Exploring the Planets

Water on Mars

Mars today is a cold, dry desert with an atmosphere so thin that any surface water evaporates or freezes. But spacecraft have found signs of a warmer and wetter past: sulfur-rich salts and other deposits that could only have formed in a water-rich environment, ancient rivers that carved networks of valleys, and evidence of lakes and vast floods. Much of the early water supply remains frozen in polar ice caps and in ice deposits just beneath the surface.


Eberswalde Crater, Mars