•Pressure is only ~1% of Earth’s
•Composition:
95% CO2
3% N2 2% Ar
•
•Water:
–Pressure too low for liquid water to
exist
•Water
goes directly from solid phase to gas phase
•CO2 (dry ice) acts like this even at
terrestrial atmospheric pressure
–Water seen in atmosphere
–Water seen in polar caps
–Evidence of running water in past
–
•Carbon dioxide (CO2)
–Gets cold enough for even this to freeze
at polar caps
–Unusual
meteorology, as atmosphere moves from one pole to other each
“year”