冥卫一

2023年6月3日

Charon: Moon of Pluto
Image Credit: NASA, Johns Hopkins Univ./APL, Southwest Research Institute, U.S. Naval Observatory

Explanation: A darkened and mysterious north polar region known to some as Mordor Macula caps this premier high-resolution view. The portrait of Charon, Pluto’s largest moon, was captured by New Horizons near the spacecraft’s closest approach on July 14, 2015. The combined blue, red, and infrared data was processed to enhance colors and follow variations in Charon’s surface properties with a resolution of about 2.9 kilometers (1.8 miles). A stunning image of Charon’s Pluto-facing hemisphere, it also features a clear view of an apparently moon-girdling belt of fractures and canyons that seems to separate smooth southern plains from varied northern terrain. Charon is 1,214 kilometers (754 miles) across. That’s about 1/10th the size of planet Earth but a whopping 1/2 the diameter of Pluto itself, and makes it the largest satellite relative to its parent body in the Solar System. Still, the moon appears as a small bump at about the 1 o’clock position on Pluto’s disk in the grainy, negative,telescopic picture inset at upper left. That view was used by James Christy and Robert Harrington at the U.S. Naval Observatory in Flagstaff to discover Charon in June of 1978.

Tomorrow’s picture: look beyond

冥卫一
影像提供: NASA, Johns Hopkins Univ./APL, Southwest Research Institute, U.S. Naval Observatory

说明: 在这片清晰无比的高解析视野里，暗淡神秘偶有魔多黄斑之称的北极区，看来像是这颗天体的帽子。这幅呈现冥王星最大的卫星土卫一（Charon）之影像，是由新视野号宇宙飞船摄于2015年7月14日最接近冥王星之时。这张分辨率约为2.9公里的影像，整合了蓝、红及红外光波段的数据，并经过特别处理以突显冥卫一表面特性的差异。这是冥卫一面向冥王星那半球的景观，其中可清楚见到看形似环绕这颗卫星的带状裂缝及峡谷，而看似以此带为界，其表面分成光滑的南方平原与崎岖多变的北方原野。宽度为1,214公里的冥卫一，其大小约是地球的1/10，但直径足足是冥王星之半，让它成为太阳系里相对于母行星最庞大的卫星。纵然如此，在左上角的粗糙望远镜负片嵌图里，这颗卫星只是冥王星盘面约1点钟方向的小凸起。于1978年6月，当时在旗竿镇的美国海军天文台工作的克里斯蒂及哈灵顿，就是靠这张粗糙的影像发现了冥卫一。

明日的图片: look beyond