Pluto has two moons with no name - they're just known as P4 and P5. The discovery team is going to propose names for them to the International Astronomical Union and would like some help in deciding. The names need to be from Greek & Roman mythology and have to do with the underworld. They’ve made a list of 20 possible names, but are open to appropriate suggestions.

Voting closes on February 25. The website is here: Pluto Rocks

I voted for Orpheus and Eurydice, the ill-fated lovers. What's your choice?

I think that the story of the great, but doomed, love of Orpheus and Eurydice is a terribly sad and moving story. And for all of the art and music that uses it as a theme, I guess I'm not alone in this.

Pluto, Charon, Nix and Hydra all represent the dark underworld. The story of Orpheus and Eurydice is about the interaction of living people with this darkness. There is a constellation that represents the story. It's Lyra, Orpheus's harp.

Currently, the names Cerberus and Styx are in hot competition for 2nd place in the moon-naming. Cerberus was the multi-headed dog that guarded the gates of Hades. The River Styx was the boundary between our world and the underworld.

But what is in 1st place? Vulcan. As proposed by William Shatner (Captain Kirk in the original Star Trek). Trekkies have been voting for it in large numbers. However the god Vulcan isn't associated in mythology with the underworld.

Today (Feb 22) is the 7th anniversary of the discovery of two of Pluto's moons, later named Nix (goddess of night) and Hydra (the many-headed snakelike creature of the underworld).

Two more days til the voting closes. Pluto Rocks

Tantalus and Sisyphus are two names on the list.

"Tantalize" comes from the name Tantalus. His punishment was to spend eternity near water and a luscious fruit tree, but not to be able to eat or drink for they were always out of reach.

Sisyphus had to spend each day rolling a heavy boulder up to the top of a hill. Whereupon it would roll down again. How many of us have had that feeling sometimes!

Here is a link to the page that shows the current tally of the votes: Pluto moons votes - current tally Still one day left to vote - voting closes at noon EST.

I see Vulcan is still way ahead. But the god Vulcan wasn't connected with the underworld, so it doesn't really meet the naming convention of the International Astronomical Union. Vulcan was the god of fire, but nothing to do with the underworld.

There is a hypothetical planet called Vulcan. 19th century French astronomer postulated a small planet inside the orbit of Mercury to explain anomalies in its orbit. Einstein's general relativity explains Mercury's orbit and there's no sign of planet Vulcan.

Yes, that was my main objection to naming this moon Vulcan.

The name Vulcan was suggested by William Shatner and his fans are supporting his choice.

I like Persephone who, as you know, was the queen of the underworld, Ceres/Demeter's daughter who was kidnapped by Pluto/Hades.

Yes, Lori, I like Persephone too. That would have been my choice for what seemed like the 10th planet when it was discovered in 2003. But it prompted a formal definition of planets that left Pluto and the new body as dwarf planets. However the final name Eris (goddess of discord) was quite appropriate in the circumstances!

Vulcan had an underground forge (under Mt. Vesuvius), and is associated with magma/lava. So he can be part of the underworld mythos in my book.

I still wish Eris was officially named Xena (and Dysnomia Gabrielle). But since Xena was played by Lucy Lawless, and Discord is about lawlessness, I am slightly appeased. ;-)

When the discovery team passed on the results of the vote, Vulcan ended up with by far the most votes.

But spot the odd one out. . . Pluto's large moon is Charon, the ferryman who rowed the dead across the river Styx to Pluto's realm. The other two tiny moons are Nix and Hydra. Nix was Charon's mother and goddess of the night. Hydra was the 9-headed serpent that guarded Pluto's realm. Vulcan was the god of fire, volcanoes and smithery.

Anyhow, not surprisingly, the International Astronomical Union rejected the name Vulcan as inappropriate and accepted the other two most popular names in the voting: Styx and Kerebros. As though a 9-headed serpent weren't enough, there was also a three-headed dog to guard the entrance to Hades. This was Kerebros. And Styx, of course, was the river that was the boundary between the living and the dead.