a Giant canyon stretching 20% around Mars, formed by the cooling of the planet, rising of crust and erosion
a system of dry drainage channels on Mars that resembles the beds of rivers and tributary streams on Earth.
Surface feature on Mars, evidence that liquid water once existed there in great quantity, believed to be the relics of catastrophic flooding about 3 billion years ago. Found only in the equatorial regions of the planet.
Atmosphere of Mars
95% CO2, 3% N, & traces of oxygen & H2O
Much less dense than Earth's
Clouds of dry ice (frozen CO2) & water ice crystals drift carried by Martian winds.
No rain b/c it's too cold & forms too little water, but fog, frost, & CO2 snow sometimes occur.
Why is liquid water not stable on mars' surface?
Thin atmosphere, low temperature and pressure for stable liquid