Internal structure of Pluto and Charon with an iron core

TL;DR

This paper proposes that Pluto and Charon may have iron cores, which impacts their internal structure, geological evolution, and the interpretation of their surface features, challenging previous models that only considered rocky cores.

Contribution

It introduces the possibility of iron cores in Pluto and Charon, prompting a revision of impact origin models and understanding of their geological processes.

Findings

Pluto may have an iron core, contrary to previous models.

An iron core affects the thermal and geological evolution of Pluto and Charon.

Surface deformations could be caused by internal core dynamics.

Abstract

Pluto has been observed by the New Horizons space probe to have some relatively fresh ice on the old ices covering most of the surface. Pluto was thought to consist of only a rocky core below the ice. Here I show that Pluto can have an iron core, as can also its companion Charon, which has recently been modelled to have one. The presence of an iron core means the giant impact origin calculations should be redone to include iron and thus higher temperatures. An iron core leads to the possibility of a different geology. An originally molten core becomes solid later, with contraction and a release of latent heat. The space vacated allows the upper rock layers to flow downwards at some locations at the surface of the core, and some of the ice above the rock to descend, filling the spaces left by the rock motion downwards. These phenomena can lead to the forces recently deforming the icy surface of Pluto, and in a lesser way, of Charon.