So recently I came across this article describing how Pluto has yet again been screwed by the scientific community: As Science Evolves, So Does Pluto. And I thought it pertinent to reminisce about my old friend, the planet, I mean dwarf planet, I mean planetoid, I mean plutoid, what?!?!?.
1930 - 2006 - Pluto was discovered and deemed the 9th planet in the solar system. Essentially completing the popular acronym MVEMJSUNP.
2006 - The IAU (International Astonomical Union) destroyed the ever loving acronym (what the hell is a MVEMJSUN?) by recalssifying Pluto as a "Dwarf Planet". This classification includes Ceres - the largest asteroid in the asteroid belt and some other objects large enough beyond Pluto's orbit in the Kuiper Belt (Like Eris). They determined this because they felt that Pluto did not "clear" its orbit (I think because its moon Charon is roughly the same size).
2008 - And they go and do it again. Pluto is now referred to as a "Plutoid". Why? I don't think there is any good reason other than their definition of a "dwarf planet" sucked so they came up with a less controversial definition and needed a new name with it. Now Plutoids are big objects outside of Neptune's orbit. Abandoning Ceres to be the only "dwarf planet".
And in 2009 the debate continues with the article previously mentioned. As Science Evolves, So Does Pluto.
My take on it is that it is all basically semantics. Nothing has changed since 1930. Pluto is still the same size. It still has the same orbit. And as far as I am aware will be like that for a long long time (until it flies into Neptune). They discovered Charon in 1979 and that didn't change anything. I say put it back to being a planet. It is different enough from the other stuff in the Kuiper Belt and it has a fairly long history as a planet. Just leave it be.
A rose by any other name...
I ranted on this a while back as well HERE.