Surface dynamics and geophysical environment of asteroid (3200) Phaethon
Abstract
Context. (3200) Phaethon is a ~5-km-diameter near-Earth asteroid with a small perihelion distance of 0.14 au and is the parent body of the Geminids. JAXA's DESTINY+ mission will fly by Phaethon in the near future. Aims. We aim to support the pre-flight planning for the DESTINY+ mission by performing a geophysical analysis on Phaethon's surface and near-surface environment utilizing the latest shape model from numerous observations. Methods. We employed the soft-sphere discrete element method code PKDGRAV to construct a "mascon" model of Phaethon and determine its gravity. We then computed the geopotential on Phaethon and derived various physical quantities related to its surface and near-surface dynamics. Results. We calculated geophysical quantities for the surface, including surface acceleration and slope. To assess whether surface objects could be launched off the surface, we computed the escape speed, return speed, Jacobi speed, and the location and stability of equilibrium points around Phaethon, and conducted a simple dynamical simulation of launched particles. Conclusions. Our results suggest that a large depression feature in the northern hemisphere could harbor exposed subsurface material and the freshest material on Phaethon. We propose that this depression be considered a key area for observation by the DESTINY+ mission
Cite
@article{arxiv.2502.09916,
title = {Surface dynamics and geophysical environment of asteroid (3200) Phaethon},
author = {Hangbin Jo and Masateru Ishiguro and Derek C. Richardson and Sean E. Marshall and Tomoko Arai and Ko Ishibashi},
journal= {arXiv preprint arXiv:2502.09916},
year = {2025}
}
Comments
19 pages, 16 figures, Accepted on 2025 February 12 for the publication of Astronomy & Astrophysics