小行星塞雷斯的差异化,由其形状所揭示
P C Thomas1, J Wm Parker, L A McFadden
1Center for Radiophysics and Space Research, Cornell University, Ithaca, New York 14853, USA. thomas@baritone.astro.cornell.edu
Nature
|September 9, 2005
概括
曾经被认为是均的矮行星塞雷斯,显示出差异化的证据. 它的形状暗示了岩石核心和冰的地幔,挑战了关于其内部结构的先前假设.
科学领域:
- 行星科学 行星科学
- 小行星研究研究.
- 太阳系的形成太阳系的形成
背景情况:
- 小行星带在太阳系历史的早期形成,保存了其形成的记录.
- 一些小行星,如4 Vesta,已经热进化和分化成层次结构.
- 科雷斯是最大的小行星,由于其低密度和光谱特征,被认为是均的.
研究的目的:
- 为了研究矮行星塞雷斯的内部结构和差异化.
- 根据新的形状和光滑度数据,重新评估Ceres的假定同质性.
主要方法:
- 对Ceres的形状和表面光滑性的分析.
- 观察到的特征与差异化和同质性物体的模型进行比较.
主要成果:
- 塞雷斯表现出一种形状和光滑,表明它是一个重力放松的物体.
- 它的形状不如同质物体所期望的那么平坦,这表明内部差异化.
- 数据支持一个中心质量度的模型,可能是一个岩石核心.
结论:
- 与之前的假设相反,Ceres已经经历了分化.
- 它的内部结构可能由岩石核心组成,覆盖着富含水冰的地幔.
- 塞雷斯是了解早期太阳系过程和行星演变的关键对象.
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