Goofy, Xena, 2003 UB313, whatever has an actual name!

I hadn't heard this, but it seems that on September 13 the IAU gave 2003 UB313 (hitherto referred to in this blog as either "Mickey" or "Goofy") a particularly appropriate official name. It's now Eris, after the Greek goddess of strife and discord, who started the Trojan War.

Touted originally as the "tenth planet," its discovery forced the IAU to come to a decision about the staus of the smaller Pluto which ended in the latter's demotion to the status of "dwarf planet," a category it shares with Eris and the asteroid Ceres. The decision was a singularly contentious one, and the grumbling is still going on.

And, no, it was never actually named "Xena." That name was a joke.

Eris's moon, similarly, is not "Gabrielle," but Dysnomia, or "Lawlessness-" in Greek mythology, the daughter of Eris.