Eris: The First Dwarf Planet
11 Jul 2019, 20:07 UTC
CALTECH
Eris was one of the first dwarf planets to be discovered in the solar system. It is almost the same size as Pluto, and its discovery directly led to the former ninth planet's demotion. Eris also has a moon, Dysnomia, which was discovered not long after Eris.
