Razor-blades & recent water... (1) - Sol 791

Cracks and fins in the sand in an American desert look very similar to features seen on Mars and may indicate the recent presence of water at the surface, according to a new study by researcher Greg Chavdarian and Dawn Sumner, associate professor of geology at UC Davis.
"Recent, as in ongoing now" Sumner said. Images from MER Opportunity show patterns of cracks across the surface of boulders and outcrops. Some of these cracks are associated with long, thin fins that protrude from the surface. Those features look very similar to cracks and fins that form on the sulfate-rich sands at White Sands National Monument in New Mexico. The Desert National Park has a similar geological environment to the area of Mars visited by Opportunity, Sumner said. Chavdarian spent weeks surveying the features at White Sands for an undergraduate research project. He conducted lab experiments to try and reproduce the effects. He found that the cracks at White Sands only form and grow in damp (--- umida) sand, especially during the wet months of the winter.