30 March 2004
Erosion has created a wide variety of landforms in the Cydonia region of Mars. Located in a zone of transition from cratered highlands to northern plains, Cydonia is a jumble of thousands of massifs, mesas, buttes, and hills---remnants of ancient cratered highlands in a state of advanced erosion. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a crater, slightly smaller than the famous 1 kilometer-diameter (0.62 miles) Meteor Crater in Arizona, U.S.A., that has been left standing high relative to the surrounding terrain because erosion removed most of the rock into which this crater originally formed. Later processes have mantled the crater and surroundings with debris that, at a finer scale, has also been eroded over time. This image occurs near 40.1°N, 13.6°W, and covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.