PlanetsI was going to write a short post about the definition of “planet” recently proposed by the International Astronomical Union (IAU). I thought some moms would find it useful when helping their children with science homework.

Geoffrey Pullam’s post at Language Log on “Gay Marriage and Counting the Planets” made me realize I was thinking in limited terms. It’s also not often I find another blog post that that draws together so many of my disparate interests: astronomy, LGBT rights, and a certain humanities geekiness. Pullam, a renowned linguist, argues that gay marriage is not, in fact, a linguistic issue, and to reduce it to a fight against the “definition” of marriage is to miss the point. It’s about who gets what rights. He compares this to the IAU’s challenge of finding a definition of “planet” that maintains current planets’ status, includes some newly discovered Solar System objects, yet is not so broad as to be meaningless. This, he says, is a true matter of terminology, and while it may cause bitter quarrels amongst astronomers, has no real consequences for people’s lives.

Worth a read if only for the unique juxtaposition of topics and Pullam’s excellent writing (though there’s a typo in the first line). I recommend Language Log overall, too, if you’re a humanities nerd like me. (If you liked the bestselling Eats, Shoots & Leaves, you’ll like Language Log.)

Finally, since we’re mixing it up here with astronomy and LGBT references, I’ll note that if astronomers do approve the IAU’s definition next week, object 2003 UB313, nicknamed “Xena,” will become a planet, encircled by moon “Gabrielle.” Unfortunately, this means they’ll then be given real names from Greek mythology. As I commented last February, if we can’t have Xena, my vote is for “Athena,” the goddess of wisdom, crafts, strategy, and war. That’s at least close. For the moon, the obvious choice is then “Nike,” goddess of victory and Athena’s constant companion. She was often depicted carrying a staff, like Gabrielle.