IAU Revisits Pluto

Last week, the International Astronomical Union, the governing organization of the world's astronomers, decided to call Pluto a "plutoid." In 2006, the IAU stripped Pluto of its status as a planet. An element in that decision charged the IAU with the task of coming up with another name for Pluto and similar objects-- hence plutoid. Most planetary astronomers think Pluto is simply the first discovered of hundreds of similar bodies.

Many astronomers, however, argue that's no reason to say Pluto isn't a planet. They see nothing wrong with a Solar System having hundreds of planets. Indeed, the controversy concerns what should be the correct definition of "planet," and that battle shows no sign of resolution. Humans, even intelligent ones, will argue about the strangest things.

One other strange aspect to this debate is that the 2006 decision demoting Pluto limited itself to this Solar System; whatever orbited other stars was not addressed. Astronomers and physicists have spent literally centuries doing the hard work of theorizing and amassing evidence that allows humans to make the rather remarkable assertion that the physical laws that operate on Earth are the same laws that operate everywhere in the universe. The IAU decision to treat our Solar System as somehow special seems to fly in the face of astronomy's greatest and most profound discovery. But that's the subject of another debate.