Thursday, August 24, 2006

It's Official

The votes are in, and it's a sad day indeed for Pluto.

At a stroke, poor Pluto goes from being the smallest planet to not even being the biggest dwarf planet.

But on balance, this new classification is a good thing. And even though astronomers have said that this definition only applies to our own solar system, I think it might be useful for classifying extrasolar planets as well. That is, once our technology is good enough to resolve such distant objects with sufficient accuracy.

The new definition categorizes a planet not just by size and shape, although it has to be big enough to pull itself into a spherical shape. It also has to be big enough to clearly dominate its region of space. This, in the end, is what kicked Pluto out.

Pluto does not dominate its region of space. Pluto is locked in orbital resonance with Neptune, which is clearly the dominant partner in that area of the Solar System. Several other objects in the Kuiper Belt are also in a 3:2 resonance with Neptune. Be that as it may, it clearly establishes Pluto as ruled rather than as ruler.

So, now we know. The arguments are over. But, I've got a sneaking suspicion that even now, after the votes have been counted, that the status of Pluto will still be good for an instant riot at any astronomers' gathering. Pluto's supporters will have to lick their wounds for a while, but they'll be back, and spoiling for a fight. Just you wait and see.

Tuesday, August 22, 2006

Downsizing? Supersizing? Ah, the heck with it...

Apparently, the draft resolution I mentioned the other day has been received with all they joy and good cheer that Osama bin Laden might expect if he were to drop in on the White House for a social call.

You may remember that in my first post on the subject, I said:

If it were up to me, I'd re-classify Pluto as a Kuiper Belt object. It has a lot more in common in terms of both composition and orbital elements with that group than it does with any planet. To be a planet, an object really has to have formed within the star's major accretion disk, and I'm not sure that applies to the KBOs.

Apparently, a Uruguayan astronomer by the name of Julio Angel Fernandez used logic like this to send the new proposal off with a shot of grape. Rather more than a shot of grape, actually; after a rebellion within the orbital mechanics community, the new proposal bore a striking resemblance to Bonnie Parker and Clyde Barrow after the Feds ran out of ammo.

Didn't I say that this question was good for an instant riot? Just add astronomers and stir...

The thing that kind of stinks about this is that we have a brand-new space probe sailing on its way to something that might not be a planet anymore by the time it gets there ... which is just as well. Somebody needed to get close-up observations of Pluto before its atmosphere froze, anyway.

It's still worth doing, even if Pluto gets demoted. Besides, the bloody thing's already on the way. It's not like we can haul it back in.

Friday, August 18, 2006

Downsizing? Supersizing?

Back in the day, if you wanted to start a fist-fight at an astronomers' convention, all you had to do was ask a random passer-by, "Is Pluto really a planet?" The ensuing scrum would have been good for hours of entertainment.

Which is why I found this news item so interesting.

For years, the controversy has largely been swept under the rug. Pluto was an odd duck, all right, but for years after its discovery, scientists thought it was more or less the same size as Earth. This was proven wrong later. The problem is, Pluto doesn't quite fit.

For one, it's orbit is very eccentric. For another, its orbit is steeply inclined relative to the orbits of the other eight planets. Also, it's composition is more like the moons of the outer gas giants, or the other Kuiper Belt objects, than the other outer planets.

There's been a low-level war seething just below the surface in the planetary science community. Most don't really care all that much, but there are a handful of hard-line partisans on either side of the question. But the thing that really tore it was last year's discovery of a large Kuiper Belt object, tentatively named Xena.

Xena, you see, is larger than Pluto.

Yeah, that tears it, all right. Because if Pluto is a for-real planet, Xena just about has to be, too. And if Xena isn't, then how do we justify Pluto?

Besides, just what is a planet, anyway?

As it turns out, that's probably the real question. Nobody really knows. But the pressure's on for them to figure it out.

We may end up with a compromise system, which has the virtue of being more accurate, at the expense of not being as simple. Planets would be classified by their type: rocky core, like Earth; gas giant, like Jupiter; and maybe a third category, ice balls like Pluto, Charon, or Xena.

If it were up to me, I'd re-classify Pluto as a Kuiper Belt object. It has a lot more in common in terms of both composition and orbital elements with that group than it does with any planet. To be a planet, an object really has to have formed within the star's major accretion disk, and I'm not sure that applies to the KBOs.

But then again, I'm not really a scientist. I'm just an educated amateur, who's enjoying the show.

UPDATE #1: A firm definition of "planet" appears to be in the works. To summarize, by the new definition, a "planet" is defined as any roughly spherical object orbiting the Sun with both a mean diameter greater than 500 miles, and a mass greater than 1/12000th that of Earth.

The list of newly-promoted planets would include both Charon and Xena, as well as the largest asteroid, Ceres. That would bring the Solar System to a total of twelve planets. Note that Charon is included even though it and Pluto orbit one another as they both orbit the Sun. This is becuase the center of mass of the Pluto-Charon system is not within either of the two. But it would exclude the Moon, since the center of mass of the Earth-Moon system lies within the Earth.

Time to go re-publish a whole bunch of encyclopedias and textbooks, boys...

UPDATE #2: Go here to see the Wikipedia article on the re-definition. There's a whole bunch of candidates that I'd forgotten about. Cold, miserable places like Sedna, Quaoar, and several others. Including, I note with interest, Vesta and Pallas, some of the other large asteroids from the Belt.

Maybe there are other more important things going on in the world. But I don't much care. This is still very, very neat.

UPDATE #3: As reported in the Wikipedia link above, the proposed definition comes up for a vote on August 24, in Prague. Mark your calendars.

Monday, August 07, 2006

Crow: It's What's For Dinner

Things aren't looking so good for our man Floyd.

The "B" sample test turned up positive, pretty much like everyone expected it would. But that's not the real problem. As we discussed last time, there are problems with the T/E ratio test. No, what's got Floyd's essentials well and truly trapped in the mangle is the isotope test.

My knowledge of biology is somewhat scanty, as discussed earlier, but this much I do know: there are subtle chemical differences between naturally-produced hormones and the synthetic varieties. I know this, because I take fistfuls of vitamin supplements, and like to know something about what I'm shoveling into my cake hole. For instance, there's a minor difference between synthetic Vitamin E, and the stuff your body produces naturally. But it's not a big difference, and it has the same chemical function that the natural stuff does.

Likewise, there are subtle chemical differences between synthetic testosterone, and the genuine, natural article. They're not produced by the exact same chemical process. This induces very minute differences in composition, differences that are detectable by gas chromatography.

Which means that, unless something truly extraordinary is revealed, it's likely that there really was some synthetic testosterone in Landis' body when he took those tests.

It's a monumentally stupid thing to have done, if he really did do it. I don't know of anyone who thinks that a testosterone boost could have done any good to improve single-day performance. And if he won big, of course he was going to be tested. Did he think they'd miss it? That by some miracle it wouldn't show up?

There's a long appeal process to churn through before this is well and truly done. But it's not looking good, not at all.

In any case, I like to think that I'm man enough to eat my crow when it's called for. The performance that I'd hailed as a triumph of iron will is probably due instead to better living through chemistry. I'm disappointed by that, I really am. And I'm still hoping against hope that, somehow, there's vindication at the end of the road. But I wouldn't bet more than pocket change on it.

Pass the Tabasco, would you, pal?