NASA Mars Picture of the Day: Boulder Rings

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-867, 2 October 2004

NASA/JPL/Malin Space Science Systems

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
image shows raised-rimmed, circular features sometimes
described as “boulder rings.” These are located on the vast
martian northern plains, and they are, basically, somewhat
filled and somewhat buried meteor impact craters. The
small, dark dots on these rings are boulders derived
from the craters’ ejecta and perhaps from erosion of the rock
in which the craters formed. This image is located
near 70.4°N, 310.4°W, and
covers an area about 3 km (1.9 mi) across.
Sunlight illuminates the scene 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.