NASA/JPL/Malin Space Science Systems
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows troughs and a pit chain (on the floor of the deeper trough) located immediately northeast of the giant Tharsis volcano, Arsia Mons. Lava flows have been cut by these troughs, which formed along fault lines when the crust expanded and rock between the fault lines was raised up or dropped down relative to its original position. Troughs formed in this way are known as graben. This image is located near 7.1°S, 115.0°W. The scene covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight 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.