This image from the Mars Reconnaissance Orbiter’s HiRISE camera features a barchan dune within the floor of Arkhangelsky Crater on Mars, one of its forward-facing “horns” displaying a sharp, serpentine ridge.
The dunes in Arkhangelsky Crater are made of darker-colored material than the surrounding landscape, although the image above is not quite true color. (For a color view of the region imaged, click here.) Also present in this area are the faded tracks of dust devils that have cut across the dunes…not easily visible in the color image above, they can be discerned in this monochrome image.
Barchan dunes (pronounced “barkan”) are found in many places on Mars as well as on Earth. They are formed by the pile-up of windblown sand particles, and their steepest “slip face” slope always faces in the direction of the wind with their longer face slope trailing behind. Wind-driven, they move across the landscape horns first.
Read more about the formation of barchan sand dunes here.
The degraded Arkhangelsky Crater is in the southern hemisphere of Mars, and is approximately 50 miles across.
Image: NASA / JPL / University of Arizona