Naming the New Planet: What About "Bob"?

Ted Chamberlain
National Geographic News
August 10, 2005
The newfound ball of ice and rock that could be the solar system's tenth planet isn't just any Tom, Dick, or Harry. But could it be a Bob?

The discovery was announced on July 29, and the International Astronomical Union (IAU) has yet to even decide whether the body is a planet. But space fans around the world are losing no time trying to name the object, which orbits beyond Pluto and is bigger than the ninth planet.

Michael Brown, the California Institute of Technology astronomer who led the discovery team, got the ball rolling.

Because the provisional, number-based names are tough to remember, "whenever we discover something big, we give it a nickname," Brown said. So in place of the object's provisional name, 2003 UB313, Brown's team adopted a catchier—and more swashbuckling—moniker.

"We had planned on calling any object bigger than Pluto 'Xena,'" Brown said, "but only tongue-in-cheek." The name refers not only to TV's warrior princess but also to the Roman numeral ten, or X.

"Besides, we thought the solar system could use another woman, to balance out the male hierarchy," he said. Of the nine recognized planets, only one, Venus, is named for a female.

The Rules of the Name

As the discoverer of UB313, Brown gets first dibs on naming it, though he is required to keep his suggestion secret. The final decision is up to the IAU.

Since the discovery of a new planet was largely unexpected, the IAU never drafted formal rules for naming planets. It does, however, restrict the naming of "small bodies." Among the guidelines:

• Names must be pronounceable.

• Names should have 16 characters or fewer.

• Single-word names are preferred.

• Individuals or events principally known for political or military activities are unsuitable until a hundred years after the death of the individual or the occurrence of the event.

• Names of pet animals are discouraged.

Reader's Choice

Despite the rules, readers managed to come up with some fairly outrageous appellations. The Web site asked readers to weigh in on August 2.

Writer and editor Sean O'Neill headed up the informal survey. "The response was huge," he wrote in an e-mail to National Geographic News. "We received about 1,500 e-mails, and the vast majority were really well thought out, considered responses."

The clear winner was "Persephone" (Greek spelling) or "Proserpina" (Roman).

In Greco-Roman mythology, Pluto/Hades, god of the underworld, kidnapped Persephone/Prosperina and made her his wife. Her mother's sadness was such that it caused winter—making the name especially apt for a cold, distant planet.

What's more, Persephone spent only half her time in the underworld—a nice twist, says Brown, the Caltech astronomer. UB313's very oblong orbit brings it close to Pluto during only half of the time.

Brown too has received "a ton" of name suggestions via e-mail, and they've been "overwhelmingly" for "Persephone/Proserpina."

The fan favorite, though, may be thrown out on a technicality. The IAU forbids a name to be used twice, and Persephone has already been assigned to an asteroid.

"But there's always a chance that the IAU will say, We don't care about that stupid asteroid," Brown said.

Brown pronounced the runner-up—"Peace," or its Latin root, "Pax"—"a good name." And according to O'Neill, of, Brown "really liked [sixth-ranked] 'Bob' as a possible name."

"Galileo," "Xena," "Rupert" (after a gag in The Hitchhiker's Guide to the Galaxy), "Titan," "Nibiru," "Cerberus," and "Loki" round out the readers' top ten.

As for nutty names, "Bob" was only the beginning. "After Pluto, there were lots of other cartoon dogs suggested, and 'Mickey Mouse' and 'Scooby' both did quite well," O'Neill said.

A few suggestions were, like UB313, firmly on the fringes. "'Spongerock Roundplanet' was never going to make the cut, for example" O'Neill said, "and neither was 'Mianus.'"

Back to the Drawing Board

As of yesterday, you and I know as much about 2003 UB313's name as the planetoid's discoverer does.

Brown's suggested name was made under the guidelines for naming a small body, which don't specify a preferred cultural origin.

"But I just heard from the IAU that, if they rule that it's a planet, they want to go with a Greco-Roman name [along the lines of 'Saturn,' 'Jupiter,' and 'Mars']," Brown said, "which is not at all what I suggested."

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