A Pluto-Charon Concerto: An Impact on Charon as the Origin of the Small Satellites
Benjamin C. Bromley, Scott J. Kenyon
We consider a scenario where the small satellites of Pluto and Charon grew within a disk of debris from an impact between Charon and a trans-Neptunian Object (TNO). After Charon’s orbital motion boosts the debris into a disk-like structure, rapid orbital damping of meter-size or smaller objects is essential to prevent the subsequent re-accretion or dynamical ejection by the binary. From analytical estimates and simulations of disk evolution, we estimate an impactor radius of 30-100 km; smaller (larger) radii apply to an oblique (direct) impact. Although collisions between large TNOs and Charon are unlikely today, they were relatively common within the first 0.1-1 Gyr of the solar system. Compared to models where the small satellites agglomerate in the debris left over by the giant impact that produced the Pluto-Charon binary planet, satellite formation from a later impact on Charon avoids the destabilizing resonances that sweep past the satellites during the early orbital expansion of the binary.
Comments: 51 pages, 10 figures, 1 table, AJ, in press
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2006.13901 [astro-ph.EP] (or arXiv:2006.13901v1 [astro-ph.EP] for this version)
Submission history
From: Benjamin Bromley
[v1] Wed, 24 Jun 2020 17:35:50 UTC (11,315 KB)
