Reply to comment

You're right about Weintraub. I mis-summarized my own review, which remarks that he didn't use the "Xena" nickname when discussing 2003 UB313, which might have given his book a more popular feel.

As for the ongoing debate, I sit bemused on the sidelines. Nature is what it is, and we humans sometimes put too much effort into classification schemes. Sometimes such schemes are an aid, and sometimes they get in the way of productive thinking. The Linnaeus classification scheme, for example, is not nearly as useful now as when we didn't know enough about evolution and DNA to make sense of the multitude of life-forms on Earth.

Laurel, I detect a sense of personal investment in this argument--perhaps nothing more than your identity among your friends as the resident Plutophile--when you write:

no criteria based on physical or astrophysical principles are sufficient to distinguish Pluto and Ceres from Mercury and Jupiter.

To me, the distinction is that Pluto and Ceres are members of "belts" of similar bodies in their orbital regions, whereas Jupiter and Mercury are unchallenged as the dominant bodies in theirs. That makes them clearly different. The argument is over whether that difference can or should be accommodated within the broader classification of "planet."

To me, there is only semantics and no scientific value in that argument. Tyson says as much in his book. My review notes that he and his colleagues "finessed" the definitional issue when designing the new Hayden Planetarium exhibits. To some people that may seem like he's "trying to have it both ways." To me, it's that he doesn't really care how the argument turns out. He sees it as a cultural phenomenon, and as a planetarium director, he has to weigh the culture into his planning as well as the science.

That's why I think The Pluto Files is so much fun to read.

Fred Bortz