This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a cluster of impact craters in northwest Arabia Terra near 30.4 deg N, 13.7 deg W. This group of craters may have formed either by secondary impact of debris thrown out of a larger meteor crater, or by the break-up and impact of many fragments from a single incoming object. The picture covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

Photo: NASA/JPL/MSSS

Craters formed by meteor impact are the "tools of the trade" for planetary geologists. Craters have formed on every solid Solar System body, and thus they can be compared to each other and provide insights as to the nature of the object on which the crater occurs. Mars is pocked with craters of a wide range of diameters, from the giant Hellas Basin, which is several thousand kilometers across, to tiny craters of only a few tens of meters in diameter. The impact crater shown in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture is located in northern Elysium Planitia near 33.1°N, 230.2°W. It is about 3.6 km (2.2 mi) across, nearly four times the size of the famous Meteor Crater in northern Arizona on the North American continent. The impact that formed this crater exposed layered bedrock (visible in the upper walls of the crater). Erosion, mostly by dry mass movement, has created gullies and piles of talus on the crater walls. Dark dots at the base of the wall are large boulders that have come down these slopes. The picture covers an area 3 km (1.9 mi) wide. The scene is illuminated by sunlight from the left/lower left.

Photo: NASA/JPL/MSSS

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.