Pluto 2.0

I hadn't intended to say any more about the Pluto debate, but unfortunately, it doesn't seem to want to die. Public interest has waned apparently, but according to Yahoo news scientiests are still squabbling.

"The IAU created a definition which is technically flawed, linguistically flawed and scientifically embarrassing," [Alan] Stern [planetary scientist at the Southwest Research Institute in Boulder, Colorado] said in a phone interview.

The 300 astronomers and planetary scientists who signed the petition said they would not use the IAU's definition.

While I still stick by my earlier statements that ultimately, the title Pluto itself is given is unimportant, I have the same reservations the Bad Astronomer has: namely that the defition is overly vague.

One of the requirements is that a planet be able to "clear" its orbit. However, what this truly means is not explicitly defined. Pluto is obviously disqualified for lurking near the edge of the Kuiper belt. But what about all the Near Earth Objects that cross our orbit? There's a lot of 'em, so do we not qualify?

I'd argue that we do. Earth's done a great job clearing out its orbit, but it's like having just dusted a room, there's more that's bound to settle immediately.

But what about other Planets? Jupiter has two groups of asteroids (one preceeding it and one trailing) known as the Trojan asteroids that follow in its orbit. I think the "cleared" is meant to imply that objects must orbit with the body in question.

Mercury's orbital area is pretty clear. But we also have to stop to consider whether or not Mercury really did this on its own. It's quite possible that its had help from a rather massive neighbor (ie, the Sun). So, if placed elsewhere in the solar system, would Mercury still be able to make the cut?

Mars too has done a good job, but its two moons (Phobos and Deimos) aren't in stable orbits. One is slowly spiraling outward while the other is slowly heading inwards to crash into the planet. Thus, do these disqualify Mars?

Another requirement is that the planet be massive enough that it be able to make itself spherical. As the Bad Astronomer points out, there's no clarification on how spherical is "spherical". While most planets are pretty round, Earth is slighly pear shaped. Not noticeable visually, but still not spherical.

Saturn meanwhile, is very noticibly oblong. Due to a rapid rate of rotation, Saturn in about 10% wider along the equator. Thus is Saturn disqualified for this reason?

So while the public may not be up in arms as much as they were when the decision was still front page news, it's obviously still a very hot button issue in the scientific realm. As petulant as those are that are refusing to use the now ratified definition are, I'm forced to agree that the new definition is inadequate in every regard (although slightly less so than the former lack of a definition).

Thus, while I wasn't planning on discussing the issue any further, I would also have to call upon the IAU to adopt a definition that is quantitative rather than ambiguous and qualitative.