Runyon K D, Moriarty D P, Denevi B W, Greenhagen B T, Morgan G, Young K E, Cohen B A, van der Bogert C H, Hiesinger H, Jozwiak L M
The Johns Hopkins University Applied Physics Laboratory Laurel MD USA.
NASA Goddard Space Flight Center Greenbelt MD USA.
J Geophys Res Planets. 2020 Jan;125(1):e2019JE006024. doi: 10.1029/2019JE006024. Epub 2020 Jan 5.
Both Earth and the Moon share a common history regarding the epoch of large basin formation, though only the lunar geologic record preserves any appreciable record of this Late Heavy Bombardment. The emergence of Earth's first life is approximately contemporaneous with the Late Heavy Bombardment; understanding the latter informs the environmental conditions of the former, which are likely necessary to constrain the mechanisms of abiogenesis. While the relative formation time of most of the Moon's large basins is known, the absolute timing is not. The timing of Crisium Basin's formation is one of many important events that must be constrained and would require identifying and dating impact melt formed in the Crisium event. To inform a future lunar sample dating mission, we thus characterized possible outcrops of impact melt. We determined that several mare lava-embayed kipukas could contain impact melt, though the rim and central peaks of the partially lava-flooded Yerkes Crater likely contain the most pure and intact Crisium impact melt. It is here where future robotic and/or human missions could confidently add a key missing piece to the puzzle of the combined issues of early Earth-Moon bombardment and the emergence of life.
在大型盆地形成的时代，地球和月球有着共同的历史，不过只有月球的地质记录保存了晚期重轰炸的任何可观记录。地球最初生命的出现大约与晚期重轰炸同时期；了解后者有助于了解前者的环境条件，而这些条件可能是限制生命起源机制所必需的。虽然月球上大多数大型盆地的相对形成时间是已知的，但绝对时间未知。危海盆地的形成时间是必须确定的众多重要事件之一，这需要识别并确定在危海事件中形成的撞击熔体的年代。为了为未来的月球样本测年任务提供信息，我们对可能的撞击熔体露头进行了特征描述。我们确定，几个被月海熔岩环绕的基普卡可能含有撞击熔体，不过部分被熔岩淹没的耶克火山口的边缘和中央峰可能含有最纯净、最完整的危海撞击熔体。未来的机器人和/或载人任务可以在这里自信地为早期地月撞击和生命出现这一综合问题的拼图补上关键的缺失部分。
