Authors: Harold F. Levison, Alessandro Morbidelli, Luke Dones, Robert Jedicke, Paul A. Wiegert, & William F. Bottke, Jr.

Status: In Science 296, 2212 (June 21, 2002 issue)

Abstract: We have calculated the number of dormant nearly-isotropic Oort-cloud comets in the solar system by (i) combining orbital distribution models with statistical models of dormant comet discoveries by well defined surveys and (ii) comparing the model results to the observed population of dormant comets. Surprisingly, dynamical models that assume that comets are not destroyed predict that we should have discovered $\sim 100$~times more dormant nearly-isotropic comets than are actually seen. Thus, as comets evolve inward from the Oort cloud, the vast majority of them must physically disrupt. Interestingly, comets from the Kuiper belt are not lost at nearly this rate, indicating a clear and significant difference between these two comet classes.

Click here for pdf file this paper.