Explaining the Topography of Mars

June 11, 2013: NASA research indicates hunks of frozen carbon dioxide, dry ice, may glide down some Martian sand dunes on cushions of gas similar to miniature hovercraft, plowing furrows as they go.

"I have always dreamed of going to Mars," said Serina Diniega, a planetary scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and lead author of a report published online by the journal Icarus. "Now I dream of snowboarding down a Martian sand dune on a block of dry ice."

Watch the experimental report at http://youtu.be/mNXBfz1iVzc

This image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter is an example of a type called "linear gullies," which may be explained by slabs of dry ice gliding down the slopes of sand dunes. Image credit: NASA/JPL-Caltech/Univ. of Arizona

Researchers deduced this process could explain one enigmatic class of gullies seen on Martian sand dunes by examining images from NASA's Mars Reconnaissance Orbiter (MRO) and performing experiments on sand dunes in Utah and California.
The hillside grooves on Mars, called linear gullies, show relatively constant width -- up to a few yards, or meters, across -- with raised banks or levees along the sides. Unlike gullies caused by water flows on Earth and possibly on Mars, they do not have aprons of debris at the downhill end of the gully. Instead, many have pits at the downhill end.

Thanks and more at NASA.