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 ...

He spotted Eris in the Kuiper belt – a region of icy objects beyond Neptune. It was more massive than Pluto and left astronomers with a dilemma, whether to add it and other larger bodies ...

Because of this, Pluto no longer fit the definition of a full-fledged planet and was reclassified as a dwarf planet on August 24, 2006. In 2005, astronomers discovered Eris, a celestial body in ...