The universe really is expanding — astronomers are proposing to rewrite the textbooks to say our solar system has 12 planets, rather than the nine memorized by generations of schoolchildren.
Much-maligned Pluto would remain a planet — and its largest moon plus two other heavenly bodies would join Earth's neighbourhood — under a draft resolution to be formally presented Wednesday to the International Astronomical Union, the arbiter of what is and isn't a planet.
"Yes, Virginia, Pluto is a planet," quipped Richard Binzel, a professor of planetary science at the Massachusetts Institute of Technology.
The proposal could change, however: Binzel and the other nearly 2,500 astronomers from 75 countries meeting in Prague to hammer out a universal definition of a planet will hold two brainstorming sessions before they vote on the resolution next week. But the draft comes from the IAU's executive committee, which only submits recommendations likely to gain two-thirds approval from the group.
Besides reaffirming the status of puny Pluto — whose detractors insist it shouldn't be a planet at all — the new lineup would include 2003 UB313, the farthest-known object in the solar system and nicknamed Xena; Pluto's largest moon, Charon; and the asteroid Ceres, which was a planet in the 1800s before it was demoted.
I can't help but think about the differences between scientists redefining planets and judges redefining marriage. The former seem to take much more care and study than the latter, who just blithely blast away with their pet theories.