136199 eris

Ultimately named for the dual-natured goddess of strife, on the one hand peddling in the aspirational jealousies that drive competition and one the other sewing discord—like when she tossed that bombshell Golden Apple in the ring and left it to Paris to decide whom was the fairest of them all, Eris was discovered on this day by a team of astronomers at Palomar Observatory in 2005.
Pluto having not been yet downgraded and suspecting that this new find might indeed but a planetary candidate and bigger that soon-to-be dwarf planet (Eris is indeed a quarter more massive than icy Pluto though the latter has a greater diameter), the team used Planet X as a provisional designation. With the campaign to give more representation to female deities and New Zealand actor Lucy Lawless’ Warrior Princess enjoying a cultural moment back then, X transitioned to Xena before in accordance with the International Astronomical Union’s protocols, Eris was decided upon in September of the following year. Meanwhile, it was discovered that the most massive dwarf planet and the largest object not visited by a space probe in the Solar System, had a satellite of its own and following the above conventions before an official name could be given, the team referred to it as Gabrielle, Xena’s sidekick. Eventually the moon was named Dysnomia, after one of the daughters of Eris—Δυσνομία, being the personification of lawlessness and an indirect tribute.