Name that planet

A group of astronomers, including Yale’s David Rabinowitz, announced recently that it had discovered the solar system’s 10th planet.

So what do we call it?

Generally, planets are named by whoever discovered them, with final approval going to the International Astronomical Union. Research team leader Michael E. Brown of the California Institute of Technology has proposed a name to a special committee of the organization, but he isn’t saying what it is. Rabinowitz said this week he hasn’t heard Brown’s suggestion. Whatever Brown chooses, Rabinowitz said, is fine with him.

“He’s the leader of the group,” he said. Chadwick Trujillo of the Gemini Observatory in Hawaii is the other member of the team.

Rabinowitz had proposed Persephone but then found out that another celestial body already had that name. “Lila” had been used as a placeholder name, which ended up being the name of Brown’s daughter. The research team informally has referred to it as “Xena,” after the Greek warrior princess from the television show of the same name.

A lot goes into naming a planet. It first has to be confirmed that it is in fact a planet, and that’s a dicey matter. About 75 years after Pluto’s discovery, astronomers still debate whether it’s big enough to be called a planet or just a giant ball of ice.

It should be a matter of weeks before the international organization will report back on the discovery’s planet status and proposed name. Rabinowitz said he’s confident that everything will check out fine. After all, he said, they know it’s larger than Pluto.

Nomenclature of the heavens can be a capricious matter. Moons orbiting Uranus are named after characters from the works of Shakespeare and Alexander Pope; Mars’ craters are named for scientists and cities and towns on Earth.

No planetary features may be named after anyone alive, political figures after the 19th century or figures from any of the major religions.

Planet names come strictly from mythology. All but Earth are named after Roman and Greek gods. By default, though, the universe has become a more culturally diverse place, as astronomers have pretty much tapped out the Greek and Roman legends. Inuit, Sumerian, Norse and Celtic mythologies are among those that have been used for craters, moons and other planetary features.