NASA Mars Picture of the Day: Secondary Field 11-01-2004

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-897, 1 November 2004

NASA/JPL/Malin Space Science Systems

The upper right (northeast) quarter of
this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
image shows a concentrated field of small impact craters.
The features form a broad line running approximately
diagonal from northwest toward southeast. These craters
pocked windblown ripples as well as the smooth-surfaced
terrain. These are secondary craters. That is, they formed
second, as the result of a larger impact,
probably within a hundred kilometers or so of this site.
Secondary craters form from impact of the debris
kicked-up by the larger impact event. Instead of rocks
from space (like a meteor), these were formed by rocks
from a nearby place on Mars. This image is located
near 29.7°S, 249.0°W.
The picture covers an area about 3 km (1.9 mi) wide.
Sunlight illuminates the scene from the upper 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.