A Complex Geologic History of Aram Chaos

This 280-kilometer diameter crater center has experienced a long history of water activity. Within the crater is a heavily faulted and fractured terrain called Aram Chaos that consists of darker volcanic rocks that were disrupted as a result of water and/or magma withdrawal in the subsurface.

Above this chaotic terrain are brighter materials made up of different kinds of sulfates that formed when water filled the crater. CRISM data collected along with HiRISE images indicate that the sulfates consist of monohydrated, polyhydrated, and ferric hydroxysulfate, with each composition representing a different geochemical environment within the waters that once resided within Aram Chaos.

The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. (The original image scale is 28.6 centimeters [11.3 inches] per pixel [with 1 x 1 binning] to 57.1 centimeters [22.5 inches] per pixel [with 2 x 2 binning].) North is up.

The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.