Endogenically sourced volatiles on Charon and other Kuiper belt objects

Stephanie M Menten; Michael M Sori; Ali M Bramson

doi:10.1038/s41467-022-31846-8

Endogenically sourced volatiles on Charon and other Kuiper belt objects

Nat Commun. 2022 Aug 9;13(1):4457. doi: 10.1038/s41467-022-31846-8.

Authors

Stephanie M Menten¹, Michael M Sori², Ali M Bramson²

Affiliations

¹ Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, USA. smenten@purdue.edu.
² Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, USA.

Abstract

Kuiper belt objects (KBOs) have diverse surface compositions, and the New Horizons mission to the Pluto-Charon system allows us to test hypotheses on the origin and evolution of these KBO surfaces. Previous work proposed that Charon's organic-rich north pole formed from radiolytically processed volatiles sourced from Pluto's escaping atmosphere. Here, we show an endogenic source of volatiles from Charon's interior is plausible. We calculate that cryovolcanic resurfacing released 1.29 × 10¹⁵-3.47 × 10¹⁵ kg of methane to Charon's surface from its interior. We modeled volatile transport and found the vast majority of this volcanically released methane migrates to Charon's poles, with deposition rates sufficient to be processed into the observed organic compounds. Irradiated methane products appear on similarly sized KBOs that do not orbit a Pluto-sized object to draw an escaping atmosphere from, so interior-sourced volatiles could be a common and important process across the Kuiper belt.