降落贝努小行星

2020年10月12日

Descending Toward Asteroid Bennu
Video Credit: NASA, OSIRIS-REx, NASA’s Scientific Visualization Studio; Data: NASA, U. Arizona, CSA, York U., MDA

Explanation: What would it be like to land on an asteroid? Although no human has yet done it, NASA’s robotic OSIRIS-REx spacecraft is scheduled to attempt to touch the surface of asteroid 101955 Bennu next week. The goal is to collect a sample from the nearby minor planet for return to Earth for a detailed analysis in 2023. The featured video shows what it looks like to descend toward the 500-meter diamond-shaped asteroid, based on a digital map of Bennu’s rocky surface constructed from image and surface data taken by OSIRIS-REx over the past 1.5 years. The video begins by showing a rapidly spinning Bennu — much faster than its real rotation period of 4.3 hours. After the rotation stops, the virtual camera drops you down to just above the rugged surface and circles a house-sized rock outcrop named Simurgh, with the flatter outcrop Roc visible behind it. If the return sample reaches Earth successfully, it will be scrutinized for organic compounds that might have seeded a young Earth, rare or unusual elements and minerals, and clues about the early history of our Solar System.

Tomorrow’s picture: opposing Mars

降落贝努小行星
影片提供: NASA, OSIRIS-REx, NASA’s Scientific Visualization Studio; 数据提供: NASA, U. Arizona, CSA, York U., MDA

说明: 降落到小行星会见到什么？虽然人类还没完成这项壮举，不过在下星期，美国航太总署的OSIRIS-REx 太空船，预定要降落在贝努小行星（101955 Bennu）的表面。这项任务的目的是要收集这个邻近 小行星的表面样品，并在2023年把它送回地球进行详细分析。用OSIRIS-REx太空船在过去1.5年之中取得的影像及数据，科学家建构出贝努多岩表面的数位地图；而上面这部据以制出的主题影片，呈现垂降这颗500米宽菱形小行星会见到的景观。影片以快速自转的贝努为开场，其转速远高于它真实的4.3小时自转。在自转停止后，虚拟相机向下垂降并悬浮在崎岖表面的上方，绕着房屋大小名为西摩格的巨岩打转，而凹凸不平的平顶大鹏岩露头位在它的后方。如果样品成功送返地球，分析的重点是寻找有机化合物与稀有元素或矿物质。因为，这些化合物或许曾为年轻地球播下生命的种子，而元素或矿物质则提供解读太阳系早期历史的线索。

明日的图片: opposing Mars