The largest known object at the fringes of the solar system, the icy body whose discovery heated up the debate about planethood, has an apt new name.
The International Astronomical Union (IAU) announced on Sept. 14 that the body, which had provisionally been called UB 313 and nicknamed Xena, would now be officially called Eris, after the Greek goddess of discord and strife. Furthermore, Eris' moon has been designated Dysnomia, the goddess of lawlessness.
Because Pluto is slightly smaller than Eris, the discovery of the body in 2005 intensified the controversy about whether Pluto should continue to be called a planet. The IAU voted on Aug. 24 to demote Pluto to "dwarf planet," a classification that the group devised to sep