Herschel Crater is a 300 kilometer (186 mi) wide impact basin
located in the martian southern cratered highlands at 14.5°S,
230°W. The floor of this ancient crater exhibits patches of
dark material that, when viewed by the high resolution Mars
Orbiter Camera (MOC) aboard the Mars Global Surveyor (MGS) spacecraft,
resolve into fields of sand dunes. In detail, these dunes have a grooved,
lineated surface. These grooves indicate that the dune sands are
cemented together and have been eroded and scoured by wind. The age
of the dunes and how their sands became cemented are unknown.
Sunlight illuminates this March 2001 scene from the upper left. The box in
the upper left corner shows the location of the high resolution view,
the 400 m scale bar is ~437 yards.
Image Credit: NASA/JPL/Malin Space Science Systems