9-1 = 8

Now that the smoke appears to be clearing, I wanted to comment on this whole Pluto demotion circus of recent weeks. Pluto has always been considered an oddity. It has a highly eccentric orbit (non-circular) as well as a very inclined orbit (Pluto leaves the "equatorial" region of the solar system, unlike the rest of the planets). We do not yet know all the details of it's composition, but we know enough to state that Pluto has compositional characteristics that put it on par with comets and general icy bodies of the outer solar system. In recent years, astronomers have discovered a number of large icy bodies in the outer solar system. This region, the Kuiper Belt and the larger Oort Cloud, are potentially populated with a dozen or so Pluto sized objects. So, when the IAU sat down to consider the definition of a planet, in my mind they were faced with two options: add more planets to the solar system, or create a new category of bodies. I think they chose the right option, which is to add one category rather than add a new planet every 5 or 10 years when we find another large Kuiper Belt object. This leaves us with eight classical planets and an open-ended number of "dwarf" planets. Pluto, or I should say 134340, is a member of a class of bodies that number in the millions. There's only one Earth, or Mars, or Jupiter. In my mind, Pluto just isn't that odd anymore. I think of it as the Kuiper Belt's ambassador to the solar system, an object that tells us the outer solar system is a very interesting and important region that may have brought water and even the seeds of life to Earth. That's not too shabby, if you can't be a planet.