Eris

+Eris is the most massive known [Dwarf Planet](/wiki/Dwarf_Planet) in our Solar System, whose 2005 discovery challenged the traditional definition of a [Planet](/wiki/Planet). Its existence in the distant Kuiper Belt redefined our understanding of celestial bodies beyond Neptune.

+## See also

+- [Pluto](/wiki/Pluto)

+- [Kuiper Belt](/wiki/Kuiper_Belt)

+- [Solar System](/wiki/Solar_System)