重建月球的晚期积累历史
Meng-Hua Zhu1,2, Natalia Artemieva3,4,5, Alessandro Morbidelli6
1State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Taipa, Macau, China. mhzhu@must.edu.mo.
Nature
|July 12, 2019
概括
月球保留的高 siderophile 元素 (HSEs) 比地球少得多,这是由于撞击者保留率较低和HSE积累较晚. 这解释了月球在晚期积聚质量的明显缺陷.
科学领域:
- 星球科学
- 地质化学
- 撞击坑
背景情况:
- 高 siderophile 元素 (HSEs) 对于理解行星形成至关重要.
- 在地球和月球的HSE预算中存在重大差异.
- 之前的模型通常假定月球的撞击器保持率很高.
研究的目的:
- 量化月球在整个历史中的撞击者-保留比率.
- 为了解释与地球相比,月球地和地幔中观察到的HSE缺乏.
- 改进月球积聚和行星进化的后期模型.
主要方法:
- 进行冲击模拟以确定冲击器的保持比率.
- 使用蒙特卡洛程序与衰减冲击流.
- 计算了月球地和地幔随着时间的推移而增加的质量.
主要成果:
- 月球的平均撞击器-保留比率大约是以前估计的三倍.
- 在月球上的岩海洋固化后, HSE的保留可能在43.5亿年前开始.
- 在此期间之前增加的质量将其HSE丢失到月球核心.
结论:
- 较低的撞击器保留比率和较晚的HSE积累解释了月球的HSE缺陷.
- 这一发现符合月球和地球的HSE预算.
- 为月球的积累历史提供了一个更现实的模型.
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