So, what is a planet?

[Quicksilvre]

Many of you know that the International Astronomical Union is meeting right now, and on Thursday, they are going to vote on a new definition of the world "planet." The recent (in the last 10-15 years) discovery of lots of Pluto- and almost-Pluto -sized objects in the solar system beyond the orbit of Neptune. All of the eight classical planets (Mercury to Neptune) will maintain their status, but Pluto is not nearly as secure.

The currently drafted plan (planet = anything round and more than 800km across that orbits the sun) keeps Pluto as a planet and adds

Chiron (Pluto's biggest moon, to be added because of its orbit around Pluto)
Ceres (the biggest asteroid in the asteroid belt)
2003 UB313 (farther from the sun than Pluto and a hair larger)

On top of all that, there are a bunch of other things that may or may not be classified as planets, depending on what else astronomers find out about them. Most of them have just numbers for names, so far.

CNN article

Space.com article

Caltech article

What does the Lounge think? As icky as its name is, 2003 UB313 is bigger than Pluto, and orbiting the sun, so it seems silly not to include it. I doubt many people would want to change their idea of the solar system, though.