NASA Mars Picture of the Day: Barchan Dunes

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-710, 28 April 2004

NASA/JPL/Malin Space Science Systems

One of the simplest forms a sand dune can take is the barchan.
The term comes from the Arabic word for crescent-shaped dunes. They
form in areas with a single dominant wind direction that are
also not overly-abundant in sand. The barchan dunes shown here
were imaged in March 2004 by the
Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
as it passed over a crater in western Arabia Terra
near 21.1°N, 17.6°W. The horns and steep slope on each
dune, known as the slip face, point toward the south,
indicating prevailing winds from the north (top).
The picture covers an area about 3 km (1.9 mi) across and is
illuminated by sunlight from the lower left.

Malin Space Science Systems and the California Institute of Technology
built the MOC using spare hardware from the Mars Observer mission.
MSSS operates the camera from its facilities in San Diego, California.
The Jet Propulsion Laboratory’s Mars Surveyor Operations Project
operates the Mars Global Surveyor spacecraft with its industrial
partner, Lockheed Martin Astronautics, from facilities in Pasadena,
California and Denver, Colorado.