April 19, 2017 – This image from NASA’s Mars Reconnaissance Orbiter (MRO) shows the location with the most impressive known gully activity in Mars’ northern hemisphere. Gullies are active in the winter due to carbon dioxide frost, but northern winters are shorter and warmer than southern winters, so there is less frost and less gully activity.
An enhanced-color image cutout shows recent gullies with bright colors.
The map is projected here at a scale of 50 centimeters (19.7 inches) per pixel. [The original image scale is 61.5 centimeters (24.2 inches) per pixel (with 2 x 2 binning); objects on the order of 185 centimeters (72.8 inches) across are resolved.] North is up
The Mars Reconnaissance Orbiter, built by Lockheed Martin Space Systems in Littleton, Colorado, has been orbiting Mars since 2006. The powerful HiRise camera was built by Ball Aerospace & Technologies Corp. in Boulder, Colorado.
The University of Arizona, Tucson, operates HiRISE. 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. Lockheed Martin Space Systems collaborates with JPL to operate the spacecraft.