Martian sand dunes. Coloured satellite image of sand dunes in the north polar region of Mars. The sand has been blown into crescent and dome shapes by

---

Martian sand dunes. Coloured satellite image of sand dunes in the north polar region of Mars. The sand has been blown into crescent and dome shapes by the wind. Dark-coloured patches are areas where the surface layer of carbon dioxide frost has sublimated (turning from sold directly to gas) and exposed the basaltic layer beneath. Image obtained by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter (MRO) on 30th January 2008. The width of this image is roughly kilometres across.

---

Size: 4048px × 6187px
Photo credit: © NASA/JPL/UNIVERSITY OF ARIZONA/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: 2008, 21st, aeolian, arid, basalt, basaltic, blown, camera, century, crescent, deposition, dome, dune, dunes, erosion, exposed, exposure, geographical, geography, geological, geology, high, hirise, image, imaging, mars, martian, mission, mro, nasa, north, orbiter, planetary, polar, poles, reconnaissance, resolution, rock, rocks, sand, satellite, science, solar, space, sublimates, sublimating, sublimation, sublime, surface, system, thawing, vaporisation, vaporise, vaporize, volcanic, wind, windblown