保护地球，探索宇宙，发现文明
2022年5月3日 Mercury’s Sodium Tail Image Credit & Copyright: Sebastian Voltmer Explanation: That’s no comet. Below the Pleiades star cluster is actually a planet: Mercury. Long exposures of our Solar System’s innermost planet may reveal something unexpected: a tail. Mercury’s thin atmosphere contains small amounts of sodium that glo...
2021年03月08日 Three Tails of Comet NEOWISE Image Credit & Copyright: Nicolas Lefaudeux Explanation: What created the unusual red tail in Comet NEOWISE? Sodium. A spectacular sight back in the summer of 2020, Comet NEOWISE, at times, displayed something more than just a surprisingly striated white dust tail and a pleasingly patchy blue ion tail. Some color...