Mars
Claim:
Mars is the planet
most similar to Earth
Evidence of similarity:
• Day length
• Axis tilt
• Seasons
• Surface gravity
• Polar ice caps
Size Comparison
• Mars’ diameter is roughly half of Earth’s
diameter.
• So, the surface area of Mars is roughly a
quarter of the surface area of Earth.
• So is the dry land on Earth
• So, the surface area of Mars is about the
same as the dry land area of Earth!
Mars
• Claim: Although Mars is the
planet most similar to Earth,
it is still very hostile to life (as
we know it)
Evidence of hostility:
• 1. Pretty Cold
•
Temperature is -130 C to 10 C
•
Average temperature is – 50 C (frosty)
• Solution: We will need to wear warm clothing
Evidence of hostility:
• 2. Very dry
•
No liquid water at all
(water would freeze or evaporate almost
instantly on the surface of Mars)
Solution: we will need to cover our mouth,
nose, and eyes, and carry water to drink
Evidence of hostility:
• 3. Thin Atmosphere (low pressure)
•
No oxygen
•
No ozone
• Solution: We will need to wear a pressure
suit
• We will need to carry a supply of air
• We will need UV protection
Weather on Mars
• Windy (carbon dioxide sublimes from the
summer pole, creates more pressure,
blows toward the winter pole)
• A third of the atmosphere snows out onto
the pole in deep winter!
• Dust devils
• Seasonal dusting of the dark grey highlands by
orange powder (iron oxide)
• Sky is brownish pink rather than deep blue
Surface Features
• Volcanoes, Tharsis plateau
• Olympus Mons, 25 km (16 miles) high
Valles Marineris,
3000 km (2000 miles) long
Valles Marineris, strong rim
Slumping in Ophir Chasma
View from Viking Lander 1
Evidence of ancient water
• Drainage patterns
Sedimentary layers exposed by
erosion from wind
Water ice lake in a crater
New deposit, between 1999 and
2005
Ancient ocean?
Ceraunius Tholus Volcano,
100x130 km, 6.6 km high
Note the unusual oval crater.
Craters on Mars
(Yuty has mud ejecta)
Remnant crustal magnetism,
another puzzle on Mars
Mars is smaller than Earth
www.black-cat-studios.com
Mars analog in Utah winter
Mars in shaded relief
from www.spacegrant.hawaii.edu/class_acts/MarsDoc.html
Red = lava, green=dry river valleys, brown=deep
craters, Blue=possible edge of ancient ocean
Landing sites of spacecraft
Sojourner investigates Yogi
What does a rover spend its
time doing?
• To go 10 meters takes the rover ________
• To go 100 meters it would take the rover
____________
• A rover usually goes only 100 m in a day.
• One day (sol) on Mars is ___________
• So, what does the rover spend most of its
time doing? ________________________
Summary questions
• What is the evidence that Mars is similar
to Earth?
• What is the evidence that Mars is hostile
to life as we know it?
• If humans go to Mars what would they
have to do to overcome these hostilities?
• What is the evidence for past liquid water
on Mars?