sand dune tagged posts

Two sizes of ripples are evident in this Dec. 13, 2015, view of a top of a Martian sand dune, from NASA’s Curiosity Mars rover. Sand dunes and the smaller type of ripples also exist on Earth. Credit: NASA/JPL-Caltech/MSSS

Some of the wind-sculpted sand ripples on Mars are a type not seen on Earth, and their relationship to the thin Martian atmosphere today provides new clues about the atmosphere’s history. The determination that these mid-size ripples are a distinct type resulted from observations by NASA’s Curiosity Mars rover. 6 months ago, Curiosity made the first up-close study of active sand dunes anywhere other than Earth, at”Bagnold Dunes” on the NW flank of Mount Sharp.

“Earth and Mars both have big sand dunes and small sand ripples, but on Mars, there’s something in between that w...