A Look at the History of Mars
This is probably what happened to Mars:
- an early warm period
- the inside of Mars cools off very fast
- volcanoes appeared, and the Tharsis Bulge is created
- there are changes in climate every once and awhile, which affect the way in which the frozen water of Mars comes to the surface.
The reason that the history of Mars is this way has to do with the fact that Mars is small, and the fact that Mars is farther from the sun that either the Earth or Venus. Some scientists call this the "Goldilocks" phenomenon.