保护地球，探索宇宙，发现文明
2021年01月06日 Striped Sand Dunes on Mars Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA; Processing: Włodek Głażewski; Text: Alex R. Howe (NASA/USRA, Reader’s History of SciFi Podcast) Explanation: Why are these sand dunes on Mars striped? No one is sure. The featured image shows striped dunes in Kunowsky Crater on Mars, photographed recently with the...
2020年8月29日 Martian Chiaroscuro Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA Explanation: Deep shadows create dramatic contrasts between light and dark in this high-resolution close-up of the martian surface. Recorded on January 24, 2014 by the HiRISE camera on board the Mars Reconnaissance Orbiter, the scene spans about 1.5 kilometers. From 250 kilomete...
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...