来源:Nature Communications 发布时间:2020/7/29 10:52:18
选择字号:
月球在8亿年前经历了一场小行星雨 |《自然-通讯》论文

论文标题:Asteroid shower on the Earth-Moon system immediately before the Cryogenian period revealed by KAGUYA

期刊:Nature Communications

作者:Kentaro Terada, Tomokatsu Morota & Mami Kato

发表时间:2020/07/21

DOI:10.1038/s41467-020-17115-6

微信链接:点击此处阅读微信文章

根据《自然-通讯》发表的一篇论文Asteroid shower on the Earth-Moon system immediately before the Cryogenian period revealed by KAGUYA大约8亿年前,月球遭遇了流星体(较小的小行星)的轰击。根据碰撞概率,该研究表明这些流星体的总质量约为成冰期(约7.2亿至6.35亿年前)之前造成希克苏鲁伯(Chicxulub)撞击事件的陨石的30至60倍。

地球上的侵蚀和表面更新过程使研究古代流星体撞击以及确定其日期变得有难度。不过,还可以通过另一种方法来了解这些撞击——研究月球上的陨石坑,因为在月球上,风化和侵蚀的影响大大减少。

日本大阪大学的寺田健太郎(Kentaro Terada)及其同事利用来自月球探测器“月女神”(Kaguya)的数据,估算了月球表面直径大于20公里的59个陨石坑的形成时间。作者发现,其中有8个陨石坑是同时形成的,包括哥白尼陨石坑。根据对哥白尼陨石坑释放物质的放射性测年结果,以及从一些阿波罗任务的撞击玻璃球粒(陨石撞击形成的玻璃珠)中获得的数据,他们得出结论:月球在大约8亿年前经历了一次小行星雨。作者推测,既然月球上发生了小行星雨,那么地球上肯定也发生过类似的事件。他们利用陨石坑标度律和碰撞概率表明,一颗质量为4亿亿至5亿亿千克的小行星与地球发生了碰撞。

59个被调查的陨石坑 | credit: Terada et al.

摘要:

Meteoroid bombardment of the Earth-Moon system must have caused catastrophic damage to the terrestrial ecosphere. However, ancient meteoroid impacts and their relations to environmental changes are not well understood because of erosion and/or resurfacing processes on Earth. Here, we investigate the formation ages of 59 lunar craters with fresh morphologies and diameters greater than approximately 20 km and first find that 8 of 59 craters were formed simultaneously. Considering the radiometric ages of ejecta from Copernicus crater and impact glass spherules from various Apollo landing sites, we conclude that sporadic meteoroid bombardment occurred across the whole Moon at approximately 800 Ma. Based on crater scaling laws and collision probabilities with the Earth and Moon, we suggest that at least (4–5) × 1016 kg of meteoroids, approximately 30–60 times more than the Chicxulub impact, must have plunged into the Earth-Moon system immediately before the Cryogenian, which was an era of great environmental changes.

(来源:科学网)

 
 
 
特别声明:本文转载仅仅是出于传播信息的需要,并不意味着代表本网站观点或证实其内容的真实性;如其他媒体、网站或个人从本网站转载使用,须保留本网站注明的“来源”,并自负版权等法律责任;作者如果不希望被转载或者联系转载稿费等事宜,请与我们接洽。
 
 打印  发E-mail给: 
    
 
相关新闻 相关论文

图片新闻
菱形石墨“透视”超导体 “黎明”号揭秘谷神星
茶产业如何打造下一个万亿级目标 新纳米孔材料打破分子交通堵塞
>>更多
 
一周新闻排行 一周新闻评论排行
 
编辑部推荐博文