NewsPlanetary Science

Are Asteroids Flying Piles of Rubble?

Science  26 Apr 1996:
Vol. 272, Issue 5261, pp. 485
DOI: 10.1126/science.272.5261.485


The rough-and-tumble existence of asteroids has led many planetary scientists to wonder whether they might be heaps of rubble rather than solid bodies. Evidence presented at last month's Lunar and Planetary Science Conference in Houston suggests that may be the case. A survey of the rotation rates of small asteroids revealed a cutoff—a maximum rotation speed—implying that they are shattered bodies held together only by their own gravity. A rubble-heap asteroid that rotated any faster than the cutoff would simply fly apart.