Gullied Recesses On Mars

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies on the wall of a martian south mid-latitude impact crater. The channels in each gully head beneath an eroding overhang of layered rock, providing support for the hypothesis that some—if not all—martian gullies result from release of groundwater to the surface. MGS MOC Release No. MOC2-1533, 24 July 2006

Credits: NASA/JPL/Malin Space Science Systems