Vulcan? Not on our tiny balls. Pluto moons named Kerberos, Styx

The International Astronomical Union has dissed William Shatner and the public to name Pluto's moons Kerberos and Styx, instead of most-popular moniker Vulcan.

Despite having won the SETI-run Pluto Rocks contest to come up with names for the fourth and fifth - and tiniest - moons of the heavenly body with 174,062 votes, Vulcan was not chosen by IAU as name of either moon. Instead, it went with second-placed Cerberus at 99,432 votes and the third most popular name Styx, which received 87,858 votes.

"They didn't name the moon Vulcan. I'm sad," Shatner, who led the internet campaign to get Vulcan votes, tweeted.

But they didn't even name the moon Cerberus, the Roman name for the three-headed dog that guards the underworld, opting for the Greek spelling Kerberos "to avoid confusion with an asteroid called 1865 Cerberus".

Cerberus and Styx were leading the field before Shatner, who played Captain James T Kirk in Star Trek, suggested Vulcan in honour of Spock's homeworld and Romulus for the Romulans' planet. Romulus was immediately off the cards because the it's already the name of a moon, which along with another moon Remus orbits the asteroid Sylvia.

Vulcan was also deemed potentially difficult because it was the name of a planet thought to exist in an orbit closer to our Sun than Mercury's. Such a world never existed, but the IAU still reckoned it was too confusing.

“Although this planet was found not to exist, the term ‘vulcanoid’ remains attached to any asteroid existing inside the orbit of Mercury, and the name Vulcan could not be accepted for one of Pluto’s satellites,” it said.

But Shatner rightly pointed out that the union had managed to make Cerberus work:

So they name a moon Kerebus because there's already a Cerebus asteroid but a mythological planet knocks out Vulcan?

— William Shatner (@WilliamShatner) July 2, 2013

However, that wasn't the only reason the IAU gave for spurning Vulcan. It also pointed out that the name doesn't fit in with Pluto's theme. Pluto was the Greek name for the ruler of the underworld and its other moons relate to the underworld as well - Charon, who ferries souls across the rivers Styx and Acheron, Nix, mother of Charon and goddess of the night and Hydra, the nine-headed monster who guards the underworld.

"To be consistent with the names of the other Pluto satellites, the names had to be picked from classical mythology, in particular with reference to the underworld — the realm where the souls of the deceased go in the afterlife," the IAU said. "Vulcan does not fit into the underworld mythological scheme."

In a Google+ hangout, SETI planetary astronomer Mark Showalter suggested that NASA's New Horizons spacecraft, due to visit the system in 2015, might find a crater somewhere it could name after a Star Trek character. But Shatner was unimpressed with his consolation prize:

Star Trek fans have had it rough. First JJ blows up Vulcan and now SETI finds a loophole to deny it from coming back!

— William Shatner (@WilliamShatner) July 2, 2013

Who'd ever thought I'd be betrayed by geeks and nerds? ;-)

— William Shatner (@WilliamShatner) July 2, 2013

Did you hear the consolation? They may name a crater after Kirk. A pockmark on a planetoid is a fitting tribute? (Rolling my eyes)

— William Shatner (@WilliamShatner) July 2, 2013

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