NASA Mars Picture of the Day: Ceraunius Tholus Feature

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-937, 11 December 2004

NASA/JPL/Malin Space Science Systems

Today’s Mars Picture of the Day features two images. The
top picture is a mosaic of Viking orbiter images acquired
in the late 1970s. The lower image is a high resolution
picture from the
Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC).
The Viking mosaic shows Ceraunius Tholus, a volcano in
the Tharsis region that was first viewed in images obtained
by Mariner 9 in 1972. Several channels run down the slope
of the Ceraunius Tholus volcano. The deepest of those channels
ends in an elliptical crater. The elliptical crater
was formed by a very oblique meteor impact. Where the channel
meets the floor of the elliptical crater, there is a small
mound of material. Presumably, this material was deposited
in the elliptical crater after running down through the
channel on the volcano’s northwest flank.

Near the top/center of the mound in the elliptical crater
is a small, circular depression. Some have speculated
for years that this depression is related to volcanism,
others thought that it may be an impact crater. The MGS MOC
image (lower of the two images) shows that crater. It is not
the source of lava flows or any other volcanic features. Most
likely, it is an old impact crater. This feature is located
near 25.2°N, 97.7°W. The MOC image covers an area
approximately 3 km (1.9 mi) wide 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.