HiRISE images shows part of an unnamed crater, itself located inside the much larger Newton Crater, in Terra Sirenum. This unnamed crater is approximately 7 km in diameter (over 4 miles) and some 700 m (760 yards) deep. Numerous gully systems are visible on the east- and south-facing walls of the crater; their characteristics are astonishingly diverse, though. HiRISE is unveiling the large diversity exhibited by Martian gully systems, thanks to its high-resolution, stereo, and color capabilities. The diverse types of gullies observed may have been produced by different mechanisms. Current leading hypotheses explaining the origin of gullies include erosion from seepage or eruption of water from a subsurface aquifer, melting of ground ice, or surface snow; and dry landslides. This is a colored version of BH5920, which is a cutout from the larger image BH5919.