New York Times article
Well, it's official. A bunch of astronomers in Prague have plucked Pluto out of the planet lineup and tossed it into an icy trash bin labeled "Trans-Neptunian Objects."
And I, for one, am pretty upset about it. Not just because Pluto’s one of my favorite planets – that small, icy changeling with the big moon and funky orbit. Like the other planets, it took its name from Roman mythology based on a specific characteristic. (Mercury is fast, Venus is pretty, Jupiter is big, Saturn is slow … you get the picture.)
Named after the God of the Underworld, Pluto’s name evokes more than an ancient god. It’s a place: dark, harsh, cold, remote, a true underworld. Its largest moon, Charon, is named after the ferryman who took dead souls across the River Styx into the Underworld. Its two smaller moons, Hydra and Nix, are named after a nine-headed monster and the Goddess of Night.
But now the International Astronomical Union, drunk with new data about the numerous icy bodies beyond Pluto, launched a thorough housecleaning of the whole classification system. Their central question: what is a planet?
It is, admittedly, a tricky question: if a planet is simply a round object that revolves around the sun, then astronomers would have to promote Ceres, the biggest asteroid in the asteroid belt and Xena, that new planet beyond Pluto. And then what if scientists find a zillion more little worlds? Are they all planets too?
The astronomers didn’t solve this problem like scientists; they solved it like bureaucrats. Determined to strip Pluto of its rank, they sought a clear way to separate it from the other planets beyond the basic criteria: “It’s really small and way the fuck out there.”
So they said a planet, in addition to being round and revolving around the sun, “must have cleared other things out of the way in its orbital neighborhood.” In other words, it had to be alone, except for objects orbiting around it, like moons or rings. That knocked out Ceres in the asteroid belt and Xena in the Kuiper Belt.
Sounds like Pluto’s safe, right? It’s got three moons. Well, Pluto was betrayed by its largest moon: Charon. Apparently Charon doesn’t orbit Pluto like most moons do, the center of gravity is between them. So boom! There goes Pluto on a technicality.
I suppose these astronomers know what they’re talking about when they discuss centers of gravities of objects 3.7 billion miles away. But they’ll look pretty stupid if the NASA's New Horizons spacecraft turns up at Pluto in 2015 and finds out they were wrong.
I think it’s kind of creepy that something so basic in our scientific culture can be changed like this, just because a planet is small and distant. Does this mean a bunch of cartographers will gather in Lisbon next month and decide that Australia isn’t a continent?
Or will Congress enact a law that Hawaii is no longer a state? (“Our new definition of a state includes 'must be connected to the North American landmass. And yeah, Hawaii is small and way the fuck out there.'”)
Scientist by their very nature like things all nice and tidy, but the universe will never cooperate. I’m rushing out today and buying Benny a Solar System mobile with NINE Styrofoam balls. Maybe I’ll have to add a little Xena, but they'll never take my Pluto away.