地球大气层对小小行星的有效破坏
1Department of Earth Science and Engineering, Exhibition Road, Imperial College London, South Kensington Campus, London SW7 2AZ, UK. p.a.bland@imperial.ac.uk
Nature
|July 18, 2003
概括
一个新的分离碎片模型显示,更大的石质小行星可以在大气中分解. 这项研究澄清了小小行星对地球的撞击速度,估计每17万年对超过220米的天体产生一次撞击.
科学领域:
- 行星科学 行星科学
- 天体物理学 天体物理学
- 地质物理学 地质物理学
背景情况:
- 精确建模玻利德与大气相互作用对于预测地球撞击速率至关重要.
- 之前的模型经常将冲击器简化为类似液体的 ("饼"模型).
- 一个更现实的分离碎片模型可以解释单个粒子运动,空气动力学和消耗.
研究的目的:
- 为了比较"饼"和分离碎片模型的大气-玻利相互作用.
- 为了统计分析大气中铁和石质沸石的破坏,高达1公里.
- 为了确定小小行星撞击地球表面的流量.
主要方法:
- 使用"饼"模型和分离碎片模型进行了超过1000次模拟.
- 模拟的铁和石头体,初始直径高达大约1公里.
- 综合模拟数据与大气前小行星流量数据.
主要成果:
- 分离碎片模型预测大气破坏的石质物体比以前估计的要大得多.
- 这项研究为各种小行星组成和大小的大气-玻利相互作用提供了统计图片.
- 创建了一个超过1000次模拟冲击的数据集.
结论:
- 分离碎片模型提供了更现实的估计玻利德进入大气层.
- 已经阐明了地球表面对小玻化物 (<1公里) 的冲击流量.
- 据估计,大于220米的小行星大约每17万年撞击地球.
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