Eris Could be Slushier Than Pluto

Dwarf planet Eris is 'squishier' than expected. Eris is about the size of Pluto but around 50% farther from the sun. The discovery of Eris in the Kuiper Belt beyond Neptune in 2005 prompted the debate that ultimately reclassified Pluto as a dwarf planet.

Scientists discern internal structure of mysterious dwarf planet Eris

Eris and Makemake might be hiding unexpected oceans of liquid water