Fragmentation of asteroids and artificial satellites in orbit

Abstract

In this paper we develop expressions for the probability density in the orbital elements resulting from a spherical explosion in orbit. The usual power law mass distribution is employed, and it is assumed that equipartition holds among velocity dispersions and masses. The asteroid families Themis, Eos, and Coronis (at least) show an envelope in the semimajor axis-diameter plane which is completely characteristic of equipartition in an explosion event. Equipartition is observed to break down when the imparted energy density exceeds about 10 8 ergs/g, and further fragmentation becomes the dominant mode of energy usage. The data for several satellite breakups in Earth orbit are then examined, providing further direct evidence of equipartition and checking the probability functions previously derived. The observation of similarities between satellite breakups and asteroid families leads to the conclusion that the asteroid families are also the result of catastrophic fragmentation events.