Just Sent The Following:

Mike,

I have to congratulate you on your positive attitude about the IAU decision. To suppport a decision that costs you the title of planet discoverer shows a great dedication to scientific objectivity. Even if you disagreed with the vote, I think it might be best to stay quiet on the issue as opposing it publicly might just be dismissed as a lack of objectivity. However, actively defending the decisions leaves no doubt about your objectivity.

I however strongly disagree with the new definition and disagree in particular with some of your defenses posted online. Since your defense of the ruling is the best I've seen and clearly comes from someone trying to be objective about the issues I hope you can find the time to address some of the issues I have with the new definition. I am a chemical engineer with minors in math and molecular biology not an astronomer, but have been a space fan since watching the Apollo and robotic exploration programs unfold as a kid. I am familiar with research and the need for well thought out accurate scientific definitions however, and don't feel the recent definition passes muster. I'm not particularly attached to Pluto or Xena being planets, but have a very visceral "that's bogus" reaction to most of the justifications I've heard for demoting Pluto.

First and formost I do not believe location should have anything to do with defining a planet. Extrasolar planet discoveries and modeling of our own solar system indicate planets can shift orbits. If you define a planet by what's around it then it's planetary status might change with an orbital change. Since it's the orbital change itself which is most likely to impact the planets characteristics rather than the change in what's around it such a condition seems ludicrous to me. You use related logic to defend the new definition by saying Neptune migrated out yet the definition does not clearly allow this. Nore for that matter do we have conclusive proof that this migration happened as far as I know. Definitions should be based on what we know, not what we theorize. The definition also implies Jupiter was not a planet until it cleared the debris around it. That is ludicrous In my opinion as anyone on Jupiter would have barely noticed the change. Astronomers have clearly discussed the possibility of extrasolar planets being detected in systems which are in the process of forming so this clause is also inconsitent with past usage. The definition also means that if we detected a planet as big as mercury or even Jupiter out in the Kuiper belt it would still not be a planet. Such a potential for inconsistency is a major flaw in my opinion.

In addition to the internal inconsistencies and potential conflicts arising from the zone cearing definition, I find the definition of zone itself to be entirely too nebulous and inconsistantly applied. The Kuiper belt is far larger in area than the asteroid belt and terrestrial planets area combined. Why should it be one zone while the terrestrial planets zone is conveniently broken down into smaller zones allowing classical planets to be planets? We really have just 2 or 3 zones. One where the temperature was high enough to prevent volatiles from condensing and one where they could. The latter is subdivided into a zone where there was enough material for gas giants to form and another where there wasn't. Any other division of zones seems just as arbitrary as drawing a line at a certain diameter and saying this is a planet and that's not. Pluto does not actually come within 1 AU of Neptunes orbit in three dimensions. If I'm eyeballing the 3D map right it appears it doesn't even come within 2 or 3 AU's of Neptune's orbit. I don't believe any KBO of significance has been found within a 3 AU distance on Pluto's orbit. If so it, passes through a volume of space much larger than Earth which is just as relatively clear.

The one comment that irritates me above all others is complaints that this or that definition would result in too many planets. What other fundamental scientific definition was construed to limit the number of objects that fall into the category? This is the most arbitrary of arbitrary conditions I can think of. In my opinion Astronomers should find a reasonable definition for a planet without worrying about what specific object meets the definition or how many objects meet it other than that all "planets" as of 2005 except Pluto have to be in it. No defintiion should be made on the basis of intentionally excluding Pluto either in my opinion which appears to be the case with the one recently passed.

I think the original proposal was far better. Some of the terminolgy needed to be changed to avoid conflicts with geology and for the sake of clarity. Charon was problematic, but If any moon we know of deserves to be considered a double planet Charon did. I don't see a more reasonable definition for a double planet than the one proposed. If Charon was a deal breaker double planets could simply have been ruled out although future exoplanet discoveries might make us regret that. I disagree profoundly with the aversion to any large increase in the number of planets. That really is just a rationalization in my opinion for discounting small planets. If we knew there were 30 objects larger than Earth in the Kuiper belt, I doubt very much the issue would be brought up.

Regards,
Mark