This image from NASA's Mars Global Surveyor 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.

24 July 2006
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.

Location near: 33.0°S, 213.4°W
Image width: ~3 km (~1.9 mi)
Illumination from: upper left
Season: Southern Autumn

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