水星全貌
影像来源与版权:NASA/JHU Applied Physics Lab/Carnegie Inst. Washington

说明:就在六年前,水星的整个表面终于绘制完成了。自2008年信使号宇宙飞船首次飞越水星以来,该飞船对太阳系最内侧行星地壳的详细观测便开始了,一直持续到2015年其受控降落到水星表面为止。在此之前,水星表面的大部分结构是未知的,因为它太过遥远,无法用地面望远镜观测清楚,而水手10号在20世纪70年代飞越水星时只观测到约一半的结构。这段精彩的视频由数千张以夸张颜色渲染的水星照片制作而成,更好地对比了不同的表面特征。在这个旋转的世界中,可以看到从北部撞击坑发出的射线,它们延伸穿过行星的大部分区域,而在该视频播放到一半时,浅色的卡洛里斯盆地旋转进入视野,这是一个充满熔岩的北部古代撞击地貌。最近对信使号数据进行的分析表明水星有一个固态内核。
翻译:北京天文馆

All of Mercury
Image Credit & Copyright: NASA/JHU Applied Physics Lab/Carnegie Inst. Washington

Explanation: Only six years ago, the entire surface of planet Mercury was finally mapped. Detailed observations of the innermost planet’s surprising crust began when the robotic have been ongoing since the robotic MESSENGER spacecraft first passed Mercury in 2008 and continued until its controlled crash landing in 2015. Previously, much of the Mercury’s surface was unknown as it is too far for Earth-bound telescopes to see clearly, while the Mariner 10 flybys in the 1970s observed only about half. The featured video is a compilation of thousands of images of Mercury rendered in exaggerated colors to better contrast different surface features. Visible on the rotating world are rays emanating from a northern impact that stretch across much of the planet, while about half-way through the video the light colored Caloris Basin rotates into view, a northern ancient impact feature that filled with lava. Recent analysis of MESSENGER data indicates that Mercury has a solid inner core.
Astronomy Picture of the Day 04/28/2019