Watch exclusive image of blue dune. NASA has shared the stunning image after taking to Twitter handle and posted comments in which it said: Once in a blue dune ... on the floor of the Lyot Crater on Mars lies a field of dunes. One particular dune, seen in this January view, appears turquoise blue in enhanced color& is made of a different composition than the surrounding dune field. Mars is currently under the grip of a massive dust storm. Watch the video for more info.