2025年5月24日
Deimos Before Sunrise
Image Credit: NASA, JPL-Caltech
Explanation: Deimos takes 30 hours and 18 minutes to complete one orbit around the Red Planet. That’s a little more than one Martian day or sol which is about 24 hours and 40 minutes long, so Deimos drifts westward across the Martian sky. About 15 kilometers across at its widest, the smallest of Mars’ two moons is bright though. In fact Deimos is the brightest celestial object in this Martian skyscape captured before sunrise by Perseverance on March 1, the 1,433rd sol of the Mars rover’s mission. The image is a composed of 16 exposures recorded by one of the rover’s navigation cameras. The individual exposures were combined into a single image for an enhanced low light view. Regulus and Algeiba, bright stars in the constellation Leo, are also visible in the dark Martian predawn sky.
Tomorrow’s picture: beneath Jupiter
日出前的火卫二
影像提供: NASA, JPL-Caltech
说明: 火卫二（Deimos）绕火星公转一圈需时30小时18分。这比火星日（24小时40分）要长上一些，以至于火卫二在火星的天空中会向西漂移。最宽处约15公里、二颗火星卫星中最小的火卫二，算是很明亮。例如在这幅由毅力号火星车摄于今年3月1日（此火星车任务的第1,433个火星日）的火星天空影像里，火卫二就是其中最明亮的天体。这张主题影像，叠合了此火星车的导航相机之一所拍摄的16张照片，以强化低光度的昏暗景观。也让轩辕十四（Regulus）及轩辕十二（Algeiba）这二颗狮子座的亮星，得以在火星黝黑的日出前天空中显现出来。
明日的图片: beneath Jupiter
