Pluto

[gfish]

For some reason the subject of Pluto's status has come up several times recently. (Probably because I've been reading a lot about planetary formation.) I certainly agree that it isn't a planet, but I'll take an even more radical stance: Earth isn't either.

That's right. I don't think Earth should be classified as a planet.

To be more precise, I think it is ridiculous to place Earth (or Mercury or Venus or Mars) in the same class as the gas giants. If you were an intelligence evolved entirely outside the context of planets and you started looking at solar systems, I think you would break things down as follows: stars - planets (gas giants) - random rocky crap (us). Our hypothetical alien intellects (vast and cool and unsympathetic), not obsessed with our particular form of wet and squishy life, would barely even notice the inner solar system. To think that the object we live on must necessarily be grouped with Jupiter and Saturn is pure provincialism. It's nothing more than an updated form of geocentrism.

But at least this means the Kuiper Belt objects would be in the same category as the Earth, so I have to assume those upset about Pluto will be happy.

Comments

[inaurolillium.livejournal.com]

I have to disagree. I think it's a bit arbitrary to decide that gas giants are planets and rocky spheroids are not. Why not have multiple classifications of "planet," or none, and class the inner-system bodies as rocky spheroids, the gas giants as gas giants, and other bodies as other appropriate types. (I'm leaving Pluto out of consideration entirely.)

[gfish.livejournal.com]

Well, sure, you can mix and match the labels however you like. I think gas giants, rocky bodies large enough to spherize themselves, and everything else would be a perfectly good distinction. If rocky spheres get the label 'planet', that's cool, it's just the hubris of placing ourselves in the same group as Jupiter I'm really arguing against here.

[inaurolillium.livejournal.com]

It might be hubristic if we'd come up with the classification from scratch, but it's obviously an artifact of etymology. But I can perhaps get on board with a call for a new set of classifications entirely.