Earth & MarsAs Different as they are

Alike

Mars vs. Earth

• Interest in Mars began long before we were able to send spacecraft to the RED Planet…

• What is earth’s nickname?• Name was given by the Romans in honor of their God of war.• Early astronomers were able to see Mars’ brightness and

position changes, but telescopes allowed us to see the surface of Mars.

• It is still a favorite of science fiction writers as the most favorable place in the solar system for human habitation…MARTIANS!

• Orson Wells – War of the Worlds – 1938 – Radio drama that caused a near panic.

Atmosphere

Mars Atmosphere

• Thin atmosphere• Need a space suit to protect you from the sun’s

rays … solar radiation• Extremely cold – rarely climbs above freezing and

can plummet to 200 degrees below 0.• Atmosphere is composed primarily of carbon

dioxide.• Air contains only 1/1,000 as much water as our

air, but it does condense out forming clouds that rise high in the sky.

Mars from Earth

Mars from Earth

• The previous picture was taken Feb 25, 1995.

• Mars was 65 million miles from earth.

• Gets so cold that the carbon dioxide freezes.

• Permanent ice caps at both poles.

Earth vs. Mars

3rd rock from the sun! 4th rock from the sun!(farther from the sun)

Year – 365 days Year – 686.7 Earth days(orbits the sun slower)

Day – 24 hours Day – 24.6 Earth hours(rotates on axis slower)

Size – 12,756 km Size – 6,794 km

Temp - -127°F - 136°F Temp - -190°F - 75°F

Satellites – 1 Moon Satellites – 2 Moons

Eccentricity – .017 Eccentricity – .093

Rotational axis tilt – 23.5 ° Rotational axis tilt – 25°

Extreme Temperaturesat Mar’s Equator

32º F

70º F

Mar’s Gravity – 1/3 of Earth’s

Surface of Mars

Image from the Viking 2 Lander – Notice the frost on the ground.

Mars is similar to the Moon

Image from the heavily cratered Southern hemisphere.

Impact Crater

Olympus Mons – Volcano!

Giant shield volcano 550 km across (about the size of the state of Colorado.)

Compare Mountains

Mars Seasons

North Days South

summer 183 winterfall 147 springwinter 158 summerspring 199 fall

Mars rotational axis tilts towards the sun at angle of 25°. Earth has a similar tilt of 23.5°. This tilt causes the seasons on both planets. The eccentricity (lack of being circular) of Mars results in seasons of unequal length.

Credits

• V01AQTOH.pdf – in pdsmovies folder