Department of Earth and Space Sciences, 3713 Geology Building, UCLA, 595 Charles Young Drive East, California 90095, USA.
Nature. 2010 Oct 14;467(7317):817-9. doi: 10.1038/nature09456.
Most inner main-belt asteroids are primitive rock and metal bodies in orbit about the Sun between Mars and Jupiter. Disruption, through high-velocity collisions or rotational spin-up, is believed to be the primary mechanism for the production and destruction of small asteroids and a contributor to dust in the Sun's zodiacal cloud, while analogous collisions around other stars feed dust to their debris disks. Unfortunately, direct evidence about the mechanism or rate of disruption is lacking, owing to the rarity of the events. Here we report observations of P/2010 A2, a previously unknown inner-belt asteroid with a peculiar, comet-like morphology. The data reveal a nucleus of diameter approximately 120 metres with an associated tail of millimetre-sized dust particles. We conclude that it is most probably the remnant of a recent asteroidal disruption in February/March 2009, evolving slowly under the action of solar radiation pressure, in agreement with independent work.
大多数内主带小行星是在火星和木星之间的轨道上围绕太阳运行的原始岩石和金属天体。据信，通过高速碰撞或旋转加速，是小行星产生和破坏的主要机制，也是太阳黄道云中尘埃的来源，而类似的碰撞在其他恒星周围则为它们的碎屑盘提供了尘埃。不幸的是，由于事件的稀有性，关于破坏的机制或速率的直接证据是缺乏的。在这里，我们报告了对 P/2010 A2 的观测结果，P/2010 A2 是一颗以前未知的内带小行星，具有奇特的彗星状形态。这些数据显示了一个直径约 120 米的核，以及与之相关的毫米大小尘埃颗粒的尾迹。我们的结论是，它很可能是 2009 年 2 月/3 月最近一次小行星解体的残余物，在太阳辐射压力的作用下缓慢演化，这与独立的工作结果一致。
