Valley Networks in the Ancient Martian Highlands

The valley networks on Mars are terrains eroded by flowing water billions of years ago.

In places where the bedrock is well exposed, we often see a variety of colors due to altered minerals and polygonal patterns perhaps due to wet, clay-rich deposits.

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