Daniel D Durda and S Alan Stern Southwest Research Institute….pdf

Collision Rates in the Present-Day Kuiper Belt and Centaur Regions: Applications to Surface Activation and Modification On Comets, Kuiper Belt Objects, Centaurs, and Pluto-Charon Daniel D. Durda and S. Alan Stern Southwest Research Institute Space Studies Department 1050 Walnut Street, Suite 426 9 Boulder, CO 80302 9 9 durda@boulder.swri.edu 1 c e D 8 1 1 v 0 0 4 2 Submitted to Icarus: 26 March 1999 1 Revised: 19 November 1999 9 9 / h Length: p - 20 Pages o r 08 Figures t s 00 Tables a : v i X r a 1 Proposed Running Header: Collisions in the Edgeworth-Kuiper Belt Address editorial correspondence to: Daniel D. Durda Southwest Research Institute 1050 Walnut Street Suite 426 Boulder, CO 80302 Tel: (303) 546-9670 Fax: (303) 546-9687 durda@boulder.swri.edu 2 ABSTRACT We present results from our model of collision rates in the present-day Edgeworth-Kuiper Belt and Centaur region. We have updated previous results to allow for new estimates of the total disk population, in order to examine surface activation and modification time scales due to cratering impacts. We extend previous results showing that the surfaces of Edgeworth- Kuiper Belt objects are not primordial and have been moderately to heavily reworked by collisions. Objects smaller than about r = 2.5 km have collisional disruption lifetimes less than 3.5 Gyr in the present-day collisional environment and have probably been heavily damaged in their