谷神星的盐水渍

2020年9月1日

Salt Water Remnants on Ceres
Video Credit: Dawn Mission, NASA, JPL-Caltech, UCLA, MPS/DLR/IDA

Explanation: Does Ceres have underground pockets of water? Ceres, the largest asteroid in the asteroid belt, was thought to be composed of rock and ice. At the same time, Ceres was known to have unusual bright spots on its surface. These bright spots were clearly imaged during Dawn’s exciting approach in 2015. Analyses of Dawn images and spectra indicated that the bright spots arise from the residue of highly-reflective salt water that used to exist on Ceres’ surface but evaporated. Recent analysis indicates that some of this water may have originated from deep inside Ceres, indicating Ceres to be a kindred spirit with several Solar System moons, also thought to harbor deep water pockets. The featured video shows in false-color pink the bright evaporated brine named Cerealia Facula in Occator Crater. In 2018, the mission-successful but fuel-depleted Dawn spacecraft was placed in a distant parking orbit, keeping it away from the Ceres’ surface for at least 20 years to avoid interfering with any life that might there exist.

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谷神星的盐水渍
影片提供: Dawn Mission, NASA, JPL-Caltech, UCLA, MPS/DLR/IDA

说明: 谷神星有地下水潭吗？小行星带最大的小行星─谷神星，感认是由岩石与冰所所构成。在此同时，谷神星的表面上有不寻常的亮斑。在2015年，黎明号近距离掠过谷神星时，曾清晰的拍下这些亮斑。检视和进行这些亮斑的光谱分析，显示它们是谷神星表面高反射率的盐水蒸发后，残留下来的水渍。最近的分析指出，有些盐水可能来自谷神星的深处，情形与数颗太阳系卫星相似，咸信都拥有深层水潭。这部主题影片以粉红假色，呈现欧卡托撞击坑内名为谷物斑的明亮干涸盐水渍。在2018年，成功完成任务但已耗尽燃料的的黎明号太空船，被留置在大半径的停泊轨道上，让它至少在20年内，不会干扰谷神星上任何可能存在的生命体。

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明日的图片: bonus moons