It's not as big as Uranus.

Astronomers are currently in heated debate on whether Pluto is really a planet. Many argue that the planet is too small to be considered a planet. The argument arises because of the discovery of a new planetary body that is slightly larger than Pluto, formally designated 2003 UB313. The planet was informally named Xena by the person who discovered it.

So if Pluto is a planet, should Xena be a planet too? If Xena has a moon, are we going to name it Gabrielle? Can we have astronomical naming conventions that can be confused for obscene things like Uranus and the Big Bang?