Mars: Where Does the Sand Come From?
Image credit: NASA/JPL-Caltech/Univ. of Arizona
This image from NASA's Mars Reconnaisance Orbiter (MRO) shows one possible place where sand grains are being produced on Mars today. Discovered in images from the Context Camera, this region exhibits dark material that is being eroded from dark layers in the bedrock of a semicircular depression near the boundary of the Southern highlands and the Northern lowlands. Downslope lineations support the notion that these dark sediments are derived locally, and did not accumulate here by coincidence because of the winds.
The grains of sand that make up sand dunes on Earth and Mars have a hazardous existence because of the way that they travel. Wind-blown sand is lifted above the surface of each planet before crashing onto the ground and bouncing in a sequence of repeated hops, a process called saltation.
Source / Image Courtesy
NASA's Curiosity rover has revealed stunning animations of Martian "dust devils" — whirlwinds carrying sand and dust — caused by the red planet's strong summer winds. The car-size Mars rover is currently on a mission to explore Gale Crater.
That's awesome ... all they need now is a beach...