Mars From Afar
Gullies
Not dramatically different from a mountainside in, say, the American
Southwest, this weathered wall of a crater displays gullies that
might have been carved by groundwater flowing downhill. Wintertime
frost dusts the wall, while below on the crater floor you can see
dunes sculpted by the wind. The Mars Global Surveyor's narrow-angle
camera took the shot, which was then "colorized" using actual colors
of the surface obtained by the spacecraft's wide-angle cameras.