An algorithm for determining collision probabilities between small solar system bodies

The introduction of surveys (e.g. Spacewatch, OCA-DLR) dedicated to the dis covery of asteroids and other small bodies is likely to increase the number of known objects to many times the current figure of roughly 30 000. Previ ous methods for determining collision probabilities amongst these objects ( e.g. those due to Opik, Wetherill, Greenberg and Kessler) all have idiosync rasies which make them inappropriate for analyses of interactions between l arge numbers of solar system bodies. Here we present an adaptation of the W etherill and Greenberg methods, which avoids approximations made by Opik bu t which remains accurate and fast enough in its implementation to allow the direct analysis of the collision probabilities and impact velocities of th ousands of potentially colliding objects.