Friday, August 25, 2006

Alas, Pluto, we hardly knew ye

Spinning through the far reaches of our solar system, the twins Pluto and Charon shadowbox their way through the heavens as they have for untold millennia: circling and spinning, never touching, locked in a gravitational embrace. They are mysterious and cold, and virtually invisible to us, even with all our new telescope technology. And until yesterday, Pluto had the honor of being called a "planet" by most of an odd race of bipedal primates who happen to live on one of the other orbs circling the same star.

My take on this not-very-important-yet-very-interesting bit of news is that if "planet" is going to receive some sort of scientific definition, that definition ought not be arbitrary, but instead rest on some innate physical property of planets. I liked the proposed, but rejected idea that a planet was an object with enough gravity to form a sphere, and which orbited a star (rather than another planet). It was universal, and didn't rely on one's opinion. This was rejected, apparently on the grounds that we'd have too many planets (a silly argument given the number of, say, asteroids or stars in the heavens). So instead, a new definition of "planet" was reverse-engineered based on a list of preferred orbs. Nevermind that Mercury (still a planet) has more in common with Pluto than Saturn or Jupiter.

I wonder what the inhabitants of Pluto call our little piece of real estate, here between Mars and Mercury?

In any case, Pluto is now a dwarf planet, not quite a real planet. News of this demotion won't reach icy Pluto for some time, and when it does, I don't know what reaction we are expecting. But somehow, I don't think Pluto itself will care. It will continue spinning and circling in its eccentric elliptical orbit, shadowboxing with Charon, just as it did before the dinosaurs walked, before Newton's theories, and before we clever chimps even knew it was there.

3 comments:

Bud said...

I believe it's a naming problem. Image is everything, you know. If Pluito had been named "Appollo" or "Zeus" it would still be a planet.
Bud

Anonymous said...

Planets are the only celestial body that there really is no quantitative definition for. Even your "spherical" definition doesn't go far enough (the Earth is not a sphere. Where does that leave us?)

Your concern over this event is appropriate, however. This is like a "JonBenet" story for stargazers. Tittillating, but void of any real significance.

As befits the "JonBenet" meme, the real news get's left by the wayside. No one seems to know astronomers apparently have verified the existence of Dark Matter. A far more important development, but not nearly as sexy. Ergo, no one knows about it.

-Marty

scot s w said...

At least the debate about Pluto lacks the prurient seaminess of the JBR snuff flick.

As for the technical fact that Earth isn't quite a sphere, I think you're sounding like a lawyer... The Earth's round shape is determined by its gravity. And as I read more about the Pluto issue, it appears that this has been in fact retained as PART of the definition of a planet.