Newly Disrupted Main Belt Asteroid P/2010 A2

Abstract: Most 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 events. Here we present observations of P/2010 A2, a previously unknown inner-belt asteroid with a peculiar, comet-like morphology that is most likely the evolving remnant of a recent asteroidal disruption. High resolution Hubble Space Telescope observations reveal an approximately 120 meter diameter nucleus with an associated tail of millimeter-sized dust particles formed in February/March 2009, all evolving slowly under the action of solar radiation pressure.