Astronomy Picture of the Day——降落龙宫小行星

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

Touchdownon Asteroid Ryugu

VideoCredit: JAXA

Explanation:Last month, humanity bounced a robot off an asteroid. The main reason was tocollect a surface sample. Despite concern over finding a safely reboundabletouchdown spot, Japan's robotic Hayabusa2 spacecraft successfully touched down-- and bounced right back from -- asteroid Ryugu. Before impact, Hayabusa2fired a small bullet into 162173 Ryugu to scattered surface material andincrease the chance that Hayabusa2 would be able to capture some. Next month,Hayabusa2 will fire a much larger bullet into Ryugu in an effort to capturesub-surface material. Near the end of this year, Hayabusa2 is scheduled todepart Ryugu and begin a looping trip back to Earth, hopefully returning smallpieces of this near-Earth asteroid in late 2020. Studying Ryugu could tellhumanity not only about the minor planet's surface and interior, but about whatmaterials were available in the early Solar System for the development of life.

降落龙宫小行星

说明：上个月，人类成功从一颗小行星上反弹回收了一台探测器。其主要目的是采集小行星的表面样本。尽管人们担心它是否能找到一个可弹回的安全着陆点，但日本的隼鸟2号探测器成功着陆，并从龙宫小行星反弹回来。在撞击之前，隼鸟2号向龙宫小行星162173发射了一颗小子弹，将小行星的表面物质溅起，增加了隼鸟2号能够获取一些物质的机会。下个月，隼鸟2号将向龙宫小行星发射一颗更大的子弹，试图获取地下物质。今年年底，隼鸟2号计划离开龙宫小行星，开始返回地球的循环之旅，希望在2020年底带回这颗近地小行星的小碎片。研究龙宫小行星不仅可以告诉人类小行星的表面和内部，而且可以告诉人类早期太阳系中有哪些物质可以帮助生命进化。