火星上融化的沙丘
2019 September 24 Sand Dunes Thawing on Mars Image Credit & License: ESA, Roscosmos, CaSSIS Explanation: What are these strange shapes on Mars? Defrosting sand dunes. As spring dawned on the Northern Hemisphere of Mars, dunes of sand near the pole, as pictured here in late May by ESA’s ExoMars Trace Gas Orbiter, began to thaw. The carbon dioxide an...