An N-body approach to modelling debris and ejecta off small bodies: implementation and application

Abstract

ABSTRACT We introduce here our new approach to modelling particle cloud evolution off surface of small bodies (asteroids and comets), following the evolution of ejected particles requires dealing with various time and spatial scales, in an efficient, accurate, and modular way. In order to improve computational efficiency and accuracy of such calculations, we created an N-body modelling package as an extension to the increasingly popular orbital dynamics N-body integrator rebound. Our code is currently a stand-alone variant of the rebound code and is aimed at advancing a comprehensive understanding of individual particle trajectories, external forcing, and interactions, at the scale that is otherwise overlooked by other modelling approaches. The package we developed – rebound ejecta dynamics (red) – is a python-based implementation with no additional dependences. It incorporates several major mechanisms that affect the evolution of particles in low-gravity environments and enables a more straightforward simulation of combined effects. We include variable size and velocity distributions, solar radiation pressure, ellipsoidal gravitational potential, binary or triple asteroid systems, and particle–particle interactions. In this paper, we present a sample of the red package capabilities. These are applied to a small asteroid binary system (characterized following the Didymos/Dimorphos system, which is the target for NASA’s Double Asteroid Redirection Test mission).