Nasa says downslope lineations support the notion that these dark sediments are derived locally, and did not accumulate here by coincidence because of the winds. Photo: AFPWashington: Nasa’s Mars Reconnaisance Orbiter (MRO) has beamed back an image showing one possible place where sand grains are being produced on the red planet on Wednesday. The grains of sand that make up sand dunes on Earth and Mars have a hazardous existence because of the way that they travel. Sand grains can also roll along the ground as they are blown by the wind, and they are also jostled by other sand gains that are similarly flying across the surface. This process, known as comminution, ultimately destroys sand grains and limits the length of time that the particles exist.

Source: Mint October 11, 2017 09:22 UTC