h a p us h pi n a n d stri n g, or a n y ot h er m et h o d. Dist a n c es i nTa bl e 4 ass u m e t h at t h e E art h or bit is 3 0 c m di a m et er, a n d c a nb e s c al e d f or ot h er si z es.

Cl assr o o m Pr o c e d ur e1. G et S et . . . ( E art h’s or bit)

E a c h t e a m s h o ul d m ar k t h e S u n p oi nt at t h e c e nt er of itsp a p er, a n d a p e n cil li n e fr o m t h e S u n e xt e n di n g 3 0 c m i n a n ydir e cti o n. T his will b e t h e r ef er e n c e li n e fr o m w hi c h a n gl esar e m e as ur e d (s e e di a gr a m b el o w).

2. G o! ( Gr a p hi n g or bits)E a c h t e a m s h o ul d gr a p h t h e or bit of t h e E art h a n d t h e or bit ofo n e ast er oi d o n t h eir p a p er. T o dr a w a n or bit fr o m t h e n u m-b ers i n Ta bl e 4, b e gi n wit h a si n gl e ti m e at t h e l eft of t h eTa bl e 4. O n t h at li n e i n t h e Ta bl e, r e a d t h e a n gl e a n ddist a n c e f or t h at ti m e i n t h e or bit.

O n t h e l ar g e pi e c e of p a p er, us e a pr otr a ct or t o m e as ur e t h ea n gl e ( cl o c k wis e) fr o m t h e S u n a n d t h e r ef er e n c e li n e, a n ddr a w a li n e at t h at a n gl e. M e as ur e o ut w ar d al o n g t h at li n e t ot h e dist a n c e list e d i n t h e t a bl e, a n d dr a w a m ar k at t h at dis-t a n c e ( c ol or- c o d e d, p er h a ps). L a b el t h e m ar k wit h t h e m o nt ha n d h alf- m o nt h.

Aft er all t h e p oi nts ar e gr a p h e d a n d l a b el e d, c o n n e ct t h e mfr e e h a n d t o m a k e a s m o ot h c ur v e. T h e p oi nts m a y n ot m a k ea f ull or bit.

A b o ut T his A cti vit yF o r A d v a n c e d St u d e ntsE v e n if t h e or bit of a nast er oi d cr oss es t h e or bit oft h e E art h, t h er e m a y b e n oc ollisi o n if t h e ast er oi d a n dE art h ar e at diff er e nt pl a c es i nt h eir or bits. I n t hise x er cis e, e a c h gr o u p ofst u d e nts will gr a p h or bitp ositi o ns of t h e E art h a n d a nast er oi d. St u d e nts willc o m p ar e t h eir r es ults, a n d s e ew hi c h ast er oi d m a k es t h ecl os est a p pr o a c h.

M a t e ri als fo r A cti vit y C❑ Kr aft or b ut c h er p a p er,

a p pr o x. 6 0 c m x 6 0 c m f ore a c h gr o u p

❑ p e n cil/ p e n ( c ol or e d p e n cilso pti o n al)

❑ r ul ers, o n e p er gr o u p❑ pr otr a ct ors, o n e p er gr o u p❑ Ta bl e 4 ( p g. 4. 1 1)

G r a p hi n g Ast e r oi d O r bits


3. And the Winner Is . . .Each team should then estimate when (month number and a fraction) their asteroid crosses theEarth’s orbit. Then, each team should measure the closest approach between theirasteroid and the Earth, by measuring the distance between corresponding time steps in theirorbits. Which asteroid comes closest to hitting the Earth? How close does the closestasteroid really come to the Earth?

The scale here is 1 cm = 10,000,000 kilometers, and the Earth (to scale) would be 1/100 mm.

Note: This scale is not the same as in Activity B!

Extensions1. The speed of an asteroid

(distance/time) can beestimated here as thedistance betweensuccessive points fromTable 4. How does thespeed of an asteroid changeas it goes through its orbit(perhaps students couldgraph speed versus dis-tance from the Sun)? How fast is each asteroid going as it passes Earth’s orbit? If the asteroid(s)hit the Earth, would the differences in speed have any effect on the force of the impact or the sizeof a resulting crater? (See Lesson 6)

2. The distance between the Earth and an asteroid depends on the relative positions of both theasteroid and the Earth. Tabulate the distances between the Earth and the asteroids through timeand make graphs of distance versus time. Why do the graphs have hills and valleys?

3. Astronomers have to know where in the sky to look for asteroids in order to study them. Theymeasure directions in the sky as angles compared to a reference direction, just as on thedrawings in Activity C. To find out where in the sky you would look for your team’s asteroid, picka time point for the Earth, and draw a line through that point parallel to your reference line (thatgoes through the Sun). Draw another line from the Earth to the asteroid’s position at that timepoint. Measure and write down the angle between these two lines; this is the direction (the longi-tude) in the sky you would have to look (to an astronomer, the “right ascension”). For your team’sasteroid, tabulate the directions you would have to look from Earth, and graph that angle versustime. Does your asteroid appear to move at a constant speed in the sky? Do any of the asteroidsappear to move backwards (retrograde motion)?


Table 4. Distances from Sun and Angles from Reference Line for Earth and Asteroids

Ast

eroi

d 1

= C

asta

lia,

(0 m

onth

is 1

.5 m

onth

s afte

r per

ihel

ion

at 0

° )A

ster

oid

2 =

Cer

ebru

s, (

orie

nted

so p

erih

elio

n is

on-

line

with

Ear

th a

nd S

un)

Ast

eroi

d 3

= A

ntin

ous,

(st

artin

g 71

hal

f-m

onth

s afte

r per

ihel

ion)

Ast

eroi

d 4

= H

ephi

asto

s, (

star

ting

at p

erih

elio

n, b

ut tu

rned

to re

trogr

ade

orbi

t)A

ster

oid

5 =

Ner

eus,

(ar

rang

ed fo

r a n

ear-m

iss)

Ast

eroi

d 6

= O

ljato

, (s

tarti

ng a

t 51

half-

mon

ths a

fter p

erih

elio

n, a

ngle

adv

ance

d by

85°

)

Ear

thA

ster

oid

1A

ster

oid

2A

ster

oid

3A

ster

oid

4A

ster

oid

5A

ster

oid

6

Mon

thD

ist

Ang

leD

ist

Ang

leD

ist

Ang

leD

ist

Ang

leD

ist

Ang

leD

ist

Ang

elD

ist

Ang

le

015

cm

0º8.

4 cm

0º23

.7 c

m32

2º30

.6 c

m19

5º55

.4 c

m50

º23

.6 c

m56

º51

.1 c

m26

1º

115

cm

30º

10.8

cm

72º

23.5

cm

333º

27.0

cm

205º

53.9

cm

48º

21.4

cm

71º

49.5

cm

264º

215

cm

60º

14.8

cm

110º

22.6

cm

344º

23.1

cm

218º

52.1

cm

46º

19.0

cm

90º

47.7

cm

267º

315

cm

90º

18.2

cm

133º

20.8

cm

356º

19.2

cm

236º

50.1

cm

44º

16.7

cm

115º

45.6

cm

270º

415

cm

120º

20.7

cm

149º

18.2

cm

11º

15.6

cm

263º

47.7

cm

42º

15.0

cm

146º

43.2

cm

273º

515

cm

150º

22.4

cm

162º

14.7

cm

30º

13.4

cm

303º

45.1

cm

40º

14.6

cm

182º

40.4

cm

277º

615

cm

180º

23.3

cm

174º

10.8

cm

59º

14.1

cm

347º

42.0

cm

37º

15.5

cm

216º

37.4

cm

282º

715

cm

210º

23.3

cm

185º

8.6

cm11

3º17

.2 c

m21

º38

.6 c

m33

º17

.5 c

m24

5º33

.9 c

m28

8º

815

cm

240º

22.5

cm

197º

11.1

cm

192º

21.0

cm

43º

34.7

cm

29º

19.9

cm

276º

30.1

cm

294º

915

cm

270º

20.9

cm

210º

15.0

cm

244º

25.0

cm

59º

30.3

cm

24º

22.2

cm

285º

25.8

cm

303º

1015

cm

300º

18.5

cm

225º

18.4

cm

272º

28.8

cm

70º

25.2

cm

17º

24.4

cm

299º

20.9

cm

316º

1115

cm

330º

15.2

cm

247º

20.9

cm

290º

32.2

cm

79º

19.1

cm

6º26

.2 c

m31

1º15

.6 c

m33

8º

1215

cm

0º11

.2 c

m28

3º22

.7 c

m30

4º35

.4 c

m86

º11

.9 c

m34

2º27

.7 c

m32

1º10

.7 c

m21

º

1315

cm

30º

8.5

cm35

2º23

.6 c

m31

7º38

.3 c

m92

º5.

4 cm

240º

28.8

cm

331º

10.0

cm

94º

Lesson 5 � Looking at AsteroidsNASA EG-1997-08-104-HQ 5.1


Lesson 5 � Looking at Asteroids


• gather data by observing, measuring, and manipulatingobjects.

• record observations, analyze data and draw analogies.

• compare samples of similar materials.

• measure and record the brightness of light in a spectrumproduced from a prism.

• discover that white light is composed of the spectrum ofcolors and that some light is invisible to the human eye.

• participate in introductory quantitative spectroscopyexperiments.

• set up and conduct an experiment to analyze reflected light.

• recognize that different materials reflect differentproportions of incident light.

About This LessonThis lesson is about theconnection between meteoritesand asteroids. The activitiesin this lesson focus on ways tolook at asteroids becausesome scientists think thatsome meteorites are fragmentsof asteroids. The lessoncenters on remote sensingtechniques using light. Stu-dents consider thebrightness (reflectivity),textures, and colors ofmaterials.

The lesson is arranged asthree work stations, an op-tional station, and a centralstation with the MeteoriteSample Disk. The MeteoriteSample Disk or photographsof the meteorites must beavailable so students mayexamine the meteorite samplesin light of the experimentalresults at each station. Thislesson could be done simulta-neously by four separategroups, one for each station,as no station relies on theresults of another. All stationsexcept Station 1 could be usedas independent exercises.


Asteroid Ida

Lesson 5 � Looking at Asteroids5.2 NASA EG-1997-08-104-HQ

BackgroundMost meteorites that land on Earth are thought to come from the asteroid belt. The connectionbetween meteorites and asteroids was suggested as soon as the asteroid belt was discovered.Asteroids come in many sizes, from 900 km down to the limits of visibility in Earth based telescopesat about 1 km. Astronomers assume that there are abundant dust size asteroid fragments also.

It is almost certain that some meteorites came from asteroids. We know this because some meteoriteorbits have been traced to the asteroid belt. Scientists have learned this by triangulating meteoriteorbits from photographs of meteors.

Many meteors are linked to comets. Yearly meteor showers occur as the Earth passes through thedebris left by passing comets. But no meteorites are known to have come from meteor showers.Scientists think this is because the meteors in showers are made mostly of ice and dust, which meltand vaporize when they encounter the Earth’s atmosphere. However, someday scientists may findmeteorites from comets.

There are many different kinds of meteorites, as shown in the Meteorite Sample Disk, and scientistswondered if there might also be different kinds of asteroids. Since we have not yet sampledasteroids directly, scientists have had to rely on telescopic measurements of thecolors (spectra) of asteroids. In spectroscopy studies, light from asteroids(reflected sunlight) is taken into the telescope, directed through a prismor diffraction grating, and spread out into its spectrum. Then thescientists measure how bright the light is at each color (wave-length) in the spectrum. These reflection spectra can becharacteristic of certain minerals or metals on the asteroidsurface, or even indicate the presence of water ice. Inthis way, astronomers can estimate the compositionof asteroids and try to correlate them withmeteorites.

There are asteroid color spectra types that seem tobe similar to most types of meteorites, includingsome chondrites, some achondrites, irons, and stonyirons. But there are many types of asteroids withspectra that do not correspond to spectra of knownmeteorites. Perhaps there are many more kinds ofmaterials in the asteroid belt just waiting to fall asmeteorites. On the other hand, there may beeffects on the surfaces of asteroids that changetheir colors in ways we do not now understand.

Additional information is available in theTeacher’s Guide and in the backgroundsections of Lesson 4 (pg. 4.2) andLesson 17 (pg. 17.1).

A b o ut T his St ati o nT h e m et e orit es ar e us e d t or ei nf or c e st u d e nt’s o bs er v ati o na n d d e d u cti o n s kills.

M at e ri als f o r St ati o n 1❑ M et e orit e S a m pl e Dis k❑ m a g nifi er❑ bi n o c ul ar mi cr os c o p e

( o pti o n al)

A b o ut T his St ati o nB y l o o ki n g at ir o n m et al a n dt h e n m a ki n g v er y s m all ir o nfili n gs, st u d e nts will o bs er v eh o w diff er e nt s o m et hi n g c a nb e w h e n diff er e nt si z es a n ds urf a c e tr e at m e nts ar e vi e w e d.C ar ef ul o bs er v ati o ns of t h em et e orit es will r e v e al t h at t h em et al l o o ks diff er e nt fr o ms a m pl e t o s a m pl e.

M a t e ri als fo r St a ti o n 2❑ l ar g e n ail or s m all pi e c e of

m et al pi pi n g❑ m et al fil e❑ o n e s h e et of w hit e p a p er❑ L a b S h e et ( p g. 5. 9)❑ Q u esti o ns ( p g. 5. 1 1)❑ m a g nifi er

( o pti o n al)❑ p e n cil/ p e n

O bj e cti v eSt u d e nts will:

• o bs er v e, a n dc o m p ar e m et e orit es.

P r o c e d u r eSt u d e nts will pr o c e e d t o t hisst ati o n t o a ns w er q u esti o nsfr o m ot h er st ati o ns.


• o bs er v e a n d c o m p ar e s a m pl es of m et al a n d r e c or d t h eiro bs er v ati o ns.

• pr e p ar e s a m pl es f or o bs er v ati o n.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. S et u p st ati o n wit h n ail a n d fil e, a s h e et of w hit e p a p er, a n d a

m a g nif yi n g gl ass.Cl assr o o m Pr o c e d ur e1. St u d e nts e x a mi n e t h e n ail or m et al pi p e. H a v e o n e st u d e nt

i n e a c h gr o u p fil e t h e n ail or m et al pi p e u ntil t h e y h a v e as m all pil e of fi n e fili n gs. St u d e nts e x a mi n e t h e ir o n fili n gs( wit h o ut s pilli n g or l osi n g t h e m) n oti n g t h eir si z e, s h a p e,a n d c ol or. P arti c ul arl y n ot e t h e v ari ati o ns of c ol or. St u d e ntss h o ul d t a k e n ot es o n t h eir o bs er v ati o ns i n t h eir l a b n ot e b o o kor o n t h e L a b S h e et. A ns w er q u esti o ns f o u n d o n s e p ar at es h e et aft er e x p eri m e nt.

2. At t h e M et e orit e S a m pl e Dis k, st u d e nts s h o ul d e x a mi n e t h em et al i n at l e ast t w o of t h e m et e orit e s a m pl es a n d r e c or dt h eir o bs er v ati o ns i n t h eir l a b n ot e b o o k or L a b S h e et.N ot e : H el p st u d e nts d et er mi n e h o w t h e y c a n t ell m et al fr o mt h e ot h er mi n er als i n t h e m et e orit e s a m pl es b y r e a di n g t h ed es cri pti o ns pr o vi d e d wit h t h e M et e orit e S a m pl e Dis k.

S u g g est t h e y l o o k f or s hi n y s p ots or r ust y s p ots. Als o h el pst u d e nts c o nsi d er t h at t h er e mi g ht b e diff e r e n c es i n t h ec o m p ositi o n of t h e m et al, t h e siz e of g r ai ns, s urf a c e r o u g h-n ess, a n d t h e w a y t h e m et al w as tr e at e d i n t h e l a b or at or y.

3. St u d e nts c a n t h e n r et ur n t o t h e st ati o n, r e- e x a mi n e t h e ir o nfili n gs, a n d r e c or d t h eir o bs er v ati o ns c o m p ari n g t h e a p p e ara n c eof ir o n fili n gs wit h t h e ir o n i n t h e m et e orit e s a m pl es.

4. Cl e a n ar e a b ef or e n e xt gr o u p arri v es.


• s et u p a n d c o n d u ct a n e x p eri m e nt t o a n al y z e r efl e ct e d li g ht.

• o bs er v e t h at diff er e nt m at eri als r efl e ct diff er e ntpr o p orti o ns of i n ci d e nt li g ht.

B a c k g r o u n d S e e t h e i nf or m ati o n wit h t h e q u esti o ns o n p a g e 5. 1 1.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. S et u p e x p eri m e nt s o t h at:

- li g ht is i n ci d e nt o n t h e bl a c k p a p er or cl ot h at a p pr o xi m at el y a 4 5 ° a n gl e,- t h e t h er m o m et er b ul b is l o c at e d i n t h e p at h of li g ht r efl e ct e d at 4 5 °,- t h e c ar d b o ar d s hi el ds t h e t h er m o m et er fr o m dir e ct li g ht (s e e Fi g ur e 1).

Cl assr o o m Pr o c e d ur e1. Pl a c e c ol or c o nstr u cti o n p a p er s q u ar es o n t h e l ar g e bl a c k

p a p er s o t h at t h e i n ci d e nt li g ht s hi n es e q u all y o n all c ol ors,a n d t h e y ar e all vi e w e d e asil y.

2. R a n k t h e r el ati v e bri g ht n ess of t h e p a p ers. T o u c h e a c hp a p er, a n d r a n k t h e r el ati v e t e m p er at ur es of t h e p a p ers.R e c or d t h e r es ults o n t h e l a b s h e ets. R e m o v e all p a p ers fr o mu n d er t h e li g hts.

3. A dj ust t h e t e m p er at ur e e x p eri m e nt e q ui p m e nt. R e a d t h et h er m o m et er a n d r e c or d t h e t e m p er at ur e.

A b o ut T his St ati o nT hr o u g h d e m o nstr ati o ns a n da n al ysis, st u d e nts willdis c o v er t h at diff er e ntm at eri als r efl e ct diff er e ntpr o p orti o ns of t h e li g ht t h atstri k es t h e m. T h e pr o p orti o nof li g ht t h at is r efl e ct e d ( “r e-fl e ct a n c e ”) is s h o w n t o b ei m p ort a nt i n d et er mi ni n g t h ec o m p ositi o ns of dist a nto bj e cts ( e. g. ast er oi ds).

M at e ri als f o r St ati o n 3❑ 8 c m s q u ar es of c o nstr u cti o n

p a p er; o n e e a c h of r e d,bl a c k, bl u e, a n d w hit e

❑ 1 t h er m o m et er❑ i n c a n d es c e nt li g ht s o ur c e❑ 2 ri n g st a n ds or ot h er t all

s u p p orts f or cl a m ps❑ t w o cl a m ps or ot h er m e a ns

of s u p p orti n g e q ui p m e nt( d u ct t a p e)

❑ c ar d b o ar d l ar g e e n o u g h t os hi el d t h er m o m et er

❑ ~ 5 0 c m s q u ar e of n o n-s hi n y bl a c k p a p er or cl ot h( bl ott er p a p er w or ks w ell)

❑ L a b S h e et ( p g. 5. 9)❑ Q u esti o ns ( p gs. 5. 1 1- 5. 1 2)❑ p e n cil/ p e n


Figure 1

About This StationThe teacher will display avisible spectrum using lightfrom an overhead projector(or other light source). As anintroduction to quantitativespectroscopy, students willmeasure and record parts ofthe electromagnetic spectrum.Students will discover thatwhite light is composed of thespectrum of colors, that theenergy output of the electro-magnetic spectrum can bemeasured, and that somewavelengths of the spectrumare invisible to the human eye.

Vocabularyreflectance, reflected,diffracted, incident light,incandescent light, emit

4. Place one colored piece of paper where the incident light willstrike it at a 45° angle. Wait five minutes and read the ther-mometer; record the results. Allow thermometer to return toroom temperature.

5. Repeat for each color of paper. Groups may do only onecolor if there are time limitations. Share data.

6. After completing the experiment answer the questions foundon the separate sheet.

7. Discuss experimental results. (See Background pg. 5.2)


• measure and record the brightness of light in a spectrumproduced from a prism.

• observe that white light is composed of the spectrum ofcolors and that some electromagnetic energy is invisible tothe human eye.

• participate in introductory quantitative spectroscopyexperiments.

Vocabularyelectromagnetic spectrum, spectroscopy, infrared, ultraviolet,voltage


Station 4: The Visible Spectrum and Beyond!

M a t e ri als fo r St a ti o n 4 ( M et h o d 1)❑ v olt m et er ( or ot h er m e a ns of m e as uri n g p o w e r

o ut p ut, e x: s m all m ot or- dri v e n f a n, s ol are n er g y kit, et c.)

❑ s ol ar c ell, m as k e d wit h t a p e s o t h at li g ht c a nhit a p at c h o nl y a b o ut 2- 3 m m wi d e

❑ t a p e ( d u ct or el e ctri c al)❑ o v er h e a d pr oj e ct or ( as li g ht s o ur c e)❑ gl ass pris m❑ c ar d b o ar d t o c o v er m ost of pr oj e ct or s urf a c e

(t o r e d u c e gl ar e fr o m pr oj e ct or)❑ w hit e p ost er or ot h er s urf a c e f or “ c at c hi n g ”

c ol or s p e ctr u m❑ w all c h art wit h el e ctr o m a g n eti c s p e ctr u m❑ L a b S h e et ( p g. 5. 1 0)❑ Q u esti o ns ( p g. 5. 1 2) Distri b ut e aft er e x p eri m e nt❑ p e n cil/ p e n

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. Te a c h er will n e e d t o e x p eri m e nt wit h a v ail a bl e m at eri als t o

m a k e a s uit a bl e s p e ctr u m. A s p e ctr u m c a n b e pr o d u c e dwit h t h e pris m h el d al m ost at t h e e d g e of t h e pr oj e cti o ns urf a c e, a n d h el d p ar all el t o t h e n e ar est e d g e of t h epr oj e cti o n s urf a c e ( a p pr o xi m at el y p ar all el t o t h e li n es i n t h epr oj e cti o n l e ns). T h e n r ot at e t h e pris m ar o u n d a n a xis p ar all el t o t h e pr oj e cti o n s urf a c eu ntil t h e s p e ctr u m pr oj e cts o nt o t h e w all. S e e t h e di a gr a m a b o v e ri g ht.

2. El e ctr o m a g n eti c s p e ctr u m c h art s h o ul d b e a v ail a bl e t o st u d e nts. I n c l u d e a d diti o n al i nstr u cti o nsif pr e p ar e d l a b s h e et is n ot us e d. Tr y t his first t o m a k e e x pl a n ati o ns e asi er. N ot e : If y o u ar ef a mili ar wit h usi n g a diffr a cti o n gr ati n g, y o u m a y pr ef er t o us e it wit h a n o v er h e a d pr oj e ct ort o dis pl a y a visi bl e s p e ctr u m.

Cl assr o o m Pr o c e d ur es1. T ur n o n o v er h e a d pr oj e ct or wit h li g ht pr oj e cti n g o nt o c eili n g or u p p er w all.2. Us e c ar d b o ar d t o bl o c k e xtr a li g ht fr o m o v er h e a d pr oj e ct or.3. All o w li g ht fr o m pr oj e cti n g s urf a c e t o p ass t hr o u g h pris m.4. E x p eri m e nt wit h p ositi o ns a n d a n gl es t o cr e at e t h e m ost cl e arl y d efi n e d s p e ctr u m p ossi bl e.5. “ C at c h ” li g ht s p e ctr u m o n a p ost er b o ar d, a n d t a p e t h e p ost er o n t h e w all.6. C o n n e ct t h e v olt m et er ( or m ot or, et c.) t o t h e s ol ar c ell.7. Ori e nt t h e s ol ar c ell s o t h at o nl y a si n gl e c ol or of li g ht hits t h e u n m as k e d b a n d (s e e s ol ar c ell

di a gr a m a b o v e l eft). M o v e t h e s ol ar c ell t hr o u g h t h e s p e ctr u m o n t h e w all, n oti n g t h e r el ati v ep o w er fr o m e a c h s p e ctr al c ol or ( eit h er v olt a g e o n t h e v olt m et er, or h o w f ast t h e m ot or r u ns).B e s ur e t o m o v e t h e s ol ar c ell a b o v e a n d b el o w t h e s p e ctr u m, i. e. b e y o n d t h e r e d (I nfr ar e d orI R) a n d b e y o n d t h e vi ol et ( Ultr a vi ol et or U V).

8. R e c or d i nf or m ati o n o n L a b S h e et, a ns w er Q u esti o ns, a n d dis c uss r es ults.N ot e: B e s ur e t o t est ar e as b or d eri n g, b ut a w a y fr o m t h e s p e ctr u m f or c o ntr ol p ur p os es.

Als o, s o m e n e w pr oj e ct ors h a v e I R filt ers t o r e d u c e h e at, t h er ef or e y o u m a y n ot g et p o w e ri n t h e I R r a n g e.

} ~ 2 m m

M a t e ri als fo r St a ti o n 4 ( 2)❑ sli d e pr oj e ct or❑ o p a q u e s cr e e n (s e e

m at eri als a n d i nstr u cti o nsb el o w)

❑ gl ass pris m❑ s u p p orts f or s cr e e n a n d

pris m ( b o o ks a n d or t a p e)❑ pr oj e cti o n s cr e e n or w hit e

p ost er b o ar d❑ L a b S h e et ( p g. 5. 1 0)❑ Q u esti o ns ( p g. 5. 1 2)

Distri b ut e aft ere x p eri m e nt

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. M a k e a n o p a q u e s cr e e n a p pr o xi m at el y 2 5 c m s q u ar e fr o m a

pi e c e of c ar d b o ar d or p ost er b o ar d. C ut a 5 c m- di a m et erh ol e o ut of t h e mi d dl e. Ta p e t w o pi e c es of o p a q u e p a p er oral u mi n u m f oil o v er t h e h ol e s o t h at t h er e is a v erti c al g a pb et w e e n t h e m t h at is n o wi d er t h a n 1 m m.

2. Arr a n g e t h e e q ui p m e nt a n d d ar k e n t h e r o o m. A dj ust e q ui p-m e nt s o pr oj e ct or li g ht d o es n ot e xt e n d ar o u n d t h e e d g es oft h e o p a q u e s cr e e n, a n d t h e visi bl e s p e ctr u m is dis pl a y e d o nt h e s cr e e n.

Cl assr o o m Pr o c e d ur es1. S e e st e ps 6- 8 i n pr o c e d ur e f or M et h o d 1.

Q u esti o ns

1. W h y is t h er e p o w er o ut p ut b e y o n d t h e r e d li g ht ? T h e r e isel e ct r o m a g n eti c e n e r g y at w a v el e n gt hs t h at o u r e y es c a n n ots e e; st u d e nts h a v e p r o b a bl y h a d e x p e ri e n c e wit h i nf r a r e d —T V r e m ot e c o nt r ols o p e r at e usi n g i nf r a r e d.

2. W h y mi g ht t h e s ol ar c ell pr o d u c e littl e p o w er fr o m bl u e orp ur pl e li g ht, e v e n t h o u g h w e c a n s e e bl u e a n d p ur pl e ? T h es ol a r c ell is n ot as s e nsiti v e t o bl u e a n d p u r pl e as o u r e y e sa r e.


• s et u p a n d c o n d u ct a si m pl e li q ui d c hr o m at o gr a p h ye x p eri m e nt.

• r e c or d o bs er v ati o ns a n d dr a w a n al o gi es.

N ot e : C hr o m at o gr a p h y is n ot us e d b y s ci e ntists t o d et er mi n e t h ec o m p ositi o n of ast er oi ds, h o w e v e r, t his is a n e as y, i n e x p e nsi v el a b or at or y e x e r cis e t h at r ei nf or c es t h e c o n c e pt of s e p ar ati n g us ef uld at a t o a n al y z e a c o m pl e x s yst e m.

V o c a b ul a r yc hr o m at o gr a p h y, wi c k,a bs or b e nt

A b o ut T his St ati o nB y a si m pl e c hr o m at o gr a p h ye x p eri m e nt, st u d e nts willl e ar n t h at o n e c ol or m a y b em a d e u p of a mi xt ur e ofdiff er e nt c ol ors j ust as w hit eli g ht is a c o m bi n ati o n of li g htat diff er e nt w a v el e n gt hs.T his will i ntr o d u c e t h ec o n c e pt t h at t h e c ol or of a no bj e ct ( ast er oi d) c a n b e us e dt o i nf er t h e c o m p ositi o n of t h eo bj e ct.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. Ass e m bl e m at eri als.2. C ut filt er p a p er as n e e d e d s o t h at t h er e ar e t w o stri ps f or e a c h m ar k er.3. Pr e p ar e c o nt ai n ers of w at er, o n e p er m ar k er. St u d e nts r e- us e w at er b ut n ot p a p ers.4. M a k e s ur e a bs or b e nt p a p er is o n h a n d f or s pills a n d f or t h e fi nis h e d c hr o m at o gr a ms.

Cl assr o o m Pr o c e d ur e1. S el e ct a m ar k er, t w o stri ps of filt er p a p er, a p e n cil, a n d a c o nt ai n er of w at er.2. Usi n g t h e m ar k er, pl a c e a d ot a b o ut 3 c m fr o m o n e e n d of a stri p. M a k e a s e c o n d d ot of

e q u al si z e usi n g t h e s a m e m ar k er o n t h e s e c o n d stri p of p a p er. Y o u s h o ul d h a v e t w oi d e nti c al stri ps.

3. At t h e o p p osit e e n d, usi n g a b all p oi nt p e n, l a b el e a c h stri p wit h t h e br a n d n a m e of t h em ar k er a n d a st u d e nt’s i niti als.

4. Pl a c e o n e of e a c h p air of stri ps o n a s h e et of a bs or b e nt p a p er. Pl a c e t h e m at c hi n g stri p n e xtt o it f or a r ef er e n c e stri p f or l at er c o m p aris o n.

5. R e p e at f or all f o ur m ar k ers ( gr o u p m e m b ers m a y d o t his si m ult a n e o usl y).6. O n t h e w or ks h e et, u n d er Filt er D es cri pti o n, d es cri b e t h e c ol or of t h e d ots f or e a c h m ar k er

a n d n ot e if a n y h a v e ti nts of a diff er e nt c ol or i n t h e m.7. R e c or d w h at y o u pr e di ct will h a p p e n w h e n t h e stri p is s us p e n d e d i n w at er.8. Ta k e t h e filt er p a p er stri p fr o m t h e a bs or b e nt p a p er a n d wr a p t h e l a b el e d e n d ar o u n d t h e

mi d dl e of a p e n cil s o t h at t h e p a p er will st a y i n pl a c e w h e n t h e p e n cil is lift e d.9. C ar ef ull y pl a c e t h e d ot e n d i n t h e c o nt ai n er of w at er s o t h at t h e filt er p a p er, b ut n ot t h e d ot,

is i n t h e w at er. R est t h e p e n cil o n t h e ri m of t h e c o nt ai n er, r olli n g t h e stri p u p or d o w n ifn e c ess ar y (s e e di a gr a m). R e p e at f or e a c h filt er p a p er stri p.

1 0. All o w a d e q u at e ti m e ( ~ 3 mi n ut es) f or t h ew at er t o wi c k u p t h e p a p er. W h e n t h e w at err e a c h es t h e t o p of t h e p a p er, c ar ef ull yr e m o v e it fr o m t h e w at er a n d pl a c e it o n t h ea bs or b e nt p a p er n e xt t o t h e r ef er e n c e stri p.

1 1. C o m p ar e t h e ori gi n al bl a c k d ot wit h t h ew at er tr e at e d d ot ( c hr o m at o gr a m).

1 2. O n t h e w or ks h e et, writ e a d es cri pti o n of e a c hof t h e f o ur c hr o m at o gr a ms.

1 3. A ns w er q u esti o ns a n d dis c uss r es ults.

❑ 4 p e n cils or w o o d e n sti c ks❑ a bs or b e nt p a p er❑ s ciss ors❑ T h e C ol or Bl a c k w or ks h e et ( p gs. 5. 1 3- 5. 1 4)❑ m a p p e n cils or cr a y o ns❑ b all- p oi nt p e n❑ m etri c r ul er

M a t e ri als fo r T h e C ol o r Bl a c kA m o u nts will v ar y a c c or di n g t o t h e m et h o d ofpr es e nt ati o n. Gr o u p si z e fr o m 4- 6.

❑ 4 bl a c k f elt-ti p p e d, w at er s ol u bl e m ar k ers( e a c h m ar k er a diff e r e nt br a n d)

❑ 4 tr a ns p ar e nt c o nt ai n ers ( b e a k e r-li k e) wit hw at er at a 2 c m d e pt h

❑ 8 pi e c es of filt er p a p er, a p pr o xi m at el y1 0 c m x 2 c m ( c off e e filt ers w or k w ell)



Lab Sheet: Stations 2-4Name________________

Date_________________

Station 2: Test Your MetalDescribe what happened to the metal when you made the iron filings. What did thefilings look like? Describe any changes and explain.

Metal In Meteorites DescriptionMeteorite name Description of the metal Does the metal resemble the iron filings?

(describe how it is alike or different)

Station 3: Reflections on Light and Heat

Paper Color Brightness Touch Temp. Thermometer Reading1= bright 1= hottest before after4 = not bright 4 = coldest

Black Red Blue White

Reflectance Bar Graph (show color verses degrees)


I-R Red O Y G Blue I V UV

voltage(label units)

Station 4: The Visible Spectrum and BeyondWhich bands generate the greatest power?

Color Volt Meter Reading or Relative Motor Power ___________ ____________________________________ ___________ ____________________________________ ___________ ____________________________________ ___________ ____________________________________ ___________ ____________________________________ ___________ ____________________________________ ___________ ____________________________________ ___________ ____________________________________ Control Area ___________ ____________________________________ ___________ ____________________________________

Graph of Voltage vs. Color of Light



Questions: Stations 2-4Name________________

Date_________________

Teacher Note: use these questions after each station, do not distribute before activity.

Station 2: Test Your Metal1. Why are the iron filings dark and the metal in some of the meteorites shiny?

2. If an asteroid were made of metal, would it be shiny?

Station 3: Reflections on Light and Heat1. Which color reflected the most light?

Was that color hottest to the touch?

Did the color which was hottest to the touch cause the highest temperature on thethermometer?

Why did this happen?

2. Scientists can understand more about the surface composition and texture ofasteroids by measuring how much visible and infrared energy is reflected oremitted. Scientists can measure the surface temperatures of asteroids bymeasuring how much absorbed solar energy they emit as infrared energy.

Return to the meteorite disk to consider these questions based on your experimen-tal results: Do you think an asteroid made of carbonaceous chondrite materialwould be hotter or colder than an asteroid of achondrite material? Why?


How do you think an iron meteorite’s infrared reflectance would be compared to acarbonaceous chondrite’s reflectance?

How would its distance from the Sun affect the temperature of an asteroid?

3. Advanced: You measured color reflectance of objects. Scientists measure colorbrightness of planetary bodies and compare those levels of brightness to knownlevels. In this way they are able to classify asteroids according to theircomponents. For example, frozen water (ice) would look white and,) therefore,very bright.

Using your findings, how would we set up a comparison table for analyzingreflectance?

Station 4: The Visible Spectrum and Beyond1. Why is there power output beyond the red light?

2. Why might the solar cell produce little power from blue or purple light, eventhough we can see blue and purple? Hint: Think about how sensitive our eyes areand the sensitivity of the solar cell.

3. Can you feel heat from the infrared?



The Color BlackName________________

Date_________________

Filter Description Chromatogram Description

Prediction

Student Background (Read after completing The Color Black station.)Just as you have probably attempted to create new colors for art by mixing colors youalready have, many colors are a combination of two or more colors (e.g. red + yellow= orange). The experiment you have conducted works the other way. You startedwith the “new” color — black — and revealed which colors were used to create it.

It’s rather like when you have a mixture of colored candies and want to know howmany candies of each color are in the bag. They have to be separated first. We oftengo from general observations to specific ones in our attempts to understand things.For example you could start with a bag of colored candies as a general observationand then be specific and state that you have 6 yellow candies, 7 green ones, 4 redones.

Substances have specific properties (color, shape, texture). The more properties wecan identify, the greater our ability to understand and classify new substances. Thebetter we can classify, the better we can see relationships among substances, objects,organisms, and occurrences. That process is similar to a detective’s work and can beVERY exciting!

Scientists are working as detectives to determine the composition of the asteroids.The color of the surface of an asteroid gives scientists clues to its mineral content.

Another way scientists investigate the composition of asteroids is to look at the lightreflected from the surface of an asteroid. Then they compare that light signature orspectrum with spectrum of known substances on Earth. This technique is used tocompare asteroids and meteorites. They attempt to determine whether asteroids havesimilar compositions to known meteorite types.


The chromatography experiment you completed is not used by scientists todetermine the composition of asteroids. This experiment was designed so that youcould easily experience the investigative process of science and to allow you to seethat substances are often made of more than you realize!

Neither of the techniques to determine mineral compositions on asteroids works aseasily as the liquid chromatography experiment you have conducted. However, younow have experience as an investigative scientist.

Questions (Use only after you have completed the experiment.)

1. What clues gave you a hint that the black inks might be made of different colors?

2. Did any of the chromatograms have similar colors in similar places? Explain.

Return to the Meteorite Sample Disk to consider the next question.3. Write a short comparison among the black meteorite samples, comparing and

contrasting how black they are, and whether they are different shades or tints ofblack.

4. What techniques do scientists use to determine the mineral content of asteroids?

5. How can meteorites help scientists understand more about asteroids?

6. Extra: Most asteroids are quite dark, and reflect only 10-20% of the light thathits them. This is very much like the Moon, where the bright areas of the Moon(the highlands) reflect about 20% and the dark areas (the mare) reflect about 10%.Using references available in your classroom, investigate the composition of thedifferent parts of the Moon and why they are brighter or darker.

Lesson 6 � Impact Craters�Holes in the Ground!NASA EG-1997-08-104-HQ 6.1


Lesson 6 � Impact Craters�Holes in the Ground!

“Wheredo theycomefrom?”Objectives

Students will:

• model impact craters in the lab.

• identify various structures caused by the cratering process.

• manipulate the conditions that control the size andappearance of impact craters.

• state the relationships between the size of the crater, size ofthe projectile, and velocity.

• demonstrate the transfer of energy in the cratering process.

BackgroundImpact craters are formed when pieces of asteroids or comets strikethe surface of a planetary body. Craters are found on all the terrestrialplanets, on the Earth’s Moon, and on most satellites of planets.

Various geological clues and studies of the lunar rocks returned bythe Apollo missions indicate that about 3.9 billion years agoasteroid-size chunks of matter were abundant in the solar system.This was a time of intense bombardment of the young planets,affecting Earth by breaking up and modifying parts of the crust.Mountain building, plate tectonics, weathering and erosion havelargely removed the traces of Earth’s early cratering period. But thenear absence of weathering on the Moon hasallowed the evidence of this ancient time tobe preserved.

Impact craters are formed by the transfer ofenergy from a moving mass (meteorite) to astationary body (planet). Kinetic energy isthe energy of motion. It is defined as onehalf the mass of an object, times the velocityof the object squared (K.E. = 1/2 Mv2).Objects in space move very fast, so this canbe a huge amount of energy! In an impactthe kinetic energy of a meteorite is changedinto heat that melts rocks and energy thatpulverizes and excavates rock. Simplified

About This LessonThis lesson allows students tocreate impact craters in plasterof Paris or layered drymaterials. They performcontrolled experiments byvarying the velocity or massof an object and observingand measuring the effects.

Vocabularycrater, impact, projectile,velocity, kinetic energy, mass,gravity, ejecta, rim,meteor

ejecta

rim

d e m o nstr ati o ns of t his tr a nsf er of e n er g y c a n b e m a d e b y cr e ati n g i m p a cts i n p o w d er e d m at eri als. Ifi d e nti c al o bj e cts ar e i m p a ct e d i nt o p o w d er e d m at eri als fr o m diff er e nt h ei g hts or usi n g diff er e nt pr o p ul-si o n s yst e ms t o i n cr e as e v el o citi es, t h e n st u d e nts c a n d et er mi n e t h e eff e ct v el o cit y h as o n t h e cr at eri n gpr o c ess. Li k e wis e if pr oj e ctil es of diff er e nt m ass es ar e i m p a ct e d fr o m t h e s a m e h ei g ht a n d t h e s a m ev el o cit y, st u d e nts will b e a bl e t o i d e ntif y t h e r el ati o ns hi p of m ass t o cr at er f or m ati o n.

T h e hi g h v el o cit y i m p a ct a n d e x pl osi o n of a n ir o n m et e orit e a b o ut 3 0 m et ers i n di a m et er c o ul d m a k e acr at er o v er o n e kil o m et er wi d e. T his is h o w M et e or Cr at er i n Ari z o n a w as f or m e d. I n t h e cl assr o o mt h e l o w v el o citi es a n d l o w m ass es will m a k e cr at ers m u c h cl os er i n si z e t o t h e i m p a cti n g b o di es.

E n e r g y C al c ul a ti o ns fo r A d v a n c e d Cl ass es

K. E. = 1/ 2 M v 2 ( m et e orit e i m p a cts li k e M et e or Cr at er)

v = 2 g h (fr e e f all)

t h u s

K. E. = M g h (f or cl assr o o m e x p eri m e nts)

Cl ass r o o m E x p e r i m e nt E x a m pl e

pr oj e ctil e - 1 0 gr a ms = Mdr o p h ei g ht - 2 m et ers = h

gr a vit y eff e ct - 9 8 0 c m/s e c 2 = g

K. E. = 1/ 2 × 1 0 gr a ms × 2 × 9 8 0 c m/s e c2 × 2 0 0 c m

K. E. = ~ 2 × 1 06 er gs

M et e o r C r at e r Esti m at e

pr oj e ctil e w as 3 0 m et ers i n di a m et erir o n ni c k el s p h er e ( m et e orit e wit h a d e nsit y of 8 g/ c m3 )

pr oj e ctil e 1. 1 × 1 01 1 gr a ms = M

4/ 3 Π ( 1. 5 × 1 03 )3 c m3 = v( 1. 4 × 1 01 0 c m3 ) = v

K. E. = 1/ 2 M v 2

K. E. = 1/ 2 × 1. 1 × 1 01 1 gr a ms × ( 2 × 1 06 )2

K. E. = ~ 2 × 1 02 3 er gs

K. E. = ki n eti c e n er g y

M = m ass of i m p a cti n go bj e ct ( pr oj e ctil e)

v = v el o cit y of i m p a cti n go bj e ct ( pr oj e ctil e)

g = gr a vit y c o nst a nt f orE art h ( 9 8 0 c m/s e c 2 )

h = h ei g ht of r el e as e ofi m p a cti n g o bj e ct

er g = gr a ms × c m2 × s e c( m e as ur e of K. E.)


• pr o d u c e e asil y r e c o g ni z a bl e cr at er f or ms.• si m ul at e i m p a cts i nt o w et m at eri als.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. Ass e m bl e m at eri als.2. Pr a cti c e mi xi n g pl ast er of P aris t o g et a f e el f or t h e h ar d e ni n g

ti m e u n d er cl assr o o m or o ut d o or c o n diti o ns. Pl ast er f or cl ass-r o o m us e s h o ul d b e mi x e d at ti m e of d e m o nstr ati o n.

3. C o p y o n e St u d e nt Pr o c e d ur e p er gr o u p.4. If L ess o n 7 will n ot b e c o m pl et e d, t h e n c o nsi d er w h et h er cr at er

sli d es c o ul d b e us e d i n t his l ess o n.5. Pr e p ar e pl ast er or dir e ct st u d e nts t o mi x pl ast er.

• Mi x t h e pl ast er of P aris. A mi xt ur e of t w o p arts pl ast er ofP aris t o o n e p art w at er w or ks b est. R E MI N D E R: T h e pl ast erh ar d e ns i n 1 0 t o 2 0 mi n ut es, s o y o u m ust w or k q ui c kl y. H a v eD at a C h art c o m pl et e a n d all m at eri als ass e m bl e d b ef or epl ast er is mi x e d.

• P o ur a 5 c m or m or e l a y er of pl ast er i n a s m all d e e pdis p os a bl e c o nt ai n er.

• O pti o n al: Usi n g a kit c h e n str ai n er or a s h a k er, s pri n kl e a t hi nl a y er of p o w d er e d t e m pr a p ai nt o v er t h e pl ast er ( us e a d ustm as k a n d d o n ot g et p ai nt o n cl ot h es).

Cl assr o o m Pr o c e d ur e1. Dis c uss b a c k gr o u n d b ef or e or d uri n g a cti vit y.2. St u d e nts w or k i n s m all gr o u ps or c o n d u ct cl assr o o m

d e m o nstr ati o n.3. F oll o w St u d e nt Pr o c e d ur e.4. Dis c uss q u esti o ns.

A b o ut T his A cti vit yI n t his a cti vit y st u d e nts cr e at ei m p a ct cr at ers i n pl ast er ofP aris. T h e y m a y p erf or mc o ntr oll e d e x p eri m e nts b yv ar yi n g t h e v el o cit y or m assof a n o bj e ct a n d o bs er vi n g t h eeff e cts.

M a t e ri als fo r A cti vit y A❑ pl ast er of P aris❑ 1 l ar g e dis p os a bl e p a n or

b o x (if us e d as a w h ol ecl ass d e m o nstr ati o n)or 3- 4 s m all a n d d e e pc o nt ai n ers s u c h asm ar g ari n e t u bs or l o afp a ns (f or i n di vi d u als orgr o u ps)

❑ mi xi n g c o nt ai n er❑ stirri n g sti c ks❑ w at er ( 1 p art w at er t o t w o

p arts pl ast er)❑ pr oj e ctil es ( m ar bl es,

p e b bl es, st e el s h ot, l e a dfis hi n g si n k e rs, b allb e ari n gs)

❑ dr y t e m pr a p ai nt,( o pti o n al) r e d or bl u e -( e n o u g h t o s pri n kl e o v e rt h e s urf a c e of t h e pl ast er)or s u bstit ut e b a b y p o w-d er, fl o ur, c or n st ar c h,fi n e- c ol or e d s a n d, p o w-d er e d g el ati n, or c o c o a

❑ str ai n er, s h a k er or sift er t odistri b ut e p ai nt e v e nl y

❑ m et er sti c k❑ St u d e nt Pr o c e d ur e ( p gs. 6. 5-

6. 6, o n e p er st u d e nt)❑ d ust m as k❑ D at a C h arts ( p g. 6. 9, o n e

p er gr o u p)

A b o ut T his A cti vit ySt u d e nts d o c o ntr oll e d cr at eri n ge x p eri m e nts i n dr y m at eri als.T h e y v ar y t h e i m p a ct orv el o cit y or m ass a n d o bs er v ea n d m e as ur e t h e eff e cts. O bj e cti v es

St u d e nts will:

• m a ni p ul at e t h e v ari a bl es of v el o cit y a n d m ass t o i n v esti g at ecr at er f or m ati o n.

• r e c o g ni z e t h e c o n diti o ns t h at c o ntr ol t h e si z e a n d a p p e ar a n c eof i m p a ct cr at ers.

• st at e t h e r el ati o ns hi ps b et w e e n t h e si z e of t h e cr at er, si z e oft h e pr oj e ctil e, a n d v el o cit y.

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. Ass e m bl e e q ui p m e nt.2. Pr e p ar e pr oj e ctil e s ets a n d l a b el.3. C o p y St u d e nt Pr o c e d ur e a n d D at a C h arts as n e e d e d.4. Pr e p ar e t ar g et tr a ys of dr y m at eri al a n d p ai nt.

( O pti o n al: st u d e nts pre p ar e)• Pl a c e 3 c m e v e n l a y er of dr y m at eri al i n t h e b ott o m of a t h e

tr a y ( or b o x).• S pri n kl e a t hi n l a y er of r e d p o w d er e d t e m pr a p ai nt o v er t h e

dr y m at eri al wit h a kit c h e n str ai n er.• Pl a c e a n ot h er v er y t hi n ( 2- 3 m m) e v e n l a y er of dr y m at eri al

o n t o p of t h e t e m pr a p ai nt, j ust e n o u g h t o c o n c e al p ai nt.• O pti o n al: S pri n kl e a n ot h er l a y er of bl u e p o w d er e d t e m pr a

p ai nt o n t o p of t h e s e c o n d l a y er of dr y m at eri al. R e p e atst e p 6. (Ver y fi n e cr aft glitt er c a n b e us e d i n pl a c e oft e m pr a p ai nt f or “s p ar kl e ” eff e ct.)

Cl assr o o m Pr o c e d ur eN ot e: T his pr o c e d ur e is f or s m all g r o u ps, it m ust b e m o difi e d if

t h e e ntir e cl ass will a ct as a si n gl e gr o u p.1. St u d e nts s h o ul d w or k i n s m all gr o u ps. E a c h gr o u p s h o ul d

c h o os e at l e ast t hr e e pr oj e ctil es fr o m S E T A or S E T B.2. Writ e a d es cri pti o n of e a c h pr oj e ctil e o n y o ur D at a C h art.3. M e as ur e t h e m ass, di m e nsi o ns of e a c h pr oj e ctil e a n d r e c or d

o n t h e D at a C h art.4. Dr o p pr oj e ctil es i nt o t h e dr y m at eri al.

S et A - Dr o p all pr oj e ctil es fr o m t h e s a m e h ei g ht or s e v er als eri es of e x p eri m e nts m a y b e c o n d u ct e d fr o m diff er e nth ei g hts. R e c or d d at a a n d cr at er o bs er v ati o ns.S et B - Dr o p t h e pr oj e ctil es fr o m diff er e nt h ei g hts (s u g g est2- 3 m). R e c or d all h ei g ht d at a a n d cr at er o bs er v ati o ns.

5. Dis c uss t h e eff e cts c a us e d b y t h e v ari a bl es.

M a t e ri als fo r A cti vit y B❑ l ar g e tr a y or st ur d y b o x 8- 1 0

c m d e e p a n d a b o ut 1/ 2 mo n e a c h si d e ( a c at litt erp a n w or ks ni c el y); 2 p ercl ass or 1 p er gr o u p

❑ b a ki n g s o d a ( 2- 3 1. 8 k g-b ox es) p er tra y, or f l o ur ( 2b a gs, 2. 2 6 k g) , or fi n e s a n d(s a n d b o x s a n d, 3 k g p ertr a y)

❑ dr y t e m pr a p ai nt - r e d a n d/ orbl u e; e n o u g h f or a t hi n l a y ert o c o v er t h e dr y m at eri als urfa c e. (Ver y fi n e cr aftglitt er m a y b e us e d as o n ec ol or.) A n os e a n d m o ut hd ust m as k s h o ul d b e us e dw h e n s p ri n kli n g p ai nt.S u g g est e d s u bstit ut es f orp ai nt m a y b e f o u n d i n t h em at eri als list f or A cti vit y A.

❑ pr oj e ctil es ( pr o vi d e o n e s et ofeit h er t y p e f or e a c h gr o u pof st u d e nts)S E T A - ( pr o vi d e e n o u g hs ets f or all gr o u ps) f o urm ar bl es, b all b e ari n gs, orl ar g e si n k ers of i d e nti c alsi z e a n d w ei g htS E T B - ( pr o vi d e o n e or t w os ets p er cl ass) t hr e e s p h er esof e q u al si z e b ut diff e r e ntm at e ri als s o t h at t h e y willh a v e diff er e nt m ass( e x a m pl e: gl ass, pl asti c,r u b b er, st e el, w o o d)

❑ str ai n er or sift er t o distri b ut et h e p ai nt

❑ m etri c r ul er s & m et er sti c ks❑ l a b b al a n c e ( o n e p er cl ass)❑ D at a C h art ( p g. 6. 9, p er gr p.)❑ St u d e nt Pr o c e d ur e ( p gs. 6. 7-

6. 8, o n e p er gr o u p)

M a t e ri als - P e r G r o u p❑ pr e p ar e d pl ast er i n c o nt ai n er ❑ pr oj e ctil es ❑ t e m pr a p ai nt a n d sift er ( o pti o n al)❑ m et er sti c k ❑ D at a C h art

P r o c e d u r e1. F or m gr o u ps a n d distri b ut e D at a C h arts.2. E a c h gr o u p s h o ul d c h o os e at l e ast t hr e e pr oj e ctil es.3. Writ e a d es cri pti o n of e a c h pr oj e ctil e o n t h e D at a C h art, i n cl u di n g t h e m ass

a n d di m e nsi o ns.4. Pr e p ar e pl ast er a c c or di n g t o dir e cti o ns fr o m y o ur t e a c h er.5. Dr o p t h e pr oj e ctil es at 2 mi n ut e i nt er v als, r e c or di n g a p pr o pri at e i nf or m ati o n.

E a c h pr oj e ctil e r e q uir es a n ar e a of a b o ut 5 x 5 c m s q u ar e. If y o u dr o p t o o m a n ypr oj e ctil es i n a n ar e a, y o ur cr at ers will b e dist ort e d (t h o u g h o v erl a p pi n g cr at ersar e i nt er esti n g t o o).

6. O pti o n al e x p eri m e nt — dr o p i d e nti c al pr oj e ctil es fr o m diff er e nt h ei g hts.R e c or d h ei g hts.

7. L e a v e t h e pr oj e ctil es i n t h e pl ast er a n d all o w it t o h ar d e n.8. Writ e a d es cri pti o n of t h e e x p eri m e nt o n t h e D at a C h art. Ill ustr at e a n d l a b el

t h e cr at ers usi n g t h e f oll o wi n g t er ms: ri m, ej e ct a, i m p a ct c r at e r.

Q u e sti o n s

1. W h er e d o y o u fi n d t h e t hi c k est ej e ct a ?

2. H o w d o y o u t hi n k t h e cr at er ri m f or m e d ?

Lesson 6 � Impact Craters�Holes in the Ground!6.6 NASA EG-1997-08-104-HQ

3. The powder represents the planet’s surface. Any material beneath the top layermust have formed at an earlier time (making it physically older).If you were to examine a crater on the Moon, where would you find the oldermaterial?

Where would you find the younger material? Why?

4. What effect did the time intervals have on crater formation? Why?

5. What effect did different projectiles have on crater formation? (If differentprojectiles were used.) Why?

6. Since large meteorites often explode at or near the surface, how would theexplosion affect impact crater formation?

7. How does the increased drop height affect crater formation? Why?

M a t e ri als - P e r G r o u p❑ pr oj e ctil es S E T A a n d/ or S E T B ( o pti o n al)

S E T A - f o ur m ar bl es, b all b e ari n gs, or l ar g e si n k ers of i d e nti c al si z e a n d w ei g htS E T B - t hr e e s p h er es of e q u al si z e b ut diff e r e nt m at e ri als s o t h at t h e y willh a v e diff er e nt m ass

❑ str ai n er or sift er t o distri b ut e t h e dr y m at eri al❑ m etri c r ul er a n d m et er sti c k ❑ l a b b al a n c e ( o n e p er cl ass) ❑ D at a C h art

P r o c e d u r e1. E a c h gr o u p s h o ul d c h o os e at l e ast t hr e e pr oj e ctil es fr o m S E T A or S E T B.2. Writ e a d es cri pti o n of e a c h pr oj e ctil e o n y o ur D at a C h art.3. M e as ur e t h e m ass, di m e nsi o ns of e a c h pr oj e ctil e a n d r e c or d o n t h e D at a C h art.4. Pr e p ar e dr y m at eri al l a y er s a c c or di n g t o dir e cti o ns fr o m y o ur t e a c h er.5. Dr o p pr oj e ctil es i nt o t h e dr y m at eri al.

S et A - Dr o p all pr oj e ctil es fr o m t h e s a m e h ei g ht or s e v er al s eri es ofe x p eri m e nts m a y b e c o n d u ct e d fr o m diff er e nt h ei g hts. R e c or d d at a a n d cr at ero b s er v ati o n s.S et B - Dr o p t h e pr oj e ctil es fr o m diff er e nt h ei g hts. R e c or d all h ei g ht d at a a n dcr at er o bs er v ati o ns.

6. E x p eri m e nt wit h diff er e nt v el o citi es b y t hr o wi n g pr oj e ctil es i nt o dr y m at eri als.7. Dis c uss t h e eff e cts c a us e d b y t h e v ari a bl es.O pti o n s:

• Pl ot r a y l e n gt h vs. m ass w h e n pr oj e ctil e v el o cit y is e q u al.• Pl ot r a y l e n gt h vs. v el o cit y at a c o nst a nt pr oj e ctil e m ass. ( M e as ur e r a y

l e n gt h fr o m t h e c e nt er of cr at er t o t h e e n d of t h e l o n g est r a y f or e a c h cr at er.)

Q u e sti o n s

1. W h at e vi d e n c e w as t h er e t h at t h e e n er g y of t h e f alli n g pr oj e ctil e w as tr a nsf err e d t ot h e gr o u n d ?

Lesson 6 � Impact Craters�Holes in the Ground!6.8 NASA EG-1997-08-104-HQ

2. How does the velocity of a projectile affect the cratering process?

3. How does the mass of a projectile affect the cratering process?

4. If the projectile exploded just above the surface, as often happens, what changesmight you see in the craters?

Lesson 6 � Impact Craters�Holes in the Ground!NASA EG-1997-08-104-HQ 6.9

Lesso

n 6 � Im

pa

ct C

rate

rs� H

ole

s in the G

round

!

Data C

hart: Activity A and BD

ateN

ames

Height

Time

Activity A onlyLongest R

ayif available

Projectile Description

mass (g)

dimensions (cm

)

Sketch of Crater

and comm

ents(note diam

eter and depth)

Lesson 7 � Crater HuntersNASA EG-1997-08-104-HQ 7.1

Exploring Meteorite Mysteries Lesson 7 � Crater Hunters “Where

do theycomefrom?”


• observe impact craters on Earth and other solar system bodies.

• discuss geologic forces that have removed most of the evi-dence of the impacts on Earth.

• locate impact craters using longitude and latitude.

• search maps for potential impact sites.

• create a field work plan to investigate possible craters.

BackgroundImpact craters are geologic structures formed when a meteorite,asteroid or comet smashes into a planet or other solid body. All theterrestrial planets and satellites have been bombarded throughout theirhistory. To us the most obvious examples of these impacts are thecraters on the Moon. If the Moon is visible, craters are visible. Youcan only see the very large craters or basins with the naked eye.Lunar craters were not described until after Galileo used one of thefirst telescopes to look at the Moon. Modern binoculars help to makethe craters on the Moon very obvious.

On the Earth, dynamic geologic forces have erased most of theevidence of its impact history. Weathering, erosion, deposition,volcanism, and tectonic activity have left only a small number ofimpacts identifiable. Approximately 140 terrestrial impact cratershave been identified. These impact craters range from about 1 toover 200 kilometers in diameter and from recent to about two billionyears in age.

About This LessonAfter viewing slides of craterson other planets, the Moon,and Earth, students will locateimpact craters on Earth usinglongitude and latitude andvarious maps. Students willlocate potential sites of im-pacts, and plan the necessaryresearch to verify their obser-vations.

Vocabularyimpact crater, longitude,latitude, weathering, erosion,deposition, volcanism, tec-tonic, terrain, geophysical,ejecta, tektites, vaporize

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. G at h er m at eri als.2. R e a d l ess o n b a c k gr o u n d.3. R e vi e w sli d es.

Cl assr o o m Pr o c e d ur e - P art 11. S h o w sli d es of M er c ur y, Ve n us, M o o n, M ars.2. Dis c uss h o w t h es e b o di es ar e ali k e a n d h o w t h e y ar e

diff er e nt, f o c usi n g o n cr at eri n g.3. As k “ W h er e ar e t h e cr at ers o n E art h ? ” S h o w sli d e of

M et e or Cr at er o nl y.4. E a c h st u d e nt ( or p air of st u d e nts) is gi v e n a m a p of N ort h

A m eri c a or t h e w orl d.5. H a n d o ut ( or p ut o n o v er h e a d) t h e Cr at ers o n E art h D at a

C h art a n d d esi g n at e t h e i m p a ct cr at ers t o b e us e d (t e a c h erm a y li mit t h e n u m b er t o b e pl ott e d).

6. St u d e nts pl ot d esi g n at e d cr at ers usi n g t h e l o n git u d e a n dl atit u d e d at a, v ar yi n g d ot si z e a c c or di n g t o cr at er di a m et er.

7. If P art 2 will n ot b e c o m pl et e d, t h e fi n al sli d es of E art h i m p a ctcr at ers m a y b e s h o w n at t his ti m e.

Cl assr o o m Pr o c e d ur e - P art 2I n t his a d v a n c e d a cti vit y st u d e nts c o nsi d er g e ol o gi c pr o c ess es li k ef a ulti n g, w e at h eri n g, a n d gl a ci al a cti vit y.

1. Distri b ut e St u d e nt S h e ets.2. B as e d o n t h e a g e, si z e, n a m e, a n d t err ai n, st u d e nts writ e a

d es cri pti o n or m a k e a s k et c h of w h at t h e y t hi n k t h e cr at ers h a p es w o ul d l o o k li k e.

3. S h o w t h e sli d es of t h e cr at ers a n d h a v e st u d e nts d es cri b ecr at ers a g ai n a n d c o m p ar e t o t h e pr e vi o us d es cri pti o ns.

Q u esti o ns1. W h er e ar e t h e cr at ers o n E art h ?2. W h at h a p p e n e d t o t h e cr at ers o n E art h ?3. W h at ar e s o m e diff er e n c es b et w e e n M o o n cr at ers a n d E art h

cr at ers ?4. C o m p ar e s e v er al E art h cr at ers. H o w ar e t h e y ali k e a n d

diff er e nt ?

A b o ut T his A cti vit yP a rt 1 - St u d e nts l o o k atot h er b o di es i n t h e s ol ars yst e m t o s e e t h at t h er e h asb e e n a hist or y of i m p a cts i nt h e e ntir e i n n er s ol ar s yst e m.F o c usi n g o n E art h, st u d e ntsdis c o v er t h at t h er e ar e n otm a n y o b vi o us cr at ers. T h e yl o c at e cr at ers o n a m a p usi n gl o n git u d e a n d l atit u d e.P a r t 2 - Wit h o ut s e ei n gpi ct ur es of t h e cr at ers,st u d e nts d es cri b e t h e cr at ersusi n g n a m e, a g e, si z e, t err ai n,et c. T h e cr at er p h ot o gr a p hsar e t h e n s h o w n t o all o wc o m p aris o n wit h t h est u d e nts’ d es cri pti o ns of t h ecr at ers.

M a t e ri als fo r A cti vit y A❑ sli d e pr oj e ct or a n d s cr e e n❑ Sli d e S et, I m p a ct Cr at ers❑ m a ps of N ort h A m eri c a or

t h e w orl d wit h l o n git u d ea n d l atit u d e d esi g n at e d( p g. 7. 4)

❑ Cr at ers o n E art h D at aC h art ( p g. 7. 3, o n e p ergr o u p or tr a ns p ar e n c y)

❑ p e n/ p e n cil❑ St u d e nt S h e et f or A cti vit y

A, P art 2 ( p g. 7. 5, o n e p erst u d e nt)


Lesso

n 7 � C

rate

r Hunte

rs

Craters on Earth D

ata Chart

Activity A, Part 1 “Where Are the C

raters on Earth?”

*Craters used in Activity A - Part 2

Lesson 7 � Crater Hunters7.4 NASA EG-1997-08-104-HQ

Less

on

7 �

Cra

ter H

unte

rs

Cra

ter H

unte

rs M

apAc

tivity

A, P

art 1

“W

here

Are

the

Cra

ters

on

Earth

?”


Longitude and Latitude for each crater can be found on Craters on Earth D

ata chart page 7.3.

Procedure1.

Use a detailed physical m

ap or atlas to locate the craters listed below; note im

portant information on the chart.

2.Fill in a description of the surrounding terrain, especially consider the geology of the area, etc.

3.Considering all the inform

ation on the chart, write a description of w

hat you think the craters look like.4.

View the pictures of the craters and w

rite your second descriptions based on the pictures.5.

Com

pare the descriptions.

Lesso

n 7 � C

rate

r Hunte

rs

Student Sheet: Activity A

Activity A, Part 2 “Where Are the C

raters on Earth?”


Scientists perform extensive field and laboratory research before they are able to verify thata geologic feature is an impact site. Ideally the scientists are looking for round structures,however geologic forces may have distorted the crater shape through faulting or other move-ment associated with plate tectonics. Ice, water, and wind, through weathering and erosionprocesses, have caused great changes in craters. Some craters have been filled with water, orcompletely covered by soil or water, and have no surface evidence. They may initially beidentified by remote testing of materials below the Earth’s surface (geophysical studies). Some of the clues that help scientists identify large impact sites are found in the physicalcondition of the structure. In addition to the crater’s round shape, they look for layers of rockthat have been turned over at the edge of the crater. A large uplift or mountain at the center isalso common in impact craters. Highly fractured rocks are usually found at impact sites but theycould be interpreted as being associated with other non-impact geologic processes. However,scientists find shatter cones, which are highly shocked rocks with distinct structures, only atareas stressed by huge impacts. Investigations usually identify large amounts of excavatedmaterial deposited around and in the craters. This material is called ejecta and may form thicklayers of breccia, a mixed broken rock material. To verify the location and origin of thesedeposits requires extensive research, including drilling. Sometimes a large volume of impactmelted rock is found in and around the craters. Some melted rock is frequently thrown far fromthe impact. These small glassy masses, which were aerodynamically shaped when they weremolten, are called tektites. Very small ones are microtektites. They are very good indicators oflarge impacts. Another way to get important information about an impact is from chemistry. The impact-melted rock sometimes contains melted meteorites. By careful laboratory research, scientistscan detect very small amounts of rare elements that are more abundant in meteorites. Thesechemical signatures are very important in meteorite research. To find a meteorite sample wouldbe the best discovery! Unfortunately this does not happen frequently. Meteorites maycompletely vaporize during the impact process, or they may be removed by erosion. Early geologists misinterpreted some impact craters. Scientists reported Meteor Crater inArizona as a volcanic crater. The Chicxulub site on the Yucatan peninsula was also wronglyreported. Early oil explorers misinterpreted extensive deposits around the Chicxulub area.Scientists now know that the material is ejecta from a huge impact and not of volcanic origin. Considering the geologically active crust that erases craters, and all the researchnecessary to verify the origin of impact craters, it is not surprising that only around 140 havebeen identified so far. But it is likely that more will be found.

Lesson 7 - Crater HuntersStudent Background: Activity B


• d e v el o p crit eri a f or i d e ntif yi n g cr at ers o n E art h.

• s e ar c h m a ps f or p ot e nti al i m p a ct sit es.

• cr e at e a fi el d w or k pl a n t o i n v esti g at e p ossi bl e cr at ers.

B a c k g r o u n dS e e St u d e nt B a c k gr o u n d ( p g. 7. 6), als o s e e b a c k gr o u n d

i nf or m ati o n i n L ess o n 1 6, p g. 1 6. 2.

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. G at h er m at eri als.2. R e a d b a c k gr o u n d i nf or m ati o n.3. Pr e p ar e s a m pl e cr at er if d esir e d.

Cl assr o o m Pr o c e d ur e1. R e a d a n d dis c uss b a c k gr o u n d i nf or m ati o n. R e vi e w

o bs er v ati o ns m a d e i n P art A of t his l ess o n. R e-s h o w sli d esif d esir e d. Br ai nst or m a n e x a m pl e cr at er a n di n v esti g ati o n if n e c ess ar y.

2. Di vi d e cl ass i nt o t e a ms of t w o t o f o ur st u d e nts.3. Assi g n e a c h t e a m a diff er e nt m a p ar e a t o o bs er v e, l o o ki n g

f or a n y f e at ur e t h at mi g ht b e t h e sit e of a n i m p a ct. All o wst u d e nts t o b e v er y cr e ati v e i n c h o osi n g t h e p ossi bl e sit es.S p e cifi c sit es ar e n ot i m p ort a nt. T h e y ar e li k el y t o c h o os eo b vi o usl y r o u n d str u ct ur es s u c h as l a k es i n C a n a d a, H u ds o nB a y, t h e G ulf of M e xi c o, t h e Ar al S e a i n U z b e kist a n (f or m erS o vi et U ni o n), L a k e O k e e c h o b e e i n Fl ori d a, a n d L a k eVi ct ori a i n Afri c a.

4. St u d e nts pl a n g e ol o gi c fi el d i n v esti g ati o ns a n d l a b or at or y t estst h at mi g ht b e d o n e t o v erif y t h at t h eir d esi g n at e d cr at er is or isn ot a n i m p a ct sit e. R e p ort i n o utli n e f or m or s e e t h e pr o p os ali d e a b el o w.

5. St u d e nts writ e a s h ort “ pr o p os al ” as ki n g f or s u p p ort m o n e y t oc o n d u ct t h eir r es e ar c h. T h e y will n e e d t o e x pl ai n a n d j ustif yt h e pl a n n e d r es e ar c h. C o nsi d er ti m e, tr a v el, p ers o n n el,l a b or at or y e x p e ns es, a n d d at a g at h eri n g.

A b o ut T his A cti vit yI n t e a ms st u d e nts vi e w p h ysi-o gr a p hi c m a ps of N ort hA m eri c a or a n ot h er p art of t h ew orl d. T h e y tr y t o fi n d ap ossi bl e i m p a ct sit e b as e d o ncir c ul ar s h a p e a n d ot h erf e at ur es o bs er v e d i n t h e sli d esof i m p a ct cr at ers o n E art h.T h e t e a ms will t h e n d e v el o p apl a n t o d o fi el d r es e ar c h,listi n g t h e d at a t h e y c o ul dc oll e ct a n d t h e t as ks t h e yc o ul d p erf or m t o h el p t h e mv erif y if t h e f or m ati o n is a ni m p a ct sit e.

M a t e ri als fo r A cti vit y B❑ St u d e nt B a c k gr o u n d

( p g. 7. 6)❑ l ar g e p h ysi c al m a ps of a n y

r e gi o n of t h e w orl d, o n ep er t e a m

❑ p a p er a n d p e n cil


Teacher notes for field investigations

Ask students “What would you look for at the site to help prove thatyou have found the remnants of an impact?” Possible answers mightbe:

• look for meteorites• map the geologic formations looking for: a basin shape,

overturned rim layers, possible uplift in the central craterregion, multiple ring structures (see Lesson 6)

• look for minerals changed by impact shocks• look for melted rocks• test deposits associated with the debris from the crater, looking

for elements that are much more abundant inmeteorites (i.e., Iridium).

“ W h atar e t h e y ? ”A b o ut T his L ess o nT his l ess o n h as b e e nd esi g n e d as a c o mf ort a bl ei ntr o d u cti o n t o d es cri bi n gm et e orit es. It h el ps st u d e ntsb e c o m e b ett er o bs er v ers b ym a ki n g a c o n n e cti o n b et w e e nt h e f a mili ar ( c a n d y b ars) a n dt h e u nf a mili ar ( m et e orit es).E di bl e “r o c ks ” ar e us e d i n as ci e ntifi c c o nt e xt, s h o wi n gst u d e nts t h e i m p ort a n c e ofo bs er v ati o n, t e a m w or k a n dc o m m u ni c ati o n s kills. I ne v er y d a y t er ms, st u d e nts dr a wa n d d es cri b e t h e f o o d.St u d e nts will p air t h eir o bs er-v ati o ns wit h s h ort d es cri pti o nst h at ar e i n g e ol o gi c “ Fi el dN ot e ” st yl e. As t h e t e a c h era n d cl ass r e vi e w, a p pr o pri at eg e ol o gi c t er mi n ol o g y m a y b es u bstit ut e d b y t h e t e a c h er a n ds u bs e q u e ntl y e m br a c e d b ye v e n v er y y o u n g st u d e nts.T h e l ast p art of t his a cti vit yall o ws t h e st u d e nt t o d es cri b er o c k s p e ci m e ns b ef or e t h e ym o v e t o m et e orit e s a m pl es i nt h e M et e orit e S a m pl e Dis k.

e e cP r o c e d u r e

A d v a n c e d Pr e p ar ati o n1. Pr e p ar e s a m pl es. Si m pl e r e ci p es ar e i n cl u d e d f or s o m e

s a m pl es. T h e first si x list e d o n t h e a ns w er k e y ar e es p e ci all yi m p ort a nt si n c e t h e y cl os el y r e pr es e nt m et e orit e c h ar a ct eristi cst h at will b e t a u g ht i n ot h er l ess o ns. T h e ot h er s a m pl es o n t h elist ar e g o o d f or m e eti n g t h e o bj e cti v es of t his a cti vit y a n doff er m or e v ari et y. Us e as m a n y as n e e d e d, a d d a f e w e xtr a st o c o m pli c at e t h e e x er cis e.

N ot e: O bj e cti v es a n d af o r m al v o c a b ul a r yi nt r o d u cti o n s h o ul d n ot b edis c uss e d u ntil t h e e n d oft h e a cti vit y.


• o bs er v e a n d d es cri b e p h ysi c al c h ar a ct eristi cs of a n e di bl es a m pl e i n pr e p ar ati o n f or d es cri bi n g r o c k or m et e orit es a m pl es.

• w or k c o o p er ati v el y i n a t e a m s etti n g.

• us e c o m m u ni c ati o n s kills, b ot h or al a n d writt e n.

M at e ri als❑ pr e p ar e d e di bl e s a m pl es (s e e att a c h e d list, p g. 8. 3 a n d

r e ci p es, p g. 8. 4)❑ s m all pl asti c b a gs f or s a m pl es ❑ k nif e❑ “ Fi el d N ot e ” S a m pl e D es cri pti o ns of c a n d y b ars, e nl ar g e d a n d c ut

i nt o n u m b er e d s e g m e nts ( p gs. 8. 7- 8. 1 0).N ot e: If i n cl u d e d r e ci p es are n ot us e d, t h e n t h e d es cri pti o ns m a y

n e e d t o b e r e vis e d b y t h e cl assr o o m t e a c h er t o m or e a c c ur at el yd es cri b e t h e a ct u al s a m pl es.

❑ St u d e nt Pr o c e d ur e ( p g. 8. 5, o n e s h e et p er t e a m of t w o)❑ c ol or e d p e n cils f or e a c h t e a m❑ p e n or p e n cil

C ut s u rf a c e of “ e di bl e r o c k. ”

Lesson 8 � Edible Rocks8.2 NASA EG-1997-08-104-HQ

2. Cut the samples so that a flat interior surface is exposed.Reserve part or most of each sample — to be eaten by the students as a reward.

3. Place each sample for student teams in a small plastic bag. Each team of two students willhave one bag containing one sample.

4. Copy Student Procedure sheets, one for each team of two.5. Cut enlarged “Field Note” Sample Descriptions into numbered segments. Descriptions are

written the way a scientist might take notes in a field record book.6. Arrange one set of prepared “Field Note” descriptions on a table(s) so that students may easily

read and reach each of them (numbered sequence is not important).7. Have answer key available for teacher.8. Have a variety of rock samples available (students may bring their own samples).

Classroom Procedure1. Distribute sample and procedure sheet to each team. Allow student teams to choose sample if

possible.

Note: Content vocabulary should not be expected initially. The processes of observing and record-ing should be kept simple.

2. Explain that each team is responsible for describing and sketching its sample. Encouragestudents to describe their observations using familiar vocabulary; however, use no foodterms. Example: The outer layer is a thin coat of light brown material containing cream or tancolored round chunks (i.e., chocolate candy bar coating that contains peanuts).Student descriptions need not be exactly like the provided descriptions. In fact theirdescriptions may be far more detailed than the short descriptions provided, which are ingeologic “Field Note” form.

3. Emphasize that working together is important.4. When sketch and description of sample are

complete, students take them, along with theirsample, and pair them with the preparedwritten descriptions. Emphasize that theirobservations will not be exactly like the “FieldNotes.” They will likely try several matchesbefore they have the accurate paring.Throughout this step, the teacher will verifycorrect pairs. Expect questions like, “Isnumber one peanut brittle?”. When they havefound the “Field Note” that describes theirsample, students should place their sketch,description, and sample next to the correct“Field Note” description. Reward thestudents by allowing them to eat the reserved part of the candy or other treat. If students havedifficulty finding the description of their candy bar then the teacher should encourage them tointeract with other groups for help. This step of the lesson will likely become a slightly noisy,cooperative process. As students find a match between “Field Note” descriptions and candy bars,some definitions may be supplied if necessary, i.e. “Platy means flaky flat material.”

Time: Classroom Steps 1 thru 4 take 25-30 minutes total.

Rice cereal treats — (meteorite breccia).

Lesson 8 � Edible RocksNASA EG-1997-08-104-HQ 8.3

5. When all students have successfully matched their samples, each team may describe its sampleto the class. The class should have access to the sample and the prepared written descriptionduring this sharing. Sketches may be displayed.

6. Conduct a discussion that includes the following points which emphasize basic skills needed tobe good scientists:

• The students made detailed observations of a sample.• The task was accomplished by using teamwork.• Although the student’s descriptions differed from those provided and each team had a

different style, the skills and processes used to observe and record the data were thesame for each group.

• The students communicated their observations and then shared the findings verballyand in writing.

7. During the discussion, the teacher may expand and help define the meteorite and geologicvocabulary in context and encourage students to apply it to their own samples as they progressto the next step. Pay particular attention to vocabulary for the first six samples that use somewords especially pertinent to meteorites.

8. Have students test their observation skills again by sketching and describing real rocks.

Vocabularytexture, density, matrix, breccia, phases, fusion crust, chondrules, inclusions, vesicles, bleb, friable,platy, porous, unfractured, unconsolidated, regolith

ExtensionUsing Meteorite Sample Disk or photographs of meteorites in disk, students repeat the sameprocedure of observing and recording (or see Lesson 9—Meteorite Sleuths!).

Teacher Key

1. Peanut Brittle (chondrites)2. Rocky Road (chondrites)3. Chocolate (iron without fusion crust)4. 3 Musketeers™ (achondrite with fusion crust)5. Rice Cereal Treats (meteorite regolith breccia)6. Chocolate brownie (carbonaceous chondrites)7. Snickers™8. Milky Way™9. “Bar None”™10. Hershey Bar™11. Twix™12. Butterfinger™

13. Skor™14. Rolo™15. Kit Kat™16. Symphony™17. M & M™18. Nestle Crunch™19. Whatchamacallit™20. Mounds™21. P.B. Max™22. Mr. Goodbar™23. Hershey with Almonds™


Recipes for samples not easily available commercially.

Note: Recipes are for a larger quantity than required for the lesson.

Rocky Road (#2 Edible Rock)170 g (6 oz.) semi-sweet chocolate pieces (melted)120 g (2 cups) mini-marshmallows

• butter loaf pan or folded foil• pour about half of melted chocolate into pan• pour marshmallows into pan and mix so

they are coated with chocolate• pour remaining chocolate over the

marshmallows and spread flat• refrigerate until cold• cut a cube so vertical surface is exposed

Solid Chocolate (#3 Edible Rock)use any thick chunk of solid chocolate

Chocolate Brownies (#6 Edible Rock)

• use any recipe for dark chocolate brownies ora box mix

• add large chunks of semi-sweet bakingchocolate or solid chocolate candy (addenough so that the solid candy will beexposed on a cut surface)

• bake and cool completely• cut, exposing some brownie and some solid

chocolate; this surface will be described• to form the breccia texture, cut the cube in

several places, then reassemble the cubein a jumbled manor, incorporating one or twojelly beans and or other edible chunks

• allow the sample to harden so that a goodsurface may be cut

• cut the sample so that chunks and variouschocolate lines are exposed

• students will describe the cut surface

Regolith Breccia Simulant ( # 5 Edible Rock)(Marshmallow cereal treats)240 g (1/2 cup) butter or margarine (melted)300 g (10-11 oz.) mini-marshmallows200 g (8 cups) crispy rice cereal170 g (6 oz.) chocolate semi-sweet pieces (melted)1 or 2 jelly beans, chocolate chunks,or other large edible lumps

• butter a deep rectangular baking pan• melt butter in microwave or in large pan on

the stove• add marshmallows and melt

(2 min. in microwave)• stir until smooth• pour over cereal and stir to coat all cereal,• press half of mixture into deep buttered pan• spread cereal layer with melted chocolate• press remaining mixture on top of the

chocolate• allow cookie to cool enough to cut but not

until completely hardened (should still bepartly moldable)

• cut one cube about 5 cm square, then cut againonce or twice

• embed one or two jelly beans in part of the cutcube

• mold cut pieces together again to form a“breccia”

• allow to harden• recut to expose interior and jelly bean

M a t e ri als - P e r T w o St u d e nts❑ s a m pl e “r o c k ” ❑ t his pr o c e d ur e s h e et ❑ p e n or p e n cil ❑ m a p p e n cils

P r o c e d u r e

1. Wit h y o ur p art n er, c h o os e o n e s a m pl e t o o bs er v e.

2. C ar ef ull y o bs er v e t h e s a m pl e. Yo u m a y r e m o v e t h e s a m pl e fr o m t h e b a g,b ut h a n dl e it c ar ef ull y a n d d o n ot t ast e .

3. M a k e a l ar g e, d et ail e d s k et c h of t h e s a m pl e. T h e s k et c h s h o ul d s h o w t h ei nt e ri o r c ut s urf a c e t h at is fl at a n d a n y i m p ort a nt d et ails of t h e e xt eri or. Yo um a y us e t h e b a c k of t his p a p er f or y o ur s k et c h.

4. Writ e 2- 3 s e nt e n c es d es cri bi n g t h e p h ysi c al c h ar a ct eristi cs of t h e c ut s u rf a c eof t h e s a m pl e. D o n ot us e a n y f o o d t e r ms . F or e x a m pl e, d o n ot us e t h ew or d c h o c ol at e. M a k e y o ur d es cri pti o n as cl e ar a n d c o m pl et e as y o u p ossi-bl y c a n.

5. W h e n y o u h a v e c o m pl et e d St e p 4 t a k e y o ur d es cri pti o n, s k et c h a n d s a m pl et o t h e t a bl e w h er e t h e “ Fi el d N ot e ” d es cri pti o ns of t h e f o o d s a m pl es ar el o c at e d. Fi n d t h e d es cri pti o n t h at fits y o ur s a m pl e. C h e c k wit h y o ur t e a c h ert o s e e if y o u i d e ntifi e d t h e c orr e ct m at c h. Yo u will li k el y tr y s e v er al of t h ed es cri pti o ns b ef or e y o u fi n d t h e o n e t h at d es cri b es y o ur s a m pl e. Y o u m a yg et h el p fr o m ot h ers. Tr y c h e c ki n g wit h t h e t e a c h er or a di cti o n ar y f oru nf a mili ar w or ds.

6. Pl a c e y o ur d es cri pti o n, s k et c h, a n d s a m pl e b esi d e t h e “ Fi el d N ot e ”d es cri pti o n f or y o ur s a m pl e.

7. Yo ur eff ort will b e r e w ar d e d wit h a n ot h er p art of t h e s a m pl e t o e at.


Lesson 8 � Edible Rocks

�Field Note� Sample Descriptions

These food descriptions are in geologic “Field Note” style. Therefore, they may be short andsometimes cryptic. Use of geologic terms will encourage students to stretch their minds.

1. Sample is a thin layer. There is a golden matrix surrounding tanrounded or broken inclusions. The inclusions have areddish brown rim or crust.

2. Sample consists mainly of white, soft rounded to angular blebscompletely surrounded by a uniform dark brown matrix.

3. Sample is a solid dark brown dense mass with no obviousfusion crust.

4. Sample has a homogeneous light brown interior with a few smallvesicles. The exterior looks like a fairly regular, dark brownfusion crust with some patterning.

5. Sample appears to have been distorted. The dominant phase ismade of rounded light tan fragments containing many void spaces.A dark brown thin layer fills spaces between some roundedfragments. There are some large foreign inclusions.


6. Sample is totally dark brown with two phases. The dominant phaseis shiny and crumbly. The other phase is dense and slightly lighterin color. A light fusion crust appears on only one side.

7. Outside: Thin medium-brown layer with ripple-markson the bottom

Inside: Bottom - (~1/3) flat dense buff layerTop - (~2/3) pebbles consolidated in a fine grainedtan matrix

8. Outside: Thin medium brown layer with wavy ripple markson the bottom

Inside: Bottom - dense dark buff layerTop - shiny, smooth, medium tan layer

9. Outside: Medium brown layer, thin on the bottom, thethicker top contains angular inclusions

Inside: Thin alternating horizontal layers ofsmooth dark brown and fragmented darkbrown

10. Dense medium brown sample, flat on the bottom with threeparallel ridges on top.


11. Outside: Thin medium brown layer with wavy ripples onthe bottom

Inside: Bottom - poorly consolidated light tanporous layerTop - shiny smooth medium tan layer

12. Outside: Thin medium brown layerInside: Poorly consolidated, friable, shiny to dull golden

platy fragments

13. Outside: Medium brown layer, very thin on bottom andside, thicker on top with large wavy ripples

Inside: Thin dense layer of shiny light-golden unfracturedmaterial

14. Outside: Thin, medium brown, edges higher on outside oftop, sides slanted

Inside: Smooth material that is yellowish brown andsticky

15. Four segments of layered material.

Outside: Thin, medium brownInside: Alternating light and medium

colored material

16. Solid medium brown throughout, single dense layer with a valleyor dip in the top.


17. Sample consists of unconsolidated pebbles with various colors andregular shape. Each individual pebble has a medium brown interiorwith a thin, hard colored shell.

18. Sample has a thin layer of dense brown material, containing verylight inclusions at the bottom. The sample top has a depression inthe middle with a ridge on each side.

19. Sample is a rectangular layer of rounded light pebblessurrounded by a thin coating of medium brown. Someyellowish brown sticky material is above the pebbles.

20. Sample interior consists of white, moist-looking fragments.These are surrounded by a dark brown exterior layer.

21. Irregular sample.

Outside: Bumpy medium brownInside: Yellow brown solid material resting on light tan

fragments, some large tan fragments are found nearthe top

22. Outside: Dense layer of medium brown with a dip in the topInside: Light tan pebbles that have settled to the bottom

23. Dense sample of medium brown material, rounded on the top andflat on the bottom, with a few light brown pebbleinclusions.

Lesson 9 � Meteorite Sleuths!NASA EG-1997-08-104-HQ 9.1


Lesson 9 � Meteorite Sleuths!

About This LessonThe activities in this lessonfocus on observation andexamination skills. AMeteorite Sample Disk (orphotos) will be at the center offour laboratory stations. Stu-dents will use several degreesof magnification to researchmeteorites in the MeteoriteSample Disk and other materi-als. Discussing the sequencewill help them understandhow scientists approachmeteorite research and classi-fication.


• simulate techniques used by scientists.

• develop skills in acquiring data through the senses.

• observe, examine, record, and sketch data.

• use magnifying glasses, microscopes, and balances.

• experience conceptual application.

BackgroundSee background information on Student Sheet, Station 4, page 9.7.

Lesson InformationScientists use a variety of methods to classify materials and objects.Specific technologies and techniques are used in the classification ofmeteorites. The Meteorite Sample Disk (or photographs if theMeteorite Sample Disk is not available) is the focal point for theseactivities presented in a laboratory format. The laboratory activity isbroken into four sections that simulate meteorite identificationmethods. A rotation lab is suggested with the Meteorite SampleDisk displayed at a central location for periodic comparisons.Teams of students will work at numbered stations, taking lab notesin appropriate sections on a prepared laboratory worksheet.Rotations will be ordered numerically; however, no specific order isnecessary in completing the lab. Since all portions of the lab arebroken down according to stations, teachers may prepare for andinclude only those portions desired.

Note: Station numbers should be clearly identified to facilitateorderly rotations. Additional duplicate stations may be set up toallow for more than 4 groups per class.

Upon completion of all rotations a “wrap-up” session in which labresults are reviewed and discussed in order, will clarify studentunderstanding. The students have made observations from generalmacroscopic inspections to microscopic details — like the game “20Questions” in which someone is asked to identify an unknown lifeform via 20 “yes/no” questions. The winner invariably goes fromgeneral to specific questions.

“Whatare they?”

Vocabularytexture, chondrite,achondrite, stony-iron, iron,mass, density, volume,specimen, classification,hypothesis, cross section,carbonaceous chondrite

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. G at h er a n d ass e m bl e m at eri als.2. R e vi e w l ess o n i nf or m ati o n a n d St ati o n 4 b a c k gr o u n d.3. S et u p M et e orit e S a m pl e Dis k or p h ot os i n c e ntr al st ati o n.Cl assr o o m Pr o c e d ur e1. Di vi d e cl ass i nt o 4 or m or e gr o u ps.2. Distri b ut e St u d e nt S h e ets.


• d e v el o p s kills i n a c q uiri n g d at a t hr o u g h t h e s e ns es.

• m e as ur e, r e c or d, a n d s k et c h r o c k s a m pl es.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. Pl a c e gr a p h p a p er, r o c k, a n d r ul er o n l a b t a bl e.

Cl assr o o m Pr o c e d ur e1. Vis u all y e x a mi n e r o c k s p e ci m e n.2. R e c or d o bs er v ati o ns r el at e d t o c ol or, t e xt ur e, a n d s h a p e of

r o c k.3. M e as ur e r o c k a n d r e c or d m e as ur e m e nts o n St u d e nt S h e et.4. S k et c h r o c k t o s c al e o n gri d pr o vi d e d.5. Pr o c e e d t o M et e orit e S a m pl e Dis k dis pl a y a n d r e c or d c ol ors

of e a c h m et e orit e.

M at e ri als❑ M et e orit e S a m pl e Dis k

or p h ot o gr a p hs❑ m a g nifi er❑ bi n o c ul ar r efl e ct e d li g ht

mi cr os c o p e ( o pti o n al)❑ St u d e nt S h e et

( p gs. 9. 5- 9. 8)

A b o ut T his St ati o nSt u d e nts vis u all y e x a mi n e ar o c k s p e ci m e n a n d r e c or do bs er v ati o ns of c ol or, t e xt ur e,a n d s h a p e. M e as ur e m e nts ar et a k e n a n d a s k et c h of t h e r o c kis m a d e. T h e st u d e nts pr o-c e e d t o t h e M et e orit e S a m pl eDis k dis pl a y a n d r e c or d c ol orsof e a c h m et e orit e.

M a t e ri als fo r St a ti o n 1❑ fist-si z e d r o c k❑ gr a p h p a p er

( 2 c m x 2 c m bl o c ks)❑ m etri c r ul er❑ p e n cil, a n d m a p p e n cils or

cr a y o ns❑ St u d e nt S h e et ( p g. 9. 5)

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. Pl a c e b al a n c e, gr a m m ass es ( w ei g hts), c o nt ai n er of m ar bl es,

a n d pr e p ar e d i n d e x c ar d ( v erif yi n g e q u al v ol u m es of allm ar bl es) o n l a b t a bl e.

2. C o nsi d er st e ps 4 or 5 f or u p p er gr a d es or a d v a n c e d st u d e nts.

Cl assr o o m Pr o c e d ur e1. M e as ur e t h e m ass of e a c h t y p e of m ar bl e.2. Writ e a c o m p ar ati v e st at e m e nt usi n g t h e w or ds “ m ass ” a n d

“ d e nsit y ” f or e a c h t y p e of m ar bl e ( d e nsit y = m ass/ v ol u m e).3. Pr o c e e d t o M et e orit e S a m pl e Dis k dis pl a y a n d

pr e di ct w h et h er t h e ir o n or t h e a c h o n drit e h as gr e at er d e nsit y.4. O pti o n al: Wei g h e q u al v ol u m e ( a p pr o xi m at el y) pi e c es of

st e el a n d b as alt t o c o m p ar e t o t h e ir o n a n d a c h o n drit e.5. O pti o n al: L o o k u p t h e s p e cifi c gr a vit y of ir o n a n d t h e

c o m m o n r o c k f or mi n g mi n er als f el ds p ar, a n d p yr o x e n ef o u n d i n a c h o n drit es. Us e t his i nf or m ati o n t o h el p d et er mi n ew h et h er t h e ir o n or a c h o n drit e is m or e d e ns e.

A b o ut T his St ati o nSt u d e nts will d et er mi n e t h em ass of s e v er al m ar bl es a n dh y p ot h esi z e w h et h er t h e ir o nor t h e a c h o n drit e h as gr e at erd e nsit y.

M a t e ri als fo r St a ti o n 2❑ b e a m b al a n c e❑ m etri c m ass es ( 2 s m all

p a p er cli ps = 1 g m)❑ m ar bl es a n d/ or ot h er

o bj e cts of e q u al v ol u m eb ut diff er e nt d e nsiti es

❑ c o nt ai n er f or m ar bl es❑ i n d e x c ar d s h o wi n g

di a m et ers of t h e m ar bl est o v erif y e q u al v ol u m es ofall m ar bl es

❑ St u d e nt S h e et ( p g. 9. 6)

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. Pl a c e pri nt e d pi ct ur e(s) a n d m a g nifi ers o n l a b t a bl e.

Cl assr o o m Pr o c e d ur e1. E x a mi n e pi ct ur e(s) wit h t h e u n ai d e d e y e.2. E x a mi n e pi ct ur e(s) wit h a m a g nifi er.3. R e c or d y o ur o bs er v ati o ns.4. Pr o c e e d t o M et e orit e S a m pl e Dis k dis pl a y a n d e x a mi n e t h e

st o n y-ir o n a n d t h e c h o n drit e A wit h t h e u n ai d e d e y e a n d am a g nifi er.

5. R e c or d y o ur o bs er v ati o ns o n St u d e nt S h e et.

A b o ut T his St ati o nSt u d e nts e x a mi n e pri nt e di m a g es a n d t h e M et e orit eS a m pl e Dis k wit h a n dwit h o ut m a g nifi c ati o n.

M a t e ri als fo r St a ti o n 3❑ f ull- c ol or pri nt e d pi ct ur e(s)

— n e w s p a p er, m a g a zi n e❑ m a g nifi er❑ St u d e nt S h e et

( p gs. 9. 6- 9. 7)


• e x p eri e n c e c o n c e pt u al a p pli c ati o n.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. C ut o n e pi e c e of fr uit i nt o h al v es.2. C ut o n e m e di u m sli c e fr o m o n e h alf s o t h at a g o o d cr oss

s e cti o n is r e v e al e d.3. C ut o n e v er y t hi n cr oss s e cti o n sli c e fr o m t h e r e m ai ni n g h alf

a n d pl a c e o n sli d e o n mi cr os c o p e st a g e.4. A dj ust mi cr os c o p e f or vi e wi n g. M a k e t hi n n er sli c e if

n e c ess ar y f or mi cr os c o pi c vi e wi n g.5. Pl a c e fr uits a n d e q ui p m e nt o n t h e l a b t a bl e i n t h e f oll o wi n g

or d er:• w h ol e fr uit (l a b el e d: # 1 w h ol e fr uit),• t hi c k sli c e fr o m h alf of fr uit (l a b el e d: # 2 cr oss s e cti o n) wit h

m a g nifi er,• t hi n sli c e m o u nt e d o n mi cr os c o p e (l a b el e d: # 3 t hi n s e cti o n).

6. R e m ai ni n g fr uit will n ot b e n e e d e d i n t his l a b e x er cis e.

N ot e: If mi cr os c o p e is n ot a v ail a bl e, a m a g nif yi n g gl ass orh a n d l e ns is a d e q u at e f or m e eti n g t h e l a b o bj e cti v es.

Cl assr o o m Pr o c e d ur e1. R e a d b a c k gr o u n d i nf or m ati o n o n St u d e nt S h e et ( p g. 9. 7).2. O bs er v e all s a m pl es i n or d er a n d r e c or d o bs er v ati o ns,

n ot w h at y o u alr e a d y k n o w.3. Vi e w t h e m et e orit es usi n g

a mi cr os c o p e if a v ail a bl e.4. Writ e a s h ort p ar a gr a p h

t h at d es cri b es t h e r el ati o ns hi pb et w e e n y o ur l a b e x p eri e n c ea n d t h e i nf or m ati o n o n t h eSt u d e nt S h e et.

A b o ut T his St ati o nSt u d e nts e x p eri e n c e t h epr o gr essi o n fr o m g e n er al t om or e s p e cifi c o bs er v ati o ns.

M a t e ri als fo r St a ti o n 4❑ t w o of t h e s a m e t y p e of

e as y-t o-sli c e fr es h fr uitst h at ar e o pti c all yi nt er esti n g ( e x a m pl e:ki wis, * a p pl es, or a n g es,t o m at o es, et c.)

❑ s h ar p k nif e❑ c utti n g b o ar d❑ m a g nifi er❑ bi n o c ul ar mi cr os c o p e❑ cl e a n sli d es a n d c o v er sli ps❑ p a p er t o w els❑ 3 i n d e x c ar ds l a b el e d “ 1,”

“ 2,” a n d “ 3 ”❑ St u d e nt S h e et

( p gs. 9. 7- 9. 8)

* Ki wi fr uit is si mil ar t o m ostm et e orit es i n t h at its o ut ers urf a c e is s o diff e r e nt fr o mt h e i nt eri or. T h e fl es h of a na p pl e is si mil ar t o m ostm et e orit es i n t h at, u n d erm a g nifi c ati o n ( e v e n wit hj ust a h a n d l e ns), t h ea p p e ar a n c e is v astl ydiff e re nt fr o m t h at s e e n wit ht h e n a k e d e y e. T h e o ut erp eri m et er of t h e p e el of a nor a n g e l o o ks si mil ar t of usi o n cr ust w h e n u n d er t h emi cr os c o p e. T h e fl es h of at o m at o a p p e ars t o h a v ec h o n dr ul es w h e n m a g nifi e d.


Color:

Texture:

Shape:

Dimensions:

Meteorite Colors:

Lesson 9 � Meteorite Sleuths!

Student Sheet: Stations 1-4

Station 1: Initial Inspection

Procedure1. Visually examine rock specimen.2. Beside the grid below, record observations related to color, texture, and shape

of rock.3. Measure rock and record measurements beside the grid below.4. Sketch rock to scale on grid provided below (be sure to add scale).5. Proceed to Meteorite Sample Disk display and record colors of each meteorite.

Rock Sketch

Lesson 9 � Meteorite Sleuths!9.6 NASA EG-1997-08-104-HQ

Station 2: How Dense Is Dense?

Procedure1. Measure the mass of each type of marble.

Mass of first marble type: ___ gm Mass of second marble type: ___ gm

2. Write a comparative statement using the words “mass” and “density” for each typeof marble (density = mass/volume).

3. Proceed to Meteorite Sample Disk display and predict whether the iron or theachondrite has greater density. (Circle one) Iron Achondrite

4. What data would be necessary to support your prediction?

5. How do density and mass relate to identification of meteorites?

Station 3: Observation with Magnification

Procedure1. Examine the picture both with the unaided eye and the magnifier. Describe or

sketch your observations. Complete the sentences below using details of yourobservation.

With the unaided eye the picture is...

Viewed through the magnifier the picture is...


Lesson 9 � Student Sheet continued

2. Proceed to Meteorite Sample Disk display. Using your unaided eye and themagnifier repeat observations for the meteorites listed below.

Stony-iron is...

Chondrite A is...

3. Why would a scientist make observations with and without magnification?

4. Which observation gives more usable data for meteorite investigations? Explainyour reasoning.

Station 4: Journey to the Center of the Fruit

BackgroundScientists studying meteorites use various types of observations. They make qualita-

tive (color, shape, texture, etc.) and quantitative (mass, volume, linear measurement, etc.)observations, recording all data carefully. They use special tools to chip off parts and sawthrough meteorites to make closer visual observations. They write careful descriptionsthroughout their investigations.

Very thin sections are cut and mounted on slides for microscopic examination. Higherpowered microscopes, such as an electron microscope, and other advanced technologygive an even clearer picture of the minerals and other materials that make up the meteorite.

Meteorites are classified based on the types, amounts and textures of minerals theycontain. The primary classification into stony, iron and stony-iron is based on the amountof metal. Stony meteorites are divided into chondrites, which contain round inclusionscalled chondrules, and achondrites, which do not contain chondrules. Previously classifiedmeteorites are frequently referred to with continual comparisons being made.

As new information about a meteorite is obtained, scientists may changetheir initial classification. The progression from general to more specificobservations helps scientists to narrow the possibilities in characterizingmeteorites. The study of these rocks from outer space helps to answerquestions about how our solar system formed and the relationships ofplanetary bodies to each other.

Lesson 9 � Meteorite Sleuths!9.8 NASA EG-1997-08-104-HQ

Procedure1. Observe all samples in order and record observations. Do not record just what you

already know.

#1. Whole Fruit

#2. Fruit Cross Section

#3. Fruit Thin Section

2. If a microscope is available at the Meteorite Sample Disk display, view all themeteorites and list one where you see much more detail in the microscope thanyou did with your unaided eye. Sketch and describe the meteorite’s detail you seein the microscope.

meteorite sample name

3. Write a short paragraph that describes the relationship between your labexperience and the background information.

4. What questions must be answered first in a scientific investigation?

5. What is the progression scientists follow in examining a specimen?

Lesson 10 � Building Blocks of PlanetsNASA EG-1997-08-104-HQ 10.1


Lesson 10 � Building Blocks of Planets“Howdid theyform?”Objectives

Students will:

• experiment with simulations that illustrate how chondrites andasteroids formed in the early solar system.

• observe and describe the meteorites in the MeteoriteSample Disk.

BackgroundChondrites are the most primitive type of rock available for study.They are 4.5 billion years old, as old as the solar system. Theircompositions are similar to the heavier elements found in the Sun(not including the abundant H and He gases). Chondrites are madeup of chondrules (spherical balls of rock), metal, and a fine matrixthat holds them together. Chondrules are considered the buildingblocks of the planets. Chondrites have many variations, due partlyto differences in the chondrules. Some of the differences are in thenumber, size, shape, and mineral content of the chondrules.Chondrites have various amounts of metal too. Metamorphismcauses some of the variations in chondrules. One of the chondritesin the Meteorite Sample Disk is metal-rich and metamorphic, anotheris metal-poor and has distinct chondrules. The third chondrite iscarbonaceous. This special type of meteorite contains water andcarbon and some organic compounds (amino acids) that are thebuilding blocks of life. They do not contain living creatures or fossilmaterial. (See Lesson 12)

Chondrites provide our best information on the earliest history ofthe solar system. Scientists think that chondrites formed bycondensation and accretion in the solar nebula, the disk of gas anddust that rotated in a plane around the early Sun. Dust particlescondensed from the gas and accreted (came together) into larger andlarger bodies: chondrules, then small rocks, and then asteroids andplanets. The forces that hold particles together include staticelectricity, gravity, and magnetism. Some asteroids were largeenough to be hot inside thus causing some metamorphism.Most meteorites are formed by the breakup of asteroids.

See additional information in the Teacher’s Guide, pages 16-17.

About This LessonIn Activity A students willobserve and describechondrite meteorites.

In Activity B they willexperiment with balloons andstatic electricity to illustratethe theories about how dustparticles collected into largerclusters.

In Activity C students willmanipulate magnetic marblesand steel balls to dramaticallyillustrate the accretion ofchondritic material into largerbodies like planets and aster-oids.

Vocabularychondrule, chondrite, sphere,matrix, solar nebula,condense, accrete, accretion,metamorphism, organic,static electricity, gravity,magnetism

NOTE: The use ofmagnets in Activity C isintended to simulate allthree forces. Do not letstudents equate magnetism,a minor force, with themajor forces, gravity andelectrostatic charge.

A b o ut T his A cti vit ySt u d e nts will o bs er v e a n dd es cri b e c h o n drit em et e orit es.

M a t e ri als fo r A cti vit y A❑ M et e orit e S a m pl e Dis k❑ M a g nifi er❑ Sli d e S et, Cl assifi c ati o n a n d

F or mati o n❑ Sli d e pr oj e ct or❑ St u d e nt S h e et ( p g. 1 0. 5,

o n e p er st u d e nt)

A b o ut T his A cti vit ySt u d e nts will e x p eri m e nt wit hb all o o ns a n d st ati c el e ctri cit yt o ill ustr at e t h e t h e ori es a b o uth o w d ust p arti cl es c oll e ct e di nt o l ar g er cl ust ers.

M a t e ri als fo r A cti vit y BP e r G r o u p of St u d e nts❑ 1 s m all b all o o n, i nfl at e d

( e xt r as t o all o w f orp o p p e d b all o o ns)

❑ 1 h a n df ul of s m all( 1- 2 m m) st yr of o a mp ell ets (fr o m cr us h e dp a c ki n g m at eri al or ab e a n b a g c h air)

❑ 1 2 2 c m gl ass p a n❑ St u d e nt S h e et ( p gs. 1 0. 5-

1 0. 6, o n e p er st u d e nt)


• e x p eri m e nt wit h st ati c el e ctri cit y t o ill ustr at e o n e of t h e f or c esi n t h e e arl y s ol ar n e b ul a.

• o bs er v e, r e c or d, a n d r el at e t h eiro bs er v ati o ns t o p h ysi c al pr o c ess es.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. R e a d Te a c h er’s G ui d e, p a g es 1 6- 1 7.2. Bl o w u p e a c h b all o o n j ust b ef or e cl ass ti m e.Cl assr o o m Pr o c e d ur e1. St u d e nts pl a c e st yr of o a m b alls i n gl ass p a n.2. St u d e nt r u bs t h e b all o o n i n o n e dir e cti o n o n h air t o cr e at e

el e ctr ost ati c fi el d.3. St u d e nt pl a c es t h e b all o o n i n dis h a n d o bs er v es t h e a cti vit y

of t h e st yr of o a m. R e c or d e a c h st e p a n d o bs er v ati o ns.4. Tr y e x p eri m e nt a g ai n a n d r u b t h e b all o o n b ot h w a ys o n y o ur

h air. R e c or d o bs er v ati o ns.5. Dis c uss q u esti o ns a n d r el at e e x p eri m e nts t o c o n c e pts.


• o bs er v e a n d d es cri b e c h o n drit e m et e orit es.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. Ass e m bl e m at eri als a n d pl a c e M et e orit e S a m pl e Dis k i n a n

e asil y a c c essi bl e l o c ati o n.2. Pr e vi e w sli d e s et, sli d e n arr ati v e a n d t h e m et e orit e

d es cri pti o ns i n t h e M et e orit e A B C’s F a ct S h e et, p a g es 2 9- 3 0.Cl assr o o m Pr o c e d ur e1. S h o w m et e orit e cl assifi c ati o n a n d f or m ati o n sli d e s et a n d dis c uss.2. E x a mi n e t h e t hr e e c h o n drit e s a m pl es i n t h e M et e orit e

S a m pl e Dis k or p h ot o gr a p hs. Us e m a g nifi er.3. S k et c h a n d d es cri b e e a c h s a m pl e o n St u d e nt S h e et.4. C o m pl et e q u esti o ns. R es er ve dis c ussi o n u ntil e n d of a cti vit y.


• m a ni p ul at em at eri als t o ill ustr at epl a n et ar y a c cr eti o n.

• o bs er v e, r e c or d, a n dr el at e t h eiro bs er v ati o ns t op h ysi c alpr o c ess es.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. Pr a cti c e t h e cir c ul ar m oti o n of

t h e pi e p a n a n d t h e a d diti o n of e a c h t y p e of b all.2. T his si m ul ati o n m a y b e d o n e o n a n o v er h e a d if a

d e m o nstr ati o n is n e c ess ar y.

Cl assr o o m Pr o c e d ur e1. Di vi d e cl ass i nt o gr o u ps of 3- 5 st u d e nts a n d assi g n

i n di vi d u al t as ks. O n e st u d e nt h ol ds t h e p a n; o n e t o t hr e est u d e nts a d d b alls t o t h e p a n; o n e r e c or ds o bs er v ati o ns a n do n e or m or e r e p orts fi n di n gs. Te a c h er mi g ht q ui c kl yd e m o nstr at e t h e pr o c e d ur e f or t h e s m all b alls.

2. First st u d e nt pi c ks u p t h e p a n a n d pr a cti c es or bit al m o v e-m e nt of t h e p a n (sl o w cir c ul ar p att er n i n o nl y o n e dir e cti o n).

3. A n ot h er st u d e nt a d ds t h e s m all b alls t o t h e p a n a n d t h e firstst u d e nt c o nti n u es t o r ot at e t h e p a n u ntil b alls st art s e p ar ati n ga n d m o vi n g i n a cir c ul ar p att er n. O bs er v e t h e m o v e m e nt a n dcl ust eri n g a n d r e c or d o bs er v ati o ns.

4. A n ot h er st u d e nt a d ds m e di u m si z e d b alls, o n e at a ti m ew hil e first st u d e nt c o nti n u es r ot ati n g t h e p a n. E x p eri m e ntwit h a d di n g diff er e nt n u m b ers of t h es e b alls. O bs er v e t h em o v e m e nt a n d cl ust eri n g of t h e s m all b alls a n d r e c or do bs er v ati o ns.

5. A n ot h er st u d e nt a d ds o n e m a g n eti c m ar bl e a n d q ui c kl y a d dst h e ot h er o n e. First st u d e nt c o nti n u es t o r ot at e t h e p a n.O bs er v e t h e m o v e m e nt a n d cl ust eri n g ar o u n d t h e m ar bl esa n d r e c or d o bs er v ati o ns.

M a t e ri als fo r A cti vit y CP e r G r o u p of St u d e nts❑ 5 0- 1 0 0 s m all st e el b alls

( 4. 5 m m st e el B Bs w or kw ell a n d a mi xt ur e ofc o p p er- a n d zi n c- pl at e dB Bs pr o vi d es c ol orc o ntr ast)

❑ 5 m e di u m st e el b alls ( 1 c mor 3/ 8 " st e el h u nti n g s h ota b o ut d o u bl e t h edi a m et er of B Bs)

❑ 2 m a g n eti c m ar bl es ( f o u n di n m us e u m gift s h o ps, a n dgift or s ci e n c e c at al o gs)

❑ r o u n d gl ass or al u mi n u m pi eor c a k e p a n ( gl ass is b est;fl at b ott o m is ess e nti al;v erti c al-si d e d p a ns c o nt ai nB Bs b ett er, b ut sl a nt-si d e d p a ns pr o d u c e m or ea cti o n)

❑ St u d e nt S h e et ( p g. 1 0. 6,o n e p er st u d e nt)

N O T E: T h e us e ofm a g n ets i n A cti vit y C isi nt e n d e d t o si m ul at e allt hr e e f or c es. D o n ot l etst u d e nts e q u at e m a g n etis m,a mi n or f or c e, wit h t h em aj or f or c es, gr a vit y a n del e ctr ost ati c c h ar g e.

A b o ut T his A cti vit ySt u d e nts will m a ni p ul at em a g n eti c m ar bl es a n d st e elb alls t o dr a m ati c all y ill ustr at et h e a c cr eti o n of c h o n driti cm at eri al i nt o l ar g er b o di es li k epl a n ets a n d ast er oi ds.

Lesson 10 � Building Blocks of Planets10.4 NASA EG-1997-08-104-HQ

6. Have student groups share results with class. Conduct aclass discussion of how this simulation illustrates theformation of meteorites and asteroids by accretion of dust inthe solar nebula. Do not let students equate magnetism withgravity—the magnets allow a dramatic visual simulationonly. Small balls represent dust, medium balls arechondrules, large balls are chondrites and clusters areasteroids.

Questions1. What happened to the small balls when the pan was moved?

2. How did the medium balls interact with the small ones? Wasthe movement of the two sizes the same or different?

3. Was there an immediate reaction when the magnetic marbleswere added? Did the reaction continue or change?

4. What did you notice about the small balls at the end of theactivity?

5. How does this simulation relate to the accretion of meteorites inthe early solar system?

6. Extra: Which way does our solar system rotate: clockwise orcounter clockwise? (Draw the solar system on a thin sheet ofpaper and place an arrow to indicate that the solar system movesin a counterclockwise motion, as viewed from above. Now lookthrough the other side of the paper and determine which direc-tion of movement is indicated by the arrow —clockwise. Therotation direction is relative to the viewing perspective!

Lesson 10 � Building Blocks of PlanetsNASA EG-1997-08-104-HQ 10.5

Lesson 10 � Building Blocks of Planets

Student Sheet: Activities A, B and C

Activity A: ChondritesCarefully observe the three chondrites in the Meteorite Sample Disk. Describe andsketch them using the space below.

How do you think chondrites may have formed?

Activity B: ZAP! Electrostatic Particle AccretionProcedure1. Place styrofoam balls in glass pan.2. Rub the balloon in one direction on hair to create electrostatic field.3. Place the balloon in the dish and observe the activity of the styrofoam.4. Try the experiment again and rub the balloon both ways on your hair.

In the space provided below record observations from each step of the procedure.

Questions1. How did the balloon and styrofoam balls react when you first put them together?

2. Why does this reaction happen?

Lesson 10 � Building Blocks of Planets10.6 NASA EG-1997-08-104-HQ

3. Why do you think the balloon reacts differently when you rub it both ways in yourhair rather than when you rub it one way?

4. How could you relate this exercise to accretion in the solar nebula?

Activity C: Crunch! Accretion of Chondrules and ChondritesProcedure:1. Practice circular motion as demonstrated by the teacher. Continue until the simulation is

complete. Predict what will happen as each set of balls is added.2. Other students add small balls, continue rotation and observe.3. Add medium steel balls (experiment with number of balls), continue rotation and observe.4. Add two magnetic marbles at different spots, continue rotation and observe.

Questions1. What happened to the small balls when the pan was moved?

2. How did the medium balls interact with the small ones? Was the movement of thetwo sizes of balls the same or different?

3. When the magnetic marble was added, what was the immediate reaction? Did thereaction continue or change?

4. What did you notice about the small balls at the end of the activity?

5. How does this simulation relate to the accretion of the meteorites in the early solarsystem? What does each type of ball represent? Why is this activity only asimulation? (Hint: consider the major forces the marbles represent.)

Lesson 11 � Changes Inside PlanetsNASA EG-1997-08-104-HQ 11.1


Lesson 11 � Changes Inside Planets“Howdid theyform?”Objectives

Students will:

• observe and describe differentiated meteorite samples.

• conduct experiments to model the separation of light andheavy materials within a planetary body.

• relate meteorites to the core, mantle and crust of asteroids.

• model the break-up of a differentiated body to expose theinterior layers.

BackgroundAchondrites are stony meteorites without chondrules or metal. Metal-rich meteorites include irons with little stony material and stony-irons which are part iron and part stone. Most of these meteoritesare, like chondrites, 4.5 billion years old. However, their compositionsare usually different from those of chondrites and different from theSun. Thus, they are grouped together as differentiated meteorites.There are three of these differentiated meteorites in the MeteoriteSample Disk. One of the meteorites is an achondrite consistingmostly of two silicate minerals. It is a basalt similar to basaltsexisting on Earth. The second sample is a metal meteorite made oftwo types of iron/nickel crystals. The third sample is a stony-ironmeteorite made of metal and a single silicate mineral, olivine. SeeTeacher’s Guide, pages 13-17, for more information.

Scientists think that these meteorites formed by differentiationin asteroids or other planetary bodies. Heat in the asteroidcaused the body to melt. Heavy metal sank to the interiorto form a core. Light silicate minerals floated to thesurface to form the crust. Moderate density silicatescrystallized in the mantle. Basalts can also form byincomplete melting in the mantle of a planetary bodyand rise to the surface as volcanic rocks.

Earth is differentiated into core, mantle and crust, but wecannot see the mantle or core. Researchers believe thatthose inner layers exist because differences in the internalstructure of Earth have been measured using seismic waves.Scientists think that iron meteorites are from the cores of aster-oids and some stony-iron meteorites are from the core-mantle

About This LessonIn this lesson students willobserve and describedifferentiated samples in theMeteorite Sample Disk (orphotographs). They willconduct an experiment usinggelatin and food thatillustrates planetarydifferentiation. Hard boiledeggs model the break-up ofdifferentiated planetary bod-ies.

Vocabularyachondrite, iron, stony iron,asteroid, metal, silicate,crystallization, differentiation,crust, mantle, core, basalt,density

b o u n d ar y. A c h o n drit es m a y r e pr es e nt t h e cr ust al m at eri al ofast er oi ds. I n or d er f or t h e d e e p-s e at e d r o c ks fr o m t h e c or e a n dm a ntl e t o b e e x p os e d, i m p a cts i n t h e ast er oi d b elt m ust br e a k u p t h ep ar e nt ast er oi ds.


• o bs er v e a n d d es cri b e diff er e nti at e d m et e orit es.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. Ass e m bl e m at eri als.2. Pl a c e M et e orit e S a m pl e Dis k or p h ot o gr a p hs i n a n e asil y

a c c essi bl e l o c ati o n s o st u d e nts m a y vi e w a n d dr a w s a m pl es.3. Pr e vi e w sli d e s et, sli d e n arr ati v e, a n d d es cri pti o ns of

m et e orit es i n t h e M et e orit e A B C’s F a ct S h e et, p a g es 2 9- 3 0.

Cl assr o o m Pr o c e d ur e1. S h o w sli d e s et a n d dis c uss m et e orit e cl assifi c ati o n.2. E x a mi n e a c h o n drit e, st o n y-ir o n, a n d ir o n i n M et e orit e

S a m pl e Dis k or p h ot o gr a p hs. Us e m a g nifi er or mi cr os c o p e.3. O n t h e St u d e nt S h e et, s k et c h a n d d es cri b e e a c h of t h e s a m pl es

list e d a b o v e.4. C o m pl et e t h e q u esti o ns o n t h e St u d e nt S h e et.5. R es er v e dis c ussi o n u ntil aft er A cti vit y B.

A b o ut T his A cti vit ySt u d e nts will o bs er v e a n dd es cri b e diff er e nti at e dm et e orit es i n t h e M et e orit eS a m pl e Dis k or i n t h ep h ot o gr a p hs.

M a t e ri als fo r A cti vit y A❑ M et e orit e S a m pl e Dis k or

p h ot o gr a p hs❑ St u d e nt S h e et ( p g. 1 1. 5)❑ m a g nifi er❑ bi n o c ul ar mi cr os c o p e

( o pti o n al)❑ Sli d e S et, Cl assifi c ati o n a n d

F or m ati o n❑ pr oj e ct or

cr u st


• c o n d u ct e x p eri m e nts t o m o d el t h e s e p ar ati o n of li g ht a n dh e a v y m at eri als wit hi n a pl a n et ar y b o d y.

• r el at e m et e orit es t o t h e c or e, m a ntl e, a n d cr ust of ast er oi ds.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n ( S e e o pti o ns b el o w.)1. R e a d cl assr o o m pr o c e d ur e a n d o pti o ns t o d et er mi n e b est

m et h o d f or cl ass.2. Ass e m bl e m at eri als. Eit h er t e a c h er will pr o vi d e n e c ess ar y

f o o ds f or e x p eri m e nts or assi g n st u d e nts t o bri n g it e ms. B es ur e t o pr o vi d e s e v er al it e ms t h at fl o at a n d s e v er al t h at si n k.Us e it e ms t h at m a y b e e at e n t o mi ni mi z e w ast e, a n d i n cr e as ee nj o y m e nt.O pti o n 1. W or ki n g i n gr o u ps e a c h st u d e nt m a k es pr e di cti o ns

a n d e x p eri m e nts wit h t h eir o w n c u p of f o o d a n d g el ati n.S e e Cl assr o o m Pr o c e d ur e.

O pti o n 2. Pri or t o cl ass m a k e a m o d el(s) f or st u d e nts t o us e.T h e pr e di cti o ns a n d o bs er v ati o ns m a y still b e m a d e b yt h e st u d e nts pri or t o vi e wi n g t h e m o d el. St u d e nt S h e etq u esti o ns, dr a wi n gs a n d dis c ussi o ns m a y b e us e d t oc o m pl et e t h e a cti vit y.

O pti o n 3. C o n d u ct e x p eri m e nt b y h a vi n g st u d e nts m a k epr e di cti o ns a n d r e c or d i nf or m ati o n a n d o bs er v ati o ns.T h e n m a k e o nl y o n e or p ossi bl y t w o l ar g e s a m pl es as ad e m o nstr ati o n f or t h e e ntir e cl ass. C o nti n u e wit hSt u d e nt S h e et q u esti o ns a n d dis c ussi o n.

Cl assr o o m Pr o c e d ur e1. Di vi d e cl ass i nt o gr o u ps of t hr e e t o fi v e st u d e nts. Distri b ut e

St u d e nt S h e ets a n dm at eri als.

2. C o n d u ct e x p eri m e ntsa c c or di n g t o t h epr o c e d ur e o n St u d e nt S h e et

3. A ns w er q u esti o ns a n d s k et c he x p eri m e nt al r es ults. H a v egr o u ps r e p ort fi n di n gs.

4. C o n d u ct a dis c ussi o n b as e d o nq u esti o ns o n t h e St u d e nt S h e et. R el at e l a y ers —i n t h ee x p eri m e nt t o diff er e nti ati o n i n a n ast er oi d or pl a n et.

M a t e ri als fo r A cti vit y BP e r G r o u p of St u d e nts,e x c e pt w h er e n ot e d.❑ 1 b o x of li g ht c ol or e d

g el ati n d ess ert ( y ell o ws h o ws pr o c ess cl e arl y)

❑ m etri c m e as uri n g c u p f orli q ui ds

❑ b o wl❑ mi xi n g s p o o n❑ 2 7 0 ml ( 9 o z.) cl e ar pl asti c

c u ps ( o n e p er st u d e nt)❑ 4 7 0 ml ( 2 c u ps) b oili n g

w at er (t his k e e ps g el ati nh ot f or a l o n g er ti m e)

❑ h e ati n g s o ur c e f or w at er(t e a k ettl e, h ot pl at e ormi cr o w a v e i n c e ntr all o c ati o n)

❑ p e n or p e n cil❑ St u d e nt S h e et ( p gs. 1 1. 5- 1 1. 7,

o n e p er st u d e nt)❑ f o o d it e ms t h at si n k *

r aisi ns, fr es h gr a p es, or a n g esli c es, c a n n e d p e a c h es,p e ars, pi n e a p pl e, * * oli v es

❑ f o o d it e ms t h at fl o at*m ars h m all o ws, p e a n uts,fr es h a p pl es, b a n a n as, p e ars

*t e m p er at ur e of g el ati n m a y c a us es o m e f o o ds t o c h a n g e si n ki n ga n d fl o ati n g b e h a vi or.

* * c a n n e d mi x e d fr uit i n li g ht s yr u pfl o ats, b ut mi x e d fr uit i n h e a v ys yr u p si n ks.

A b o ut T his A cti vit ySt u d e nts will c o n d u cte x p eri m e nts wit h f o o d i ng el ati n t o si m ul at e t h ediff er e nti ati o n of pl a n et ar yb o di es i nt o a c or e, m a ntl e, a n dcr ust.


• r el at e m et e orit es t o t h e c or e, m a ntl e a n d cr ust of ast er oi ds.

• m o d el t h e br e a k- u p of a diff er e nti at e d b o d y t o e x p os e t h ei nt eri or l a y ers.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. B oil e g gs, t h e n fr e e z e e g gs usi n g o n e of t h e f oll o wi n g

m et h o ds. D o n ot fr e e z e l o n g er t h a n s u g g est e d or t h e t e xt ur ewill n ot b e i d e al. Fr e e zi n g m et h o ds:• 1 0- 1 5 mi n ut es i n or o n dr y i c e ( d e p e n ds o n n u m b er of

e g gs fr o z e n at o n e ti m e). Pr ef err e d m et h o d.• 2 mi n ut es i n li q ui d nitr o g e n ( o n e e g g at a ti m e). I d e al,

b ut diffi c ult m et h o d.• 4 8 h o urs i n fr e e z er. Si m pl est m et h o d, b ut l e ast s atisf a ct or y.

Us e p r o p e r l a b s af et y p r e c a uti o ns!! Al w a ys h a n dl e dr y i c e, ors o m et hi n g fr o z e n b y dr y i c e, wit h t h er m al pr ot e cti o n gl o v es.L a b a pr o n, f a c e pr ot e cti o n, a n d t h er m al pr ot e cti o n gl o v e sm ust b e w or n w h e n usi n g li q ui d nitr o g e n or s o m et hi n gfr o z e n b y li q ui d nitr o g e n. C o ns ult t h e M at eri als S af et y D at aS h e et f or f ull s af et y pr e c a uti o ns.

2. C h o os e a h ar d s urf a c e li k e a c o n cr et e dri v e w a y w h er e e g gsm a y b e br o k e n, a n d cl e a n- u p will n ot b e diffi c ult. O RC h o os e a n ar e a of w all a w a y fr o m wi n d o ws a n d d o ors w h er et h e c o n cr et e fl o or m e ets t h e si d e of a b uil di n g.Ta p e a pl asti c t ar p s e c ur el y t o t h e w all. M a k e s ur e t h at p artof t h e c o v er e xt e n ds t o c o v er t h e gr o u n d. ( T his m a k es cl e a nu p m or e effi ci e nt.)

Cl assr o o m Pr o c e d ur e1. S af et y g o g gl es a n d t h e r m al p r ot e cti v e gl o v e s

s h o ul d b e w o r n.2. Wit h cl ass m at es at a s af e dist a n c e, o n e st u d e nt t hr o ws a

fr o z e n, h ar d b oil e d e g g at t h e d esi g n at e d ar e a (r e p e at if itd o es n ot br e a k t h e first ti m e). R e p e at wit h ot h er e g gs.

3. Usi n g St u d e nt S h e et, all st u d e nts writ e o bs er v ati o ns a n dill ustr at e t h e br o k e n e g g, l a b eli n g t h e cr ust, c or e a n d m a ntl e.

4. Us e q u esti o ns t o f o c us dis c ussi o n a n d r el at e br o k e n pi e c es t om et e orit e t y p es.

A b o ut T his A cti vit ySt u d e nts will dis c o v er, b ys m as hi n g h ar d- b oil e d e g gs,h o w i m p a cts br e a k u p adiff er e nti at e d b o d y s o t h at t h ec or e a n d m a ntl e ar e e x p os e d.T h e y will r el at e t h e m et e orit esi n t h e M et e orit e S a m pl e Dis kt o p arts of a diff er e nti at e db o d y.

M a t e ri als fo r A cti vit y C❑ fr o z e n h ar d b oil e d e g g ( o n e

p er st u d e nt if p ossi bl e —st or es m a y d o n at e o ut ofd at e e g gs — w asti n g f o o dis n ot t h e o bj e cti v e of t hise x er cis e)

❑ dr y i c e ( e asil y o bt ai n a bl e ats o m e gr o c er y a n d i c ec r e a m st or es)

❑ pi c ni c c o ol er t o h ol d dr y i c e❑ s af et y g o g gl es❑ t h er m al pr ot e cti v e gl o v e s❑ l a b a pr o n❑ li q ui d nitr o g e n a n d

c o nt ai n er ( o pti o n al)❑ St u d e nt S h e et ( p g. 1 1. 8)❑ l ar g e pl asti c t ar p

a p pr o xi m at el y 4 m x 4 m❑ d u ct t a p e❑ w all❑ br o o m❑ w ast e c o nt ai n er

C ar ef ull y o bs er v e t h e a c h o n drit e, ir o n, a n d st o n y-ir o n s a m pl es i n t h e M et e orit e S a m pl eDis k or p h ot o gr a p hs. D es cri b e a n d s k et c h t h e m usi n g t h e s p a c e b el o w.

H o w d o y o u t hi n k t h es e m et e orit es f or m e d ?

M a t e ri als P e r G r o u p of St u d e nts ( e x c e pt w h er e n ot e d)❑ 1 b o x of li g ht c ol or e d g el ati n d ess ert ❑ 2 7 0 ml ( 9 o z.) cl e ar pl asti c c u ps ( o n e p er st u d e nt)❑ m etri c m e as uri n g c u p f or li q ui ds ❑ 4 7 0 ml ( 2 c u ps) b oili n g w at er❑ b o wl ❑ f o o d it e ms❑ mi xi n g s p o o n ❑ St u d e nt S h e et a n d p e n cil ( o n e p er st u d e nt)

P r o c e d u r e1. Gr o u ps c oll e ct m at eri als f or e x p eri m e nt (s e e list a b o v e).2. E a c h gr o u p m e m b er will pr e di ct a n d r e c or d i nf or m ati o n b el o w.

• E a c h m e m b er will s el e ct t w o f o o d it e ms: o n e y o u pr e di ct will si n k a n do n e y o u pr e di ct will fl o at. M a k e s ur e y o ur gr o u p us es a v ari et y of f o o d it e ms.

• R e c or d pr e di cti o ns. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ will fl o at i n g el ati n _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ will si n k i n g el ati n

• E a c h m e m b er pl a c e a s p o o nf ul or l ess of b ot h f o o d it e ms i n y o ur i n di vi d u alpl asti c c u p.

Lesson 11 � Changes Inside Planets11.6 NASA EG-1997-08-104-HQ

3. The teacher, or a group member, will mix gelatin and 470 ml (2 cups) ofboiling water in the bowl. Using all boiling water will keep the gelatin hotfor all team members. Stir gelatin until powder is dissolved.

4. Carefully pour gelatin into each cup, filling about 2/3 full. Do not stir.5. Observe and record movement of food in gelatin.6. In your group discuss the results and draw conclusions. Discussion should

include consistency of sinking and floating and why items sink or float.7. Answer questions below.8. Using the information from the Student Sheets, one group member shares the

group’s findings with the class. Discuss results.9. Allow gelatin to harden. Observe and record any changes. Eat the results.

Questions1. Describe the gelatin cup in your own words. Sketch and label your

experimental results.

2. How do you think the different layers formed?

3. Could the same layers occur in a different order? Why or why not?

Lesson 11 � Changes Inside PlanetsNASA EG-1997-08-104-HQ 11.7

Lesson 11 � Student Sheet continued

4. Why did you choose the particular foods in your experiement? Have you everhad an experience with this food and its floating properties before? Describe.

5. Were some foods used by your group not consistent in their floatingbehavior? Why do you think this happened?

Could you change the conditions to make the floating more consistent?

6. Compare what happened in the gelatin experiments with the core, mantle andcrust of differentiated planetary bodies like Earth. Be sure to discuss whichparts of the gelatin represent parts of Earth.

7. Which meteorites in the Meteorite Sample Disk relate to each of the gelatinlayers?

Lesson 11 � Changes Inside Planets11.8 NASA EG-1997-08-104-HQ

Activity C: Egg Smash

Questions

1. What parts of a differentiated asteroid do the yolk, egg white, and shell represent?Sketch and label an egg and include the comparable planetary layers.

2. How is the core or the inside of a differentiated asteroid exposed?

3. If you wanted to study the metal in an asteroid, which section of the asteroidwould you study?

4. How are Earth and an achondrite asteroid alike? Different?

Lesson 12 � Building Blocks of LifeNASA EG-1997-08-104-HQ 12.1


Lesson 12 � Building Blocks of Life“Howdid theyform?”Objectives

Students will:

• recognize that carbonaceous chondrite meteorites containamino acids, the first step towards living plants and animals.

• conduct experiments that simulate how the carbon materialand water from carbonaceous chondrites may have helpedearly life on Earth.

BackgroundPeople have repeatedly asked the questions “How did life begin?” and“Are we alone in the universe?”. The exploration of our solar system hasshown that Earth is the only body currently capable of supporting surfacelife. However, there is fascinating evidence that other bodies may havebeen habitable in the past or below the surface. Mars may once havebeen capable of supporting surface life. In places on Mars wherevolcanic and impact heat interacted with water, hot springs may haveformed. On Earth thermal springs harbor microbial life. Mars may stillbe capable of supporting simple life in subsurface groundwater, ice, orcracks in rocks. Scientists have found intriguing evidence that may befossil bacteria in cracks in an ancient martian meteorite, but that interpre-tation is still hotly debated. Other habitable environments might include apossible liquid ocean under the ice of Jupiter’s moon, Europa, or someof the newly discovered planets around other stars. If conditions wereright, could life have developed elsewhere? Meteorites provide theevidence that the building blocks of life were available to other worlds.

Carbonaceous chondrites contain the two essential components for life,water and complex carbon compounds. Some of the carboncompounds are amino acids, the building blocks of DNA molecules,which contain hereditary information for all life on Earth. Detailed studiesof the amino acids in meteorites show that they were not formed by livingthings. This means that inorganic processes in the solar nebula, or laterwithin the rock itself, were able to make complex carbon compoundsfrom simple molecules containing carbon, hydrogen, oxygen, and nitro-gen. Carbonaceous chondrites may have delivered these building blocksof life to various bodies in the solar system. Some scientists believe thatthe beginnings of life on Earth partially depended upon availability ofwater and carbon compounds from carbonaceous chondrites. Thesematerials would certainly also have been delivered to early Mars.

About This LessonThe team activities in thislesson explore the importantmaterials carbonaceouschondrites brought to Earth.A jumbled letter activity leadsstudents to look at the aminoacids found incarbonaceous chondrites asthe building blocks of life.Students also experiment withgrowing yeast inmediums that representcarbonaceous chondritematerial.

Vocabularyamino acids, DNA, carbon,carbonaceous chondrites


• r e c o g ni z e t h at c ar b o n a c e o us c h o n drit e m et e orit es c o nt ai na mi n o a ci ds, t h e first st e p t o w ar ds li vi n g pl a nts a n d a ni m als.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. Pr e p ar e o n e e n v el o p e f or e a c h cl assr o o m t e a m. E n v el o p es

s h o ul d e a c h h a v e t h e l ett er s n e c ess ar y t o s p ell “ a mi n o a ci ds ”a n d a n a p pr o pri at e n u m b er of a d diti o n al l ett ers t o c h all e n g et h e st u d e nts.

S u g g est e d l ett e r g r o u pi n gs:# 1 - a mi n o a ci ds b e g hl m n ust# 2 - a mi n o a ci ds a bffj kl m mr# 3 - a mi n o a ci ds cfij o p prrt y# 4 - a mi n o a ci ds c d e e hjl o or# 5 - a mi n o a ci ds d gi klls u w z# 6 - a mi n o a ci ds d e g gj mrt u y# 7 - a mi n o a ci ds a c e gi m n n qt# 8 - a mi n o a ci ds cffill n p p u

F or m or e a d v a n c e d st u d e nts us e t h e n a m es ofi n di vi d u al a mi n o a ci ds.Gl y ci n e, Al a ni n e, Vali n e, L e u ci n e, Is ol e u ci n e, S eri n e, C yst ei n e,C ysti n e, As p arti c A ci d, As p ar a gi n e, T hr e o ni n e, M et hi o ni n e,Gl ut a mi c A ci d, Gl ut a mi n e, Pr oli n e, L ysi n e, Ar gi ni n e, Histi di n e,Tr y pt o p h a n, P h e n yl al a ni n e Tr y osi n e

2. T h e a cti vit y m a y b e si m plifi e d b yusi n g o n e c ol or f or t h e l ett ers t h at

s p ell “ a mi n o ” a n d a n ot h er c ol or f or“ a ci ds ” a n d diff er e nt c ol ors f or t h ee xtr a l ett ers. N o t w o c oll e cti o ns

s h o ul d b e t h e s a m e i n c ol or orl ett ers.

3. C o p y St u d e nt S h e et.4. R e vi e w t h e l ess o n b a c k gr o u n d.

A b o ut T his A cti vit ySt u d e nt t e a ms tr y t o dis c o v ert h e hi d d e n w or ds “ a mi n oa ci ds ” usi n g c ut o ut, j u m bl e dl ett ers. T h e y pr o gr ess t o t h ea n al o g y t h at j ust as t h e l ett ersar e ess e nti al t o “ b uil di n g ”w or ds s o ar e a mi n o a ci ds,f o u n d i n c ar b o n a c e o us c h o n-drit es, ess e nti al as b uil di n gbl o c ks of lif e.

M a t e ri als fo r A cti vit y A❑ i n di vi d u al l ett er s ets f or

e a c h t e a m ( pr ess c ut- o uts,et c.) s e e A d v a n c e d Pr e p a-r ati o n

❑ e n v el o p es l ar g e e n o u g h t oh ol d a p pr o xi m at el y 2 0l ett ers ( 1 p er t e a m)

❑ p a p er a n d p e n cil f or e a c ht e a m

❑ St u d e nt S h e et ( p g. 1 2. 5)


Classroom Procedure1. Divide class into teams and distribute envelopes with letters.2. Using the letters, teams list words they can think of that

could be made if just one more letter was available.3. Teams spell words using the letters in the envelopes.

A team recorder writes all words discovered.Note: Teacher should monitor the progress being made.

After appropriate “wait” times, teams will be instructed toprogress through the remaining procedural steps.

4. Teams compare letters with a nearby team. At teacher’ssignal, sharing teams will compare with other teams, seekingcommon letters and words.

5. Exercise continues until students discover the term “aminoacids,” with or without teacher intervention.

Intervention “Hints” from broad to narrow:• “Do teams near you have any of the same letters?”• “You’re looking for two words.”• “Both words begin with the letter a.”• “The words are associated with carbonaceous

chondrites.”• “The words represent something important to life.”• “Here are the blanks to play Hang Man. What letters are

common to all teams?”

6. Distribute Student Sheet.7. Teacher leads a discussion based on the lesson background

information and the questions on Student Sheet. Stress thecomparison of letters as building blocks of words to aminoacids as building blocks of life.

a mn

oi

a c id

A b o ut T his A cti vit ySt u d e nts m o d el t h e eff e cts ofm et e orit es bri n gi n g w at er a n dc ar b o n a c e o us m at eri al t oE art h. T h e y e x p eri m e nt wit hgr o wi n g y e ast i n m e di u mst h at r e pr es e nt c ar b o n a c e o usm et e orit e m at eri al.


• c o n d u ct e x p eri m e nts t h at si m ul at e h o w t h e c ar b o n m at eri ala n d w at er fr o m c ar b o n a c e o us c h o n drit es m a y h a v e h el p e de arl y lif e o n E art h.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. G at h er e q ui p m e nt.2. C o p y St u d e nt S h e et.

Cl assr o o m Pr o c e d ur e1. St u d e nts g at h er m at eri als.2. M e as ur e 1/ 2 p a c k a g e of y e ast i nt o b ot h c o nt ai n ers.3. A d d 0. 1 0 lit er w ar m w at er t o e a c h c o nt ai n er a n d stir.4. A d d cr us h e d c o o ki es t o o n e c o nt ai n er a n d stir.5. L e a v e b ot h c o nt ai n ers i n a w ar m pl a c e.6. Pr e di ct w h at will h a p p e n i n e a c h c o nt ai n er.7. O bs er v e h o w b ot h b at c h es of y e ast r e a ct a n d gr o w.8. C o n d u ct cl ass dis c ussi o n o n t h e eff e cts of a d di n g w at er or

b ot h w at er a n d c ar b o n c o m p o u n ds.9. C o m pl et e t h e q u esti o ns o n t h e St u d e nt S h e et.

M a t e ri als fo r A cti vit y BP e r S m all G r o u p o r Cl ass❑ 1 p a c k a g e b a k ers’ y e ast❑ 0. 2 0 lit er w ar m w at er

( 1 1 0 ° F/ 4 3. 3 ° C)❑ 3- 4 cr us h e d c h o c ol at e

s n a ps ( or ot h erc ar b o h y dr at e i. e., s u g ar)

❑ m e as uri n g c o nt ai n er❑ l ar g e s p o o n❑ 2 l ar g e cl e ar c o nt ai n ers

(lit er j ars)❑ t h er m o m et er❑ St u d e nt S h e et ( p g. 1 2. 6,

p er st u d e nt)


O

Questions1. What are some words you could have made if you had been given just one more

letter.

2. What are some of the words you were able to make with your letters?

3. Fill in the blanks: We could not have spelled _____ ___ if ourenvelope had not contained the letter “_ _”?

4. Extra: How are amino acids the building blocks of life?

5. Extra: What is the significance of the discovery of amino acids in carbonaceouschondrite meteorites?

Lesson 12 � Building Blocks of Life

Student Sheet: Activity A

AT

MN

S

DKL B

I

P r o c e d u r e1. G at h er e q ui p m e nt2. M e as ur e 1/ 2 p a c k a g e of y e ast i nt o b ot h c o nt ai n ers.3. A d d 0. 1 0 lit er w ar m w at er t o e a c h c o nt ai n er a n d stir.4. A d d cr us h e d c o o ki es t o o n e c o nt ai n er a n d stir.5. L e a v e b ot h c o nt ai n ers i n a w ar m pl a c e.6. Pr e di ct w h at will h a p p e n i n e a c h c o nt ai n er.7. O bs er v e h o w b ot h b at c h es of y e ast r e a ct a n d gr o w.

R e c or d b el o w.8. P arti ci p at e i n cl ass dis c ussi o n o n t h e eff e cts of a d di n g w at er

or b ot h w at er a n d c ar b o n c o m p o u n ds.9. C o m pl et e t h e q u esti o ns b el o w.

P r e di cti o n

M at e ri als❑ 1 p a c k a g e b a k er’s y e ast❑ 0. 2 lit er w ar m w at er ( 1 1 0 ° F/ 4 3. 3 ° C)❑ 3- 4 cr us h e d c o o ki es or s u bstit ut e

c ar b o h y dr at e❑ m e as uri n g c o nt ai n er❑ l ar g e s p o o n❑ 2 l ar g e cl e ar c o nt ai n ers❑ t h er m o m et er

Q u e sti o n s

1. S k et c h a cl os e- u p vi e w of t h e r es ults of y o ur e x p eri m e nt.

2. H o w ar e t h e m at eri als i n t his a cti vit y si mil ar t o c ar b o n a c e o us m et e orit es a n d h o war e t h e y diff er e nt ?

3. H o w di d c ar b o n a c e o us m et e orit es c o ntri b ut e t o m a ki n g lif e p ossi bl e o n E art h ?

4. E xt r a: T his e x p eri m e nt w as d esi g n e d t o r efl e ct h o w m et e orit es c o ntri b ut e d t oc o n diti o ns t h at pr o m ot e d lif e o n E art h! H o w is t h e e x p eri m e nt si mil ar a n d h o wis it diff er e nt ?

?O bjecti v esSt u d e nts will:

• c o n d u ct a n i n v esti g ati o n.

• o bs er v e a n d r e c or d t h e p h ysi c al c h ar a ct eristi cs of a nu n k n o w n r o c k ( m et e orit e).

• d et er mi n e t h e m ass of t h e u n k n o w n r o c k usi n g m at h s killst o tr a c k s a m pl e c hi ps.

• d et er mi n e t h e d e nsit y of a r o c k.

• d es cri b e a n d cl assif y a m et e orit e.

• a p pl y o bs er v ati o ns a n d k n o wl e d g e t o t h e pr o c ess of as ci e ntifi c i n v esti g ati o n.

• pr es e nt e vi d e n c e t o v erif y cl assifi c ati o n d e cisi o ns.

• e x pl or e c o n c e pts of s p ati al r el ati o ns hi ps.

L ess o n St r u ct u r e ( All p arts A- D ar e n e c ess ar y f or c o m pl eti o n.)F o ur p h ot o gr a p hs pr o vi d e t h e e vi d e n c e f or t h e st u d e nts’i n v esti g ati o ns. T h e g o al is t o g at h er e n o u g h i nf or m ati o n t o i d e ntif yt h e u n k n o w n r o c k i n t h e p h ot o gr a p h. At e a c h st e p t h e st u d e nts willc h e c k w h et h er t h er e is e n o u g h d at a t o i d e ntif y t h e u n k n o w n, or atl e ast eli mi n at e s o m e of t h e p ossi biliti es.

P a rt A. L o o ki n g f o r Cl u es— St art i n v esti g ati o n of u n k n o w n b y o bs er vi n g t h e r o c k i n

Lit h o gr a p h I.— E m p h asis is o n d es cri bi n g c ol or, t e xt ur e, a n d s h a p e.— Us e Lit h o gr a p h II t o vi e w fr o m a diff er e nt p ers p e cti v e.O pti o n al— C o nstr u ct p a p er c u b e a n d us e a di e t o d e v el o p

u n d erst a n di n g of s p ati al r el ati o ns hi ps.— M a ni p ul at e t h e ori e nt ati o n c u b e us e d wit h m et e orit e

s a m pl es t o u n d erst a n d w h y it is i m p ort a nt.

P a rt B. Vit al St atisti cs— M e as ur e t h e di m e nsi o ns of t h e u n k n o w n ( Lit h o gr a p h I

a n d II).— D et er mi n e t h e d e nsit y of t h e r o c k.

A b o ut T his L ess o nT his is a c ul mi n ati n g l ess o n i nf o ur p arts. It is d esi g n e d t of oll o w m et e orit e i d e ntifi c ati o na cti viti es. A mi ni m u m s e-q u e n c e is L ess o ns 1, 8, 9, 1 0,1 1, a n d 1 3. It w o ul d als o b eus ef ul aft er g e ol o gi c s a m pl ei d e ntifi c ati o n a cti viti es. T h eg o al f or t h e cl ass is t o g at h ere n o u g h i nf or m ati o n t o i d e ntif yt h e u n k n o w n r o c k. T his willb e a c c o m plis h e d b y usi n gp h ot o gr a p hs t o o bs er v e,d es cri b e, m e as ur e, ill ustr at e,a n d cl assif y t h e “ u n k n o w n ”( N o bl es vill e m et e orit e).S ci e ntifi c i d e ntifi c ati o npr o c ess es will b e si m ul at e d.As t h e cl ass pr o gr ess est hr o u g h e a c h st e p of t h ea cti vit y t h e y will b e as k e d“ W h at w o ul d b e y o ur n e xtst e p t o cl assif y t his r o c k ? ”.T h e t e a c h er will l e a d t h est u d e nts t o r e c o g ni z e t h e n e e df or a d diti o n al, us u all y m or ed et ail e d, i nf or m ati o n. Str esst h at e v e n t h o u g h t h e y m a yg u ess or h a v e a “ h u n c h ” w h att h e u n k n o w n is ( a m et e orit e),t h e y m ust p r es e nt e vi d e n c et o v e rif y t h ei r d e cisi o ns. S e e“ Hi nts ” t hr o u g h o ut t h epr o c e d ur e.

“ H o wdi d t h e yf or m ? ”

Lesson 13 � Solving a Mystery13.2 NASA EG-1997-08-104-HQ

Part C. Narrowing the Suspect List — Observe the interior of the rock in detail (Lithograph III).

Part D. Nabbing the Culprit— Use a microscope photo of a thin section of the rock to complete the

identification (Lithograph IV).

Background (See also Lesson 1)After Brodie Spaulding and Brian Kenzie observed the fall of the

Noblesville meteorite, they sent the specimen to astronomer Dr.Solomon Gartenhaus at Purdue University for classification and study.

Dr. Gartenhaus contacted Purdue meteoriticist Dr. Michael Lipschutz wholed a group of scientists to study the meteorite. He arranged for curation at

the National Aeronautics and Space Administration’s Johnson Space Center(NASA-JSC). The meteorite was sent to NASA for initial description and

classification by the curators at the lab. The curators photographed, weighed,measured, and described the meteorite, then took 20 grams of chips for further scientific study. Onechip was used to prepare thin sections for mineral analysis and microscopic textural observations.They found that Noblesville is a meteorite breccia consisting of numerous large white clasts in a darkgray matrix.

Abundant metal and a few small chondrules can be seen in the specimen, showing that it is a metal-rich chondrite. Mineral analyses confirmed the high-iron nature of both clasts and matrix and showedthat the clasts are highly metamorphosed, while the matrix is only slightly metamorphosed. This typeof chondrite breccia is rare. It is a regolith breccia similar to some lunar breccias. The curators alsosent chips of the meteorite to several geochemists for elemental and isotopic analyses. These scientistsfound that Noblesville is rich in gases deposited by the solar wind.

Vocabularyastronomer, attrition, breccia, chondrite, chondrule, classification, clast, curation, curator, density,fusion crust, geochemist, isotope, matrix, metal, metamorphic, meteoriticist, regmaglypt

Advanced Preparation1. Be familiar with background information and comfortable with vocabulary (see glossary).2. Assemble all materials and be very familiar with the order in which they will be used.3. If only one original set of photographs is available, good photo copies will work. Use copies

for the groups and display originals for consultations.


• o bs er v e a n d r e c or d i nf or m ati o n fr o m cl os e e x a mi n ati o n oft w o p h ot o gr a p hs of t h e u n k n o w n r o c k.

P r o c e d u r e - St e p 1S u g g est e d i ntr o d u cti o n t o b e us e d b y t e a c h er:

H a v e y o u e v er b e e n c o nfr o nt e d wit h a r e al m yst er y ?— S o m e o n e h as writt e n a n a n o n y m o us l o v e n ot e t o y o u,

a n d y o u c a n’t fi g ur e o ut w h o it is!— S o m et hi n g h as dis a p p e ar e d a n d y o u K N O W it w as

t h er e a mi n ut e b ef or e.— Y o u’ v e f o u n d s o m et hi n g w eir d a n d y o u c a n’t fi g ur e o ut

w h at it is or w h er e it c a m e fr o m.S o m e pr of essi o n als s p e n d t h eir e ntir e c ar e ers s ol vi n gm yst eri es f or p e o pl e. T HI S ti m e, Y O U will b e t h ei nv esti g at ors.

1. Di vi d e cl ass i nt o gr o u ps of 3- 5 st u d e nts.2. St u d e nts e x a mi n e Lit h o gr a p h I as a gr o u p a n d usi n g t h e

Te a m D at a S h e et writ e i n di vi d u al d es cri pti o ns of t h e r o c k.I n cl u d e s h a p e, c ol or, t e xt ur e, a n d h y p ot h esi z e as t o itsi d e ntit y. All o w st u d e nts t o c h e c k ori gi n al c ol or p h ot o ift h e y ar e usi n g p h ot o c o pi es.

3. St u d e nts m a y s h ar e d es cri pti o ns a n d h y p ot h es es.4. S oli cit i d e as f or f urt h er i n v esti g ati o n a n d l e a d st u d e nts t o

r e c o g ni z e t h e n e e d f or m or e i nf or m ati o n — a pi ct ur e oft h e r o c k fr o m a diff er e nt p ers p e cti v e.

Hi nt: St u d e nts m a y as k f or t h e a ct u al r o c k. P oi nt o ut t h atpri v at e i n v esti g at ors oft e n s e ar c h f or missi n g p ers o ns a n dh a v e o nl y a p h ot o gr a p h f or t h eir first cl u e.

P r o c e d u r e - St e p 21. E x a mi n e Lit h o gr a p h II. St u d e nts r e c or d si mil ariti es a n d

diff er e n c es of t h e t w o p h ot o gr a p hs ( Lit h os I a n d II) o n t h eTe a m D at a S h e et. F o c us o n bi g r o c k, n ot s m all pi e c es.

M a t e ri als fo r P a r ts A- DP e r G r o u p of St u d e nts

N ot e: M at eri als s h o ul d b edistri b ut e d as n e e d e d f ore a c h st e p of t h ei n v esti g ati o n.

❑ Lit h o gra p h S et ( Lit h o gr a p hsI-I V s h o w 4 p h ot o gr a p hs ofN o bl es vill e m et e orit e)

❑ Lit h o gr a p h c o pi es if n e e d e d❑ S us p e ct List, p g. 1 3. 1 5,

( us e d i n P arts C a n d D)❑ Te a m D at a S h e et, p gs.

1 3. 1 3- 1 3. 1 4, ( p er st u d e nt)❑ M et e orit e A B C’s F a ct

S h e et ( p gs 2 9- 3 0)( us e d i n P art D)

❑ N A S A J S C N ot es -E xt e n d e d C o m m e nts( p g. 1 3. 1 1)

❑ i n di vi d u al writi n g m at eri als❑ p a p er cli ps❑ tr a ns p ar e n c y or si mil ar

pl asti c s h e et❑ tr a ns p ar e n c y m ar k er❑ m etri c r ul er❑ o n e o v er h e a d pr oj e ct or f or

cl ass❑ si n gl e di e - o pti o n al❑ p att er ns f or ori e nt ati o n

c u b es f or e a c h st u d e nt -o pti o n al ( p g. 1 3. 1 2)

❑ siss ors❑ gl u e

A b o ut P a r t ASt u d e nts will st art t h eiri n v esti g ati o n b y o bs er vi n gt h e r o c k i n p h ot o gr a p hs.


Hint: Two photographs of the same person often look like different people. A different per-spective can make a big difference.

2. Allow students to discuss comparisons, and reveal all evidence they have observed.

Hint: Exterior “coat” which could be fusion crust should be identified by this point; therefore, this rock “may be a meteorite.” Since they have presumably been studyingmeteorites this is a logical step since hypotheses come from evidence coupled with priorknowledge. But they must present evidence!

Looking for Extra Clues Optional Extension (use after Part A)

ObjectiveStudents will:

• explore concepts of spatial relationships.

ProcedureSuggested introduction:

Just as an investigator might start off with a photograph of a missing person, we have twophotographs of an unidentified rock. Is there anything else in either photograph thatmight provide additional clues about this rock? (Lead class to notice orientation cube ifnecessary.) What do you think the little block is? (Point out letters. Solicit comments.)

Sometimes investigators make simulations of items they can see in photographs. I havesome patterns to make cubes. If we experiment, maybe we can figure out why cubes arein both of the pictures?

1. Distribute individual cube pattern sheets and scissors.2. Students label sides of cube shown in pictures. This may be done after construction if

desired.3. Teacher leads class in supplying “missing” letters and students finish labeling cubes.

Hint: Looking at the two cubes, I see the letter ‘E’ on both of them. Assuming that both cubesare identical, how would the ‘T’ and ‘B’ relate to each other? (Opposite each other — T forTop & B for Bottom) Now that we’ve dealt with the T and the B, let’s look at the leftoverletters. Where have you seen an N and an E together before? What could they stand for?(North and East) If students do not recognize the letters as directions, identify them assuch. S and W are not visible in the photographs but students should put them on theircube model.

4. Students fold and glue cubes.5. Teacher solicits possible uses for cubes.6. Students relate cubes to picture, determining that the rock has been turned upside down in

the second photograph.

S

Lesson 13 � Solving a MysteryNASA EG-1997-08-104-HQ 13.5

Hint: When police arrive at a crime scene, it is common practice toorient objects (bodies) using strips of tape before photographingthe scene. This allows for effective “further investigation.”

7. Demonstrate the use of orientation cube using die.— Group leader will place cube next to die on lab table

with the cube’s “T” face on top and “N” face indicatingnorth. Die should be placed with “5” and “6” faces ofdie oriented to “T” and “N” respectively.

— As other members of each group record instructions,group leader will flip or rotate both the cube and diesimultaneously as teacher calls out and modelsinstructions. Note: Both die and cube must be flippedor rotated the exact same number of times in the exactsame direction(s).

— Teacher will point out that the relationships of the “T”and “5” as well as the “N” and “6” are still the sameafter the first few instructions.

— Teacher will verify comprehension.— Group leader, aided by recorded data of teammates, will

return both die and cube to initial placements andorientations.

— Groups will divide into two teams each. While one teamlooks away, the other team will change the orientationof the die and cube simultaneously, flipping and rotating atleast 3 times (one teammate must record “moves”).

— The inactive team will attempt to return both the die andcube to their initial positions without help (if asked, theactive team may give hints after a reasonable effort hasbeen made).

— Teacher will support teams struggling with taskthroughout exercise.

— Teams will switch “jobs.”8. Class will work with cubes, and demonstrate initial

orientation of a variety of objects in the classroom.

Hint: Noting the placement of cubes in photographs, we can determinethe exact placement of an object when it was found: both “whichend was up” and its geographical orientation (whether it was“facing” north, south, etc.). If items must be moved, either during acrime or scientific investigation, the investigator often must dupli-cate the scene. Without orientation devices, this would be impos-sible. Geologists use this technique when they saw rocks intopieces. They must know exact placements of parts in relation tothe original specimen, particularly when they are being heldaccountable for national treasures like the lunar samples or raremeteorites.



• measure the size of the unknown rock.

• determine the mass of the unknown rock using math skills totrack sample chips.

• estimate the density of a rock.

Procedure - Step 1Suggested introduction:

Just as an investigator needs vital statistics on a missingperson, measurements are the next logical step in identifyingthis rock. For all we know, this thing is as big as a house.Is it a pebble or a boulder? How can we find out its size?

1. Solicit suggestions as to how the rock might be measured.2. Disclose actual dimensions of cubes in photographs. Cubes

are 1 cm on a side, not the same size as cube in optional step.3. Groups measure or estimate dimensions of unknown, based

upon Lithographs I and II and record data on the Team DataSheet.

4. Optional: Class may average data to estimate size or theycould create a table or graph based on the data.

Procedure - Step 2

1. Students find the total mass of all the parts of the unknown.2. Have students compare initial mass of the unknown and the

total mass of broken pieces (see Team Data Sheet for data).The difference is 0.1g (not 4.1g - some may neglect toinclude the 4g piece removed prior to processing at NASA).

3. Class will hypothesize about reasons for the difference inmass. The difference is due to attrition, fine dust and tinypieces lost in sample processing. However, some studentsmight suggest a weighing mistake or a rounding error (bothare possible).

Lesson 13 � Solving a Mystery

Part B: Vital Statistics

About Part BStudents will takemeasurements and determinethe density of the specimen.

Optional1. Optional - Students may

calculate the approximatedensity (grams per cubiccentimeter).

2. Bonus Question - Askstudents how aninvestigator could findthe volume of anirregular object. Answercould be the standardliquid displacementprocedure or a newcomputer imagingprocess.

Hint: If density iscalculated, “ironmeteorite” may beeliminated at this point(iron density = 8, stonedensity = 3.3 - 4.5)Actual NoblesvilleDensity is 3.9.



• describe and draw details of an unknown rock.

• apply observations and knowledge to the process of ascientific investigation.

ProcedureSuggested introduction:

If you get a present and want to know what it is, you might shakeit, heft it, sniff it, etc., but you will eventually OPEN it. We’veexamined the rock in our photograph pretty thoroughly. Where dowe go from here? (Solicit “look inside” response.)

Looking inside something is another typical investigativetechnique. Since we don’t have the actual rock we’re attemptingto identify, we’ll use an additional photograph of the interior ofthe rock. The inside was exposed when a section of it was re-moved.

This magnified photograph is helpful because it allows us to seeINSIDE the rock. What additional clues can we obtain from thisdetailed view of the unknown rock? (Solicit answers.)

Investigators often use another technique when attempting tolocate a suspect. They call in a police artist and, based ondescriptions of witnesses, compile an artist’s sketch.

Your job is easier than that. I’d like you to examine this detailedview and prepare an artist’s sketch of it.

1. Students examine Lithograph III as a group. Each studentwill draw this detailed portion of the unknown. Labels will beadded after step 3 below.

2. Distribute Suspect Lists and have students fill in theirobservations based on the investigations to this point.

3. Teacher will lead students to begin the narrowing process.


Part C: Narrowing the Suspect List

About Part CObservations of the interiorof the specimen are made.


Just as investigators label drawings to clarify information, I’dlike you to label your drawing. Since it appears more andmore that this rock may be a meteorite, try using terms fromthis word bank for your labels: breccia, chondrules, clast,fusion crust, matrix, metal.

4. Instruct students to label their illustrations with at least threeappropriate vocabulary words. Depending on the level ofexperience students have with meteorites, the words may befrom a word bank or from the students’ previous studies.

Hint: The texture of the unknown is a breccia texture — clasts(broken fragments) contained in a matrix. Carbonaceouschondrite will be eliminated at this point (very few black veinsand little matrix). If chondrules are recognized, achondritemay also be eliminated.

Suspect List



Part D: Nabbing the Culprit


• observe and draw detailed microscope view of unknown.

• present evidence to verify classification decisions.

ProcedureSuggested activity introduction:

We’ve observed and recorded information about our rock frommore than one perspective. Any ideas on a next step? I’mremembering a picture I’ve seen of an investigator peering atsomething on the floor through a magnifying glass — likeSherlock Holmes. Why would he have done that?(To make things look larger so more details may be seen.) Withall the technology available to us now, how would a moderninvestigator accomplish that same thing? (Microscope)

Along with microscopes, modern investigators now have specialcameras they can attach to microscopes for taking pictures.Geologists have even figured out a way to cut a skinny little pieceof rock that is so thin that light will pass through. It’s called athin section. Lithograph IV is a thin section of our rock. This iswhat scientists see through a special microscope.

1. Groups will receive transparency sheet and marker. They willlay the transparency sheet over lithograph of thin section andsecure with paper clips. Trace corners on transparency tomake it obvious if the paper slips.

2. Possible chondrules and bits of metal, (shaded) will be traced.(Metals block light and look black under the microscope.)

3. Groups will compare transparencies by aligning and stackingthem on the overhead and viewing simultaneously to detectdifferences in observations. Help students clarify the clastboundaries.

4. Using the Suspect List the class will attempt to eliminate“suspects” by process of elimination. If further information isneeded, students may use the Meteorite ABC’s Fact Sheet onpgs. 29-30, of the Teacher’s Guide.

Hint: Chondrules WILL be identified at this point; therefore,achondrite is eliminated. If density has not been calculated

About Part DStudents use a microscopephoto of a thin section of therock to complete theidentification.


then students will need to use the photographs anddescriptions in the Introductory materials to eliminate ironand stony-iron. See the Background Information on pg. 13.2of this lesson for a detailed description of the Noblesvillemeteorite.

5. Class will discuss/summarize investigative process andconclusions reached.

6. Students will only be expected to identify the unknown as achondrite or possibly as a chondrite breccia. Noblesville is ametamorphic regolith breccia made of clasts of Hchondrites in a matrix.

7. Teacher will identify the rock as the Noblesville meteorite andthe original investigators as the meteoriticists who identifiedand classified it.

8. Class will compare and contrast the descriptions of themeteorite prepared by the students with the initialdescriptions prepared by NASA scientists at the JohnsonSpace Center. See NASA JSC Notes - Extended Commentspg. 13.11.


NASA JSC

Notes / Extended Comments

Sample: Noblesville non -Antarctic meteorite

Description By: Satterwhite 10/17/91

Dimensions - 9.5 x 8 x 3.5 cm

Exterior of this sample is covered with dull black fusion crust. Bottom surface ofexterior is brown, top surface has several regmaglypts and some residual dirt. Small areaon exterior is chipped away and reveals a medium grey matrix with some white angularclasts.

Interior is fine-grained medium grey with numerous angular white clasts. A fewdistinct chondrules are visible. Some very small chondrules and fragments are seen.Abundant fragmented grains with metallic luster are visible. White clasts are coarsergrained. More metal sulfide and some medium-grained yellow grains(olivine ?).

Weathering - A+ recent fallFractures - AWeight - 483.7 g

Lesson 13 � Solving a Mystery NASA JSC Notes

Use only after students have completed Part D

Initial description prepared by NASA scientistsat the Johnson Space Center

Compare this description with students’ descriptions of Noblesville.Point out similarities in their descriptions but do not expect students’ observations to be exact.


(not same scale as photographs)

1. Cut out pattern.2. Fold along lines to make a cube shape.3. Glue tabs to inside of cube.

Lesson 13�Solving a Mystery

Orientation Cube Pattern


Name:

Team:


Team Data Sheet

Part A: Looking for for CluesStep 1: Lithograph IDescribe the rock (shape, color, texture, etc.) What do you think it is?

Step 2: Lithograph IIView both photos and record the similarities and differences revealed aboutthe rock.

Part B: Vital StatisticsStep 1:How big is this rock?

Estimate the rock’s volume in cm3. Why is this estimate not very exact?


Step 2: Finding the rock’s massThe mass of the rock described in the NASA Lab was 483.7g before chips werechiseled off for scientific studies. A small 4.0g piece was removed before itarrived at NASA, thus the total initial mass of the rock was 487.7g.

What was the total mass of the rock including all the pieces? (chip 0 weighed466.4g, chip 1 weighed 12.4g, chip 2 weighed 1.6g, chip 3 weighed 3.2g)

Why was there a difference in the original weight and the total weight of thepieces?

Step 3: OptionalEstimate the rock’s density in g/cm3, showing your math. How could this esti-mate be inaccurate? How should you adjust your estimate?

Part C: Narrowing the Suspect ListSketch the inside of the mystery rock using Lithograph III. Note significant featuresobserved.

Part D: Nabbing the CulpritTrace the features shown in the microscope photograph onto a transparency sheet.Show detail. Use the space below to describe what you see in Lithograph IV.



Suspect List

Name:

Yes or No Reason (be specific)

Earth RockSedimentary

Igneous

Metamorphic

MeteoriteIron

Stony - Chondrite

- Carbonaceous Chondrite

- Achondrite

Stony-Iron

Lesson 14 � Direct Hit at the K-T BoundaryNASA EG-1997-08-104-HQ 14.1

Exploring Meteorite MysteriesLesson 14 � Direct Hit at the

K-T Boundary“Whateffectdo theyhave?”Objectives

Students will:

• evaluate and apply data from a narrative to a scientificselection process.

• demonstrate or visualize simulations of some of the effectsof a huge impact.

• write a point of view narrative.

About This LessonIn this lesson, students exploreinformation about the effectsof large impacts.A critical thinking activityhelps students select the likelyimpact site associated with theextinction of thedinosaurs.

Using simple simulationsstudents will find it easier torelate to the massivedestruction caused by largeimpacts. Creative writingskills are developed bywriting a first personnarrative to illustrate thedestruction.

O bj e cti v eFr o m a n arr ati v e, st u d e nts will:

• s el e ct crit eri a a n d t h e n a p pl y t h e m t o a s ci e ntifi c pr o bl e m b yusi n g criti c al t hi n ki n g s kills.

B a c k g r o u n dSi xt y-fi v e milli o n y e ars a g o t hr e e q u art ers of t h e lif e f or ms o n E art hb e c a m e e xti n ct. T h e m ost w ell- k n o w n gr o u p t o di e o ut w er e t h edi n os a ur s. H o w e v er, bir ds m a y b e li n e al d es c e n d a nts of o n e gr o u pof di n os a ur s. Ot h er s p e ci es t h at b e c a m e e xti n ct w er e t h e a m m o nit es( m ari n e m oll us cs li k e t h e c h a m b er e d n a util us), r u disti d cl a ms (s oa b u n d a nt t h at t h e y f or m e d h u g e r e efs), a n d w h ol e gr o u ps of s m allm ari n e or g a nis ms. T h e o nl y gr o u ps of a ni m als t h at w er e n otaff e ct e d li v e d d e e p i n t h e o c e a ns. S o m e l a n d a ni m als li k e t h e e arl ym a m m als s ur vi v e d als o. T his e xti n cti o n m ar ks t h e e n d of t h eCr et a c e o us p eri o d of g e ol o gi c al hist or y a n d t h e b e gi n ni n g of t h eT erti ar y p eri o d. R o c ks t h at f or m e d d uri n g t h es e disti n ct p eri o ds ar er e c o g ni z e d b y t h eir f ossils, w hi c h ar e e n or m o usl y diff er e nt b e c a us eof t h e gr e at e xti n cti o n. As a s h ort h a n d ( or j ar g o n), g e ol o gists c allt his g e ol o gi c al i nst a nt t h e K- T b o u n d ar y ( K f or t h e G er m a n w or df or Cr et a c e o us; T f or Terti ar y).

T h e e xti n cti o n of t h e di n os a urs h as b e e n a s o ur c e of s ci e ntifi cs p e c ul ati o n. H y p ot h es es a b o ut t h e c a us e of t h e e xti n cti o n h a v ei n cl u d e d:

—it w as n’t a si n gl e e v e nt, b ut a s eri es of u nr el at e d l o c al e xti n cti o ns;

—t h e e xti n cti o n w as a sl o w d e cli n e i n n u m b ers a n d di v ersit y, n ot ac at astr o p h e;

—t h e e xti n cti o n w as c a us e d b y a r a pi d c h a n g e i n cli m at e fr o m w ar ma n d w et t o c o ol a n d dr y;

—t h e di n os a urs b e c a m e a n e v ol uti o n ar y d e a d e n d a n d c o ul d n ol o n g er a d a pt t o mi n or c h a n g es i n t h eir e n vir o n m e nt;

—li vi n g t hi n gs w er e kill e d b y t h e eff e cts of m assi v e v ol c a ni c er u p-ti o ns (s p e cifi c all y t h os e i n t h e D e c c a n r e gi o n of I n di a);

—t h e eff e cts of a m et e orit e i m p a ct c a us e d t h e e xti n cti o ns.

A b o ut T his A cti vit yT his a cti vit y st arts wit h as h ort i nf or m ati v e n arr ati v ea b o ut t h e e xti n cti o n of m a n ys p e ci es, i n cl u di n g t h edi n os a urs. A n ast er oi d i m p a ctw as i d e ntifi e d as t h e m aj orr e as o n f or t h e l o n g l asti n ggl o b al c h a n g es t h at kill e d s om a n y li vi n g t hi n gs. B ut t h el o c ati o n of t h e l ar g e cr at er,c a us e d b y t h e i m p a ct, w as n oti m m e di at el y o b vi o us. Li k et h e s ci e ntists, t h e st u d e nts willb e as k e d, “ W h er e is t h ecr at er ? ” St u d e nts willd e v el o p t h e crit eri a f or e v al u-ati n g cr at er c a n di d at es fr o mt h e b a c k gr o u n d n arr ati v ei nf or m ati o n. I n t e a ms t h e ywill e v al u at e s el e ct e d cr at erst o s e e w hi c h o n e(s) mi g hth a v e c a us e d t h e e xti n cti o n oft h e di n os a urs.

M a t e ri als fo r A cti vit y A❑ St u d e nt B a c k gr o u n d

( p gs. 1 4. 7- 1 4. 8)❑ G e o gr a p hi c F e at ur es

S us p e ct List (f o ur s etsar e pr o vi d e d,p gs. 1 4. 9- 1 4. 1 2)

❑ G e o gr a p hi c F e at ur es Te a c h er K e y ( p g. 1 4. 6)

❑ p h ysi c al m a ps(s) of t h ew orl d

❑ o v er h e a d pr oj e ct or( o pti o n al)


Until 1980, each of these hypotheses had strong adherents and there was no consensus at all. In thatyear, a crucial paper was published in Science that thrust the meteorite impact hypothesis into promi-nence and eventual acceptance by most scientists.

The K-T boundary had been investigated for many years as scientists searched for the cause of theextinctions. The rocks seemed to indicate a global catastrophe. Rocks at the exact boundary are notexposed at the Earth’s surface in very many places. Some of the best exposures are in northern NewMexico, southern Canada, Italy, Spain, Denmark, and New Zealand. At all of these sites, the K-Tboundary is defined by a thin layer of grayish clay. Rocks at these sites include sandstones fromancient river valleys, limestones from ocean reefs, and cherts from the ocean floor. The gray clay ispresent in all of them. Cretaceous fossils, marine or terrestrial, are present below the gray clay and arenever found in rocks above the gray clay.

Scientists at the University of California at Berkeley (led by Nobel laureate Walter Alvarez and his sonLouis) decided to investigate the clay layer at the K-T boundary to see if they could determine justhow much time was represented by the gap between K and T times. A meteorite researcher suggestedthat the fairly constant inflow of micrometeorites that contain trace amounts of the element iridiummight yield a measure of the time. Iridium is extremely rare in rocks from the Earth’s surface, averag-ing about 0.1 parts per billion, but is much more abundant in common meteorites at about 500 partsper billion. Also, analyses for such small quantities of iridium is relatively cheap, easy and reliableusing a technique called neutron activation analysis. Alvarez and his co-workers collected samples ofthe K-T gray clay and the surrounding rocks and analyzed them for iridium. They found an extremelyhigh concentration of iridium (from 1 to 90 parts per billion). The iridium concentration was so highthat at expected micrometeorite fall rates, the gap would represent tens of millions of years. This timesequence was not likely so they were forced to look for another reason for the unexpected amount ofiridium.

Thus, the discovery reported by Alvarez, of the worldwide distribution of iridium from meteorites, hasadded to the evidence that a large meteorite impact did occur at the K-T time. Many scientists con-ducted investigations that would link this new information with the mass extinction of species.

The extra iridium at the K-Tboundary also allowedAlvarez and his co-workersto estimate the size of theimpacting meteorite. Theycalculated how much extrairidium, in grams/cm2, hadfallen at each of the K-T sitesand computed the averageiridium fallout. Assumingthat the iridium had beenoriginally deposited world-wide, they calculated theirextra iridium values and

Painting courtesy of Don Davis©.

Lesson 14 � Direct Hit at the K-T Boundary14.4 NASA EG-1997-08-104-HQ

computed the total iridium fallout over the Earth. Their total iridiumcould have been supplied if the impacting “meteorite” were10 kilometers in diameter, and made of ordinary chondrite material.An object this size can hardly be called a meteorite; it was an asteroid.

Once the iridium excesses in the K-T clay were known, other scientistsbegan looking for additional evidence for a meteorite impact at the K-Tboundary time. In the gray clay they found other features consistent witha meteorite impact, including grains of the mineral quartz that showed theeffects of enormous shock pressure, and globules of melted rock thatcould have been formed in an impact. Scientists also found soot in theclay layer — enough soot to suggest that enormous fires consumed much

of the Earth’s vegetation. In the rocks below the gray clay, they also recognized deposits from enormousocean waves that might have been tsunamis caused by an impact. In addition, they found broken rock inunusual places that suggested earthquakes (which could have been triggered by an impact).

The impact of a 10 km diameter meteorite (actually a small asteroid) must have produced a circular crater,probably more than a 150 km in diameter. A crater that size would likely have multiple ring structures, likethe larger craters on the Moon. Although remnants of a few large craters like that are known on the Earth,they are all much older than the 65 million year age of the K-T boundary. The lack of a known crater mademany scientists suspicious of the whole meteorite impact hypothesis, and inspired others to look for theimpact crater. Many features around the world were suggested and investigated as possible impact sites.

The work centered first on North America because the largest fragments of shocked rock were foundthere. The Manson meteorite crater, beneath Iowa, was first targeted because it formed about65 million years ago. But Manson is only 35 kilometers in diameter, probably too small to havecaused global devastation and too small to have been made by a 10 kilometer asteroid.

Then the search focused on the Caribbean area, because the clay layer was thickest there, and had thelargest rock fragments and globules of melted rock. Finally, suspicion focused on an unusualsub-surface structure on the northern coast of Yucatan (Mexico), centered under the town ofChicxulub. Studying rocks from drill cores of the area and data from remote sensing methods(gravity measurements, seismic profiles) showed that the Chicxulub structure is ameteorite impact crater. The most recent estimate of its size is 300 kilometers across, certainly largeenough to have caused a global environmental catastrophe.

The effects of the meteorite hitting the Earth can hardly be described. As the meteorite hit, all lifewithin about 300 km (the size of the eventual crater) would be vaporized instantly. Then the hot blastwave from the impact explosion would kill all life for several hundred kilometers in all directions.Farther out, the blast wave would kill, deafen and disorient many animals. In the ocean, the shockfrom the impact would generate enormous, world-wide tsunamis, perhaps with waves a kilometer tall.Gigantic hurricanes might also be triggered. In the Earth, the shock from the impact would be felt ashuge earthquakes, and would set off other earthquakes over the whole globe.

Ejecta from the impact (sand-sized and larger) would shoot out and rain down for thousands ofkilometers around. Other ejecta would leave the Earth’s atmosphere but not Earth’s gravity; it wouldreturn to Earth as meteorites so abundant that their heat would “broil” the Earth’s surface and set off

Merida

Y U C A T A N P E N I N S U L A

Gulf Of Mexico


wildfires over the whole planet. Over the impact site, a mushroom cloud would rise, carrying dustfrom the explosion far into the stratosphere. This dust would mingle with the soot from wildfires toform a world-wide haze so thick as to block out all light from the sun. Over time, without the Sun’sheat, surface temperatures on the Earth would drop 20-30oC. The combined effects of the fires, thedarkness, and the cold must have devastated life and caused the collapse of almost all ecologicalinterrelationships. Months later, when the dust cleared and the Sun finally shone again, only someseeds and the most enduring animals would still be alive. Three quarters of all species would die in thenext few years, due to the loss of the ecosystems on which they depended. Early shrew-like animalswere the only mammals so far discovered to have survived the disaster.

ProceduresAdvanced Preparation1. Review background.2. Read and be familiar with the Teacher Key for Geographic Features.3. Prepare envelopes containing sets of Geographic Features: Suspect Lists.

• one set of four features per envelope, per team• repeat sets if there are more than four teams

Classroom Procedure1. Read the Student Background as a group or individually.2. Ask “Where is the Killer Crater?” and “What criteria (parameters) would you use to narrow

the list of suspect features?”Note: Some students may already know the name or location of the likely crater. Encourage themnot to reveal the name and remind them that, like scientists, they must present proof and logicalreasons for their crater choice not just “I read/ saw that it was down in the Yucatan.”

3. Brainstorm the criteria as a class. Take all suggestions and then combine and focus on thecategories listed below. Some classes may develop only three criteria and some may havefour. Be flexible, but do not focus on age alone, the true age of a feature may be difficult todetermine. (Criteria: Shape, Size, Target Material, and Age)

4. Divide the class into teams of 3-4 students (more if necessary).5. Distribute the envelopes of “Suspect Features”, keeping the numbered groupings so that each

team will have a variety of criteria to assess.6. Ask each team to assess whether their assigned features are “likely,” “unlikely,” or

“possible” candidates for the “Killer Crater.” Maps may be used.7. Have each group report their findings to the class. (A simple list on the chalkboard or a chart

may be developed if needed.)8. Have the class prioritize the list of craters, from “most likely” to “maybe.”9. Provide information from background as needed.

Vocabularycrater, meteorite, asteroid, impact, iridium, clay, shock, quartz, fossil, Cretaceous, Tertiary, catastrophe, soot.

Questions1. Could there have been more than one impact that contributed to the global catastrophe?

Justify your answer.

Extensions1. Ask students to bring articles from books or magazines that give more background information.


Teacher KeyGeographic Features


Lesson 14 � Direct Hit at the K-T Boundary

Student Background

The death of the dinosaurs was part of a large extinction — a time when threequarters of the kinds of life (species) on Earth were killed. Most scientists areconvinced that the dinosaurs and other life forms died when a giant meteorite hit theEarth. You may have heard about the crater from this impact. Just like the scientistswho study the death of the dinosaurs, you too can use reason to choose which craterwas the killer.

The dinosaurs died out about 65 million years ago, along with many kinds ofplants and marine animals, especially ones that lived in shallow water. This change inlife on Earth, and the fossils left behind, marks the end of the Cretaceous period ofgeological history and the beginning of the Tertiary period. Geologists commonlycall this time the K-T boundary. In many places, the rock at the K-T boundary is afew centimeters of clay. Below the clay are abundant fossils of Cretaceous animals(dinosaurs or marine animals, depending on the rocks); above the clay layer, in thesame kind of rocks, the fossils are gone. This clay layer marks a global ecologicalcatastrophe, the extinction of three quarters of the life forms on Earth.

One idea was that the K-T extinctions were caused by meteorite impacts. In1980, scientists from the University of California at Berkeley set out to test this idea.They thought that the K-T clay might contain meteorite material, and that the elementiridium might be a good “fingerprint” for a meteorite impact. Iridium is a rare metal,much like platinum, and about 5000 times more abundant in most meteorites than inEarth rocks. The scientists analyzed samples of the clay, and found that it had up to400 times the iridium of the surrounding rocks! This result proved that a hugemeteorite had hit the Earth at the time of the K-Textinction. A meteorite of about 10 kilometers indiameter could have provided all of the iridiumin the worldwide clay layer.

But the proof of a meteorite impact left manyquestions unanswered. How could a meteorite impacthave caused massive deaths over the whole world? Andwhere was the crater caused by this meteorite?


How could a meteorite impact have caused a global ecological catastrophe?Everything at the impact site would have been vaporized, and the blast wave wouldhave killed all life for hundreds of kilometers around. Earthquakes, tsunamis, andhurricanes would also have killed many animals. But how could the effects havebeen global? The evidence is in the K-T clay, which is found all over the world.That clay was originally dust from the impact, and must have spread throughout theatmosphere, and then settled out to form the clay layer. In addition, the K-T clay isrich in soot, suggesting that the meteorite impact was followed by huge fires overmuch of the globe. The dust and soot would have blocked out the Sun for months,and temperatures would have dropped 20 to 30oC. Only the most enduring animalsand seeds could have survived until the air cleared and the Sun shone again.

And where did the killer meteorite land? Where is the smoking gun? The im-pact of a 10 km meteorite must have made a crater, a huge circular scar, somewhereon the Earth’s surface, similar to craters on the Moon, Mars, and other planets. TheK-T clay again holds clues, now in the form of grains of the mineral quartz, heavilyshocked by the meteorite impact. Quartz is very rare in rocks from the ocean basins,so the impact crater is likely to be on a continent or continent edge.

But exactly where? Which crater pulled the trigger on the dinosaurs? This isyour chance to pick the killer crater from this line-up of suspects. Just don’t botherlooking for a motive.


Geographic Features: Suspect List Group 1

Acraman - In South Australia, Lake Acraman is a hexagonal salt lake about20 km in diameter at 32°S, 135.5°E. Surrounding the lake are two, muchlarger, circular structures, which are barely visible in aerial or spaceshuttle imagery; the largest structure is 160 km in diameter. Rocks in thearea are deformed, and a belt of broken and melted rock is present 300 kmto the East of Acraman. The broken and melted rock formed about 600million years ago, which may be the age of the Acraman structure.

Manson Structure - The Manson Structure, beneath the surface in Iowa at42.5°N, 94.5°W, is detectable only through geophysical means (seismicprofiles). It is a circular ring of granitic rock, 35 km in diameter, buriedunder hundreds of feet of other rocks which appear to have covered overthe ring. The rocks in the Manson structure are severely broken. Theywere subjected to great shock pressures, and melted. The age of theManson structure is about 65 million years.

Valle Grande - The Valle Grande is a circular basin, 22 km in diameter, in themountains of central New Mexico at 36°N, 106.5°W. The edge of thebasin is a sharp scarp, and the land slopes away on all sides. Rocks at thewall of the basin are broken and jumbled together. Within the basin is acentral peak surrounded by a ring of smaller peaks. Rocks in the ValleGrande are all volcanic, with ages of younger than 2 million years.

Elgygytgyn - Elgygytgyn is a circular lake (the meaning of the name in thelocal tribal language) in easternmost Siberia, Russia: 67.5°N, 172°E.Around the slightly raised rim of Elgygytgyn is a ring of broken andpartly melted rock. Farther away there is a halo of fractured and stronglyshocked rocks. There are no volcanoes or recent volcanic rocks in thearea. The crater formed 3.5 million years ago.



Crater Lake - Crater Lake is a circular basin, 8 kilometers in diameter, at thepeak of a 2400 meter tall mountain in Oregon at 49°N, 122°W. The edgeof the basin is a sharp scarp, and the mountain slopes away on all sides.The basin is filled with water. One peak forms an island in the basincenter. Crater lake formed 6,000 years ago.

Crater Elegante - This circular depression, about 1 kilometer in diameter, is innorthwestern Mexico at 30°N, 115°W. The crater has steep sides and araised lip; the land surface slopes gently away from the crater in alldirections for a kilometer or so. The crater is near the flanks of a largevolcano, Cerro Pinacate, which is surrounded by many cinder cones andlava flows.

Chicxulub Structure - Chicxulub is a circular structure in bedrock beneath theYucatan Peninsula, Mexico, consisting of concentric rings of upliftedbedrock centered at 23°N, 90°W. The largest ring is 300 km in diameter.The Chicxulub structure is buried under a great thickness of limestone,and has been mapped by remote geophysical methods (gravity andseismic profiles). Within the structure are lava rocks and minerals whichhave been shattered or subjected to high pressure. The Chicxulubstructure is apparent at the Earth’s surface only as a series of sinkholesover one of the concentric rings. The Chicxulub structure formed 65million years ago.

Vredefort - The Vredefort ring appears as concentric circles of ridges inbedrock in South Africa at 27°S, 27.5°E. The outermost ring is 140 kmin diameter and is partly covered by younger rocks. Vredefort does notlook like a crater now, but it is thought to be an eroded crater. It formed2 billion years ago.



Kamensk - The Kamensk crater is an impact scar in south-central Russia, at48°N, 40°E. It was formed 65 million years ago and is 35 km across.Because of political instability in the region, nothing more is known aboutthe Kamensk crater.

Charlevoix - The Charlevoix structure is marked by a semicircular valley alongthe St. Lawrence River in southern Quebec, Canada: 47.5°N, 70°W. If thestructure was originally circular, its southern half is now under the river.Outside the valley is a band of hills, giving an overall diameter of46 kilometers (if the structure is circular). Rocks around the structurehave been strongly deformed. In the center of the semicircular valley is acentral peak, composed of broken and melted rock. The age of the meltedrock is 357 million years.

Iceland - This roughly circular island is located in the North Atlantic at 20°W,65°N. It sits on the Mid-Atlantic Ridge, a volcanically active spreadingcenter. The island is about four hundred kilometers in diameter and hasmany lava flows and active volcanic vents. Scientists estimate the age ofIceland to be as much as 20 million years old.

Lake Toba - Lake Toba is located in an elongate basin structure on the Islandof Sumatra, Indonesia at 3°N, 99°E. The land slopes gently away fromthe outer edge of the fifty kilometer basin. The surrounding volcanic ashflows have been dated at about 75,000 years old.



Lake Baikal - This beautiful, elongate lake is located in southeastern Russia at107°E, 52°N. It is the Earth’s deepest continental depression with thetotal depth of water plus sediments at over 9 km. The lake is 650 kmlong and 8 km wide. The oldest sediments are estimated to be 25 millionyears old.

Sudbury - The Sudbury structure is an elliptical area of igneous rocks andsediments in southern Ontario (Canada) at 46.5°N, 81°W. Sudbury isinferred to be an impact crater because rocks around it show characteristicfeatures of intense shock. Now the Sudbury structure is 140 km by 50 km,and may have been as large as 200 km diameter when it formed,1.85 billion years ago.

Deccan Traps - The Deccan structure, located at 75°E, 20°N, covers a large partof west-central India. About sixty-five million years ago huge lava flowsformed a thick, roughly circular area of approximately 520,000 squarekilometers.

Barringer (Meteor) Crater - The Barringer Crater is a circular hole in theground in northern Arizona, 35°N, 111°W. It is 1.2 km in diameter.Many pieces of iron meteorite have been found scattered around thecrater. It is estimated to have formed 49,000 years ago.

A b o ut T his A cti vit yI n t his a cti vit y st u d e nts willus e si m pl e si m ul ati o ns t od e v el o p a b ett er u n d erst a n di n gof t h e s h ort t er m a n d l o n gt er m c h a n g es t h at h a p p e nw h e n gi g a nti c i m p a cts o c c uro n E art h. T h es e e x er cis esm a y b e d o n e as d e m o nstr ati o ns,e x p eri m e nts or as v er b alvis u ali z ati o ns, i. e. “ T hi n ka b o ut w h at h a p p e ns w h e ny o u t hr o w a l ar g e r o c k i n ap u d dl e! ”.

M a t e ri als fo r A cti vit y B❑ 2 t w o lit er cl e ar s oft dri n k

b ottl es❑ 2 o n e h ol e r u b b er st o p p ers

or st yr of o a m or cl a y t obl o c k t o p

❑ 2 l a b t h er m o m et ers (l o n g)❑ w at er❑ p a p er ( w o o d e n s pli nts

w or k w ell als o)❑ m at c h es❑ li g ht s o ur c e (s u nli g ht is

b est b ut l a m p or o v er h e a dwill w or k)

❑ At m os p h eri c C h a n g es D at aS h e et f or t e m p er at ur e a n dti m e ( p g. 1 4. 1 6)

❑ t w o pi e p a ns❑ r o c k or ot h er o bj e ct 3- 5 c m

di a m et er❑ w at er t o fill p a n❑ fl o ur t o fill p a n❑ p e n cil/ p e n


• vis u ali z e or p h ysi c all y d e m o nstr at e si m ul ati o ns of s o m e of t h eeff e cts of a h u g e i m p a ct.

B a c k g r o u n dN ati o n al G e o gr a p hi c S e pt. 1 9 8 6. S e e B a c k gr o u n d fr o m L ess o n 1 4,A cti vit y A ( p gs. 1 4. 2- 1 4. 5).

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. G at h er m at eri als.2. R e vi e w b a c k gr o u n d m at eri al.

Cl assr o o m Pr o c e d ur e

At m os p h e ri c C h a n g es (s e e di a gr a m)1. P ut w at er i n e a c h b ottl e t o a d e pt h of 1 c m.2. Pl a c e a st o p p er i n e a c h b ottl e, i ns ert o n e t h er m o m et er

t hr o u g h e a c h st o p p er.3. Pl a c e t h e t w o pr e p ar e d c h a m b ers w h er e all st u d e nts m a y

o bs er v e.4. Distri b ut e t h e At m os p h eri c C h a n g es D at a S h e et.5. H a v e t h e st u d e nts pr e di ct w h at will b e t h e eff e ct of s u nli g ht

o n t h e c h a m b ers if o n e c h a m b er c o nt ai ns s m o k e p arti cl es.

cl e ars oft dri n kb ottl e


6. Put burning paper (splint or wooden stir stick) in onechamber and immediately replace stopper (this may be donebefore students are present).

7. Allow time for the temperature to come down to the sametemperature as in the control container.

8. Place chambers in sunlight (or use lamp if necessary).9. Using data table, students record temperature of each

chamber at 1 minute intervals or more, allowing enough timeto show a significant difference in temperature).

10. Based on the results, students should evaluate theirhypotheses.

Tsunami1. Fill one pie pan with water.2. Drop rock in water.3. Observe what happens.4. Compare and contrast the effect of the “rock” to the possible

effect of an asteroid over 10 km in diameter with an impactspeed of about 15 km per second.

Ejecta and Base Blast1. Fill one pie pan with flour.2. Drop rock or large heavy object into flour (layered with

another fine powder if desired).3. Observe the ejecta and fall out.4. Discuss the probable similarities and differences between

this demonstration and what happened at the impact site atChicxulub.



Activity C: You Were There!

About This ActivityStudents will write andillustrate a narrative from thepoint of view of dinosaurs asa meteorite struck the Earthsixty-five million years ago.

ObjectiveStudents will:

• write and illustrate a point of view narrative on theextinction of the dinosaurs.

BackgroundConsult the Background in Lesson 14, Activity A (pgs. 14.2-14.5).

ProcedureThe time is sixty-five million years ago. A huge meteorite has hitthe Earth. Imagine that you are a dinosaur and you notice thingsseem different!

Write a paper from the point of view of your dinosaur.How do you feel? How is your environment changing?

Make an illustration to accompany your paper.



Atmospheric Changes Data Sheet

Describe lab setup.

What will happen to the temperature in the chamber containing smoke particles?

What happened in the chambers and why?


• r e a d a b o ut l ar g e hist ori c al m et e ors a n d m et e orit e f alls.

• dis c uss t h e eff e cts t h e i m p a cts h a v e h a d o n p e o pl e.

• c o m p ar e t h e r es p o ns es r e c or d e d i n hist or y t o t h eir o w nr es p o ns es.

B a c k g r o u n d

P a r t A: T h e T u n g us k a M et e o r . T his r e a di n g d es cri b es t h e l ar g estm et e or a n d e x pl osi o n i n r e c or d e d hist or y. M a n y eff e cts of its e x pl o-si o n w er e li k e t h os e of v er y l ar g e m et e orit e i m p a cts. Yet, t h er e is n oa gr e e m e nt o n w h at t y p e of pl a n et ar y m at eri al e x pl o d e d i n t h e E art h’sat m os p h er e t o c a us e t h es e eff e cts.

P a rt B: T h e E nsis h ei m M et e o rit e . T h e st or y of t h e f all of t h eE nsis h ei m M et e orit e f o c us es o n h o w p e o pl e r e a ct e d t o a l ar g e m et e-orit e f all i n t h e y e ar 1 4 9 2.

P a rt C: F all of t h e Si k h ot e- Ali n M et e o rit e . T his r e a di n gs el e cti o n d es cri b es o n e of t h e l ar g est m et e orit e s h o w ers i n r e c or d e dhist or y. T h e pri m ar y e m p h asis is o n t h e p h ysi c al e v e nts of t h e f all,wit h a s e c o n d ar y e m p h asis o n t h e p oliti c al c o nt e xt of t h estr at e gi c all y s e nsiti v e ar e a w h er e t h e f all o c c urr e d.

P a rt D: T h e P e e ks kill F all .T h e st or y of t h e P e e ks kill f all, li k e t h at of N o bl es vill e i n L ess o n 1, isa st or y of or di n ar y p e o pl e i n t h e 1 9 9 0s. T his m et e orit e cr as h e d i nt o at e e n a g er’s c ar aft er t h e bl a zi n g m et e or h a d b e e n s e e n b y m a n y f a nsw at c hi n g f o ot b all g a m es.

P a r t E: T h e F all of All e n d e.T his r e a di n g d es cri b es a l ar g e m et e orit e s h o w er a n d t h e s u bs e q u e nts ci e ntifi c r e v ol uti o n. All e n d e is a s p e ci al t y p e of m et e orit e t h atg e n er at e d e xtr a e x cit e m e nt b e c a us e it w as st u di e d b y a l ar g e n u m b erof s ci e ntists t esti n g t h eir e q ui p m e nt i n pr e p ar ati o n f or t h e i m mi n e ntarri v al of t h e A p oll o M o o n r o c ks. T h e y dis c o v er e d t h at t his m et e orit er e v e al e d n e w i nf or m ati o n a b o ut t h e e arl y hist or y of t h e s ol ar s yst e m.

“ W h ateff e ctd o t h e yh a v e ? ”A b o ut T his L ess o nT his l ess o n c o nt ai ns fi v er e a di n g s el e cti o ns a n dass o ci at e d q u esti o ns. T h er e a di n gs a n d q u esti o ns ar em ostl y a b o ut t h e r es p o ns es ofp e o pl e t o m et e or a n dm et e orit e f alls.

M at e ri als❑ c o pi es of r e a di n gs

( p gs. 1 5. 3- 1 5. 1 2)❑ r ef er e n c e m at eri als❑ writi n g m at eri als❑ m a p s

P r o c e d u r eGi v e att a c h e d r e a di n gs t ost u d e nts t o r e a d a n d dis c uss.H a v e st u d e nts l o c at e e a c he v e nt sit e o n a m a p.

V o c a b ul a r yast er oi d, m et e orit e, m et e or,cr at er, c o m et, e x p e diti o n,s u p erstiti o n, fir e b all

Lesson 15 � Historical Meteorite Falls15.2 NASA EG-1997-08-104-HQ

Teacher Key - Questions

Part A: The Tunguska Meteor1. Why would an explosion blow down trees all around it?2. Why might the trees nearest the explosion site still

be standing?3. Why might the Russian Academy of Sciences have

waited 19 years to make an expedition to theTunguska site? (World War I, the RussianRevolution)

4. How might the world react today to a Tunguska-typeexplosion at the same place? What if it happened inTexas?

5. What could you do today to find sand-sized grains fromthe asteroid or comet that hit at Tunguska? What typesof material might have survived 85 years of weather?(Metal, minerals) The sand-sized grains from themeteor might have been propelled by the explosion;where might you find this sand separate from locallygenerated sand? Might any Tunguska material bepreserved anywhere else?

Part B: The Ensisheim Meteorite1. How large was the stone, if its density was 3 grams

per cubic centimeter? (About the size of a cube 40cm on an edge.) How would you get a stone thatheavy out of a hole in the ground?

2. After they found the stone, why do you supposethe townspeople argued? Why might the towns-people have thought the stone was good luck?What would you have thought?

3. Why didn’t the person who owned the field claimthe stone as his own? (This is a difficult question.The concept of property ownership that we nowaccept was not known in 1492. Farmland arounda village was considered “common land,” to beused by the whole village.)

4. Why might the mayor have taken the stone to theChurch? Why didn’t he take it inside the church?If a meteorite landed near your town, where wouldit be taken, or would it be moved at all?

5. Why was King Maximilian interested in the fall ofthe Ensisheim meteorite?

6. What other event happened in the year 1492?

Part C: Fall of the Sihkote-Alin Meteorite1. Where is Sikhote-Alin? Locate the area on a globe or

a map. The towns nearest to the meteorite fall areDainerecensk and Vostrecovo. Can you find these ona map? (45.8°N, 134-135°E)

2. Why might people not have rushed out immediatelyto find the meteorites?

3. Russia and Japan were fighting during World War II,just a few years before the Sikhote-Alin meteoritefall. What might people have thought about the fallif it had happened during the war?

4. China and the United States were fighting allacross Korea during the Korean conflict, just afew years after the Sikhote-Alin meteorite fall.What might people have thought about the fallif it had happened during that conflict?

Part D: The Peekskill Fall1. Why would someone want to buy a meteorite?2. Compare how the people in Peekskill responded

to a meteorite fall with how those in Ensisheimresponded five hundred years earlier.

3. How does the geography of the Earth affect howmany meteorites are found?

4. How do you think population density affectsrecovery rates of meteorite falls?

5. Using the many videos of the meteor streak, howcould you determine the direction of flight andthe speed of the meteor?

Part E: The Fall of Allende1. In February 1969, many scientists:

a. had developed ways to study moon rocks, but didn’thave any samples yet.

b. were studying lunar samples that had been broughtback from the moon the previous summer.

c. believed that life existed on the Moon.d. were in Pueblito de Allende when the meteorite

shower occurred.2. In this passage, it seems:

a. seeing a fireball in the sky in central Mexico is anormal event.

b. Pueblito de Allende is a large, busy town.c. meteorite fragments are interesting to villagers and

farmers as well as scientists.d. after several days, people lost interest in the

meteorite fragments.3. The statement “The meteorite proved to be most

unusual.” means:a. the meteorite was average.b. the scientists did not like the meteorite.c. the meteorite was special.d. the meteorite was from the Moon.

4. Which of these statements best summarizes the passage?a. The Allende meteorite shower gave scientists a very

unusual meteorite to study and an opportunity topractice using labs and procedures that would be usedlater with the lunar samples.

b. The Mexican government was very cooperative asscientists looked for meteorites in 1969.

c. Although meteoriticists were very interested in theAllende shower in early 1969, they soon turned theirattention to the lunar samples and forgot this wonderfulevent and the important information it revealed.

d. The Allende meteorite shower was an important scientificevent because it happened near NASA JSC.

Lesson 15 � Historical Meteorite FallsNASA EG-1997-08-104-HQ 15.3

Lesson 15 � Historical Meteorite Falls

Part A: The Tunguska Meteor

scorched from the heat.The Tunguska meteor

and explosion were widelyreported in newspapers andmagazines. However, therewas little scientific interestuntil 1927, when the RussianAcademy of Sciences organizedan expedition to map the areaand find meteorites. Theexpedition had to battle deepswamps, thick forests, and

The biggest meteor in recorded history shot across the Tunguska River inRussia in 1908, and exploded like a nuclear bomb. The Tunguska meteor did notmake an impact crater, but some of the effects of its explosion are similar to whatcould happen in a large meteorite impact.

At seven in the morning on June 30, 1908, a blazing meteor streaked acrossthe sky in central Russia. It sped northwest from Lake Baikal toward the tradingpost of Baikit in central Siberia, an area of dense forests, wide swamps, and mean-dering rivers. Before reaching Baikit, the meteor exploded in a gigantic column offire near the Tunguska River (61oN, 101.5oE).

The effects of the explosion were felt worldwide. Around the globe scientistswondered at the rapid changes in atmospheric pressure and unusual vibrations in theEarth. People within a thousand kilometers of the explosion saw both the meteorand the fire column. They also heard the explosion like a series of bombs. Closerto the explosion, people felt the ground rumble and shake. At about a hundredkilometers from the explosion, people, animals and houses were scorched andthrown by a hot blast of air. Only a few people were nearer to the blast, and theyreported fires, houses being blown down and burnt, and reindeer being killed by fallingtrees. For 20 kilometers around the center of the explosion, the forest was flattened, withthe downed trees pointing away from the explosion. At the center of the blown downarea, tree trunks still stood, but all their limbs had been stripped off. Everything was

Courtesy of the Smithsonian Institution.


hungry insects. Almost 20 years had passed since the explosion, and the explorerswere not sure what would be left. At the explosion site, they found the blowndown tree trunks and traces of fire among the new growth that had developed dur-ing those years. The explorers did not find meteorite craters, but guessed that somebogs were the remains of craters. After working very hard to drain and dig out themost promising bogs, they found no meteorites at all and finally realized that bogswere common all over the region, not only near the explosion. Later expeditionsfound tiny traces of melted rock in the soil, but never any meteorites.

Scientists have debated for years about what hit the Earth at Tunguska in1908, especially since it left no meteorites behind. Some people have claimed thatan alien spacecraft or a black hole hit the Earth. Most scientists think it was a cometbecause comets are made mostly of ice and would leave no meteorites. But it mayhave been a small rocky asteroid, which completely exploded in the air so that norocks were left. Now, over 85 years later, it may be impossible to learn any moreabout the Earth’s largest meteor explosion in modern history.

Questions

1. Why would an explosion blow down trees all around it?

2. Why might the trees nearest the explosion site still be standing?

3. Why might the Russian Academy of Sciences have waited 19 years to makean expedition to the Tunguska site?

4. How might the world today react to a Tunguska-type explosion at the sameplace? What if it happened in Texas?

5. What could you do today to find sand-sized grains from the asteroid or cometthat hit at Tunguska? What types of material might have survived 85 years ofweather? The sand-sized grains from the meteor might have been propelledby the explosion; where might you find this sand separate from indigenoussand? Might any Tunguska material be preserved anywhere else?



Part B: The Ensisheim Meteorite

In early November of 1492, the people of central France were astonished tohear a thunderclap from a clear sky rumble across their hills and farms. Today, asound like that would probably be ignored as an airplane’s sonic boom or an indus-trial accident. But no one in 1492 had ever heard such a loud explosion. Theymust have thought it was a “sign.”

As the sound of the thunderclap died out, the people searched for its causeand meaning. Their world was apparently unchanged, except in the small town ofEnsisheim, near the border of what are now France and Germany. There, a youngboy saw a very large stone fall from the sky and land in a wheat field. He musthave told his parents, and a crowd soon gathered where the stone had fallen. It satat the bottom of a hole, one meter deep in the field. After arguing about what to do,the crowd finally pulled the 150 kilogram stone out of its hole and began breakingpieces off for good-luck charms. The mayor ordered them to stop and had the stonecarried into the town and placed in front of the church.

News of this marvelousstone traveled quickly toKing Maximilian ofAustria, heir to the HolyRoman Empire. He arrivedin Ensisheim two weekslater, on his way to battlewith the French. The Kingexamined the stone,consulted with his advisors,

and decided that it was a sign from God foretelling victory in his upcoming battles.After taking his own piece of the stone from Heaven, the King ordered that it bekept forever in the town church. King Maximilian and his soldiers then marchedoff to battle and managed to defeat a much larger French army in the battle ofSalins. The stone was preserved in the Ensisheim church, where it hangs today.The stone from Heaven got as much credit for the victory as did Maximilian.

Brant, 1492; courtesy of Zentralbibliothek, Zurich.


Questions

1. How large was the stone, if its density was 3 grams per cubic centimeter?How would you get a stone that heavy out of a hole in the ground?

2. After they found the stone, why do you suppose the townspeople argued?Why might the townspeople have thought the stone was good luck? Whatwould you have thought?

3. Why didn’t the person who owned the field claim the stone as his own?

4. Why might the mayor have taken the stone to the Church? Why didn’t hetake it inside the church? If a meteorite landed near your town, where wouldit be taken, or would it be moved at all?

5. Why was King Maximilian interested in the fall of the Ensisheim meteorite?

6. What other event happened in the year 1492?


Lesson 15 � Historical Meteorite Falls Part C: The Fall of the Sikhote-Alin

Meteorite

An area of Russia called the Sikhote-Alin hills, north of Vladivostok along theSea of Japan, was enjoying a quiet, cold morning in February, 1947. AlthoughSikhote-Alin lies next to China and near Japan, two of Russia’s traditional enemies,all was peaceful in 1947. World War II had ended a year and a half earlier, and theKorean conflict was years in the future. The few people in Sikhote-Alin went abouttheir business, mostly surviving the long winter and preparing for spring.

At 10:30 in the morning on February 12, the mid-morning calm was shatteredas a huge red and yellow meteor streaked acrossthe sky. The fireball, with its trail of smoke andsparks, was visible for more than 300 kilometers.As it roared over the hills, it broke apart with athunderous explosion, and the burning fragmentsflew downward and crashed into the forest.

Apparently no one rushed to investigate thefall. The next day two airmen discovered wherethe meteorite had landed when they happened tofly over the site. Where there had been unbrokenforest, the airmen saw downed trees, craters, andopen clearings. The airmen reported what theyhad seen to the Soviet government, and ascientific expedition was organized immediately.After slogging through the dense forest, theexpedition arrived at the fall site on February 24,1947.

There, scientists found more than 100 holes and craters in the rocky soil. Thelargest crater was 26 meters across and 6 meters deep; in the crater were many piecesof iron meteorite, together weighing 150 kilograms. The force of the meteorite’simpact had twisted the meteorite pieces like taffy candy, blasted trees apart, andthrown rocks a kilometer from the crater. More than 23,000 kilograms of meteoriteswere found, equal to an iron ball 1.6 meters in diameter.


Questions

1. Where is Sikhote-Alin? Locate the area on a globe or a map. The townsnearest to the meteorite fall are Dainerecensk and Vostrecovo. Can you findthese on a map?

2. Why might people not have rushed out immediately to find the meteorites?

3. Russia and Japan were fighting during World War II, just a few years beforethe Sikhote-Alin meteorite fall? What might people have thought about thefall if it had happened during the war?

4. China and the United States were fighting all across Korea during the Koreanconflict, just a few years after the Sikhote-Alin meteorite fall. What mightpeople have thought about the fall if it had happened during that conflict?



Part D: The Peekskill Fall

Crash! Boom! Pow!

No, it wasn’t Batman, Superman or an automobile accident. Michelle Knapp,a typical eighteen year old high school senior from Peekskill, NY, was home watch-ing television at 7:50 Friday evening October 9, 1992, when she heard a loud crash.She rushed out of her house to investigate and found that her 1980 red Malibu had ademolished trunk.

In other parts of eastern United States, video cameras that had been focused onhigh school football games shifted upward and caught glimpses of an object streakingacross the night sky. Later that evening, local television stations broadcast the videos ofthis spectacular meteor. Once a meteor makes it through the Earth’s atmosphere andstrikes the ground, it is called a meteorite.

Under her mangled car, Michelle found a 11.8 kg, football-sized rock fromspace. The first clue that suggested this rock might be a meteorite was the meltedappearance of the front or leading edge. This exterior texture, called fusion crust, isproduced by the friction of the speeding meteorite with the atmosphere. WhenMichelle touched the rock it was still warm, another good clue. The rock fell withsuch a great force that the red paint from the car was imbedded in the meteorite.Also, after passing through the car’s trunk, the rock made a 15 cm deep crater in thedriveway.

The Peekskill Police Department transported the meteorite to the AmericanMuseum of Natural History in Manhattan to be classified. Scientists identified it asan ordinary chondrite, the most common type of meteorite found. Meteorite falls are

a regular occurrence; thousands ofkilograms are distributed onto Earth’ssurface each year. Even so, the oddsagainst a meteorite hitting Michelle’s carwere extremely high. There have onlybeen a few recorded instances ofmeteorites striking anything but theground or the ocean. A dog was report-edly killed in Egypt in 1911 by theimpact of a meteorite. In Alabama ameteorite passed through the roof of ahouse and injured a woman.Credit: Dr. Dimitri Mihalas, courtesy of Science Graphics.


The Peekskill meteorite sold for about $ 69,000. What about Michelle’s car?Would insurance cover it? Would you believe someone bought it for $10,000 sothey could put it on display?

Questions

1. Why would someone want to buy a meteorite?

2. Compare how the people in Peekskill responded to a meteorite fall with howthose in Ensisheim responded five hundred years earlier.

3. How does the geography of the Earth affect how many meteorites are found?

4. How do you think population density affects recovery rates of meteorite falls?

5. Using the many videos of the meteor streak, how could you determine thedirection of flight and the speed of the meteor?



Part E: The Fall of Allende

The Allende Meteorite Shower — A Scientific Revolution

Early on the morning of February 8, 1969, the peaceful sleep of villagers incentral Mexico was disturbed by a brilliant fireball and loud explosions. The fireballcame from the south-southwest and scattered thousands of meteorite fragments over ahuge area around the town of Pueblito de Allende. The villagers and farmerscollected many pieces of meteorite. One of the pieces was taken to the nearest cityand reported in the newspaper. Within days scientists from NASA and theSmithsonian Institution were at the site in Mexico, collecting specimens anddescribing their distribution. Over the following months many other collectors visitedthe area. Altogether the Mexican and foreign collectors recovered thousands offragments weighing a total of 1,000 kg!

The earliest samples collected by U.S. meteoriticists were rapidly distributed tomany other scientists who were preparing their labs for the imminent return of Apollolunar samples. The scientists welcomed the chance to study a new meteorite and testtheir new procedures. The meteorite proved to be anything but ordinary. It was a veryprimitive carbonaceous chondrite containing evidence of the earliest history of thesolar system. This special meteorite fell at the right place and the right time. The rightplace was in Mexico only a day’s drive from NASA’s Johnson Space Center inHouston. The right time was early 1969, five months before the return of the firstApollo Moon rocks. The information about the early solar system revealed in theAllende meteorite created a revolution in meteorite science that is still felt today.


Questions

1. In February 1969, many scientists:

a. had developed ways to study moon rocks, but didn’t have any samples yet.b. were studying lunar samples that had been brought back from the moon the

previous summer.c. believed that life existed on the Moon.d. were in Pueblito de Allende when the meteorite shower occurred.

2. In this passage, it seems:

a. seeing a fireball in the sky in central Mexico is a normal event.b. Pueblito de Allende is a large, busy town.c. meteorite fragments are interesting to villagers and farmers as well as scientists.d. after several days, people lost interest in the meteorite fragments.

3. The statement “The meteorite proved to be most unusual.” means:

a. the meteorite was average.b. the scientists did not like the meteorite.c. the meteorite was special.d. the meteorite was from the moon.

4. Which of these statements best summarizes the passage?

a. The Allende meteorite shower gave scientists a very unusual meteorite to studyand an opportunity to practice using labs and procedures that would be usedlater with the lunar samples.

b. The Mexican government was very cooperative as scientists looked formeteorites in 1969.

c. Although meteoriticists were very interested in the Allende shower in early1969, they soon turned their attention to the lunar samples and forgot thiswonderful event and the important information it revealed.

d. The Allende meteorite shower was an important scientific event because ithappened near NASA JSC.

Lesson 16 � Near MissNASA EG-1997-08-104-HQ 16.1


Lesson 16 � Near Miss


• apply science to daily life as they simulate possibleresponses to a meteorite impact.

• produce articles for a newspaper.

• role-play in a panel discussion (after they have researchedscientific careers).

About This LessonThis lesson involves thestudents in creativeinteractions by asking them totake on the roles ofcommunity members whoreact to a large andfrightening, but notdevastating, impact. Thereare two activities whichrequire different research andmodes of response. Thestudents will write newspaperarticles from the point of viewof a variety of citizens. Inpreparing for andconducting a communitybriefing, the students will gainscientific knowledge aboutmeteorite impacts and careers.

Undetected asteroid streaksperilously close to Earthby Blaine P. Friedlander

“In May 1993, the Earth survived a nearmiss by an asteroid. This “projectile” wasabout 10 meters in diameter and weighedabout 5.4 million kilograms — about themass of a Navy destroyer! A groupcalled Spacewatch in Arizona discoveredit after it had passed within 145,000kilometers of Earth!”

Adapted from: Houston Chronicle,Monday, June 21, 1993.

“Whateffectdo theyhave?”


• a p pl y s ci e n c e t o d ail y lif e as t h e y e x pl or e t h e i m pli c ati o ns ofa fi ctiti o us m et e orit e i m p a ct i n t h e vi ci nit y of t h eirc o m m u nit y.

B a c k g r o u n dFr o m J ul y 1 6 t hr o u g h J ul y 2 2, 1 9 9 4, fr a g m e nts of C o m etS h o e m a k er- L e v y 9 c olli d e d wit h J u pit er, wit h dr a m ati c eff e ct. T hisw as t h e first c ollisi o n of t w o s ol ar s yst e m b o di es e v er t o b epr e di ct e d a n d o bs er v e d. S h o e m a k er- L e v y 9 c o nsist e d of at l e ast 2 0fr a g m e nts wit h di a m et ers esti m at e d at u p t o 2 kil o m et ers, w hi c hi m p a ct e d t h e pl a n et at 6 0 k m/s e c. T h e i m p a cts r es ult e d i n pl u m es ofg as a n d d ust w hi c h r os e m a n y t h o us a n ds of kil o m et ers hi g h, h ot“ b u b bl es ” of g as i n t h e at m os p h er e, a n d l ar g e d ar k “s c ars ” o n t h eat m os p h er e w hi c h l ast e d f or w e e ks. E v e n aft er t h e m ai n b o di es h a dhit, s m all er bits of t h e c o m et c o nti n u e d t o i m p a ct t h e pl a n et.S h o e m a k er- L e v y 9 is g o n e n o w, a n d J u pit er is g etti n g b a c k t o n or-m al. If t h e c o m et h a d hit E art h i nst e a d, t h e eff e cts w o ul d h a v e b e e nd e v ast ati n g.

A b o ut T his A cti vit ySt u d e nts will r e a d a b o ut t h er e c e nt n e ar miss of a n E art hcr ossi n g ast er oi d a n d a b o utt h e i m p a ct of c o m etS h o e m a k er- L e v y 9 o nJ u pit er. T h e y als o h a v e h e ar da b o ut t h e i m p a ct t h at kill e dt h e di n os a urs a n d m ost ot h ers p e ci es.

N o w st u d e nts will c o nsi d erh o w t h e y a n d ot h er p e o pl ew o ul d r e a ct if a n i m p a cto c c urr e d n e ar t h eirc o m m u nit y. St u d e nts willwrit e arti cl es f or a n e ws p a p er,r efl e cti n g t h e m a n y diff er e ntr e a cti o ns of citi z e ns.

M a t e ri als fo r A cti vit y A❑ St u d e nt S h e et ( p g. 1 6. 6)❑ p a p er a n d p e n cils

( c o m p ut er if p ossi bl e)

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. R e pr o d u c e St u d e nt S h e et as n e e d e d.2. R e vi e w t h e b a c k gr o u n d i nf or m ati o n a b o v e a n d t h e

b a c k gr o u n d i n L ess o n 1 4, A cti vit y A ( p gs. 1 4. 2- 1 4. 5), a n dL ess o n 1 5 ( p g. 1 5. 1).

Cl assr o o m Pr o c e d ur e1. St u d e nts r e a d b a c k gr o u n d i nf or m ati o n a n d n e ws p a p er arti cl e

o n St u d e nt S h e et.2. Aft er r e a di n g, h a v e t h e st u d e nts dis c uss h o w t h e y f e el a b o ut

k n o wi n g t h at t h er e ar e l ar g e o bj e cts t h at c o ul d s o m e d a yi m p a ct t h e E art h.

3. Te a c h er as ks, “ W h at if a m et e orit e l a n d e d o utsi d e o urc o m m u nit y a n d m a d e a cr at er 3 0 m et ers a cr oss ? ”

4. St u d e nts dis c uss t h e q u esti o n fr o m diff er e nt vi e w p oi nts.Te a c h er l e a ds t h e dis c ussi o n t o diff er e nt pr of essi o ns.

5. St u d e nts writ e a n e ws p a p er arti cl e fr o m t h e vi e w p oi nt ofdiff er e nt pr of essi o n als.

Dr. H y “ R o c k y ” M o u nt ai nG e ol o gist

Dr. S us a n St arrAstr o n o m er

Dr. M atti e R. Wri g htM et e oriti cist

C ol. C at h y “ Cr as h ” C arlst o nTest Pil ot

M aj or I a n L as erL o n g- R a n g e We a p o nsS p e ci alist

S e cr et ar y L y o nsS e cr et ar y of D ef e ns e

R e pr es e nt ati v e B. N o bl eC o n g r essi o n al D el e g at e fr o m Te x as

A b o ut T his A cti vit yT h e a cti vit y st arts wit h a“si m ul at e d ” m et e orit e i m p a cto utsi d e t h e c o m m u nit y. T hism a y f oll o w A cti vit y A orst a n d al o n e. St u d e nts t a k e o nt h e r ol es of c o n c er n e dciti z e ns a n d “ e x p erts ” as t h e yc o n d u ct a t o w n m e eti n g h el dt o a d dr ess t h eir q u esti o ns a n dc o n c er ns a b o ut t h e e v e nt a n dg o v er n m e nt pl a ns f ors af e g u ar di n g t h eirc o m m u nit y fr o m l ar g eri m p a cts. St u d e nts will n e e d t or es e ar c h i nf or m ati o n f or t h ep a n el dis c ussi o n. If t h e cl assh as c o m pl et e d m a n y of t h el ess o ns o n m et e orit es a n dast er oi ds, t his a cti vit y c o ul db e us e d as a n ass ess m e nt oft h e k n o wl e d g e g ai n e d b y t h est u d e nts.

M a t e ri als fo r A cti vit y B❑ q u esti o n c ar ds❑ f a ct c ar ds❑ n a m e pl a c ar ds f or p a n el

m e m b ers o n l eft


• e v al u at e i m pli c ati o ns of s ci e ntifi c pri n ci pl es a n d t h efi n di n gs of r es e ar c h.

• r e c o g ni z e t h at t h e s ci e ntifi c c o m m u nit y h as a v ast a m o u nt ofi nf or m ati o n a b o ut m et e orit es a n d is a w ar e of t h e h a z ar dsass o ci at e d wit h m et e orit e f alls.

B a c k g r o u n dJ ust as t e c h n ol o g y h as pr o vi d e d a wi d e m ar gi n of s af et y fr o m h urri-c a n es (t hr o u g h e arl y d et e cti o n a n d w ar ni n g), e art h q u a k es (t hr o u g hf a ult d et e cti o n a n d ar c hit e ct ur al m o difi c ati o ns), a n d ot h er n at ur aldis ast ers, s ci e ntists c o nti n u e t o w at c h f or E art h- cr ossi n g ast er oi ds a n dm et e ors. T h e y st u d y p ossi bl e di v ersi o n a n d/ or d estr u cti o n of t h ep ot e nti all y d a n g er o us o n es.

N A S A’s “ S p a c e w at c h ” is o n e ast er oi d d et e cti o n s yst e m w hi c h h asb e e n pl a c e d “ o n li n e.” I n a d diti o n t o d et e cti o n, s ci e ntists h a v e cr e at e da n u m b er of crisis s c e n ari os t o c o nsi d er h o w t h e y w o ul d d e al wit h at hr e at e n e d i m p a ct i n t h e f ut ur e. S o m e p ossi bl e a cti o ns t o r es p o n d t oa n i m p a ct crisis h a v e b e e n d e v el o p e d. S u g g est e d str at e gi es i n cl u d ee x pl o di n g or di v erti n g t h e i n c o mi n g b o d y. T h e t e c h n ol o g y n e c ess ar yf or i m pl e m e nti n g m a n y of t h es e d ef e nsi v e m a n e u v ers is a v ail a bl et o d a y. O n e i m p ort a nt el e m e nt n e c ess ar y t o d e v el o pi n g a d ef e ns ea g ai nst a n y gl o b al t hr e at is c o o p er ati o n. S ci e ntists h a v e tr a diti o n all ye x hi bit e d a willi n g n ess t o c o o p er at e wit h c oll e a g u es w orl d wi d e a n dg o v er n m e nts c a n f oll o w t h eir e x a m pl e.

Lesson 16 � Near Miss16.4 NASA EG-1997-08-104-HQ

Question: How will thescientific community keepcitizens informed if there is areal impact crisis?

Expert: Dr. Susan Starr orSecretary LyonsQuestion: Do you know

what’s going to happen if anasteroid hits us?

Expert: Dr. Hy “Rocky”Mountain, Geologist orDr. Mattie R. Wright,Meteoriticist

ProcedureAdvanced Preparation1. Assemble background information.2. Gather or identify research materials for questions and facts.Classroom Procedure1. Introduce the topic and provide the background necessary to establish a plausible non-

threatening, yet alarming impact event (see Activity A).2. All students research the topic and prepare for the town meeting. Each will produce fact cards

or information “crib sheets” for the expert of their choice. Each will develop questions that willchallenge the experts and inform their community. Allow students to see the cards above.

3. Set up the town hall meeting. Panel members may be chosen at random, by the teacher, theclass, or by trying out for the teacher.

4. Read the following to the class: “Our class is going to act out a nationally televised “townmeeting.” It will be conducted to answer questions, allay fears, and develop community inputfor an emergency plan to respond to the approach of a large meteor and its impending fall. Ourpanel members will represent science advisory and governmental officials. The audience hasquestion cards, but anyone may ask questions. Panel members may refer to their fact cardswhen questioned, but remember that even the experts don’t have all the answers. Just do yourbest.” (The teacher will act as panel moderator.)

5. Panel moderator starts the meeting with the statement: “There is concern that just as meteoritefalls have caused destruction in the past, such as the Tunguska Fall of 1908, future meteoritescould also pose a danger to life on Earth. The purpose of this meeting is to answer questionsfrom the public about the threat of possible asteroid, comet or meteorite impacts, and to gatherinput for an emergency plan. We have assembled a panel of experts who have been studyingabout asteroids, impacts, and the possible defenses against potentially dangerous meteors, bothbefore and after they actually strike the Earth. I will now call for a question from the audience.”

6. Panel moderator ends the meeting with several summarizing statements.

Information: Earth-crossing asteroids

are made of stony material, or metal. We

know this from studies of meteorites and

spectral reflectance studies of asteroids.Expert:Dr. Mattie R. Wright, Meteoriticist or

Dr. Susan Starr, Astronomer

Lesson 16 � Near MissNASA EG-1997-08-104-HQ 16.5


Student Sheet

BackgroundFrom July 16 through July 22, 1994, fragments of Comet Shoemaker-Levy 9 collidedwith Jupiter, with dramatic effect. This was the first collision of two solar systembodies ever to be predicted and observed. Shoemaker-Levy 9 consisted of at least 20fragments with diameters estimated at up to 2 kilometers, which impacted the planetat 60 km/sec. The impacts resulted in plumes of gas and dust which rose manythousands of kilometers high, hot “bubbles” of gas in the atmosphere, and large dark“scars” on the atmosphere which lasted for weeks. Even after the main bodies hadhit, smaller bits of the comet continued to impact the planet. Shoemaker-Levy 9 isgone now, and Jupiter is getting back to normal. If the comet had hit Earth instead,the effects would have been devastating.

“In May 1993, the Earth survived a nearmiss by an asteroid. This “projectile” wasabout 10 meters in diameter and weighedabout 5.4 million kilograms — about themass of a Navy destroyer! A groupcalled Spacewatch in Arizona discoveredit after it had passed within 145,000kilometers of Earth!”

Adapted from: Houston Chronicle,Monday, June 21, 1993.

Undetected asteroid streaksperilously close to Earthby Blaine P. Friedlander

Lesson 17 � Asteroid ResourcesNASA EG-1997-08-104-HQ 17.1

“Howcan I usethem?”

Exploring Meteorite MysteriesLesson 17 � Asteroid Resources:

The Stepping Stone to Beyond

About This LessonIn teams, students willresearch and document someof the requirements formounting an expedition to anasteroid. Activity B allowsthe students to simulate aminiature mining expeditionof an edible asteroid.


• actively explore the potential resources available to spacetravelers through research, assessment, team cooperation,and exploration simulations.

• develop the background to make the connection betweenmeteorite research and potential planetary resources.

• map and core an edible asteroid.

Background — What can we get from an asteroid? Two types of materials on asteroids appear to be attractive formining - metals and volatiles. Both of these are essential for spacetravel. The cost of launching any material from the Earth isextremely high, so useful materials which are already in space canbe very valuable.

Most of the asteroids are found in orbits between Mars and Jupiter.However, several hundred have orbits that bring them close to theEarth. Rocket trips to some of these “near-Earth” asteroids woulduse even less fuel than a trip to the Moon, though the travel time toan asteroid might be much longer.

Metals - An asteroid of the composition of an ordinary chondritecould be processed to provide very pure iron and nickel. Valuablebyproducts would include cobalt, platinum, gallium, germanium,and gold. These metals are basic to the production of steel andelectronic equipment. Some metals from an asteroid mine mighteven prove valuable enough to be returned to Earth. Iron meteoriesare high grade ores.

Volatiles - Water, oxygen, and carbon compounds are useful in anyspace settlement, both for life support and for producing rocket fuel.These volatiles could be found in an asteroid that resembles acarbonaceous chondrite or the nucleus of a former comet. Watercontents may range from 5-10% by weight for a chondrite to 60%by weight for a comet nucleus. In some asteroids large quantities ofsulfur, chlorine and nitrogen may also be available.

(Adapted from “Asteroid Resources” byJohn S. Lewis in Space Resources, NASASP-509, Vol. 3, pg. 59-78, 1992)


• pl a n a n e x p e diti o n or ot h er l ar g e e n gi n e eri n g pr oj e ct.

• i n v esti g at e o pti o ns i n m a n y as p e cts of s p a c e fli g ht.

• pr es e nt t h eir o pti o ns, r e as o ni n g, a n d r e c o m m e n d ati o ns t o t h egr o u p.

S c e n a ri o

Ti m e: S o m eti m e i n t h e n e xt c e nt ur y.

Pl a c e: E art h.

N A S A, i n c o o p er ati o n wit h n ati o n al a n d i nt er n ati o n al s p a c ea g e n ci es, is pl a n ni n g f or h u m a n e x pl or ati o n of t h e o ut er s ol ars yst e m. T h e i nt e nti o n is t o s e n d e x p e diti o ns t o t h e m o o ns of J u pit er,S at ur n, Ur a n us, a n d N e pt u n e t o e x pl or e, c oll e ct s a m pl es, a n d s e ar c hf or cl u es t o t h e b e gi n ni n gs of t h e s ol ar s yst e m. It is i m pr a cti c al t os e n d all t h e r o c k et f u el a n d c o ns u m a bl es ( dri n ki n g w at er, air, f o o d)fr o m t h e E art h b e c a us e t h e y ar e h e a v y, b ul k y it e ms. T h er ef or e,N A S A is l o o ki n g f or s o ur c es of r o c k et f u el a n d c o ns u m a bl es at a ni nt er m e di at e d esti n ati o n, t h e ast er oi d b elt. Y o ur cl ass h as b e e ns el e ct e d t o pl a n a pr os p e cti n g e x p e diti o n t o t h e ast er oi ds t o l o o k f orr es o ur c es t h at c o ul d b e t ur n e d i nt o r o c k et f u el, dri n ki n g w at er, et c.

M a t e ri als fo r A cti vit y A❑ r es o ur c e m at eri als a b o ut: s p a c e tr a v el, s p a c e r es o ur c es,

ast er oi ds, r o c k ets, s p a c e s h uttl e, s p a c e cr aft(s e e E d u c ati o n R es o ur c es, p g. B. 2)

❑ p ers o n al l o g (j o ur n al)❑ art s u p pli es❑ St u d e nt B a c k gr o u n d s h e et ( p g. 1 7. 7)

P r o c e d u r esA d v a n c e d Pr e p ar a ti o n1. R e a d b a c k gr o u n d m at eri al.2. Ass e m bl e r es e ar c h m at eri als or k n o w w h er e st u d e nts m a y

fi n d t h e m.3. C o p y St u d e nt B a c k gr o u n d s h e ets as n e e d e d.

A b o ut T his A cti vit yT his is a gr o u p- p arti ci p ati o nsi m ul ati o n b as e d o n t h epr e mis e t h at w at er a n d ot h err es o ur c es fr o m t h e ast er oi db elt ar e r e q uir e d f or d e e ps p a c e e x pl or ati o n. T h e cl asswill br ai nst or m or i n v esti g at et o i d e ntif y us ef ul r es o ur c es,i n cl u di n g w at er, t h at mi g ht b ef o u n d o n a n ast er oi d. Te a msof st u d e nts ar e as k e d t o t a k er es p o nsi bilit y f or pl a n ni n gv ari o us as p e cts of a n ast er oi dpr os p e cti n g e x p e diti o n, a n d t opr es e nt t h e r es ults of t h eirpl a n ni n g.

T h e st u d e nts s h o ul d l e ar n t h ata l ar g e pr oj e ct r e q uir es t h ec o o p er ati o n of m a n y diff er e ntt e a ms, c o nsi d eri n g m a n y i d e asa n d n e e ds. El e m e nt ar y l e v elcl ass es c o ul d f o c us o n t h esi m pl est as p e cts of v e hi cl ed esi g n, h ar d w ar e a n dp ers o n n el; a d v a n c e d l e v elcl ass es c o ul d als o c o nsi d erfi n a n ci n g f or t h e missi o n,crit eri a f or cr e w s el e cti o n,E art h s u p p ort t e a ms, tr ai ni n g,a n d m ai nt e n a n c e, et c.


Classroom Procedure1. Present background for the problem, and then brainstorm what facts about asteroids might be

needed to prepare for a mission that would prospect for water, oxygen, or metals.2. Brainstorm the important components that must be designed or built to mount a prospecting

expedition to an asteroid. Topics to be addressed may vary, depending upon the grade levelsof students, availability of information and materials, etc. They could include: propulsion(type of rocket), power, life support, communications, financing (including valuable thingsthat could be mined on an asteroid and returned to Earth), crew selection (including humanvs. robotic), ground support, vehicle design, maintenance, prospecting tools, and training.

3. Each team selects a topic from those suggested — all members of the team should reachconsensus.

4. Teams will research and document their topic, keeping a log of sources investigated, relevantdata found, relevant conversations, meetings, etc. The research should include a “majorpoints” outline, visual aids, references used, and list of possible problems to be resolvedthrough research. Teams should also list “interfaces” with other aspects of the expeditiondesign, (e.g., the electrical power team needs to know how large the crew is, how the life-support system runs, and whether the prospecting tools require electricity).

5. Team results should include the basic questions or trade-offs for their part of the prospectingexpedition, advantages and disadvantages for each option (e.g., power from solar cells versuspower from a nuclear reactor), and a recommendation of which option is best for theexpedition. Groups should present their results to the class.

Questions1. Why do humans explore?2. Where does the money for space exploration come from?3. Might the money be spent better on the many problems on Earth?4. What are possible economic benefits of space exploration?5. Might a lunar base be cheaper to run than a space station in low-Earth orbit?6. What are the advantages/disadvantages of gender-mixed crews?7. What are the different abilities of human crews and robotic instruments (e.g. compare initiative,

adaptability, hardiness, need for life-support)?8. What types of support teams (on Earth or other home base) are necessary to a mission? Consider

human and/or robotic crews.9. How does destination and crew selection affect vehicle design?10. What skills/programming would astronauts/robots

need during each phase of a mission?11. Imagine some emergencies that might occur in

flight. How might we plan to deal with them?What kinds of problems could not be fixed in aspacecraft millions of miles from home base?

Extensions1. Create a web showing the interconnections of

support personnel necessary to a mission.2. Research and debate “Human vs. Robotic

Exploration.”

M a t e ri als fo r A cti vit y BT his will m a k e o n e l ar g e ort w o s m all “ ast er oi ds ” f ora b o ut 1 0 st u d e nts ( gr o u psm a y t a k e t ur ns).

❑ 1 l ar g e p a c k a g e ofc h o c ol at e s a n d wi c hc o o ki es

❑ 1 0- 2 0 gr a p es ( d e p e n ds o nsiz e of gr a p es)

❑ 1 l ar g e b a g of m ars h m all o ws❑ 1 sti c k of m ar g ari n e❑ 4 0 p e a n uts

( a p pr o xi m at e)❑ 1 l ar g e mi cr o w a v e a bl e

b o wl❑ 2 c o nt ai n ers t o h ol d

cr us h e d c o o ki es❑ 1 h e a v y gl ass or ot h er

o bj e ct t o cr us h c o o ki es❑ mi cr o w a v e❑ s p at ul a❑ w a x e d p a p er❑ r efri g er at or❑ a p pl e c or ers, k ni v es, or

c or k b or ers❑ t o ot h pi c ks❑ s m all t a bs f or l a b els❑ St u d e nt W or ks h e et

( p g. 1 7. 8)❑ m etri c r ul er❑ p e ns/ p e n cils


• d e vis e a n d c arr y o ut a n i n v esti g ati o n pl a n t o pr os p e ct f orr es o ur c es o n a n artifi ci al ast er oi d.

• us e r e as o ni n g, o bs er v ati o n, a n d c o m m u ni c ati o n s kills.• m a p a n e di bl e ast er oi d.• c o n d u ct c ori n g or di g gi n g e x c a v ati o ns t o ass ess a n d r e p ort

t h e “ mi n er al r es o ur c es ” a v ail a bl e.

B a c k g r o u n dS ci e ntists h a v e f o u n d t h at m et e orit es c o nt ai n m at eri als t h at c o ul d b eus ef ul t o s u p p ort s p a c e tr a v el. Ast er oi ds ar e t h e s o ur c e of m a n ym et e orit es; t h er ef or e, it h as b e e n pr o p os e d t h at mi n es a n dm a n uf a ct uri n g pl a nts o n ast er oi ds w o ul d b e a bl e t o s u p pl y orr e pl e nis h n e e d e d c o ns u m a bl es f or d e e p s p a c e e x p e diti o ns.

S o m e of t h e r es o ur c es i n c l u d e, but ar e n ot li mit e d t o:w at e r - f o u n d i n mi n er als i n c ar b o n a c e o us c h o n drit es ( us e df or lif e s u p p ort or r o c k et f u el)di a m o n ds o r pl ati n u m - f o u n d i n ur eilit es ( m o n et ar y ori n d ustri al v al u e)i r o n, ni c k el, c o b alt, o r g ol d - f o u n d i n or di n ar y c h o n drit esa n d ir o ns (i n d ustri al v al u e)fi n e s u rf a c e m at e ri als si mil a r t o s oils - (f or n utri e nt orpl a nt gr o wt h m at eri al, i ns ul ati o n, or b uil di n g bl o c ks)g alli u m o r g e r m a ni u m - f o u n d i n or di n ar y c h o n drit es ( us e df or el e ctr o ni c cir c uitr y)o x y g e n - c a n b e e xtr a ct e d fr o m mi n er als ( us e d f or lif es u p p ort a n d r o c k et f u el)c a r b o n - f o u n d i n c ar b o n a c e o us c h o n drit es ( us e d f or lif es u p p ort a n d m a n uf a ct uri n g)

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. If t h e t e a c h er will b e m a ki n g t h e “ ast er oi d(s),” all o w at l e ast

1 0 h o urs of r efri g er ati o n b ef or e cl ass ti m e (s e e cl assr o o mpr o c e d ur e a n d r e ci p e o n p a g e 1 7. 6).

2. If t h e cl ass will m a k e t h e “ ast er oi d(s),” all o w t w o cl asss essi o ns f or t his a cti vit y.

3. Ass e m bl e or assi g n m at eri als.4. R e vi e w t h e b a c k gr o u n d m at eri al.

A b o ut T his A cti vit yT his a cti vit y all o ws st u d e ntst o si m ul at e a mi ni at ur e mi ni n ge x p e diti o n t o a n e di bl east er oi d.


Classroom ProcedureDay 1

1. Discuss resources on asteroids; brainstorm the material needs of deep space travelers.2. Establish and assign tasks (may be based on Activity A or Background

Information).3. Students decide what and why they could prospect on asteroids.4. Team tasks: make an edible “asteroid”, class or team determines what the ingredients

represent (see recipe directions below).Day 2

5. Exchange “asteroids” with another team (to make the coring a discovery).6. Name the “asteroid” (see naming criteria in Lesson 4 — The Meteorite-Asteroid

Connection).7. Draw or map the “asteroid” using the student worksheet; illustrate in detail.8. Locate the best site for a core sample (a deep cylindrical hole) that will help

determine the interior resources.9. Mark the core location on the map, and on the “asteroid,” using a small flag or toothpick.10. Take one or more core samples using a sharp apple corer or knife.11. Draw and describe the core on the Student Worksheet, noting the type and amount of

“mineral resources” present.12. Write a brief report to headquarters on Earth, describing the research, findings,

and suggestions for further research.

Questions1. Why would we want to go other places to mine?2. If the resources of an asteroid are needed to support a deep space exploration mission, where

would be a better place from which to launch a resource mining expedition: Earth, a spacestation, a lunar base, other? Why?

Extensions1. Create a poster indicating the substances and resources that could be found or produced on

different planets, moons, and asteroids. Use information scientists have learned from meteoritesand lunar materials.

2. Estimate the cost differences of launching a mining operation from various “jumping off” places.3. Construct a prototype of a mining facility located on the planetary body of your choice.4. Set up a booth at a

science event todemonstrate yourconcept for a miningfacility.

Aster-oid

Painting courtesy of Dennis Davidson, American Museum of Natural History, Hayden Planetarium.

Lesson 17 � Asteroid Resources17.6 NASA EG-1997-08-104-HQ

Recipe*See materials list for ingredients

1. Remove filling from approximately 8 cookies, crush cookies into fine particles andset aside on waxed paper for step 7, save filling.

2. Crush remaining cookies (with fillings) into medium-large pieces (add filling fromstep 1).

3. Mix grapes and peanuts with crushed cookies.4. Place margarine and marshmallows in microwaveable bowl and melt thoroughly, stir.5. Combine marshmallow mixture with cookie mixture, blend gently but thoroughly.6. Using lightly buttered hands, gather the gooey mass into an “asteroid” shape, add

“impacts” or “collision fragments” by making indentations in the warm mass.7. While still warm, roll the “asteroid” in crushed chocolate cookies (this creates a regolith

or soil-like surface layer), immediately wrap firmly in waxed paper.8. Refrigerate overnight.

* For typical asteroid shape and topography, review the picture of asteroid Ida in the slidesand below. This recipe will produce a very dark surface, possibly like a “C” classasteroid, which might correspond to carbonaceous chondrite meteorites.

Asteroid Ida


Lesson 17 � Asteroid Resources

Student Background: Activity A

ScenarioTime: Sometime in the next century.Place: Earth.National and international space agencies are cooperatingto plan for human exploration of the outer solar system.Their intention is to send expeditions to the moons of Jupiter,Saturn, Uranus, and Neptune to explore, collect samples, and search for clues to thebeginnings of the solar system. It is impractical to send all the rocket fuel andconsumables (drinking water, air, food) from the Earth because they are heavy,bulky items. Therefore, the space agencies are looking for sources of rocket fuel andconsumables at an intermediate destination, the asteroid belt. Your class has beenselected to plan a prospecting expedition to the asteroids to look for resources thatcould be turned into rocket fuel, drinking water, etc.

Background — What can we get from an asteroid?Two types of materials on asteroids appear to be attractive for mining - metals

and volatiles. Both of these are essential for space travel. The cost of launching anymaterial from the Earth is extremely high, so useful materials which are already inspace can be very valuable.

Most of the asteroids are found in orbits between Mars and Jupiter. However,several hundred have orbits that bring them close to the Earth. Rocket trips to someof these “near-Earth” asteroids would use even less fuel than a trip to the Moon,though the travel time to an asteroid might be much longer because the asteroid isnot orbiting Earth.

Metals - An asteroid of the composition of an ordinary chondrite could beprocessed to provide very pure iron and nickel. Valuable byproducts would includecobalt, platinum, gallium and germanium. These metals are basic to the productionof steel and electronic equipment. Some metals from an asteroid mine might evenprove valuable enough to be returned to Earth. Iron meteorites are high grade ores.

Volatiles - Water, oxygen, and carbon compounds are useful in any space settle-ment, both for life support and for producing rocket fuel. These volatiles could befound in an asteroid that resembles a carbonaceous chondrite or the nucleus of aformer comet. Water contents may range from 5-10% by weight for a chondrite to60% by weight for a comet nucleus. In some asteroids large quantities of sulfur,chlorine and nitrogen may also be available.

(Adapted from “Asteroid Resources” by John S. Lewis in Space Resources, NASA SP-509, Vol. 3, pg. 59-78, 1992)

Lesson 17 � Asteroid Resources17.8 NASA EG-1997-08-104-HQ

Le

sso

n 17

� A

ste

roid

Re

sour

ce

s

Stu

de

nt W

ork

she

et:

Ac

tivity

B P

rosp

ec

ting

on

Aste

roid

s

Gro

up: _

____

____

____

____

Nam

e:

___

____

___

___

___

1. M

ake a

dra

win

g or

map

of t

he fr

ont a

nd b

ack

of y

our a

ster

oid,

add

appr

opria

te la

bels

. Lis

t im

porta

nt m

ater

ials

foun

d in

core

s.

Not

e th

e sc

ale

(exa

mpl

e 1

cm o

n gr

id =

3 c

m o

n th

e as

tero

id).

3. D

raw

and

labe

l a d

etai

led

illus

tratio

n of

the c

ore s

ampl

e in

the s

pace

bel

ow. T

he sc

ale m

ay n

eed

to b

e diff

eren

t fro

m th

e sca

le a

bove

.

4. W

rite a

brie

f rep

ort t

o he

adqu

arte

rs o

n Ea

rth d

escr

ibin

g yo

ur re

sear

ch. R

epor

t fin

ding

s, es

peci

ally

the t

ype a

nd am

ount

of “

min

eral

reso

urce

s” p

rese

nt, a

nd su

gges

tions

for f

urth

er ex

plor

atio

n or

rese

arch

.

Lesson 18 � Antarctic Meteorite TeamsNASA EG-1997-08-104-HQ 18.1


Lesson 18 � Antarctic MeteoriteTeams

“Is there acareer forme?”


• view slides and read about meteorite collecting.

• explore science careers.

• evaluate characteristics and skills of scientific teams dealing withmeteorites.

• create scientific teams.

• make written and oral presentations about chosen scientificteams.

Background — Antarctic Meteorite TeamsAntarctica is a special place for collecting meteorites. Since the discov-ery of nine meteorites on the ice in 1969, over 17,000 fragments ofmeteorites have been recovered by U.S., Japanese, and Europeanexpeditions. Several factors that contribute to this huge number ofmeteorites are listed below.

— It is easier to find meteorites on ice than on soil or vegetation, somany small meteorites are recovered on the ice.

— The movement of Antarctic ice helps to concentrate meteoriteswhere the ice comes to a rock barrier. This concentration makesit difficult to tell which meteorites are individuals and which arefragments from large meteorite showers. Thus the 17,000meteorite fragments may come from only 3,000 separatemeteorites.

— The ease of collecting large numbers of meteorites led to system-atic searches by various national and international groups, whichin turn led to discovery of many more meteorites.

The recovery of large numbers of Antarctic meteorites led to an in-creased interest in studying meteorites in laboratories around the world.Facilities were created where the new meteorites could be classified,distributed and stored. Meteorite recovery, curation, and research,is done by teams of scientists working together on a common goal. Eachof the teams has a leader, an assistant leader and several workers withdifferent qualifications. Factors that help in the selection of team membersare education, experience, special skills and sometimes personality — age,race, and gender are less important.

About This LessonThis lesson is designed toenhance students’ awarenessof scientific career possibilitiesand requirements. A series ofslides will provide studentswith background informationabout expeditions toAntarctica to recovermeteorites. Meteorite curationand research will bediscussed, emphasizingeducation and skillrequirements. Afterconsidering potential teamcandidates, students will workin cooperative groups tocreate three scientific teamsthat deal with the recovery,curation, and study ofmeteorites from Antarctica.

M at e ri als❑ Sli d e S et, A nt ar cti c M et e orit e Te a ms, pr oj e ct or

a n d s cr e e n❑ St u d e nt B a c k gr o u n d r e a di n g — A nt ar cti c

M et e orit e Te a ms ( p gs. 1 8. 5- 1 8. 7)❑ M e m b er Pr ofil es f or Pr os p e cti v e A nt ar cti c

M et e orit e Te a ms — Pr ofil es of s ci e ntists a n d ot h erp ot e nti al t e a m m e m b ers ( p gs. 1 8. 8- 1 8. 9, o n e f ore a c h st u d e nt)

❑ l ar g e s h e et of p a p er a n d m ar k ers t o r e c or dr es ults, p er gr o u p

P r o c e d u r eA d v a n c e d Pr e p ar ati o n1. Ass e m bl e m at eri als.2. R e vi e w b a c k gr o u n d.3. C o nsi d er p ossi bl e o pti o ns list e d i n st e p 3 of

Cl assr o o m Pr o c e d ur e a n d t h e e xt e nsi o ns at t h e e n d of t h e l ess o n — i n c or p or at e if d esir e d.4. C o p y M e m b er Pr ofil es a n d St u d e nt B a c k gr o u n d s h e ets as n e e d e d.

Cl assr o o m Pr o c e d ur e1. S h o w sli d e pr es e nt ati o n a b o ut A nt ar cti c m et e orit es.2. C o n d u ct a t e a c h er l e d dis c ussi o n or br ai nst or m s essi o n t o e x pl or e t h e i m p ort a n c e of t e a m m e m b ers

w h o ar e s kill e d a n d c o o p er ati v e. ( W h at s kills a n d q u aliti es d o A nt ar cti c M et e orit e t e a m m e m b ersr e q uir e ?)

3. Di vi d e st u d e nts i nt o t hr e e or m or e gr o u ps. Distri b ut e M e m b er Pr ofil es a n d St u d e ntB a c k gr o u n d s h e ets t o e a c h st u d e nt.O pti o ns:

• Us e t h e pr ofil es as t h e y ar e list e d a n d gi v e e a c h t e a m a f ull listi n g.• C ut i n di vi d u al pr ofil es i nt o stri ps a n d h a v e st u d e nts dr a w b y s e p ar at e g e n d er gr o u pi n gs.• C ut off t h e n u m b er a n d g e n d er d esi g n ati o n o n e a c h pr ofil e a n d l et st u d e nts dr a w sli ps r a n d o ml y.• H a v e st u d e nts m a k e u p t h eir o w n pr ofil es.

N ot e : A pr ofil e d p ers o n m a y fit o n s e v er al diff er e nt t e a ms (t his r e all y h a p p e ns).4. E a c h gr o u p h as t h e r es p o nsi bilit y of cr e ati n g o n e of t h e f oll o wi n g t e a ms: c oll e cti o n, c u r ati o n, or

r es e a r c h . T h er e m a y b e m or e t h a n o n e t e a m p er c at e g or y. ( T h e t e a c h er m a y h el p g ui d e gr o u ps t oe ns ur e t h at at l e ast o n e of e a c h t e a m c at e g or y is f or m e d.)

5. At s o m e ti m e i n t h e gr o u p dis c ussi o n h a v e e a c h st u d e nt s el e ct a “ p ers o n ” w h o m t h e y will r e pr es e nt i nt his a cti vit y. S el e cti o ns ar e m a d e fr o m t h e M e m b er Pr ofil es f or Pr os p e cti v e A nt ar cti c M et e orit eTe a ms or fr o m pr ofil es cr e at e d b y t h e st u d e nts.

6. Gr o u ps e v al u at e t e a m m e m b ers’ s kills a n d e d u c ati o n first. T h e n d e ci d e w h at t e a m c at e g or y t h e y willb est b e a bl e t o cr e at e as a w h ol e gr o u p. St u d e nts m a y m a k e u p a d diti o n al q u alifi c ati o ns or s kills f ora n y of t h e pr ofil e d p e o pl e. C o nsi d er t h e y e ars of “ e x p eri e n c e ” a n d e x p a n d o n t h e p ossi biliti es.T h er e ar e m a n y p e o pl e w or ki n g i n fi el ds n ot ass o ci at e d dir e ctl y wit h t h eir d e gr e e(s). Fl e xi bilit y willb e n e c ess ar y — s o m e i n di vi d u als m a y n e e d t o m o v e t o a n ot h er gr o u p if s kills d o n ot m at c h t h et e a ms’ n e e ds.


7. Make specific job assignments for each person based on theneeds of the team and the individual characteristics and skills.Make up information about the character and abilities of your“person” that will allow them to be better team members.(Individuals might be chosen for more than one team and havedifferent roles on each team.)

8. The groups’ choices and job assignments should be recordedand shared with the class. Groups should be prepared to explaintheir decisions.

Questions1. Imagine that you are the organizers of an expedition to collect

meteorites.— What kinds of personality traits would make the team’s job

more enjoyable?— What specific items would you include in your plan for

transportation, clothing, shelter, food, water, andcommunication? Explain why you need each item.

— What would you do in your spare time on the meteoritecollecting expedition?

2. What other things, in addition to education, interests and skills, wouldbe important in choosing your meteorite collection, curatorial, orresearch team? What other things would not be important?

3. Would you actually want to collect, curate or study meteorites?Explain your answer.

Vocabularycuration, research, classification, expedition, technician, Bachelor’sDegree, Master’s Degree, Doctor of Philosophy (Ph. D.)

EvaluationThe groups’ lists and explanations could be used as the evaluations ofthis activity.

Extensions1. The class could be required to reach a consensus for one set of

teams based on the individual group recommendations.2. Each group could role play the team members and introduce them-

selves to the class.3. Each group member could choose a team applicant and write an

acceptance/rejection letter explaining the group’s decision.4. Research other historic Antarctic expeditions and compare them to

present day expeditions.


Lesson 18 � Student Background

Meteorite Recovery Team

Collecting meteorites in Antarctica is a difficult and potentially dangerous task. Antarctica isthe coldest continent on Earth, with summer temperatures of 0 to -25°C and wind chills thatmake it feel much colder. Teams work for about two months during Antarctic summer(November to January) in the remote regions along the Transantarctic Mountains. Becausemeteorites are found long distances from the few scientific bases, teams are transported tocamps by air and must have everything they need to survive. They have lots of food and fuel,special clothing and tents for protection, snowmobiles for transportation, and radios forcommunication.

Team Members — Their Skills, Duties, and ResponsibilitiesTeam Leader and Assistant

— have scientific backgrounds.— write the proposal for funding and support to the National Science Foundation

which operates bases and oversees Antarctic science.— plan which locations to search for meteorites.— arrange for transportation and equipment.— select the other team members and lead the field expedition.

Ice Specialist— is responsible for finding safe routes on ice and avoiding crevasses.— manages the mapping project and prepares a computer database of locations of all

meteorites.Team Members (3-4)

— are scientists or science students selected by the leaders for their interest inmeteorites and desire to work in Antarctica.

— are in good health andphysical condition.

— are often from the curationand research teams.

— have a personality suitableto working and livingclosely with team membersfor two months in thisisolated, hazardousenvironment. The membersof U.S. teams have includedboth men and women of manynationalities, with ages rangingfrom under 30 to over 60.

Lesson 18 � Antarctic Meteorite Teams18.6 NASA EG-1997-08-104-HQ

Lesson 18 � Student Background U.S. Antarctic Meteorite Curation Teams

There are two curation teams, one at NASA’s Johnson Space Center and the other at theSmithsonian Institution’s National Museum of Natural History. They share the tasks of classi-fication, distribution, and storage. Each team consists of curators, scientists, specialists, andtechnicians. Duties of team members are often interchangeable. Curatorial staff members mayhave a variety of educational backgrounds. Members of the curation team may also serve on thecollection team.

Team Members — Their Skills, Duties, and ResponsibilitiesCurators

— write funding proposals.— interact with administrators, oversight committees, other curators, the field team,

research scientists, and the general public.— classify both Antarctic meteorites and other meteorites sent by individuals.— direct the work of the laboratory scientists, computer specialists, and technicians.— publish classifications in newsletters and bulletins.— some also conduct research projects.— some work on public displays and education.

Computer Specialist— manages the database of meteorite classifications and weight inventories.— prepares data for publication in newsletters and reports to administrators and

committees.Laboratory Scientists

— do the actual handling of meteorites.— describe new meteorites in laboratory notes.— take subsamples to distribute to researchers.

Technicians— prepare meteorite thin

sections for microscopicexamination and analysis.

— maintain the laboratoryequipment, and cleanspecial tools andcontainers.


Lesson 18 � Student Background

Meteorite Research Team

Meteorite Research TeamThe research group usually consists of university or college professors, research staff, postdoctoral associates, graduate, and undergraduate students. All members of the team need to beskilled in the use of computers. Members of the research team participate on the collectionteam.

Team Members — Their Skills, Duties, and ResponsibilitiesLead Researcher

— is usually a professor who teaches classes or may be a research staff member of an institute.

— writes research proposals to secure funding.— directs the research.— writes some of the papers reporting the results.— makes oral presentations to colleagues at scientific meetings.

Research Associate/Assistant— is a research staff member, a post doctoral associate, or sometimes a graduate

student.— conducts much of the actual research, including requesting meteorites from the

curation team.— interprets and reports the results.— writes papers.— makes oral presentations to colleagues at scientific meetings.

Technician— may be a regular employee or a student employee in training to be a technician or

scientist.— maintains and operates the

laboratory equipment.— does many of the experiments

or analyses.— contributes to written

articles.

Lesson 18 � Antarctic Meteorite Teams18.8 NASA EG-1997-08-104-HQ

Member Profiles for Prospective Antarctic Meteorite Teams

Member Education / Experience Interests / Skills

# 1 Geology Univ. of Hawaii BackpackingFemale Masters Degree Cross-country skiing

# 2 Communications U.S. Army Computer programmingFemale Bachelors Degree + 8 years Reading

# 3 Creative Writing Alvin Community College First aidMale Associates Degree + 15 years Photography

# 4 Chemistry Texas A&M - Ph.D. Student PianoMale Masters Degree + 2 years Gourmet cooking

# 5 Agriculture Texas Tech Bird watchingMale Bachelors Degree + 10 years Ham radio

# 6 Pilot U.S. Navy HorsesMale Bachelors Degree + 5 years Stamp collecting

# 7 Physics/Geochemistry Oregon State Univ. Sail boardingFemale Ph. D. + 5 years Classical music

# 8 Physical Sciences Univ. of Texas at Dallas Baking breadFemale Bachelors Degree + 40 years Computers

# 9 Accounting Univ. of California SurfingMale Bachelors Degree + 15 years Restoring cars

# 10 Math Univ. of Texas - Ph.D. Student GeologyFemale Masters Degree + 5 Years Conservation

# 11 Astronomy/ Univ. of Arizona TennisMale Planetary Science Ph. D. + 15 years Car repair

# 12 English Univ. of Houston Desktop publishingMale Masters Degree + 5 Years Bicycling

# 13 Mechanical Engineer Southern Methodist Univ. GolfFemale Masters Degree + 1 year Chess

# 14 Business Austin College SailingMale Bachelors Degree + 2 years Microscopes


# 15 Physical Education/ TCU - Ph.D. Student Stock market analysisFemale Geochemistry Masters Degree + 10 years Weaving

# 16 Forestry Univ. of Alaska WoodcarvingFemale Ph.D. + 1 year Cooking

# 17 Music Rice Univ. ElectronicsFemale Masters Degree + 5 years Texas history

# 18 Chemical Engineer Baylor Univ. ArcheryMale Masters Degree + 2 years Videotaping

# 19 Electrician San Antonio Comm. Coll. SoccerMale Associates Degree +15 years Radio controlled airplanes

# 20 Theater Trinity Univ. Short story writingFemale Bachelors Degree + 5 years Rock climbing

# 21 Dentist Louisiana State Univ. Model buildingMale DDS + 5 years Crossword puzzles

# 22 Psychology Univ. of Florida Jet skiingMale Masters Degree + 15 years Horses

# 23 Marine Biology Univ. of Delaware OperaFemale Masters Degree + 5 years House building

# 24 Photography U.S. Air Force KayakingMale Masters Degree + 2 years Bowling

# 25 Electrical Engineer Univ. of Oklahoma RunningMale Bachelors Degree + 30 years Square dancing

# 26 Electron microscopy Arizona State Univ. MeteoritesMale Ph.D. + 15 Body building

# 27 Political Science Georgetown Univ. Marine mammalsMale Bachelors Degree + 25 years Canoeing

# 28 Scientific Illustrator Univ. of Michigan GardeningFemale Masters Degree + 25 years Karate

# 29 Computer Science Miss. State Univ. - Masters Student BaseballMale Bachelors Degree + 10 years Sewing

# 30 Librarian Univ. of Missouri Exploring cavesMale Masters Degree + 5 years Cooking ethnic food

“ W h atc a n w eb eli e v e ? ”


• r e a d pr e p ar e d t a bl oi d arti cl es a b o ut m et e orit es.

• d et er mi n e w h et h er n e ws arti cl es ar e f a ct or fi cti o n.

B a c k g r o u n dTr ut h is oft e n str a n g er t h a n fi cti o n a n d s o m eti m es it is diffi c ult t odisti n g uis h b et w e e n t h e t w o. N e wsst a n ds ar e fill e d wit h t a bl oi dst hri vi n g o n o ur f as ci n ati o n wit h t h e o utl a n dis h. Arti cl es p ert ai ni n gt o s p a c e a n d ass o ci at e d s u bj e cts ar e c o m m o n a n d s o m eti m es s o u n dpl a usi bl e. Si n c e m a n y of t h e t hi n gs s ci e ntists h a v e l e ar n e d fr o mm et e orit es ar e h ar d t o b eli e v e, t h e y l e n d t h e ms el v es p erf e ctl y t o t hist y p e of m e di a.

P r o c e d u r eA d v a n c e d Pr e p ar a ti o n1. C o p y arti cl es fr o m T h e D ail y S h o oti n g St ar or pr e p ar e

tr a ns p ar e n ci es.Cl assr o o m Pr o c e d ur e1. I nstr u ct st u d e nts t o r e a d arti cl es a n d d et er mi n e w hi c h ar e

f a ct or fi cti o n. E a c h m a y pri v at el y r e c or d d e cisi o ns a n dk e e p f or f ut ur e r ef er e n c e if t his is b ei n g us e d as apr e ass ess m e nt.

2. If d esir e d, t a k e a tr u e/f als e cl ass v ot e a n d k e e p r es ultsf or l at er r e vi e w.

N ot e : J ust as t h e s ci e ntifi c st u d y of m et e orit es l e a ds us t oq u esti o n t h e e arl y ori gi ns of t h e u ni v e rs e, t h es earti cl es w e re d esi g n e d t o e n g e n d er u n c ert ai nt y.C o m p etiti o n is n ot t h e f o c us of t his e x e r cis e.

3. As k st u d e nts t o j ustif y t h eir d e cisi o ns o n av ol u nt ar y b asis a n d all o w n o n-j u d g m e nt aldis c ussi o n — st u d e nts j ust mi g ht h a v e t o e at t h eirw or ds ot h er wis e!

4. U p o n c o m pl eti o n of t h e u nit, r e p e at st e ps 1 a n d 2.C o m p ar e t h e t w o s ets of r es p o ns es. R e q uiri n gj ustifi c ati o n f or a ns w ers t h at c h a n g e d w o ul d b e a g o o dass ess m e nt t o ol.

A b o ut T his L ess o nT h e D ail y S h o oti n g St ar us esa t a bl oi d f or m at t o g e n er at ei nt er est i n m et e orit es. T h earti cl es m a y b e us e d as a ni ntr o d u cti o n or pr e ass ess m e ntb ef or e a n y l ess o ns ar e st art e d,or it m a y b e a fi n al ass ess m e ntaft er t h e u nits ar e c o m pl et e d.

M at e ri als❑ T h e D ail y S h o oti n g St ar

( p gs. 1 9. 3- 1 9. 8)❑ writi n g m at eri als❑ bl a c k b o ar d a n d c h al k❑ o v er h e a d pr oj e ct or a n d

m ar k ers

Lesson 19 � The Daily Shooting Star19.2 NASA EG-1997-08-104-HQ

Questions1. Is there one or more specific thing(s) in the article which influenced your decision about its truth

or falsehood?2. Describe articles you have read in the past which remind you of those you just read. What topic

was addressed, did you believe the material presented, why or why not?3. What difficulties might an author of articles about space encounter?4. Identify concepts in any of the articles which might be considered to be beyond today’s

technology but within reason in the future.

Extensions1. Allow students to write their own sensational scientific articles, based upon truth or fiction.

Local newspapers often run material related to scientific topics which may be used for the “truth”articles and “the sky is the limit” when composing the fiction. “Yellow journalistic” tabloidarticles provide useful models; however, care should be taken. Some of these articles tend to berisqué.

2. Allow students to prepare and present a dramatic presentation of either true or false articles. Ashowcase might be presented for younger students where the audience votes on whether theybelieve the dramas to represent truth or fiction. This could be followed by a “confession session”in which actors emphasize the amazingly true vignettes and tell what was wrong with thefictional ones.

3. If it is available, play a tape of the original “War of the Worlds” radio broadcast for the class. Ifit is unavailable read a shortened version to them. Follow up with information about the panicaudiences experienced when this broadcast aired in the late 1930’s. Instruct students to comparethe response of that first audience to the response they would expect of a modern day audience.

4. Have groups create and perform commercials for products using meteorites, micro-meteorites,etc., claiming an end to baldness, super-human powers, etc. Packaging and promotionalconsiderations may be included.

Tabloid Answer Key

1. True Amateur Astronomer Discovers Comet2. True Annihilation Narrowly Avoided3. False Intelligence Enhancing Meteorites No studies have been done, nor has the

need for any been confirmed.4. False Extraterrestrials Hurl Rock at Earth No evidence has been found of

extraterrestrial life; however, 65 million years ago an impact did causemassive destruction.

5. False Longevity Secret Revealed No studies have been done.6. True Giant Impact Thought to Cause Mass Extinctions7. False Huge Diamond Discovered in Meteorite Although diamond chips have been

found in meteorites, none of significant weight has ever been discovered.8. True History of Solar System Revealed9. True Oldest Meteorite Found10. False Phenomenal New Energy Resource Discovered No technology exists

for the harnessing of either lightning or streaking meteors.11. True Microbes from Mars

S E P T E M B E R 3 0 , 1 9 9 4

o f m o u nt ai n s a n d t h o u s a n d s of s m all er fr a g m e nt s.S ci e ntists ar e n o w st u d yi n g d at a o n t h es e c ollisi o ns g at h er e db y t el es c o p es a n d s p a c e cr aft l o c at e d i n diff er e nt p arts oft h e s ol ar s yst e m. T h e or biti n g H u b bl e S p a c e Tel es c o p ew as ai m e d at J u pit er d uri n g t h e i m p a ct. T h e r es ults oft h e i m p a ct wit h J u pit er h a v e f ar r e a c hi n g i m pli c ati o ns f ort h e pl a n et E art h. C o ul d w e s ur vi v e a n i m p a ct of t hism a g nit u d e ? ★

c o m et si g hti n g s ar e m a d eb y a m at e ur s. Pr of e s si o n ala str o n o m er s C ar ol y n a n dt h e l at e E u g e n e S h o e m a k erc o - di s c o v e r e d t h e c o m etw hi c h w a s d e si g n at e d a sC o m et S h o e m a k er- L e v y 9. As t h e c o m et a p pr o a c h e dJ u pit er, it w as t or n a p art t or es e m bl e a “stri n g of p e arls ”wit h at l e ast 1 7 c h u n ks t h e si z e

A N NI HI L A TI O NN A R R O W L Y A V OI D E D

S ci e ntists r e c e ntl y d et e ct e d a na st er oi d, n a m e d 1 9 9 3 K A 2,w hi c h p ass e d wit hi n 1 4 5, 0 0 0kil o m et ers of E art h. It w ass p ott e d b y D a vi d R a bi n o wit z, a na st r o n o m e r i n A ri z o n a,s e v er al h o urs aft er it p ass e dE art h. T h e ast er oi d w as n otd et e ct e d e arli er b e c a us e of itsl o w vi s u al m a g nit u d e. It sesti m at e d m ass is a b o ut fi v e a n do n e h alf t o ns — a b o ut t h e s a m eas a n oil t a n k er. T h e ast er oi d’ss p e e d w as c al c ul at e d at 7 7, 0 0 0k m/ hr., r el ati v e t o E art h. M osto bj e cts ai m e d at E art h b ur n u pi n t h e at m o s p h e r e, b uts ci e ntists s p e c ul at e t h at 1 9 9 3K A 2 c o ul d h a v e cr e at e d asi g nifi c a nt cr at er h a d it e nt er e do ur at m os p h er e, s ur vi v e d, a n di m p a ct e d. T h e aff e cts of t h ec ollisi o n w o ul d h a v e b e e n f eltw orl d wi d e! I n hi s p a p ere ntitl e d “ C olli si o n o fa str o n o mi c all y o b s er v a bl eb o di e s wit h t h e E a rt h, ”G. W. Wet h erill c o n cl u d e s,“. . . t h at i m p a cts of h alf ak m- di a m et er E art h- cr o s si n go bj e cts, e n er g eti c e n o u g h t opr o d u c e a 1 0 k m- di a m et ercr at er, o c c ur wit h a fr e q u e n c yof a b o ut o n c e e v er y h u n dr e dt h o us a n d y e ars! ” ★

A m at e ur A str o n o m er Di s c o v er s C o m et

A dis c o v er y b y a n a m at e ur astr o n o m er h as f o c us e d t h ew orl d’s att e nti o n o n t h e m ost e x citi n g astr o n o mi c al e v e nt i nhi st or y. D a vi d L e v y, usi n g a n 1 8-i n c h t el es c o p e o n M o u ntP al o m ar, C alif or ni a, dis c o v er e d a c o m et w hi c h l at er c olli d e dwit h J u pit er. S ur prisi n gl y, s e v e nt y p er c e nt of all i niti al

○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○

S E P T E M B E R 3 0 , 1 9 9 4

S ci e ntists s a y t h e y h a v e pr o oft h at si xt y-fi v e milli o n y e arsa g o e xtr at err estri als h url e d am assi v e r o c k at t h e E art ha n d al m ost d estr o y e d it! T h e

h e at a n d pr ess ur e cr e at e d b yt h e m et e orit e l a n di n g i n t h eo c e a n i nj e ct e d a v ast a m o u ntof w at er v a p or i nt o t h eat m o s p h er e a n d c a u s e d at s u n a mi o v er a kil o m et erhi g h.

“ T h e f o s sil r e c or d pr o v e st h e t s u n a mi c o v er e d t h ec o nti n e nt wit h w at er,” s a ysDr. C h arl e n e Br as hi er. “ T h et s u n a mi i n st a ntl y kill e ds e v er al s p e ci es of l a n d pl a ntsa n d a ni m als, b ut cr e at e d av ast o c e a n f ull of lif e. T h ew ar m w at er c a us e d b y t h em et e orit e i m p a ct a c c el er at e d

t h e gr o wt h of all o c e a ni cor g a ni s m s. ” W h e n a s k e da b o ut t h e e xtr at err e stri al s,Dr. Br as hi er r es p o n d e d, “Ik n o w it s o u n ds f ar f et c h e d,

b ut Dr. I o h asc o n v i n c e dm e.”

D r. I o, at h e o r e t i c a lp h y s i c i s t ,c o ul d n ot b er e a c h e d f o rc o m m e nt b uthi s a s si st a ntt ol d us a b o ut

his t h e or y. “ T h e o nl y f or c estr o n g e n o u g h t o h url a nast er oi d of t h at m a g nit u d eh a d t o b e e xtr at err e stri al.T h e H u b bl e t el es c o p e s e ntu s s o m e v er y i nt er e sti n gpi ct ur es of t h e pl a n et Ve n us.O n t h e s urf a c e of t h e pl a n etar e m a n y f ossils. T h e f ossilr e m ai n s cl e arl y s h o w t h esi g ns of a pl a n et at w ar.” ★

I N T E L LI G E N C EE N H A N CI N GM E T E O RI T E S

A fift e e n y e ar st u d y c o n d u ct e db y a n i nt er n ati o n al t e a m ofp s y c h ol o gi st s h a s d et er-mi n e d t h at f et al e x p os ur e t on e wl y f all e n m et e o rit e si n c r e a s e s I. Q. s c o r e s.S ci e ntists b e c a m e i nt er est e di n eff e cts fr o m m et e orit es aft erM e xi c a n e d u c at ors, w or ki n gwit h 7 c hil d p r o di gi e s,dis c o v er e d t h at all w er e b or ns h ortl y aft er t h e All e n d em et e orit e f ell t h er e i n 1 9 6 9.A w orl d- wi d e st u d y w as s etu p e n c o m p assi n g ar e as wit hi n5 kil o m et ers of m et e orit e f allso c c urri n g b et w e e n 1 9 7 7 a n d1 9 8 7. T h e r es ults str o n gl yi n di c at e t h at i nt elli g e n c e isaff e ct e d i n d e v el o pi n g f et us esb y o n e o r m o r e o f t h eat m os p h eri c c h a n g es w hi c ho c c ur as a r es ult of m et e orit ei m p a cts. I. Q. s c or es 2 0 p oi ntsa b o v e a v er a g e a p p e ar t o b ec o m m o n i n c hil dr e n w h os em ot h er s w er e e x p o s e d t om et e o rit e i m p a ct a r e a sd uri n g t h e s e c o n d tri m est erof pr e g n a n c y. A d diti o n alst u di es ar e pl a n n e d. ★

1 9 6 9 1 9 7 7 1 9 8 70

2 0

4 0

6 0

8 0

1 0 0

1 2 0

1 4 0

1 6 0

1 9 6 9 1 9 7 7 1 9 8 7

> 5 k m

< 5 k m

S E P T E M B E R 3 0 , 1 9 9 4

M et e o r ol o gi st s a n dg e ol o gists ar o u n d t h e w orl d

h a v e c o n -fi r m e d t h eo c c u r r e n c eof a m aj orc at a str o p h ei n E a rt h ’s

hi st or y w hi c h l e d t o t h ed e at hs of n u m er o us lif e f or msi n cl u di n g t h e gi a nt s e an a util u s. S c arri n g of t h e o c e a nfl o or a n d l a n d o n t h e Y u c at a nP e ni n s ul a i d e nti f y t h atar e a as t h e sit e of a h u g e

m et e orit e f all. F ossils f o u n di n t h e ar e a s h o w t h at m assi v ee xti n cti o n s o c c urr e d a s ar es ult of t h e i m p a ct. N oto nl y l a n d i n h a bit a nt s b utal s o o c e a ni c s p e ci e s w er ee n d a n g er e d w h e n t h e l o w eror g a nis ms o n t h e f o o d c h ai nb e g a n t o dis a p p e ar. A m o n gt h os e u ni q u e cr e at ur es l ostf or e v er w a s t h e gi a nt s e an a util us, a v al u a bl e li n k t ou n d er st a n di n g a d a pt ati o n sof s p e ci es. S ci e nti st s r e g ul arl yu n d ert a k e w orl d wi d e st u d-

i es of c ori n gs of gl a ci al i c e,g e ol o gi c al st r at a, a n dm at ur e tr e es t o tr a c e cli m at ec h a n g es. T h e p er c e nt a g e ofc ar b o n di o xi d e f o u n d i nA nt a r cti c i c e f r o m t h ata n ci e nt ti m e c h a n g e ddr a m ati c all y f oll o wi n g t h ei m p a ct of t h e h u g e m et e or-it e o n E art h. B a s e d o nc u r r e nt k n o wl e d g e o ft h e “ gr e e n h o u s e ” eff e ct,s ci e nti st s r e c o g ni z e d t h ei n di c ati o n s of t h e a n ci e ntc h a n g e i n cli m at e. Al o n g E xti n cti o n c o nti n u e d o n p a g e 1 9. 6

M eri d a

Y U C A T A N P E N I N S U L A

G ulf Of M e xi c o

R e v e al e d

A g e o gr a p hi c al st u d yc o n d u ct e d b y gr a d u at e st u d e ntsh as li n k e d mi cr o m et e orit es t ol o n g e vit y. R es e ar c h er D o u gJ a c ks o n, w hil e r e vi e wi n g d at ac o m pil e d b y his l o n g e vit y st u d yt e a m, n ot e d a si g ni fi c a ntsi mil arit y t o a st u d y his wif e,K ar e n, is w or ki n g o n. S h e is ag e ol o g y st u d e nt s p e ci ali zi n g i nmi cr o m et e orit e s. It w as r e all y q uit e b y

○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○

T h o u g ht t o C a u s eM a s s E xti n cti o n s

a c ci d e nt, ” J a c ks o n s ai d. “ Wew er e sitti n g ar o u n d t al ki n g a b o uto ur w or k a n d it s u d d e nl y hit m e

t h at K ar e n’s d at a t a bl es w er eal m ost i d e nti c al t o mi n e. ” F urt h er i n v e sti g ati o nr e v e al e d a si g ni fi c a nt

r el ati o ns hi p b et w e e n l o n g lif ea n d h e a v y mi cr o m et e orit ec o n c e ntr ati o ns. “ T h es e p e o pl eh a v e pr o b a bl y b e e n i n g esti n gmi cr o m et e orit e s f or y e ar s, ”J a c ks o n a d d e d. I niti al st u di esi n di c at e t h at a u ni q u e n utri e nt,f o u n d i n t h e ti s s u e s o fc e nt e n ari a ns, is a c o m p o n e nt ofm o st mi cr o m et e orit e s w hi c ha p p e ars t o b e t h e k e y t o l o n glif e. S yst e mi c S u p pli es, I n c.h a s pr o p o s e d a p at e nt f orvit a mi ns c o nt ai ni n g t h e n e wl ydis c o v er e d n utri e nt. ★

S E P T E M B E R 3 0 , 1 9 9 4

H u g e Di a m o n dDis c o ve re di n M et e o rit e

M et e orit e r es e ar c h ers at apr esti gi o us s ci e ntifi c i nstit ut ei n H o u st o n, T e x a s h a v edis c o v er e d a m assi v e 6. 7 4 c ar atdi a m o n d i n a n A nt ar cti cm et e orit e. S ci e ntists h a v e b e e nc oll e cti n g m et e o rit e s i nA nt ar cti c a f or s e v er al y e ars.Aft er c oll e cti o n t h e s a m pl esar e p a c k a g e d a n d s hi p p e d t oH o u st o n f o r s ci e nti fi ca n al y si s. A n u m b e r o fdi a m o n d c hi p s h a v e b e e nr e c o v er e d fr o m m et e orit es, b utt h e l ar g est t ot al w ei g ht t o d at eh a d b e e n l ess t h a n . 0 7 c ar ats. Dr. L y n n All e n, i n v esti g a-ti v e t e a m l e a d er, e x pr e s s e dmi x e d f e eli n gs o v er t h e fi n d.“ F u n di n g f or t h e A nt ar cti cpr oj e ct will n ot b e s u c h apr o bl e m n o w, ” s h e t ol d t hisr e p ort er. “ T hi s st o n e i so b vi o usl y v er y v al u a bl e a n dwill e n h a n c e t h e vi a bilit y ofo u r r e s e a r c h. S ci e nti fi ck n o wl e d g e i s i m p ort a nt t om a n y p e o pl e, b ut w h e n ad oll ar fi g ur e c a n b e ass ess e d,fi n a n ci ers ar e m or e willi n g t os u p p ort o ur w or k. T h e s a d p arti s t h at p e o pl e w h o mi g hth a v e willi n gl y r eli n q ui s h e dm et e orit e s t o t h e s ci e ntifi cc o m m u nit y m a y b e m or er el u ct a nt t o d o s o n o w. ” Offi ci als h a v e m a d e n od e cisi o ns as t o t h e dis p ositi o n

of t h e di a m o n d. ★

E xti n cti o n c o nti n u e d fr o m p a g e 1 9. 5

wit h t h e c h a n g e i n w e at h er p att er ns, f o o d c h ai ns br o k e d o w na n d m assi v e e xti n cti o ns r es ult e d. I n r es p o ns e t o a r e p ort er's q u esti o ns a b o ut w h at w o ul dh a p p e n if a si mil ar i m p a ct w er e t o h a p p e n i n m o d er n ti m es,g e ol o gist Dr. Vir gil L. “ B u c k ” S h ar pt o n q ui p p e d, “It w o ul db e a r e al b a d d a y. B ut it w o ul d s ol v e t h e pr o bl e ms of n u cl e arpr olif er ati o n a n d gl o b al w ar mi n g! ” ★

Hi st or y of t h eS ol ar S y st e m

S ci e ntists at t h e L u n ar a n d Pl a n et ar y I nstit ut eh a v e r el e a s e d st artli n g i nf or m ati o n w hi c hs u p p orts t h e t h e or y t h at t h e s ol ar s yst e m ar os e

fr o m g a s e o u s a n d p arti c ul at e m att er. T hi si nf or m ati o n w as o bt ai n e d t hr o u g h i nt e nsi v e st u d y of

m et e orit es fr o m t h e M o o n, M ars, a n d t h e ast er oi d b elts. Dr. All a nH. Tr ei m a n st at es, “ M et e orit es ar e t h e b est cl u es t o h o w t h e s ol ars yst e m f or m e d. I n o ur l a bs, w e c a n t a k e m et e orit es a p art a n d l e ar nj ust h o w t h e y w er e p ut t o g et h er, w h et h er it w as o n t h e M o o n, o nM ars, or i n a d ust y g as cl o u d or biti n g a v er y y o u n g S u n. ” Pr e vi o us st u di es of r o c ks h a v e h el p e d s ci e ntists u n d erst a n dt h e E art h’s f or m ati o n. M at eri als a n d str u ct ur e f o u n d i n E art hr o c ks a n d m et e orit es ar e v er y si mil ar. T h os e si mil ariti es l e dr es e ar c h ers t o t h e c o n cl usi o n t h at, as t h e y ar e l e ar ni n g a b o uth o w m et e orit es w er e f or m e d, t h e y w er e als o l e ar ni n g h o w ot h erpl a n et ar y b o di es w er e f or m e d. J ust as pl a n ets h a v e l a y ers ( c or e,m a ntl e, cr ust), m et e orit es dis c o v er e d o n t h e E art h’s s urf a c er e v e al s a m pl es of t h e s a m e t y p es of l a y ers fr o m ot h er c el esti alb o di es. T h o u g h s m all i n si z e, m et e orit es pr o vi d e wi n d o ws t oe x pl or e t h e pr o c ess es t h at f or m e d t h e s ol ar s yst e m. As m or e m et e orit es ar e dis c o v er e d a n d st u di e d, s ci e ntists f e elc o nfi d e nt t h at m or e i nf or m ati o n a b o ut t h e ori gi ns of t h e s ol ar

s yst e m a n d p er h a ps lif e its elf will b e u n d erst o o d. ★

S E P T E M B E R 3 0 , 1 9 9 4

of “ o b s er v e d f all s. ” “Ita p p e ars t o us t h at o bs er v a-ti o n of t his m et e orit e f all h asb e e n h a n d e d d o w n b y w or dof m o ut h,” st at e s A ki hi k oO k a d a of t h e I n stit ut e ofP h y si c al a n d C h e mi c alR es e ar c h i n J a p a n. S ci e ntists h a d pr e vi o usl yc o n si d er e d t h e E n si s h ei mst o n e, w hi c h f ell i n G er m a n yi n 1 4 9 2, t o b e t h e ol d e stwit n ess e d f all. T h e N o g at a-S hi pr e d at es t h e E nsis h ei mst o n e b y o v er 6 0 0 y e ars a n dr e n e w s s p e c ul ati o n a b o utt h e e xi st e n c e o f ot h e ru n di s c o v er e d, pr e s er v e dm et e orit es. ★

M a s a k o S hi m a a n dass o ci at es r e c e ntl y pr es e nt e di n f o r m ati o n t o t h eM et e oriti c al S o ci et y a b o utt h e N o g at a- S hi m et e orit e, ac h o n drit e. T h e N o g at a- S him et e orit e f ell at a S hi nt os hri n e o n M a y 1 9, 8 6 1, b yt h e J uli a n c al e n d ar. It h asb e e n p r e s e r v e d at t h er eli gi o us sit e as a tr e as ur e oft h e s hri n e i n a s p e ci all ym ar k e d w o o d e n b o x . M a n y m et e orit es h a v eb e e n o n t h e E art h’s s urf a c ef or t h o u s a n d s of y e ar s.H o w e v er, o nl y s p e ci m e n sw h os e si g hti n gs h a v e b e e nd o c u m e nt e d m a y b ec o nsi d er e d i n t h e c at e g or y

O L D E S TM E T E O RI T E

F O U N D

A m et e orit e w hi c h f ell i nJ a p a n i n 8 6 1 h a s b e e ni d e nti fi e d a s t h e ol d e stwit n ess e d f all of w hi c h pi e c esar e pr es er v e d.

P h e n o m e n al N e w

E n er g y R e s o ur c eDI S C O V E R E D

L e wi s B e r k el e y L a b( L B L) h a s a n n o u n c e d t h ed e v el o p m e nt o f a n e wpr o c ess w hi c h will h ar n esst h e v a st e n er g y a v ail a bl efr o m str e a ki n g m et e ors.

“ T h e t e c h n ol o g yn e c e s s ar y t o c o n str u ct af u n cti o ni n g pl a nt utili zi n gt hi s t y p e o f p o w e r i sa v ail a bl e n o w,” Dr. R o b ertF ar a d e y st at e s. “ M u c h

d e p e n d s u p o n w h et h er orn ot utilit y c o m p a ni e s ar ewilli n g t o m a k e t his dr asti c ac h a n g e i n t h eir o p er ati o ns.”

B as e d o n t e c h ni q u esus e d i n c oll e cti n g el e ctri cit yfr o m li g ht ni n g fl as h es, L B Lh as pr oj e ct e d t h e h ar n essi n gof billi o ns of kil o w atts ofp o w er, d uri n g p eri o d s ofa cti v e m et e or s h o w ers. T hisc o ul d b e e q ui v al e nt t o t h epr o d u cti o n of t hr e e n u cl e arp o w er pl a nts. It is esti m at e dt h at t h e s a vi n g s t ot h e c o n s u m er w o ul d b es u bst a nti al o n c e t h e s yst e m

h as b e e n pl a c e d “ o n li n e.”N o offi ci al c o m m e nts

w e r e o f f e r e d b y utilit yi n d ustr y r e pr es e nt ati v es, b uto n e w a s h e ar d t o r e m ar kaft er t h e n e w s c o nf er e n c ewit h L B L, “ T his is a h ar e-br ai n e d s c h e m e — a w ast eof p u bli c r es o ur c es.” ★

S E P T E M B E R 3 0 , 1 9 9 4

I n A u g ust 1 9 9 6, a p a n el of s ci e ntistsr e v e al e d a s e cr et h el d f or t w o y e ars.T h e y u n v eil e d t h e first e vi d e n c e ofp ossi bl e lif e o n t h e R e d Pl a n et. T h eM ars m et e orit e r es e ar c h t e a m, l e db y D a v e M c K a y a n d E v er ettGi bs o n, d es cri b e d st artli n g fi n di n gsi n a n a n ci e nt m et e orit e w hi c h w asbl ast e d off M ars a n d l a n d e d i nA nt ar cti c a. T his r o c k c o nt ai nsor g a ni c m ol e c ul es a n d mi cr os c o pi cbit s of ir o n o xi d e s li k e t h o s epr o d u c e d b y b a ct eri a. E v e n m or ea m a zi n g ar e i m a g es of w or m-li k ef or ms s o s m all t h at t h e y c a n o nl y b es e e n b y t h e m ost p o w erf ul el e ctr o nmi cr os c o p e. E v e n t h o u g h t h er e ar eot h er i nt er pr et ati o ns of e a c h of t h epi e c es of e vi d e n c e, t a k e n t o g et h er,“ w e b eli e v e t h at t h es e ti n y g u ys c a nb e i nt er pr et e d as (f ossil) b a ct eri a, ”s a ys M c K a y.

R e a cti o n of ot h er s ci e ntists t o t h edis c o v er y h as b e e n s k e pti c al, a n d i ns o m e c as es, d o w nri g ht h ostil e.S o m e s ci e ntists, w h o h a v e st u di e dt h e m et e orit e, s a y t h at t h e c ar b o n at emi n er als c o nt ai ni n g t h es e f e at ur esf or m e d at t e m p er at ur es t o o hi g h f orlif e t o e xist. R al p h H ar v e y s u g g estst h e w or m-li k e f or m s ar e n’tmi cr of ossils, b ut ar e el o n g at e d ir o no xi d es, f or m e d i n v ol c a ni c f u m ar ol est o o h ot t o s u p p ort lif e. L u a n n B e c k ers u g g ests t h at t h e or g a ni c m ol e c ul esar e pr o d u c e d b y c o nt a mi n ati o n i nA nt ar cti c a.

T h e d e b at e r a g es h ot a n d c ol d. T h eLif e o n M ars t e a m c o nti n u es t oc oll e ct m or e d at a — m a g n eti cs a n dis ot o p e c h e mistr y s u g g est a c ol dori gi n. M e a n w hil e, t h e n a ys a y ersa d d m or e li n e s of n e g ati v e

e vi d e n c e — t h e f ossil-li k e f or ms ar et o o s m all t o h ol d a m ol e c ul e ofD N A. Ti m S wi n dl e, w h o t o o k a ni nf or m al p oll of pl a n et ar y s ci e ntists,s a ys it c a m e o ut e v e n, wit h m osts ci e ntists sitti n g o n t h e f e n c e w aiti n g

f or m or e d at a. ★

Exploring Meteorite Mysteries � GlossaryNASA EG-1997-08-104-HQ A.1


Glossary

Words that appear in italic type within a definitionalso are defined in the Glossary.

Absorbent: able to suck up liquid like a sponge.Accrete (accretion): accumulate under the influence

of gravity and some minor forces.Achondrite: stony meteorite without chondrules.Amino Acids: organic acids that are the components

of proteins.Angular: a shape description that indicates an object

has one or more angled edges rather than roundededges.

Anorthosite: an igneous rock made up almost entirelyof plagioclase feldspar.

Aphelion: the point of a celestial body’s orbit mostdistant from the Sun.

Asteroid: one of thousands of small (diameters under1000 km) solid planetary bodies orbiting the sun; mostorbit the Sun between Mars and Jupiter, but a fewcome closer as they cross the orbits of Earth or Mars.

Asteroid belt: area between Mars and Jupiter wherethousands of asteroids orbit the Sun.

Astronomer: one who studies the science of celestialbodies and their origins, magnitudes, motions, andcompositions.

Atmosphere: mixture of gases that surround a planet.Attrition: the amount of material worn away during

sample preparation; small losses.Bachelor’s degree: usually the lowest academic

degree given by a college or university.Basalt: fine-grained, dark-colored igneous rock

composed primarily of plagioclase feldspar and

pyroxene; other minerals such as olivine and opaquesare usually present.

Basaltic achondrite: a type of meteorite consistingof the minerals feldspar and pyroxene; they aresimilar to basalts from lava flows on Earth.

Bleb: a small, usually rounded inclusion of one materialin another.

Breccia: rock consisting of angular, coarse fragmentsembedded in a fine-grained matrix.

Carbonaceous chondrite: a primitive type ofmeteorite usually with chondrules; they containwater and carbon compounds, including organicmolecules.

Carbon compounds: forms of carbon combined withother elements, includes organic molecules such asamino acids.

Catastrophe: a great disaster or misfortune.Chromatography: separation of complex solutions into

chemically distinct layers, usually different colors, byseepage through an absorbent material.

Chondrite: stony meteorite containing chondrulesembedded in a fine grained matrix of pyroxene, olivine,and metallic nickel-iron.

Chondrule: a small rounded body of various materials,chiefly olivine or pyroxene, found embedded in ausually fragmental matrix in certain of the stonymeteorites.

Classification: the formal system of arranging objectsor information into like groups.

Exploring Meteorite Mysteries � GlossaryA.2 NASA EG-1997-08-104-HQ

Clast: a broken piece of rock formed by the breakupof a larger object.

Clay: a size term denoting particles, regardless ofmineral composition, with diameters less than 1/256mm.

Comet: a small body of ice and dust circling the sun inan elliptical orbit; when it comes near the Sun gasesare released to form a tail that points away from theSun.

Composition: the amounts of all the elements in arock or mineral.

Condensation: to form a liquid or solid from thegaseous state.

Core: the central region of a planet or moon, frequentlymade of different materials than the surroundingregions (mantle and crust); Earth and the Moon arethought to have cores of metallic iron and nickel.

Cosmic spherules: melted droplets of meteorites, lessthan 1mm in size, found in ocean sediments and ice.

Crater : a hole or depression (see impact); most areroughly circular or oval in outline; on Earth mostnatural craters visible at this point in geologic timeare of volcanic origin; on the Moon most craters areof impact origin.

Cretaceous: the period of geologic time fromapproximately 140 million years ago to about 65 millionyears ago; abbreviated symbol is K.

Cross section: a profile portraying an interpretationof a vertical section of the Earth explored bygeophysical and/or geological methods.

Crust: the outermost layer of a planet or moon, abovethe mantle.

Crystallization: to form crystals.Cumulate: collection of minerals that have been

separated from molten rock by density settling.Curation: taking care of collections of samples and

distributing information on those samples.Curator: one in charge of a collection or exhibit of

items such as in a museum.Deposition: the process of accumulation of a

sedimentary layer of rock or precipitate.Diameter: the length of a line that goes from edge to

edge of a circle or other shape and also passesthrough the center of that shape.

DNA: deoxyribonucleic acid; functions as the transferof genetic information from cells in living organisms.

Dense: means the mass of an object is relatively highper unit volume of the object; object could bedescribed as “heavy for its size”.

Density: mass per unit volume; how much material isin a given space.

Differentiation: chemical zonation caused bydifferences in the densities of minerals; densematerials sink, less dense materials float.

Diffracted: when light beams are deflected or bent byinteraction with an object (diffraction).

Doctor of Philosophy: usually the highest academicdegree given by a university or college in any field ofacademic study (Ph.D. or doctorate).

Ecliptic plane: the plane defined by the orbit of theEarth around the Sun; most planets orbit in or nearthe ecliptic plane.

Ejecta: material thrown out from and deposited aroundan impact crater.

Electromagnetic spectrum: energy ranges fromgamma-rays through x-rays, ultraviolet, visible light,infrared, microwave, all radio waves (all havingspecific energy).

Ellipse: (elliptical) a closed curve of oval shape.Emit: to give off, such as light or sound.Erosion: process of physically changing and or moving

rocky material; on Earth this especially includesweathering and transport of material by water andwind.

Expedition: a journey for a particular purpose suchas research or discovery.


Fall: is a designation for a meteorite that was observedas it came through Earth’s atmosphere and wasretrieved soon afterward.

Find: is a meteorite that was not observed to fall; itmay have been on Earth for a long time.

Fireball: the streak of light and loud noise of a largemeteor going through the Earth’s atmosphere.

Friable: easily crumbled rock fragments.Fusion crust: dark glassy coating on the surface of a

meteorite, caused by heating as the meteorite entersthe atmosphere.

Geochemist: a scientist who studies the chemicalcomposition of, and chemical changes in the Earthor other planetary bodies.

Geologist: scientist who studies Earth, its materials,the physical and chemical changes that occur on thesurface and in the interior, and the history of the planetand its life forms; planetary geologists extend theirstudies to the Moon, planets, and other solid bodiesin the solar system.

Geophysics: extensive experimental and modelingstudies of the Earth and other planetary bodies withrespect to their structure and development.

Gravity: a force of attraction pulling any two thingstoward each other, dependent on the mass of theobjects.

Heterogeneous: composed of several different typesof material.

Highlands: oldest exposed areas on the surface ofthe Moon; extensively cratered, and chemicallydistinct from the Mare.

Homogeneous: composed of one type of material.Hypothesis: an idea or group of ideas that attempt to

explain an observed or predicted event oroccurrence.

Igneous: rocks or processes involving the formationand solidification of hot, molten magma on the surfaceof a planetary body or below the surface.

Impact: the forceful striking of one body, such as ameteorite, against another body such as a moon orplanet (crater).

Impact crater: hole or depression formed by ameteorite colliding with a surface.

Impactor: object that strikes (impact) a surface, maycreate a crater (projectile, meteorite).

Incandescent light: light which came from anelectrically heated filament.

Incident light: light that has struck an object (seealso reflected light).

Inclusions: a fragment of another rock enclosed in arock.

Infrared: the portion of the electromagnetic spectrumwith wavelengths of from 0.7 to about 1.0micrometers, just beyond the red end of the visiblespectrum.

Inorganic: compounds that are not formed by livingorganisms.

Interplanetary dust particles: microscopic bits ofasteroids or comets; these particles can be collectedfrom high in the atmosphere.

Iridium: a hard, brittle, very heavy, metallic chemicalelement used in alloys; found in greater percentagesin meteorites as compared to Earth rocks.

Iron meteorite: meteorite consisting of metallic ironand nickel.

Isotope: elements having an identical number ofprotons in their nuclei but differing in their numberof neutrons.

Kinetic energy: the energy of a body or mass inmotion; with greater speed and mass the kineticenergy increases.

Latitude: the angular distance North or South fromthe Earth’s equator measured in degrees; Equatorbeing 0° and the poles 90°N and 90°S.

Lava: fluid magma that flows onto the surface of aplanet or moon; erupted from a volcano or fissure;


the rock formed by solidification of magma.Layer: a bed of stratum or rock.Longitude: the angular distance East or West,

between the meridian of a particular place on Earthand that of Greenwich, England, expressed in degreesor time.

Lunar meteorites: meteorites that have beenidentified through their chemistry and minerals asbeing from the Moon.

Magma: term applied to molten rock in the interior ofa planet or moon; when it reaches the surface,magma is called lava.

Magnetism: a property possessed by certain bodies,whereby under certain circumstances, they repel orattract one another according to determined laws.

Magnetic field: a force that acts over a region ofspace around a magnetically charged body.

Mantle: a mostly solid layer of Earth lying beneaththe crust and above the core; consisting mostly ofiron and silicate minerals.

Maria: dark areas on the Moon covered by basaltlava flows (singular Mare).

Martian meteorites: meteorites that have beenidentified as pieces of Mars by a combination of theirrelatively young age and their chemical similarity toViking data from Mars.

Mass: the amount of matter in a given object.Master’s Degree: academic degree higher than a

bachelor’s degree but lower than a doctoral degree.Matrix: the smaller sized grains in a rock, where the

rock consists of large grains or fragments surroundedby smaller grains.

Metal: any of a class of substances that typically areopaque, are good conductors of electricity, and oftenhave a shiny luster like gold.

Metamorphic (metamorphosed): rocks that haverecrystallized in a solid state as a result of changesin temperature, pressure, and chemical environment.

Meteor: relatively small body of matter travelingthrough interplanetary space.

Meteorite: a metallic or stony (silicate) body thathas fallen on Earth, Moon or other planetary bodyfrom outer space (see Impactor, Projectile).

Meteor shower: group of meteors or comet dust,traveling together, which enter the atmosphere withina few hours.

Meteorite shower: a large number of similarmeteorites falling together; caused by the breakupof a large meteorite in the atmosphere.

Meteoriticist: someone who studies meteorites.Micrometeorites: meteorites smaller than 1 mm.Mineral: naturally occurring inorganic solid with a

definite chemical composition and crystal structure.Mineralogy: the mix of minerals which make up a

rock.Orbit: the path of an object in space moving about

another under gravitational attraction.Ordinary chondrites: the most common class of

meteorites, consisting of variable amounts of metaland chondrules in a matrix of mostly silicateminerals.

Organic molecules: compounds of carbon, hydrogenand oxygen, that form complex molecules (may ormay not be from living organisms).

Perihelion: the point of a celestial body’s orbit closestthe Sun.

Planetary geology: the study of the planets in oursolar system concerning the history and formationof the interior and surface.

Planetary meteorites: a class of igneous orbrecciated meteorites from other planets; currently,meteorites have been found that come from the Moonand Mars.

Platy: the texture of a rock that is composed of flatminerals or rock fragments.

Porous: contains open or void spaces between solid


material.Post doc: researcher who has completed a Doctor

of Philosophy degree and has a temporary positionsuch as a fellowship to pursue a specific type ofresearch.

Projectile: object that impacts a surface.Quartz: a common, often transparent crystalline

mineral that is a form of a silica.Research: studious and critical inquiry aimed at the

discovery and interpretation of new knowledge.Reflectance: the amount of light of a particular color

reflected by a surface, divided by the amount of lightof the same color that strikes the surface.

Reflectance spectroscopy: the study of the colorsof light reflected from a surface.

Reflected light: light which strikes a surface andbounces back, as happens with a mirror.

Regmaglypt: any of various small indentations or pitson the surface of meteorites.

Regolith: loose, unconsolidated rock, mineral, andglass fragments; on the Moon and some otherplanetary bodies, this debris is produced by impactsand blankets the surface.

Retrograde: an orbit that moves in the oppositedirection of Earth’s orbit.

Rim: the border of a land form, such as the curvededge surrounding the top part of a crater.

Scale model: an object that gives the size of the samplein proportion to the size of the actual thing.

Sediment: solid rock or mineral fragments transportedand deposited by wind, water, gravity, or ice;precipitated by chemical reactions; or secreted byorganisms; accumulated as layers in loose,unconsolidated form.

Sedimentary: rock formed when sediment iscompacted and solidified.

Shock: a sharp impact or violent shake; evidence oflarge shocks may be seen in the rocks and minerals

near an impact crater.Silicate: minerals that contain the elements Si and O,

plus one or more metals: Mg, Fe, Ca, Na, Al.Solar nebula: gravitational accumulation of solid

particles and dust around the Sun.Solar power: energy derived from the Sun or sunlight

for use as a source of electricity.Solar system: the Sun and all the objects such as the

planets, moons, asteroids, and comets that orbit theSun.

Solar wind: the stream of charged particles, mainlyionized hydrogen, moving outward from the Sun withvelocities in the range of 300-500 kilometers persecond.

Soot: a black substance that is formed whensomething burns.

Specimen: a sample, as a rock, fossil, or ore.Spectroscopy: the excitation of the spectrum, its visual

or photographic observation, and the precisedetermination of wavelengths.

Sphere: an object that is round or almost round in alldimensions like a ball.

Static electricity: stationary charges of electricity.Stony-iron: a class of meteorites composed mostly

of an intimate mixture of silicates and iron metal.Stony meteorite: a class of meteorites composed

mostly of silicate minerals.Strewn field: a generally elliptical pattern of

distribution of recovered meteorites, formed whena meteor is fragmented as it passes through theatmosphere.

Superstition: beliefs or practices resulting in fear ofthe unknown, ignorance and trust in magic or chance.

Technician: a person who has acquired the techniqueof a specialized skill or subject.

Tektites: small fragments of melted andaerodynamically shaped rock that were ejected froma large impact crater.


Tectonic: pertaining to rock forms due to deformationin the crust of Earth and other planetary bodies.

Terrain: area of the surface with a distinctive physicalor geological character.

Tertiary: the period of geologic time between 65 and2 million years ago, abbreviation is T.

Texture: general physical appearance of a rock.Triangulation: method of finding the distance to an

object or location of an event in the sky by creating atriangle, with two vertices the ground, and the objectat the third vertex.

Ultraviolet: having a wavelength shorter than visiblelight and longer than x-rays.

Unconsolidated: materials loosely pack but notcemented to each other.

Unfractured: does not contain breaks or cracks.Uniform: having always the same form, manner, or

degree.Vaporize: to change something from a liquid or a solid

to a gaseous state as in rock that is completely alteredto gas during large impacts.

Velocity: rate of motion in a specific direction.Vesicle: bubble-shaped cavity in a volcanic rock formed

by expanding gases.Volatiles: chemical elements that enter a gas phase

at relatively low temperatures.Volcanism: the physical processes of a volcano.Volcano: mountain formed from the eruption of

igneous matter through a vent; volcanism refers toall natural processes resulting in volcanoes and otherigneous surface events.

Voltage: electromotive force measured in volts.Volume: space occupied, as measured by cubic units.Weathering: the mechanical breakdown and chemical

alteration of rocks and minerals.Wick: (verb) to draw a liquid on to or up a solid

(i.e. a towel).Zoologist: scientist who studies animals.

Exploring Meteorite Mysteries � Education ResourcesNASA EG-1997-08-104-HQ B.1


Education Resources

Meteorite Resources

Teacher’s Guide:The following companion volume is available from

NASA Educator Resource Centers or NASACentral Operation of Resources for Educators:

Exploring the Moon, G. Jeffrey Taylor et al, 1994,NASA EP-306.

Video:Meteorites-Vol. 1: Menace from the Sky. Vol. 2:

Witnesses from Beyond the Times, AustrianBroadcasting Corporation, 1993, 84 minutes.AtlasVideo, Inc. Bethesda, Maryland.

Slides:Accompanying Exploring Meteorite Mysteries slide

set is available from NASA CORE.Terrestrial Impact Craters, set of 26 slides with guide

and A Spacecraft Tour of the Solar System, 40slides with guide.

Lunar Planetary Institute3600 Bay Area BoulevardHouston, Texas 77058-2186281-486-2172 or FAX 281-486-2186

Posters:Meteorites Poster (#328)

The Planetary SocietySales Department65 North Catalina AvenuePasadena, California 91106-2301

Comet Chart (#31-0) and Cosmic Catastrophies(#46-9)

Hansen Planetarium Publications1845 South 300 West, #ASalt Lake City, Utah 84115-18041-800-321-2369

Web Sites:http://www-curator.jsc.nasa.gov/curator/curator.htmhttp://www-curator.jsc.nasa.gov/curator/antmet/

antmet.htmhttp://www-sn.jsc.nasa.govhttp://www.jsc.nasa.gov/pao/educators/http://www.ewu.edu/CNRU/Dept/Antsci/geol/

ANSMET/ANSMET.htmhttp://hurlbut.jhuapl.edu/NEAR/http://pdcsrva.jpl.nasa.gov/stardust/home.htmlhttp://nssdc.gsfc.gov/planetary/planets/

asteroidpage.html

Bibliography

Children’s Books:Asteroids, Comets and Meteors, Gregory L. Vogt, 1996, Millbrook Press, 32 p.Comets and Meteors, Isaac Asimov, 1990, Dell Publishing, 32 p.Magical, Mysterious Meteorites, Madelyn Wood Carlisle, 1992, Barron’s Educational Series Inc., 32p.

Introductory Book:Meteorites: The Key to Our Existence, Robert Hutchison and Andrew Graham, 1992, Natural History

Museum Pub. 60p.

In Depth Books:Rocks from Space, O. Richard Norton, 1994, Mountain Press, 449p.Thunderstones and Shooting Stars: The Meaning of Meteorites, Robert T. Dodd, 1986, Harvard University

Press, 196p.Meteorites and Their Parent Planets, Harry Y. McSween, Jr., 1987,Cambridge University Press, 236p.

Exploring Meteorite Mysteries � Education ResourcesB.2 NASA EG-1997-08-104-HQ

NASA’s Central Operation of Resources for Educators (CORE)was established for the national and international distribution ofNASA-produced educational materials in audiovisual format.Educators can obtain a catalogue and an order form by one of thefollowing methods:

• NASA CORELorain County Joint Vocational School15181 Route 58 SouthOberlin, OH 44074

• Phone (440) 774-1051, Ext. 249 or 293• Fax (440) 774-2144• E-mail [email protected]• Home Page: http://spacelink.nasa.gov/CORE

Educator Resource Center NetworkTo make additional information available to the educationcommunity, the NASA Education Division has created the NASAEducator Resource Center (ERC) network. ERCs contain a wealthof information for educators: publications, reference books, slidesets, audio cassettes, videotapes, telelecture programs, computerprograms, lesson plans, and teacher guides with activities.Educators may preview, copy, or receive NASA materials at thesesites. Because each NASA Field Center has its own areas ofexpertise, no two ERCs are exactly alike. Phone calls are welcomeif you are unable to visit the ERC that serves your geographic area.A list of the centers and the regions they serve includes:

Regional Educator Resource Centers (RERCs) offer moreeducators access to NASA educational materials. NASA has formedpartnerships with universities, museums, and other educationalinstitutions to serve as RERCs in, many states. A complete list ofRERCs is available through CORE, or electronically via NASASpacelink.

NASA On-line Resources for Educators provide currenteducational information and instructional resource materials toteachers, faculty, and students. A wide range of information isavailable, including science, mathematics, engineering, andtechnology education lesson plans, historical information relatedto the aeronautics and space program, current status reports onNASA projects, news releases, information on NASA educationalprograms, useful software and graphics files. Educators andstudents can also use NASA resources as learning tools to explorethe Internet, accessing information about educational grants,interacting with other schools which are already on-line, andparticipating in on-line interactive projects, communicating withNASA scientists, engineers, and other team members to experiencethe excitement of real NASA projects.

Access these resources through the NASA Education Home Page:http://www.hq.nasa.gov/education

or, for more information send an e-mail to:[email protected]

NASA Television (NTV) is the Agency’s distribution system forlive and taped programs. It offers the public a front-row seat forlaunches and missions, as well as informational and educationalprogramming, historical documentaries, and updates on the latestdevelopments in aeronautics and space science. NTV is transmittedon the GE-2 satellite, Transponder 9C at 85 degrees West longitude,vertical polarization, with a frequency of 3880 megahertz, andaudio of 6.8 megahertz.

Apart from live mission coverage, regular NASA Televisionprogramming includes a News Video File from noon to 1:00 pm, aNASA History File from 1:00 to 2:00 pm, and an Education Filefrom 2:00 to 3:00 pm (all times Eastern). This sequence is repeatedat 3:00 pm, 6:00 pm, and 9:00 pm, Monday through Friday. TheNTV Education File features programming for teachers and studentson science, mathematics, and technology. NASA Televisionprogramming may be videotaped for later use.

For more information on NASA Television, contact:NASA Headquarters, Code P-2, NASA TV, Washington, DC20546-0001 Phone: (202) 358-3572Home Page: http://www.hq.nasa.gov/office/pao/ntv.html

How to Access NASA’s Education Materials and Services,EP-1996-11-345-HQ This brochure serves as a guide to accessinga variety of NASA materials and services for educators. Copiesare available through the ERC network, or electronically via NASASpacelink. NASA Spacelink can be accessed at the followingaddress: http://spacelink.nasa.gov.

MSNASA Educator Resource CenterBuilding 1200NASA John C. Stennis Space CenterStennis Space Center, MS 39529-8000Phone: (601 ) 688-3338

NASA Educator Resource CenterJPL Educational OutreachMail Stop CS-530NASA Jet Propulsion Laboratory4800 Oak Grove DrivePasadena, CA 91109-8099Phone: (818) 354-6916

CA cities near the centerNASA Educator Resource Center forNASA Dryden Flight Research Center45108 N. 3rd. Street EastLancaster, CA 93535Phone: (805) 948-7347

KY, NC, SC, VA, WVVirginia Air and Space MuseumNASA Educator Resource Center forNASA Langley Research Center600 Settlers Landing RoadHampton, VA 23669-4033Phone: (757) 727-0900 x 757

VA and MD’s Eastern ShoresNASA Educator Resource Lab EducationComplex - Visitor Center Building J-1NASA Wallops Flight FacilityWallops Island, VA 23337-5099Phone: (757) 824-2297/2298

IL, IN, MI, MN, OH, WINASA Educator Resource CenterMail Stop 8-1NASA Lewis Research Center21000 Brookpark RoadCleveland, OH 44135-3191Phone: (216) 433-2017

AK AZ, CA, Hi, ID, MT NV, OR UT, WA, WYNASA Educator Resource CenterMail Stop 253-2NASA Ames Research CenterMoffett Field, CA 94035-1000Phone: (415) 604-3574

AL, AR, M, LA, MO, TNU.S. Space and Rocket CenterNASA Educator Resource CenterNASA Marshall Space Flight CenterP.O. Box 070015 Huntsville, AL 35807-7015Phone: (205) 544-5812

CT, DE, DC, ME, MD, MA, NH, NJ, NY, PA,Rl, VTNASA Educator Resource LaboratoryMail Code 130.3NASA Goddard Space Flight CenterGreenbelt, MD 20771-0001Phone: (301) 286-8570

CO, KS, NE, NM, ND, OK, SD, TXJSC Educator Resource CenterSpace Center HoustonNASA Johnson Space Center1601 NASA Road OneHouston, TX 77058-3696Phone: (281) 483-8696

FL, GA, PR, VlNASA Educator Resource LaboratoryMail Code ERLNASA Kennedy Space CenterKennedy Space Center, FL 32899-0001Phone: (407) 867-4090

NASA Resources for Educators

Litho I

Litho II

Litho III

Litho IV

Exploring meteorite mysteries - USRA Houston Repository

Documents

Transcript of Exploring meteorite mysteries - USRA Houston Repository