2026年2月9日
Miranda Revisited
Image Credit: NASA, JPL, Voyager 2; Processing & License: Flickr: zelario12; Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST II)
Explanation: What is Miranda really like? Visually, old images from NASA’s Voyager 2 have been recently combined and remastered to result in the featured image of Uranus‘s 500-kilometer-wide moon. In the late 1980s, Voyager 2 flew by Uranus, coming close to the cratered, fractured, and unusually grooved moon — named after a character from Shakespeare’s The Tempest. Scientifically, planetary scientists are using old data and clear images to theorize anew about what shaped Miranda’s severe surface features. A leading hypothesis is that Miranda, beneath its icy surface, may have once hosted an expansive liquid water ocean which may be slowly freezing. Thanks to the legacy of Voyager 2, Miranda has joined the ranks of Europa, Titan, and other icy moons in the search for water, and, possibly, microbial life, in our Solar System.
Jigsaw Moon: Astronomy Puzzle of the Day
Tomorrow’s picture: swirling sky
重访米兰达
影像提供: NASA, JPL, Voyager 2; 处理与许可: Flickr: zelario12; 文稿: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST II)
说明: 米兰达（天卫五）究竟是什么样子？从视觉上来看，NASA旅行者2号探测器拍摄的旧影像最近被重新组合和处理，最终呈现出这张天王星卫星米兰达的主题影像。这颗卫星直径约500公里。在1980年代末，旅行者2号探测器飞掠天王星，近距离观察了这颗表面布满陨石坑、裂缝纵横、沟壑交错的卫星——它的名字来自莎士比亚戏剧《暴风雨》中的一个角色。从科学的角度来看，行星科学家正在利用旧数据和清晰影像重新理论化米兰达表面严酷地貌的成因。一项主要结论是米兰达冰冷的表面下可能曾经存在一片广阔的液态水海洋——如今这片海洋可能正在缓慢冻结。这样的海洋可能源于过去的潮汐加热与内部活动，并曾在一定程度上重塑其表面。得益于旅行者2号的长久影响，米兰达加入了欧罗巴（土卫二）、泰坦（土卫六）和其他冰卫星的行列，成为在我们的太阳系中寻找水，甚至可能的微生物生命的探索对象。
月亮拼图: 每日天文谜题
明日的图片: swirling sky
