THEMIS Image of the Day, November 30, 2017. Today’s image of the southern section of the canyon shows a large region of sand dunes. The presence of dunes indicates wind action as the most recent geologic process modifying the canyon. The dunes’ dark tint suggests they are relatively free of dust, hence likely active currently.
Melas Chasma is part of the largest canyon system on Mars, Valles Marineris. At only 563 km long (349 miles) it is not the longest canyon, but it is the widest.
Located in the center of Valles Marineris, it has depths up to 9,000 meters (30,000 feet) from the surrounding plains, and is the location of many large landslide deposits, as will as layered materials and sand dunes. There is evidence of both water and wind action as modes of formation for many of the interior deposits.
NASA’s Mars Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69,000 times. It holds the record for longest working spacecraft at Mars. THEMIS, the IR/VIS camera system, has collected data for the entire mission and provides images covering all seasons and lighting conditions.
Over the years many features of interest have received repeated imaging, building up a suite of images covering the entire feature. From the deepest chasma to the tallest volcano, individual dunes inside craters and dune fields that encircle the north pole, channels carved by water and lava, and a variety of other feature, THEMIS has imaged them all.
For the next several months the Image of the Day will focus on the Tharsis volcanoes, the various chasmata of Valles Marineris, and the major dunes fields. We hope you enjoy these images!
More THEMIS Images of the Day by geological topic.