MGS MOC Release No. MOC2-547, 17 November 2003

This November 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows gullies, sand dunes, and streaks formed by dust devils in southern Galle Crater. The gullies are seen in the upper left (northwest) corner; they originate at layered rock exposures on a hillslope, and meander downslope through a deposit of dark, windblown sand. The gullies might have formed by running water. All of the darker surfaces in this image are dunes; these dunes were covered with bright dust during the previous winter (it is now summer in the southern hemisphere of Mars). Dust devils have been darkening the dunes by removing or disrupting the coating of dust, leaving behind a chaotic plethora of darks streaks. The image is located near 51.9°S, 31.4°W. The area shown is about 3 km (1.9 mi) wide by 6.8 km (4.2 mi) high. Sunlight illuminates the scene from the upper left.