NASA Mars Picture of the Day: 10 Weeks of Change

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-754, 11 June 2004

NASA/JPL/Malin Space Science Systems

These four Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
images show north polar sand dunes as they appeared on four
different days over the past ten weeks. In summer, the dunes
would be darker than the substrate on which they occur. However,
it is currently spring in the northern hemisphere, and the
dunes are still covered with frost from the previous
winter. The MGS MOC has been busy over the past several
months, documenting the changes in frost patterns that
occur on dunes and interdune substrates all over the north
polar region. The site shown here was imaged on 30 March,
23 April, 16 May, and 9 June 2004. The bright frost that covers
the dunes progressively changes from one image to the next,
as dark spots develop and frost sublimes away.
This defrosting dune monitor site is located
near 80.0°N, 237.5°W. Each strip is
about 1.1 km (0.7 mi) wide and
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.