Really Long Travel Post

So, because I feel it is my duty as a blogger who is an astronomer, I feel I should tell you that the International Astronomical Union -- the organization that defines and names everything in the sky -- has developed a definition of planet. (So far we've had an upper bound of 'anything that never fused deuterium in its core' but no lower bound, besides 'Mercury is, and we're not so sure about Pluto') The official definition of a planet is a body that orbits a star that is too small to have every fused deuterium in its core and large enough that it is roughly spherical.

So, it's in. Pluto is a planet. So is the asteroid Ceres. Actually, Pluto is two planets, since its largest moon, Charon, is so big it's more correct to call them a double planet system. We also have a Kuiper Belt Object that doesn't have a name yet (I think it's the one that scientists nicknamed Xena) that is also a planet.

I look forward to seeing Dr. Margot's reaction when I get back to work. He's gonna be in a sulk. (He gave a whole 'why I think the definition of planet should exclude Pluto' speech to the Astro 102 students last spring)

( Now I'm going to talk about my trip. )