26 April 2006
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark-toned sand dunes on the floor of Russell Crater in south-central, Noachis Terra. A dune at the right (east) edge of the image is host to several small gullies whose channels extend predominantly to the west-southwest. The formation of these features is not well-understood, but they might result from a combination of downslope movement of sand and a lubricating agent, perhaps carbon dioxide gas or water that had been trapped in the dune as ice. The randomly-oriented dark streaks seen on the dunes and on the interdune surfaces were created by the passage of spring and summertime dust devils.
Location near: 54.7°S, 347.4°W
Image width: ~3 km (~1.9 mi)
Illumination from: upper left
Season: Southern Summer