It’s official. The ninth planet in our solar system is no more. Today in Prague the International Astronomers Union stripped Pluto of its planetary status, noting that the tiny celestial object did not meet new guidelines required to join the now exclusive club of eight ”classical” planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Already second-graders and other Plutonian fans are mourning Pluto’s fate. “I just can’t stand by and watch as the solar system’s Fat Girl gets pushed down into ever-more ignominious substrata of social ostracism”, writes NYTimes op-ed contributer Tim Kreiger. The reclassification also raises the interesting question of whether libraries will toss out their astronomy books, or at least tear out the Pluto chapter.

But, as they say, it ain’t over until the fat lady sings. Coming in January from Princeton University Press is Vanderbilt University astronomy professor David W. Weintraub’s Is Pluto a Planet? A Historical Journey through the Solar System, which traces the history of how ”planet” has been defined over the centuries. ”Our author would actually beg to differ with the IAU’s decision, ” writes Weintraub’s editor in an email to LJ. “Weintraub says that Pluto IS a planet—and not just a minor planet either. He argues that Ceres, Vesta, Pluto, and Sedna should all be called planets, and that in fact, the solar system has more than 20 planets!  But these objects are all more than just planets.  Pluto is a planet and a Plutino and a Kuiper Belt Object.  According to Weintraub, it’s unsatisfactory to come up with a one-size-fits-all solution, since there is a veritable zoo of different kinds of planets actually out there. Acknowledging this will give us a better sense for the reality of a complex and nuanced universe.” —Wilda Willams