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160万年前的小行星破裂是K/T撞击器的可能来源
William F Bottke1, David Vokrouhlický, David Nesvorný
1Southwest Research Institute, 1050 Walnut St, Suite 300, Boulder, Colorado 80302, USA. bottke@boulder.swri.edu
Nature
|September 7, 2007
概括
小行星巴蒂斯蒂娜1亿6千万年前的解体可能导致了小行星撞击的激增,包括引发白-第三纪大规模灭绝的事件.
科学领域:
- 行星科学 行星科学
- 冲击石坑的形成
- 小行星动力学 小行星动力学
背景情况:
- 长期的陆地和月球石坑率通常被认为是恒定的.
- 有证据表明,在过去的1亿年里,公里大小的物体的撞击流量显著增加.
研究的目的:
- 为了调查最近冲击流量激增的原因.
- 为了确定Chixulub撞击器的起源,负责白纪/三级纪大规模灭绝.
主要方法:
- 对冲量流量数据的分析.
- 小行星碎片的动态建模.
- 小行星破坏模拟. 小行星破坏模拟.
主要成果:
- 巴蒂斯蒂娜小行星母体的灾难性破坏 (大约. 170公里的直径) 大约1.6亿年前.
- 这一事件将碎片释放到内侧的主小行星带.
- 这些碎片被缓慢地传送到地球行星交叉轨道.
结论:
- 巴蒂斯蒂娜小行星雨是奇克苏鲁布撞击器最可能的来源 (>90%).
- 这一事件很可能引发了白/三级时期的大规模灭绝事件.
- 这项研究挑战了在地质时间尺度上恒定的撞击速度的假设.
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