火卫一：火星上的卫星
(原标题: Phobos: Moon over Mars)
2024-03-22
浏览次数: 13
这是一颗有着可怕名字的小卫星，火卫一从这颗红色星球的后面出现。这是哈勃太空望远镜在绕地球轨道运行时拍摄的延时序列。在22分钟内，这13张独立的照片是在2016年火星最接近地球的地方拍摄的。火星人必须向西看才能看到火卫一升起。这颗小卫星距离它的母行星比太阳系中的任何其他卫星都近，距离火星表面约3700英里（6000公里）。它在7小时39分钟内完成了一个轨道。这比火星自转要快，火星自转约为24小时40分钟。因此，从火星表面看，火卫一在火星的一天里会从西方地平线上升2次。不过，火卫一注定要失败。
查看原文解释
A tiny moon with a scary name, Phobos emerges from behind the Red Planet in this timelapse sequence from the Earth-orbiting Hubble Space Telescope. Over 22 minutes the 13 separate exposures were captured near the 2016 closest approach of Mars to planet Earth. Martians have to look to the west to watch Phobos rise, though. The small moon is closer to its parent planet than any other moon in the Solar System, about 3,700 miles (6,000 kilometers) above the Martian surface. It completes one orbit in just 7 hours and 39 minutes. That's faster than a Mars rotation, which corresponds to about 24 hours and 40 minutes. As a result, seen from the surface of Mars speeding Phobos rises above the western horizon 2 times in a Martian day. Still, Phobos is doomed.