These ice caps have frozen carbon dioxide in them too. Scientists think that there might have been regular water on Mars at one time, but they haven't proven it. They are a lot like the asteroids in the asteroid belt. Mars has the tallest mountain of any planet in the solar system. Washington D.C. This sure makes our Grand Canyon look pretty pathetic in comparison.
Scientists think that they have possible evidence for life existing on Mars.
They found tubular structures in Martian meteorites that landed in the Antarctic. Some think that these structures are the fossils of microorganisms that lived on Mars billions of years ago. Through the Universe, 2nd ed.