2 Pluto Moons Get New Names: Styx & Kerberus

The International Astronomical Union has officially approved Kerberos and Styx as the new names for two of Pluto's moons. Image released on July 2, 2013.

CREDIT: IAU

It's official! Two tiny moons orbiting the dwarf planet Pluto finally have new names: Styx and Kerberos.

The International Astronomical Union — the organization responsible for naming celestial objects — has approved "Kerberos" and "Styx" as the new monikers for two of Pluto's moons that were previously called P4 and P5 respectively, but fans of TV's "Star Trek" might not be too happy about the new names.

The IAU selected the names based on the results of the Pluto Rocks Internet poll sponsored by SETI (the Search for Extraterrestrial Intelligence), but the top vote-getter, Vulcan, ultimately wasn't chosen as a name for one of the tiny moons.

Actor William Shatner — who portrayed the Starship Enterprise captain James T. Kirk in the original "Star Trek" TV series — suggested Vulcan (the home planet of the show's pointy-eared Vulcan people) as a possible candidate, and voters overwhelmingly cast their ballots in favour of it.

In total, nearly 500,000 votes were cast, with about 170,000 of those going to Vulcan alone. In second place was Cerberus with Styx coming in third in the online poll. But for Vulcan, it was not meant to be.

"The IAU gave serious consideration to this name, which happens to be shared by the Roman god of volcanoes," SETI officials wrote in a statement.

"However, because that name has already been used in astronomy, and because the Roman god is not closely associated with Pluto, this proposal was rejected."

IAU rules states that Pluto's moons should be named for mythological characters of the underworld in Greek and Roman mythology. Pluto is known as the ruler of the underworld in ancient mythos.

Cerberus, the three-headed dog in Roman mythology, came in a clear second in the Pluto Rocks ballot with nearly 100,000 votes, but IAU officials decided to tweak the name slightly, instead opting to name the moon Kerberos — Cerberus' equivalent in Greek myth.

The name Styx, the river that separates the living from the dead in ancient myth, garnered about 88,000 votes for a third place finish.

William Shatner names Pluto Moon: Vulcan

In a voting campaign to pick names for two of Pluto's smallest moons one clear winner is "Vulcan," proposed by U.S. actor William Shatner of "Star Trek" fame.

Online ballot casting allowing the public to vote for the name of two recently discovered moons of the dwarf planet -- for now known as just P4 and P5 -- ended Friday, with Vulcan in first place followed by Cerberus.

Although a late addition to the candidate names the public could vote on, Vulcan piled up a big lead after Shatner, who played Capt. James T. Kirk in the popular television series and movies, campaigned for the name on Twitter.

Vulcan was the home planet of Kirk's first officer, Spock, played by Leonard Nimoy.

Officials at SETI, which conducted the public poll, said they considered it an appropriate candidate since Vulcan is also the name of the god of fire in Roman mythology.

"Vulcan is the Roman god of lava and smoke, and the nephew of Pluto." SETI scientist Mark Showalter wrote in a blog when the name was added to the list on Feb. 12. "Thanks to William Shatner for the suggestion!"

Although Vulcan and Cerberus won the name poll, the final decision on names for the moons will rest with the International Astronomical Union.

Astronomers have found five moons around Pluto so far, with three of them named: Charon, Nix and Hydra.

P4 was discovered in 2011, and P5 in 2012; both are only about 20 miles in diameter.