The Pluto Files: The Rise and Fall of America's Favorite Planet. By Neil deGrasse Tyson. New York & London: W.W. Norton & Co. 2009. Pp. 194. $23.95.
In case you haven't heard, Pluto isn't a planet anymore (and maybe it never was). In grade school, we all memorized the planets, giving little thought to what made something a planet besides revolving around the Sun and being part of some familiar mnemonic. However, scientific discoveries about Pluto and other parts of space led scientists to question Pluto's planetary status and ultimately, to strip Pluto of its standing among the planets. This leads to the inevitable question-what is a planet?-which turns out to be a more difficult and fascinating question than one might think.
The Pluto Files grapples with the question of what it is to be a planet. The book is as much a cultural study as an astrophysical one. "Gathered here in one place is a record of Pluto's rise and fall from planethood, given by way of media accounts, public forums, cartoons, and letters I received from disgruntled schoolchildren, their teachers, strongly opinionated adults, and colleagues" (p. xi). The Pluto Files thus presents the question of the meaning of planet not through rigorous argumentation but through the crosswinds of culture and science.