This new image from NASA’s Mars Reconnaissance Orbiter reveals dark, windblown sand covering intricate sedimentary rock layers in Ganges Chasma, a canyon in the Valles Marineris system.
These features are at once familiar and unusual to those familiar with Earth’s beaches and deserts. Most sand dunes on Earth are made of silica-rich sand, giving them a light color; these Martian dunes owe their dark color to the iron and magnesium-rich sand found in the region.
The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. The original image scale is 26.7 centimeters (10.5 inches) per pixel (with 1 x 1 binning); objects on the order of 80 centimeters (31.5 inches) across are resolved. North is up.