Nasa has caught a unique picture of a towering dust devil on Mars. The dust devil shadow appears like a serpentine shadow over the Martian surface.
Astronomers from Nasa took the picture from the High Resolution Imaging Science Experiment (HiRISE) camera on Nasa's Mars Reconnaissance Orbiter. HiRISE captured the image on 16 Febwhen the orbiter passed over the Amazonis Planitia region of northern Mars.
The length of the shadow indicates that the dust plume reaches more than 800 metres, or half a mile, in height. Astronomers also found that the unique serpentine curve in the plume was produced by a westerly breeze that blew on top of the plume towards the east.
Dust devils are strong whirlwinds. Daredevils range in different sizes from small (half a metre wide and a few metres tall) to large (more than 10 metres wide and more than 1,000 metres tall). Dust devils occur on earth as well as on Mars. A dust devil typically forms on a clear day when the ground is heated by the sun. As the heated air near the surface rises quickly through a small pocket of cooler air above it, it begins to rotate.
Watch the video: