Great title of the day

by John MacBeath Watkins

How I Killed Pluto and Why It Had It Coming

by Mike Brown

 I haven't read this one, but I've heard an interview with the author and I'm betting it's a good one.  It's a great title, but still not up to Words of the big-footed Giants, by Pigafeta. Brown was part of the team of astronomers who discovered the dwarf planet Eris, slightly bigger than Pluto, sparking a controversy that eventually resulted in Pluto being demoted from planet status.  In all likelyhood there are many objects close to the size of Pluto in the solar system, so it was a question of making them all planets or demoting Pluto.  Astronomy chose the small-tent approach, preserving the exclusivity of the planets. 

Edited to add: For another view of the matter, check here.


  1. "Astronomy" did NOT choose the "small tent approach." The IAU demotion was done by only four percent of its members, most of whom are not planetary scientists. It was opposed by hundreds of planetary scientists in a formal petition led by Dr. Alan Stern, Principal Investigator of NASA's New Horizons mission to Pluto. Even Dr. Neil de Grasse Tyson admits the debate is ongoing.

    In November 2010, astronomers discovered that Eris is not bigger than Pluto at all; this was determined when Eris occulted a star. Therefore, Pluto is the largest body known in the Kuiper Belt, and only a few known other Kuiper Belt Objects, not many, are close to its size. Significantly, Dr. Stern coined the term dwarf planet in 1991 to indicate a third class of planets in addition to terrestrials and jovians; small objects large enough to be planets because they are rounded by their own gravity (hydrostatic equilibrium) but of the dwarf subcategory because they do not gravitationally dominate their orbits. He never intended for dwarf planets to not be considered planets at all.

    I encourage people to learn both sides of the issue. Some good pro-Pluto as a planet books are "Is Pluto A Planet?" by Dr. David Weintraub, "The Case for Pluto" by Alan Boyle, and my own book, hopefully out in 2011, "The Little Planet that Would Not Die: Pluto's Story."

  2. This is wonderful! Thank you for setting me straight!


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