Martian dunes in winter - March: Winter view of Dunes - Detail on dunes in...

Martian dunes in winter - March: Winter view of Dunes - Detail on dunes in a crater located in the southern hemisphere of Mars. Clearly, areas covered with gel appear on this image obtained by the HIRISE camera of the Mars Reconnaissance probe orbiter on November 25, 2006. HIRISE is a 50 cm telescope that observes visible and near infrared. Dunes within a crater on Mars are visible in this HiRise image. This crater is located in the southern hemisphere where it was winter at the time this image was taken on November 25, 2006. This observation documents new seasonal processes occurring on dunes at this latitude, as well as other interesting phenomena. The bright tones are interpreted as carbon dioxide or water frost. This is generally concentrated on the east - facing slopes of the dunes, which are in shadow and therefore cooler. Some dark spots on the dunes may be areas that have defrosted more than surrounding terrain. Landslides and dark - toned streaks are seen on many of the west - facing dune slopes. The general dune morphology indicates formation by westerly winds