James Webb Telescope Detects Signs of Oceans and Organics on Dwarf Planets

Dwarf planets Eris and Makemake (out by Pluto) have surfaces bearing methane ice of unknown origin. This ice can provide important insights into the origin and evolution of volatiles in the outer solar system.

We probably need to send new probes to the Dwarf planets to conclusively determine if liquid oceans have microbial life.

Because producing abiotic or thermogenic methane likely requires temperatures above ~150°C, they infer that Eris and Makemake have rocky cores that underwent substantial radiogenic heating. Their cores may still be warm/hot enough to make methane. This heating could have driven hydrothermal circulation at the bottom of an ice-covered ocean to generate abiotic methane, and/or metamorphic reactions involving accreted organic matter could have occurred in response to heating in the deeper interior, generating thermogenic methane. Additional analyses of relevant thermal evolution model results and theoretical predictions of the D/H ratio of methane in the solar nebula support our findings of elevated subsurface temperatures and an apparent lack of primordial methane on Eris and Makemake. It remains an open question whether their D/H ratios may have evolved subsequent to methane outgassing. They also suggest that lower-than-expected D/H and 84Kr/CH4 ratios in Titan’s atmosphere disfavor a primordial origin of methane there as well. Recommendations are given for future activities to further test proposed scenarios of abiotic and thermogenic methane production on Eris and Makemake, and to explore these worlds up close so that they can see if they bear additional evidence of endogenic processes.