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小行星在近日距离的超级灾难性破坏
Mikael Granvik1,2, Alessandro Morbidelli3, Robert Jedicke4
1Department of Physics, PO Box 64, 00014 University of Helsinki, Finland.
Nature
|February 19, 2016
概括
接近地球的小行星通常因热分解而在太阳附近消失. 低度的小行星更容易分解,这解释了太阳附近观测到的暗物体的稀缺性.
科学领域:
- 天文学
- 星球科学
- 天体物理学
背景情况:
- 接近地球的物体 (NEOs) 起源于小行星带.
- 不引力热力和共振逃生路线将近地行星推向行星交叉轨道.
- 模型预测太阳附近有大量的近地物体,
研究的目的:
- 将近地物体的检测量与观察选择效应的模型进行量化比较.
- 调查太阳附近预测和观察到的新星体数量之间的差异,特别是关于白色分布.
- 确定太阳系内部低度小行星不足的原因.
主要方法:
- 将实际的小行星探测数据与近地物体模型进行比较.
- 对小行星探测中的观测选择效应的分析.
- 基于周日距离和度的小行星破裂机制的定量评估.
主要成果:
- 很大一部分小行星在几十个太阳半径的周日距离处经历了超级灾难性解体.
- 分裂的距离与小行星的大小相反;较小的小行星离太阳更远.
- 低射率的小行星比高射率的小行星更容易从太阳中分裂,这解释了它们在太阳附近的观测缺陷.
结论:
- 在太阳附近观测到的低光 NEO 的缺陷是由于它们更频繁和更遥远的热分解.
- 低度的小行星似乎更容易受到热解体的影响,导致它们几乎完全解体.
- 这种低度小行星的热脆弱性解释了太阳系内部明显过多的高度近地行星.
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