NASA Mars Picture of the Day: Rock Slide in Ophir

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-719, 7 May 2004

NASA/JPL/Malin Space Science Systems

The dark streaks, just left of center, on the steep slope in
this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
image were formed by a relatively recent rock slide.
The streak closest to the center of the image resolves into
a series of small depressions, indicating the path of a large,
rolling boulder. The rock slide is inferred to have been
recent (i.e., within the past several Mars years) because it is
so much darker than its surroundings—there has not been
sufficient time for the streak surfaces to become mantled
by dust. The other talus accumulations on this slope are
most likely lighter in tone because they are older and coated
with dust. These features are located in Ophir Chasma, part of
the Valles Marineris trough system,
near 4.2°S, 74.0°W. The picture is illuminated
by sunlight from the lower left and
covers an area about 3 km (1.9 mi) across.

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.