Dust storm season on Mars

Dust storm between late May and early June on Mars
Dust storm season on Mars
Between late May and early June, several different irregular and spiral-shaped dust storms were seen to be forming at the north polar ice cap on Mars. The images shown here were acquired by the High Resolution Stereo Camera on board ESA’s Mars Express spacecraft from an altitude of approximately 10,000 kilometres. The long image strips cover an area of about 2000 by 5000 kilometres, extending from the north pole equatorward to the large volcanoes Olympus Mons and Elysium Mons. The montage of images shows three different storms developing on 22 May, 26 May, and 6 June. In the latter case, the cameras watched the storm evolve until 10 June, as it moved southward towards the volcanoes. Thin patches of light-coloured clouds can be seen at the outer margin of the polar cap and also several thousand kilometres away, close to the Elysium volcanoes. At the same time, wispy clouds can be seen along the edge of the ice cap, and also further south (left), around the large volcanoes. The dark patches are dune fields composed of dust-blown volcanic material on the surface that built a giant erg around the polar cap.