NASA Mars Picture of the Day: Sand Dunes in Noachis Terra

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-633, 11 February 2004

NASA/JPL/Malin Space Science Systems

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
image shows dark-toned sand dunes in a crater in eastern
Noachis Terra. Most big martian dunes tend to be dark,
as opposed to the more familiar light-toned dunes of
Earth. This difference is a product of the composition
of the dunes; on Earth, most dunes contain abundant
quartz. Quartz is usually clear (transparent), though
quartz sand grains that have been kicked around by wind
usually develop a white, frosty surface. On Mars, the sand
is mostly made up of the darker minerals that comprise
iron- and magnesium-rich volcanic rocks–i.e., like
the black sand beaches found on volcanic islands like
Hawaii. Examples of dark sand dunes on Earth are found in
central Washington state and Iceland, among other places.
This picture is located
near 49.0°S, 326.3°W.
Sunlight illuminates this scene from the upper left; the image
covers an area 3 km (1.9 mi) wide.

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.