QUOTE (Rob Pinnegar @ Aug 24 2006, 07:44 AM)
...Which makes it perfectly suited for making the news.
And yes, we *are* lucky that New Horizons is already launched. It's hard to see how Pluto's demotion from planetary status could have failed to affect the mission, had this happened a few years ago.
I disagree. It was a long, slow fight to get a Pluto mission, and I don't think anyone involved would want to have any extra ammunition whatsoever in the hands of the political opponents of it.
I could see someone in a House committee saying, "The damn thing's not even a planet any more," getting a round of laughs, and a representative or two thinking that the same line would seem persuasive to a few voters or fundraisers, etc. Or Goldin pushing the same line. I don't see the impetus towards the mission having been so solid that it might not have been derailed by an additional flyspeck of resistance.
NH has 9 years to go. I would be very surprised if this issue remains settled. Anticipation of NH's arrival itself might spur reconsideration of the issue. It's credible that NH's observations might rekindle the issue if Pluto is found to be particularly lively.
If the scads of rival definitions has made anything clear, it's that "planet" is a category with many properties that one person or another finds to be relevant in its conceptualization. Most of the reasoning that has gone into the debate has involved appeals to intuitions: Gut-level reactions to hypothetical cases have been used repeatedly as the test of a definition. If this tells us anything, it should be that the gut-level reaction is the real definition of "planet", and we're just trying to reverse-engineer it into a codification. We all know that Saturn and Mars are planets, and we pretty much all "know" that Charon isn't. When we get a definition that counters what we "know", we reject it. Again, what we already "know" *is* the definition of planet, and there's no guarantee that it codifies elegantly. As the Supreme Court justice said of pornography vs. art, you know it when you see it. Of course, different people have different opinions. That, to me, is the end of the line. The embarrassment and the indecision shows that it was a damaging exercise that missed an opportunity to do the right thing and NOT define the undefinable. And this issue is not settled, I promise.