Dynamics of 2D electrostatic dust levitation at asteroids

Abstract

Electrostatic dust levitation is the phenomenon where dust grains hover above the surface of an airless body due to the approximate balancing of the forces attracting the grain to and repelling the grain from the body. The dynamics of levitating grains have been investigated previously for the case where the grain's motion is constrained to one dimension. Additionally, other prior investigations have observed the 2D motion of grains near surface features (e.g. craters). In this work, we systematically investigate the 2D motion of electrostatically levitating grains about a circular asteroid cross section. We find that solar radiation pressure strongly depresses the altitudes of grain levitation leading to more strongly damped altitude oscillations. We show that a dynamical systems approximation can provide useful information about the grain dynamics, especially over short timescales. We also demonstrate that grains are able to levitate in a spatially inhomogeneous plasma environment. These results are significant for assessing the feasibility of global dust transport through electrostatic levitation on asteroids.