National A

eronautics andS

pace A

dm

inistrationM

ars

LG

-2000-10-481-HQ

The red planet M

AR

Shas inspired w

ild flights of imagi-

nation over the centuries,as well as intense scientific inter-

est. Whether fancied to be the source of hostile invaders of

Earth,the hom

e of a dying civilization,or a rough-and-tum

ble mining colony of the future,M

ars provides fertileground for science fiction w

riters,based on seeds plantedby centuries of scientific observations.

We know

that Mars is a sm

all rocky body once thought tobe very E

arth-like. Like the other “terrestrial”

planets—M

ercury,Venus,and E

arth—its surface has been changed

by volcanism,im

pacts from other bodies,m

ovements of

its crust,and atmospheric effects such as dust storm

s. Ithas polar ice caps that grow

and recede with the change of

seasons; areas of layered soils near the Martian poles sug-

gest that the planet’s climate has changed m

ore than once,perhaps caused by a regular change in the planet’s orbit.M

artian tectonism—

the formation and change of a planet’s

crust—differs from

Earth’s. W

here Earth tectonics involve

sliding plates that grind against each other or spread apartin the seafloors,M

artian tectonics seem to be vertical,w

ithhot lava pushing upw

ards through the crust to the surface.Periodically,great dust storm

s engulf the entire planet. The

effects of these storms are dram

atic,including giant dunes,w

ind streaks,and wind-carved features.

Scientists believe that 3.5 billion years ago,Mars experi-

enced the largest known floods in the solar system

. This

water m

ay even have pooled into lakes or shallow oceans.

Yet the central question about M

ars remains:w

here is thew

ater? Where did the ancient flood w

ater come from

,howlong did it last,and w

here did it go? At the present,M

arsis too cold and its atm

osphere is too thin to allow liquid

water to exist at the surface for long. W

e know that som

ew

ater exists today frozen in the polar ice caps,and enoughw

ater exists to form ice clouds,but the quantity of w

aterrequired to carve M

ars’great channels and flood plains isnot evident on the surface today. R

ecent images from

NA

SA’s M

ars Global Surveyor spacecraft suggest that

underground reserves of water m

ay break through the sur-face as springs. U

nraveling the story of water on M

ars isim

portant to unlocking its past climate history,w

hich will

help us understand the evolution of all planets,includingour ow

n. Water is also believed to be a central ingredient

for the initiation of life; the evidence of past or presentw

ater on Mars is expected to hold clues about past or pre-

sent life on Mars,as w

ell as the potential for life elsewhere

in the universe. And,before hum

ans can safely go to Mars,

we need to know

much m

ore about the planet’s environ-m

ent,including the availability of resources such as water.

Mars has som

e remarkable geological characteristics

including:the largest volcanic mountain in the solar sys-

tem,O

lympus M

ons (27 km high and 600 km

across); vol-canoes in the northern T

harsis region that are so huge theydeform

the planet’s roundness; and a gigantic equatorialrift valley,the V

alles Marineris. T

his canyon systemstretches a distance equivalent to the distance from

New

York to L

os Angeles; A

rizona’s Grand C

anyon could easi-ly fit into one of the side canyons of this great chasm

.

Mars also has tw

o small m

oons,Phobos and Deim

os.A

lthough no one knows how

they formed,they m

ay beasteroids snared by M

ars’gravity.

Fa

st Fa

cts

Nam

esakeR

oman G

od of War

Distance from

SunM

aximum

249 million km

Minim

um206 m

illion kmD

istance from E

arthM

aximum

399 million km

Minim

um56 m

illion kmR

otational Period

24.6 hoursE

quatorial Diam

eter6,786 km

Equatorial Inclination to E

cliptic25º.2

Gravity

38% of E

arth’sA

tmosphereM

ain Com

ponentC

arbon Dioxide

Pressure at Surface

4–8 millibars (vs 1,013 on E

arth)Tem

perature Range

-143ºC to +

17ºCM

oons (2)Phobos (Fear),21 km

mean diam

eterD

eimos (Panic),12 km

mean diam

eterR

ingsN

oneO

rbital Eccentricity

0.093O

rbital Inclination to Ecliptic

1º.85M

agnetic Field D

ensityL

ocalized at surface;not global.

Sig

nific

ant D

ate

s1965—

Mariner 4 m

ade first close-up pictures of the surface during flyby.

1969—M

ariner 6 and Mariner 7 flybys resulted in high resolution

images of the equatorial region and southern hem

isphere.1971—

Mariner 9 becam

e first satellite to orbit another planet.1973—

U.S.S.R

. Mars 3 and M

ars 5 first attempt to land on M

ars.1976—

U.S.A

. Vikings 1 and 2 orbited M

ars. Viking L

ander 1 provided first sustained surface science. V

iking Lander 2

discovered water frost on the surface.

1988—U

.S.S.R. probe Phobos returned detailed pictures of

Phobos.1996—

Launch M

ars Global Surveyor and M

ars Pathfinder.1997—

Mars Pathfinder lands on M

ars. Sojourner Rover

explores Ares V

allis area for 3 months.

1997—M

ars Global Surveyor m

aps the surface of Mars from

orbit.present

_________________________________R

eferences1)

Mars E

xploration:http://mars.jpl.nasa.gov/

2)Planetary Photo Journal:http://photojournal.jpl.nasa.gov/

3)V

iews of the Solar System

:http://ww

w.solarview

s.com/eng/m

ars.htm

4)Stardate,T

he University of Texas of A

ustin,McD

onald Observatory,

2609 University A

ve.,#3.118,Austin,T

X 78712

Mars 6 Inch M

ini Globes

FLA

GS

TA

FF, A

RIZ

ON

A

A

A

-6-8

-4 0

-2 2

6 4

81

21

01

4+

EL

EV

AT

ION

(kilo

meters)

A

North Hemisphere

Mars Digital Image Mosaicin a "Flower Petal" Projection for Making Globes

FLAGSTAFF, ARIZONA

Instructions for constructing a 6 inch mini globe1.) Cut out the north and south hemispheres. Make sure to remove all the white space surrounding the petals.2.) After adding a small amount of glue to the center of the north hemisphere, glue it onto the 6 inch globe.3.) Glue each petal down, starting at one end and proceeding in order around the 6 inch globe.4.) Place a small amount of glue on the south hemisphere petal labeled with an 'A'. Line up this petal with the corresponding northern hemisphere petal which is also labeled with an 'A' and glue to the 6 inch globe.5.) Glue down the center of the southern hemisphere.6.) Glue each remaining petal down, starting next to the petal already in place and proceeding in order around the 6 inch globe.

A

South Hemisphere

Mars Digital Image Mosaicin a "Flower Petal" Projection for Making Globes

FLAGSTAFF, ARIZONA

Instructions for constructing a 6 inch mini globe1.) Cut out the north and south hemispheres. Make sure to remove all the white space surrounding the petals.2.) After adding a small amount of glue to the center of the north hemisphere, glue it onto the 6 inch globe.3.) Glue each petal down, starting at one end and proceeding in order around the 6 inch globe.4.) Place a small amount of glue on the south hemisphere petal labeled with an 'A'. Line up this petal with the corresponding northern hemisphere petal which is also labeled with an 'A' and glue to the 6 inch globe.5.) Glue down the center of the southern hemisphere.6.) Glue each remaining petal down, starting next to the petal already in place and proceeding in order around the 6 inch globe.

A

Mars Topographyin a "Flower Petal" Projection for Making Globes

-6-8 -4 0-2 2 6 4 8 1210 14+

ELEVATION (ki lometers)

North HemisphereFLAGSTAFF, ARIZONA

Instructions for constructing a 6 inch mini globe1.) Cut out the north and south hemispheres. Make sure to remove all the white space surrounding the petals.2.) After adding a small amount of glue to the center of the north hemisphere, glue it onto the 6 inch globe.3.) Glue each petal down, starting at one end and proceeding in order around the 6 inch globe.4.) Place a small amount of glue on the south hemisphere petal labeled with an 'A'. Line up this petal with the corresponding northern hemisphere petal which is also labeled with an 'A' and glue to the 6 inch globe.5.) Glue down the center of the southern hemisphere.6.) Glue each remaining petal down, starting next to the petal already in place and proceeding in order around the 6 inch globe.

A

South Hemisphere

Mars Topographyin a "Flower Petal" Projection for Making Globes

-6-8 -4 0-2 2 6 4 8 1210 14+

ELEVATION (ki lometers)

FLAGSTAFF, ARIZONA

Instructions for constructing a 6 inch mini globe1.) Cut out the north and south hemispheres. Make sure to remove all the white space surrounding the petals.2.) After adding a small amount of glue to the center of the north hemisphere, glue it onto the 6 inch globe.3.) Glue each petal down, starting at one end and proceeding in order around the 6 inch globe.4.) Place a small amount of glue on the south hemisphere petal labeled with an 'A'. Line up this petal with the corresponding northern hemisphere petal which is also labeled with an 'A' and glue to the 6 inch globe.5.) Glue down the center of the southern hemisphere.6.) Glue each remaining petal down, starting next to the petal already in place and proceeding in order around the 6 inch globe.