Evidence of geothermal activity within icy dwarf planets

A team found evidence for hydrothermal or metamorphic activity within the icy dwarf planets Eris and Makemake, located in the Kuiper Belt. Methane detected on their surfaces has the tell-tale signs of warm or even hot geochemistry in their rocky cores, which is markedly different than the signature of methane from a comet.

https://www.sciencedaily.com/releases/2024/02/240215142301.htm