Martian Dunes


An amazing shot of a Martian dunescape. The dunes are dark grayish basalt. The red is typical Martian dust. The tendrils?

In the Martian winter, carbon dioxide freezes out of the air (and you thought it was cold where you are). In the summer, that CO2
sublimates; that is, turns directly from a solid to a gas. When that
happens the sand gets disturbed, and falls down the slopes in little
channels, which spreads out when it hits the bottom. But this disturbs
the red dust, too, which flows with the sand. When it’s all done, you
get those feathery tendrils. Note that at the tendril tips, you see
blotches of red; that’s probably from the lighter dust billowing a bit
before settling down.

Posted January 13, 2010 at 4:55pm ETC by Andy Towle
in News, Space