Mysterious Martian Gouges Carved By Sand-surfing Dry Ice

sciencehabit writes: After the Mars Reconnaissance Orbiter began beaming back close-up images of the Red Planet, researchers spotted peculiar features along the slopes of dunes: long, sharply defined grooves that seem to appear and disappear seasonally. They look like trails left behind by tumbling boulders, but rocks never appear in the sunken pits at the trail ends. Researchers initially took these gullies as signs of flowing liquid water, but a new model suggests they're the result of sand-surfing dry ice that breaks off from the crests of dunes and skids down slopes. This is no ordinary tumble — according to the model, the bases of the chunks are continually sublimating, resulting in a hovercraftlike motion that gouges the dune while propelling the ice down slopes.

Comments

and on earth...

[swell]

This reminds me of the recent controversy over the mysterious sailing stones of Death Valley California.
http://worldgeographicchannel....

Many attempted to explain the phenomena but only a cleverly timed photographic sequence was able to explain the relatively simple process by which stones moved across the sand. Not everything on earth and in the heavens is beyond human comprehension.