Best known for depriving Pluto of planethood by showing that there are many similar bodies in orbit beyond Neptune, Eris's great distance from the sun means the effects of general relativity become negligible. (newscientist.com)
Last August, after 75 years of planethood, Pluto lost its status when the International Astronomical Union (IAU) came up with a new definition of what it means to be a planet. (sciencenewsforstudents.org)
According to a draft definition of the term planet that was presented for approval at a meeting of the International Astronomical Union in Prague, Czech Republic, in 2006, Charon would have met both qualifications for planethood. (newscientist.com)