The surface is cratered, but not as much as our Moon or Mercury. The craters have probably been weather worn over the years by fierce, planet-wide Martian windstorms. These windstorms are common on the red planet, lifting rust-colored dust well up into the atmosphere encircling the entire globe. The rest of Mars has patches of green. But it is not clear what is producing this green color as it certainly is not vegetation.
Evidence does exist in the terrain that water has eroded some of the soil.
No flowing water is present today, but could have been in the past. A NASA research team in 1984 found a meteorite in Antarctica which may have come from Mars. The meteorite was dated back 4.5 billion years, and researchers theorize that Mars may have been a warmer and wetter place about 3.5 billion years ago. This is due to some evidence of microscopic life left in the rock. At present, Mars' water appears to be trapped in its polar ice caps and possibly below the surface.