It saw the discovery of dwarf planet Eris and how those very observations led to a new way to describe the Solar System and heralded the eventual change of Pluto’s planetary status. On that ...

Eris is similarly sized to Pluto, but it's three times further from the Sun than Pluto, sitting about 68 AU away. Eris is named after the Greek goddess of discord and strife, and the dwarf planet ...