Transcript Mars: The Red Planet

Earth & Mars
As 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 Temperatures
at 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
fall
winter
spring
183
147
158
199
winter
spring
summer
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