M. Showalter / NASA / ESA

An image from the Hubble Space Telescope shows Pluto and its largest moon, Charon, surrounded by four smaller moons. Astronomers have proposed naming P4 and P5 after Vulcan and Cerberus.

Astronomers have decided to go with the people's choice and propose Vulcan and Cerberus (or Kerberos) as the names for Pluto's tiniest known moons, one of the discovery team's leaders said Tuesday. Vulcan bubbled up to the top of the list in a non-binding "Pluto Rocks" contest in February, thanks in part to a strong endorsement from "Star Trek" captain William Shatner. The International Astronomical Union, which traditionally approves celestial names, still has to weigh in on the discoverers' proposal.

"We did not feel rigidly bound by the vote totals, but in the end we decided that Vulcan and Cerberus/Kerberos were pretty good names," said Mark Showalter, a planetary scientist at the SETI Institute who organized the contest. Showalter discussed the selection process in an email to NBC News after Nature reported that the IAU was considering the names.

Shatner, who played Captain James T. Kirk on the original "Star Trek" series, proposed the name Vulcan in honor of the home planet of Kirk's pointy-eared science officer, Mr. Spock. He put out the word to more than a million Twitter followers, and Vulcan ended up receiving 174,062 of the 450,324 votes cast. Cerberus was No. 2 on the list, with 99,434 votes.

Astronomers needed two names — one for the Plutonian moon P4, discovered in 2011; and another for P5, found in 2012. Although Vulcan and Cerberus were the favorites, it was not assured that the discovery team would go with those choices.

Stating the case
Traditionally, Pluto's moons are named after figures of the underworld from Greek or Roman mythology. Cerberus fit that scheme, because that was the name of the dog that guarded the gates of the Greco-Roman underworld. Vulcan, which is the name of the Roman god of fire as well as Mr. Spock's home world, posed more of a challenge.

"For the IAU proposal, I had to make the connection between Vulcan and the Greco-Roman underworld, because I knew that the nomenclature working groups would not be swayed by Star Trek mythology," Showalter explained. "We don't normally associate Vulcan with Pluto, but in fact when you go back to the literature, the Greeks and Romans understood the underworld to encompass everything beneath the surface of the earth, not just the realm of the dead. So Vulcan, the god of lava and volcanoes, really does have a natural connection to underworld.

"That being said, the nomenclature working group has to grapple with the issue that in astronomy, the name Vulcan has previously been associated with a hypothetical object or objects orbiting interior to Mercury. They also will probably have concerns about the fact that Cerberus has already been used as the name of an asteroid. I still believe that it is very important to give the working group latitude in this decision. I remain optimistic that a consensus will emerge."

One possibility would be to use Kerberos as an alternate spelling for Cerberus, to avoid any potential confusion. That's how the discoverers of another moon of Pluto, Nix, got around the fact that there was already an asteroid named after Nyx, the Greek goddess of the night.

Nicknaming an exoplanet
Meanwhile, another celestial naming contest has come to a surprise ending. For weeks, a commercial venture called Uwingu has been running a contest to come up with an unofficial nickname for Alpha Centauri Bb, the closest exoplanet. Thanks to a last-minute surge of vote-buying, the winner of the planet-naming game is "Albertus Alauda."

"I chose this name to honor my grandfather," Jason Lark wrote in his online citation for the name. He explained that Albertus Alauda is the Latin translation of Albert Lark, his grandfather's name.

Uwingu charges $4.99 for each planet nomination, and 99 cents for each vote. A spokeswoman for Uwingu, Ellen Butler, told NBC News in an email Tuesday that Lark "came in with a $742.50 payment last night to take the win." The mass voting is perfectly in accordance with the rules of Uwingu's game.

"I am overjoyed that my nomination won," Lark told NBC News in an email. "I think my grandfather would be very happy, and I hope my citation does him justice. I am very proud of my granddad. As with any other star or planet, they along with their names live on much longer than any one man, and most have a story behind them, such as in the days of old when stars were used to navigate the globe. I would like to think that Albertus Alauda will take its place alongside them in the generations to come, along with the story behind it."

Uwingu was created last year to offer space-based entertainment, to generate revenue and raise money for space science and education projects. The aim is to distribute at least half of the proceeds in the form of grants to programs such as the SETI Institute's Allen Telescope Array, Astronomers Without Borders and the Galileo Teacher Training Program. The contest to nickname Alpha Centauri Bb, which was discovered last year just 4.3 light-years from Earth, brought in about $10,000.

Among the runner-up names were Sagan and Einstein, Ron Paul and Heinlein, Rakhat (the Alpha Centauri planet featured in a sci-fi novel called "The Sparrow"), Tiber (the Alpha Centauri planet that moonwalker Buzz Aldrin made famous in his novel "Encounter With Tiber") and Amara (the first name of the nominator's fiancee). In all, more than 1,200 names were nominated.

Neither Albertus Alauda nor any of those other names has official status with the IAU. In a stinging news release, the IAU said Uwingu's campaigns "will not lead to an officially recognized exoplanet name, despite the price paid or the number of votes accrued."

There is currently no IAU-sanctioned process for approving popular names for the hundreds of extrasolar planets detected beyond our solar system. Instead, astronomers take the name of the star (for example, Alpha Centauri B or Kepler-62) and tack on a letter of the alphabet, starting with "b." (Hence, Alpha Centauri Bb or Kepler-62f.) For the time being, the IAU is sticking with that system, although it said members would discuss establishing a friendlier naming scheme this year.

Meanwhile, Uwingu's "baby book of names" for exoplanets remains open for business. "Also, next week we'll debut a new way to engage in exoplanet naming," Uwingu's CEO, planetary scientist Alan Stern, said in an email.

More about exoplanet names:

• Who gets to name alien planets?
• Newfound planets need better names
• Why Pluto can't have a Mickey moon

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

PHL @ UPR Arecibo

An artist's conception shows Alpha Centauri Bb, the nearest known exoplanet. Will it end up being called "Amara," or "Tiber," or plain old Alpha Centauri Bb?

Zeb Gray thought naming an exoplanet after his girlfriend would be the perfect tribute to "the eternal love that we share for each other" — and whether or not the name sticks, the decision arguably changed his life. On Friday, Gray asked Amara Somers to marry him, and she said yes.

Did the fact that Gray proposed the name "Amara" for the planet now known as Alpha Centauri Bb have anything to do with the way his more personal proposal was received? "I think it weighed on her decision," Gray, a 25-year-old security guard from Carson City, Nev., told NBC News.

The planet-naming gap
Amara is currently the top vote-getter in Uwingu's online contest to give Alpha Centauri Bb, the closest-known exoplanet, a more mellifluous name. Traditionally, the International Astronomical Union has had the job of naming celestial bodies — but for now, the IAU has held off on setting up an exoplanet-naming system. Instead, astronomers refer to alien worlds using a combination of the star's name (for example, Alpha Centauri B) and a lower-case letter (which is where that second "b" comes from).

Uwingu, a space-themed entertainment venture, has stepped into the gap with a system that lets users suggest planet names for $4.99, and cast ballots for 99 cents a vote. Half of the proceeds will go to support space science and education projects.

The contest to rename Alpha Centauri Bb runs until April 15, and although the resulting name won't have any official standing with the IAU, Gray would love to see Amara win. "I'm glad to see it has a decent lead, but that could go away pretty quickly," Gray said.

Uwingu

Zeb Gray pays tribute to his fiancee, Amara Somers, with an online card as well as an exoplanet name suggestion.

It helps that Amara is also the name of a magical world featured in Graham Edwards' "Stone" science-fiction trilogy. In Edwards' books, Amara is also known as Stone. It's structured like a spiraling stone wall, and inhabited by hundreds of civilizations.

There's another contender with a strong science-fiction connection, and a high-profile backer to boot. The name "Tiber" is favored by Apollo 11 moonwalker Buzz Aldrin, who's the co-author of a 1977 sci-fi novel titled "Encounter With Tiber." The Tiberians hail from a planet in the Alpha Centauri, and that's one of Aldrin's selling points.

"Don't forget to vote for TIBER in the contest to replace the name for Alpha Centauri Bb," Aldrin told his nearly 800,000 followers in a Twitter update last week. As of this writing, Tiber is No. 17 on the charts with 35 votes — ranking below Amara as well as Heinlein, Pele, Sagan, Asimov and Ron Paul.

Wooed by a moon
Gray, who met Somers at the state agency where they both work four months ago, isn't the first guy to impress a woman by naming a celestial body after her. When Naval Observatory astronomer James Christy discovered Pluto's biggest moon in 1978, he proposed naming it "Charon" — not only because Charon was the ferryman of the dead in Greek mythology, but also because the name paid tribute to his wife, Charlene.

("Char" was Christy's pet nickname for his wife. In her honor, the name is often pronounced "Shar-on" rather than "Care-on, " which is the pronunciation associated with the Greek ferryman. That's one of the many fun facts you'll find in my book, "The Case for Pluto.")

Is it really worth all this fuss to give Alpha Centauri Bb a better name? Astronomer Xavier Dumusque, the lead author of the paper that announced the exoplanet's discovery last year, thinks so.

"I would definitively endorse the name for public outreach and lectures," Dumusque told NBC News in an email. "In astronomy, we have some chance to be able to make people dream, by showing a wonderful picture, by discovering new worlds. If someone is interested in astronomy, he should not face troubles to understand all the nomenclature. Therefore, giving memorable names for planets is one way to get more people interested in our wonderful research."

Do you agree? What names would you suggest? Check out the Uwingu list, and feel free to leave your suggestions as comments below.

More about the celestial name game:

• Baby name book to raise science funds
• Why Pluto can't have a moon named Mickey
• Newfound planets need better names

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday.

Vulcan and Cerberus (or Kerberos) emerged as the people's choices for naming Pluto's tiniest moons in the SETI Institute's "Pluto Rocks" contest, which ended on Monday. But in the course of running the contest, the organizers fielded 30,000 write-in suggestions — and you may well see some of those suggestions surface in the future.

"I've been delighted by the response," said Mark Showalter, a planetary scientist at the SETI Institute who played a leading role in the discovery of Pluto's fourth and fifth moons. Showalter was the point person for the moon-naming contest, which drew more than 450,000 online votes over the past two weeks.

More than 20 names were on the ballot, including Vulcan (the Roman god of fire) and Cerberus (the watchdog of the underworld). Vulcan was added to the list after the contest started, at the urging of "Star Trek" actor William Shatner, and grabbed the lion's share of the votes. But there were scads of other suggestions that weren't used, mostly because they weren't in line with the International Astronomical Union's tradition that the moons of Pluto should be named after figures from Greek or Roman mythology with some sort of connection to the underworld. Pluto was himself the mythological god of the underworld.

It's the IAU that has the final say over the names for the moons, which were discovered over the past couple of years and are now known merely as P4 and P5. Now that the crowdsourcing contest is over, Showalter willl be meeting with his colleagues on the discovery team and discussing whether to go with Vulcan and Cerberus or some other names. The names selected by the discoverers will then be considered by IAU committee members for adoption or reconsideration.

"It could take one to two months for the final names of P4 and P5 to be selected and approved," Showalter said on the "Pluto Rocks" website. "Stay tuned."

M. Buie / SwRI / NASA / ESA

These two pictures of Pluto represent the Hubble Space Telescope's most detailed view of the dwarf planet, but pictures from NASA's New Horizons probe should provide better resolution.

During a Google+ Hangout, Showalter mentioned the two most frequently suggested names that were left off the ballot. No surprise there: Considering that Pluto is a Disney cartoon character as well as a dwarf planet, you'd expect that Mickey and Minnie (as in Walt Disney's talking mice) would be the favorites.

"Yes, I am a big fan of Disney myself, but no, they are not compliant names," Showalter said. Although Mickey and Minnie make a cuter couple than Orpheus and Eurydice, they're not Greek or Roman mythological characters connected with the underworld.

Some of the other names, however, may come up again. When NASA's New Horizons probe sails past Pluto in 2015, still more mini-moons might be spotted. P6, P7 and so on would provide additional opportunities for the "compliant names" on Showalter's newly expanded list. And that's not all: New Horizons' camera could to snap pictures of previously unseen features on Pluto and its moons, That opens up a new frontier for names.

The names of planetary features don't have to follow the rules about Greek or Roman mythology: On Mercury, for example, craters are named after famous writers and artists. The hydrocarbon lakes detected on Titan, Saturn's largest moon, are named after the earthly lakes they resemble. Titan's mountains are named after the fictional mountains from "The Lord of the Rings" and other works by J.R.R. Tolkien, while the Saturnian moon's dark plains are named after planets from the "Dune" science-fiction series.

For Pluto and its moons, "we have all kinds of options," Showalter said. He noted that the naming suggestions followed some potentially appealing trends — specifically, Norse mythological figures as well as characters and locations from the "Star Wars" movie series and H.P. Lovecraft's fantasy and horror tales. Might we hear about Mount Loki, the Hoth ice sheet or Cthulhu Crater in the years to come? Will some scientist pick up on the Vulcan connection and start naming the hills of a Plutonian moon after Worf, Quark, Chakotay and T'Pol? To paraphrase another character from the "Star Trek" saga: "Make it so!"

More about planetary names:

• Uwingo aims to create Baby Planet Name Book
• How about better names for alien planets?
• Solar system's not changing — just the lingo

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

M. Showalter / NASA / ESA

An image from the Hubble Space Telescope shows Pluto and its largest moon, Charon, surrounded by four smaller moons. P4 and P5 will be getting new names. One of them might be called Vulcan.

The organizer of a contest to name Pluto's two tiniest moons can't guarantee that either one of them will be called "Vulcan" — but now that the name nominated by the original captain on the "Star Trek" TV show has won first place in the voting, planetary scientist Mark Showalter promises to argue the best case he can.

"My starting position is that we should work with the names that received the most votes," Showalter told NBC News on Friday.

The "Pluto Rocks" voting concluded at noon ET Monday, and is being followed by a 1:30 p.m. Google+ Hangout sponsored by the SETI Institute, the place where Showalter works. Vulcan came out on top with 174,062 of the 450,324 votes cast. But don't expect Showalter to declare immediately that Vulcan is the choice for one of Pluto's moons.

"There will not be an announcement on Monday," he said.

For one thing, it's not totally up to Showalter to make the nomination. He's just one of the leading scientists on the discovery teams for P4 and P5, the two moons that were found in 2011 and 2012. All the members from each of the teams will have to agree on the names to be submitted to the International Astronomical Union for approval. Even then, the IAU could voice concerns about the names they submit, leading to alternate suggestions. Showalter said he's actually seen that happen in the case of the Uranian moon that ended up being called Cupid.

Kirk ... takes ... command
Vulcan wasn't on Showalter's initial list of prospects, but he added it to the ballot at the urging of William Shatner, the actor who played Captain James T. Kirk on the original "Star Trek" series in the late 1960s. Shatner favored the name because it was the fictional home planet of Kirk's pointy-eared science officer, Mr. Spock. "Let's hope the IAU thinks Vulcan is a good name," Shatner wrote in a tweet to his 1.35 million Twitter followers.

Showalter said Shatner's endorsement definitely skewed the results. "Early on, it's pretty clear there were some Trek fans who seem to have resorted to augmented voting technologies," Showalter said. But he's convinced that the groundswell of support for Vulcan is genuine, and he said he's "come up with a pretty good case" for using the name.

"I want people to feel that their vote counted," Showalter said.

The IAU's guidelines for Pluto's moons stipulate that they should be named after Greek or Roman gods who have some connection to the mythological underworld. Those guidelines worked for Pluto's three other moons, Charon (ferryman of the dead), Nix (goddess of darkness) and Hydra (a many-headed monster).

Vulcan has a family relationship to the underworld, in that he was Pluto's nephew. And in his capacity as the god of fire, Vulcan tended to hang out in the depths beneath Mount Etna and other volcanoes, rather than on the heights of Mount Olympus. That may not be Hell, exactly, but it's certainly the underworld.

Showalter admitted that it might be tricky to have the god of fire associated with one of the coldest places in the solar system. "It may well be there's a consensus that it's a great name, but not a great name for a moon of Pluto," he said. Also, the name Vulcan has been associated with a hypothetical planet that was thought to circle the sun within Mercury's orbit. The 19th-century French astronomer who discovered Neptune, Urbain Jean Joseph Le Verrier, spent fruitless years looking for it. Pluto's moon is in an entirely different place, but Showalter sees that as a potential plus.

"Maybe we'd be doing Le Verrier a favor by saying that when he was looking for the ninth planet inside Mercury's orbit, he was looking in the wrong direction," Showalter joked.

Some have said the name Vulcan should be reserved for a planet beyond our own solar system. In response, Showalter points out that there's no IAU procedure for giving names to extrasolar planets (beyond generic designations such as Kepler-37b or Gliese 163c). That situation may change if planet-naming ventures such as Uwingu take hold. But in the meantime, Showalter feels that Vulcan should at least be given a fair shot at solar system fame.

Another moon to name
So it's a sure thing that Showalter will try making the case for Vulcan. But what about the other Plutonian moon?

Cerberus held onto the No. 2 spot in the voting, with 99,432 votes, and so Showalter will argue the case for Cerberus as well. That name fits perfectly with the mythological underworld theme, because Cerberus was the three-headed hound that guarded the gates of the underworld.

One drawback is that there's already an asteroid named Cerberus, and the IAU doesn't want newly named celestial bodies to be confused with previously named objects. Showalter said there are at least two ways around that issue: One is to argue that the asteroid and the moon wouldn't be confused. The precedent for this is Io, a mythological name that refers to a Jovian moon as well as an asteroid. Another way out is to change the spelling slightly — say, to the Greek name Kerberos. One precedent for this is the Plutonian moon Nix, which uses an alternate spelling to avoid confusion with the asteroid Nyx. (By the way, there's already an asteroid named Vulcano, but that name is considered different enough from Vulcan,)

Opening the moon-naming process up to a vote has been a lot of work, even if it's a non-binding vote, and Showalter said he doubts that he'll do it again. But he's gratified by the response: The contest attracted hundreds of thousands of votes from scores of countries around the world, generated more than 30,000 write-in suggestions for names, and gave Pluto fans and "Star Trek" fans lots to think about.

What would Spock think about all this? Leonard Nimoy, the actor who played the alien on the original "Star Trek" show, said via Twitter that "'Vulcan' is the logical choice." I can imagine Spock saying that, but I can also imagine him uttering just one word. ...

More about Pluto and its moons:

• Pluto's moons offer clues to alien worlds
• Pluto's atmosphere larger than previously thought
• All about Pluto from NBCNews.com
• Cosmic Log archive on Pluto

This report was originally published Friday and was updated with the results of the "Pluto Rocks" contest on Monday.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

This story was originally published on Fri Feb 22, 2013 7:35 PM EST

Paramount TV via AP file

The original "Star Trek" TV cast included Leonard Nimoy as Mr. Spock, the Starship Enterprise's pointy-eared science officer, and William Shatner as Captain James T. Kirk.

Just one day after astronomers asked Internet users to pick from a list of 12 names for Pluto's tiniest moons, they added a 13th name — Vulcan — at the urging of Star Trek icon William Shatner.

"Vulcan is the Roman god of lava and smoke, and the nephew of Pluto. (Any connection to the Star Trek TV series is purely coincidental, although we can be sure that Gene Roddenberry read the classics.) Thanks to William Shatner for the suggestion!" discovery team leader Mark Showalter of the SETI Institute wrote Tuesday in an update to the "Pluto Rocks" blog.

You don't have to be a hard-core Trek fan to know that Vulcan was the fictional home planet of Mr. Spock, the pointy-eared science officer on the original TV series' Starship Enterprise. Roddenberry was the series' creator. And long before he became a Priceline pitchman, Shatner played the Enterprise's skipper, Captain James T. Kirk.

The point of the "Pluto Rocks" balloting, which runs through Feb. 25, is to weigh public sentiment for the naming of Pluto's two most recently discovered moons, now known as P4 and P5. As the moons' discoverers, Showalter and his colleagues have the right to recommend formal names for adoption by the International Astronomical Union. They thought it would be fun to give the general public a non-binding advisory role.

The contest caught Shatner's eye, and he made a couple of suggestions in a Twitter update: "So what do you think of the idea of naming the two moons of Pluto Vulcan and Romulus? You have mythology, pos[itive] and neg[ative]."

Any voter can suggest write-in names, as Shatner did, but the names should refer to people, places or things in Greek or Roman mythology that have a connection to the underworld. Right now, the two favored names are Styx (which refers to a major river of the underworld as well as the rock band) and Cerberus or Kerberos (which refers to the underworld's guard dog as well as the modern-day network protocol).

More than 120,000 votes have been cast already, with less than 5,000 of them going to Vulcan — so Shatner would have to get those Vulcan votes multiplying like Tribbles to catch up to Styx and Cerberus. But that's not impossible, especially if he puts the word out to his 1.3 million Twitter followers.

As for Shatner's other suggestion, Romulus certainly has a connection to Roman mythology and Trek lore. In mythology, Romulus was one of the founders of Rome, while in the Star Trek universe, the name refers to the homeworld of a race that rivaled the Vulcans. However, one of the IAU's guidelines is that a proposed name should not be confused with pre-existing names for other celestial bodies. That poses "a bit of a problem," Showalter said.

"Romulus, along with his brother Remus, are the names of the moons of the asteroid 87 Silvia," he wrote. "They were discovered by a team led by my good colleague Franck Marchis, now a senior scientist at the SETI Institute."

Sorry, Captain. Because there's already a Romulus in this sector of the galaxy, scientists can't reuse the name. They just cannae do it.

Can you think of other mythological names with science-fiction connections? If they're not already taken, share your ideas in the comment section below — and send them along to the "Pluto Rocks" folks as well.

Update for 8:45 p.m. ET Feb. 14: Vulcan is now the top pick in the "Pluto Rocks" poll, with more than 60,000 votes out of the 234,720 responses registered. Styx and Cerberus are second and third on the list. Showalter has added eight more names to the ballot, bringing the total list to 21. The eight additions are Elysium, Hecate, Melinoe, Orthrus, Sisyphus, Tantalus, Tartarus and Thanatos. "Pluto needs more moons!" Showalter writes in a Cosmic Diary entry.

More about Pluto and its moons:

• Pluto's moons offer clues to alien worlds
• Pluto's atmosphere larger than previously thought
• All about Pluto from NBCNews.com
• Cosmic Log archive on Pluto

Check out Monday's Google+ Hangout about Pluto and the moon-naming project on the SETI Institute's website.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

This story was originally published on Tue Feb 12, 2013 11:30 PM EST

NASA / ESA / STScI

Internet users can vote on what to name Pluto's most recently found moons, P4 and P5.

The discoverers of Pluto's fourth and fifth moons are letting Internet users have a say in what they should be named, by throwing the question open for a non-binding advisory vote.

The "Pluto Rocks" project, organized by the SETI Institute, is part of a trend pointing toward getting the public involved in the outer-space naming process. NASA, for example, has solicited name suggestions for the asteroid due to be visited by the OSIRIS-REx probe, and for one of the modules on the International Space Station (more on that later).

This time, the objects to be named are two tiny satellites of Pluto that were found during a detailed analysis of data from the Hubble Space Telescope: P4, which was discovered in 2011; and P5, detected just last year. The moons are only 15 to 20 miles (20 to 30 kilometers) across, at the limit of Hubble's observing power. The astronomers behind the discoveries were checking out Pluto's surroundings just to make sure the way was clear for NASA's New Horizons probe to fly past the dwarf planet in 2015.

Convention dictates that the discoverers of celestial bodies get to suggest names for adoption by the International Astronomical Union. When P4 and P5 were revealed, "I received literally hundreds of suggestions," said one of the leaders of the discovery teams, Mark Showalter, an astronomer at the SETI Institute's Carl Sagan Center for the Study of Life in the Universe.

Showalter has been involved in the naming of moons before (Saturn's Pan, as well as Uranus' Mab and Cupid), but that was nothing compared with the clamor over P4 and P5. "It seems that the public has a much greater interest in Pluto," he said.

He said it was Alan Stern, the principal investigator for the $700 million New Horizons mission, who suggested putting the name question up for a public vote. "I just jumped on it when he suggested it," Showalter said.

The ballot on the Pluto Rocks website offers 12 potential names for perusal, all of which follow the precedent that Pluto and its moons are named after Greek or Roman mythological figures with a connection to the underworld. Pluto, for example, was master of the underworld. Charon, Pluto's largest moon, is named after the boatsman that ferried the souls of the dead across the River Styx. The moons Nix and Hydra, discovered in 2005, were named after the goddess of the night and a many-headed monster that guarded one of the entrances to the underworld.

The 12 suggested names for P4 and P5 are Acheron, Alecto, Cerberus, Erebus, Eurydice, Heracles, Hypnos, Lethe, Obol, Orpheus, Persephone and Styx. Some of these names have already been used for asteroids, and in those cases, the teams might go for variant spellings just to avoid any confusion (for example, Orfeus instead of Orpheus, or Kerberos instead of Cerberus). Write-in votes are also allowed, and some of those write-ins might end up being added to the official ballot.

The voting deadline is Feb. 25. After the vote, the discovery teams will choose two names to submit to the IAU, and announce which names won out after their formal approval — most likely by April or so. "We're not going to guarantee that they'll be the top two names [in the voting], but they'll probably be high on the list," Showalter said. "We're not going to all this trouble just to pick names that we chose already."

Showalter and his colleagues want to retain some control just to make sure that they don't get railroaded by a media-driven ballot-stuffing campaign, such as the one that marked NASA's "name-the-module" contest in 2009. Back then, talk-show comedian Stephen Colbert drummed up more than 200,000 write-in votes to get a space station module named after himself. The space agency ended up calling the module Tranquility instead, but named the treadmill inside the module "C.O.L.B.E.R.T." as a consolation prize.

There could be similar shenanigans this time around, especially in light of Pluto's pop-culture popularity. "I suspect Minnie and Mickey will be high on the list of write-ins," Showalter joked.

The moon-naming contest could reignite the years-long controversy over the IAU's classification of Pluto as a "dwarf planet" rather than an honest-to-goodness planet — but Showalter said the labels don't matter all that much to him. "It's a very small planet, and it seems to me appropriate, based on its size, to call it a dwarf planet," he said. "I don't see that as a demotion."

Could Pluto have even more moons? That's the big reason why the discovery teams took so long to address the naming of P4 and P5. "Frankly, we wanted to wait until we scoured the data," just in case there was a sixth moon to add to the list, Stern said. But after months of scrutinizing the Hubble data, the astronomers concluded that the next discoveries would have to come from the New Horizons probe.

"Come 2015, I wouldn't be at all surprised if we have a P6, P7 and P8 to deal with," Showalter said.

More about Pluto and its moons:

• Pluto's moons offer clues to alien worlds
• Pluto's atmosphere larger than previously thought
• All about Pluto from NBCNews.com
• Cosmic Log archive on Pluto

A Google+ Hangout is scheduled on Feb. 11 at 2 p.m. ET (11 a.m. PT) with Showalter and another scientist involved in the Pluto moon discoveries, Hal Weaver of the Johns Hopkins University Applied Physics Laboratory. Questions from viewers will be taken during the event using Twitter (hashtag #PlutoRocks), the SETI Institute Facebook page and the Google Hangout.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Published at 9 a.m. ET Feb. 11, 2013.

M. Showalter / SETI Institute / NASA / ESA

This photo from the Hubble Space Telescope shows Pluto and its five known moons, including a newly discovered satellite indicated as P5. Its provisional name is S/2012 (134340) 1.

Astronomers using the Hubble Space Telescope have discovered Pluto's fifth moon, a little more than three years before a NASA space probe is due to sail past the dwarf planet and its tribe of satellites.

The irregular moon, estimated to be 6 to 15 miles (10 to 25 kilometers) across, was found in the course of checking out the potential collision hazards facing NASA's New Horizons spacecraft for the Bastille Day flyby on July 14, 2015. "The inventory of the Pluto system we're taking now with Hubble will help the New Horizons team design a safer trajectory for the spacecraft," the mission's principal investigator, Alan Stern of the Southwest Research Institute, said in a Hubble news release.

Stern and his colleagues suspect this fifth moon won't be the stuff they find in Pluto's neighborhood. "The discovery of so many small moons indirectly tells us that there must be lots of small particles lurking unseen in the Pluto system," said Harold Weaver of the Johns Hopkins University Applied Physics Laboratory.

Call it P5 ... for now
The fifth moon is currently known only by its provisional names: S/2012 (134340) 1, or P5 for short. It'll be up to the discoverers to propose a more lyrical name to the International Astronomical Union, which classified Pluto as a dwarf planet in 2006.

P5 was detected in 14 separate sets of images taken by Hubble's Wide Field Camera 3 on June 26, 27 and 29 plus July 7 and 9. The Hubble team says it's in a 58,000-mile-diameter circular orbit around Pluto that steers clear of the dwarf planet's four other satellites — including the biggest moon, Charon. Two other moons, Nix and Hydra, were discovered in 2006, and the fourth moon (P4) was found in Hubble data last year.

"The moons form a series of neatly nested orbits, a bit like Russian dolls," team leader Mark Showalter of the SETI Institute said in today's news release. He told me that small moons have now been found in the Pluto-Charon system at close to a 1-to-3 orbital resonance with Charon (P5), a 1-to-4 resonance (Nix), 1-to-5 (P4) and 1-to-6 (Hydra). This suggests that the moons were formed from debris blasted away by the collision that led to the coalescence of Pluto and Charon as we know them today.

"This is a very tidy system, and what that means is, it's an orbitally evolved system," Showalter said. "Literally there are shells where the orbits are stable."

Pluto's moons are traditionally named after Greek mythological characters associated with the underworld. Nix, for example, is an alternate spelling for Nyx, the name of the Greek goddess of the night and the mother of the Fates. (The more typical spelling, Nyx, was used previously in the name of an asteroid.) Hydra is the serpentine monster that guarded the gates of the underworld. "It's a very colorful cast of characters," Showalter told me.

For P4 and P5, the team members are holding off on proposing names for now, just in case a P6 comes along. "It's still a moving target, because we don't know what might come along," Showalter said. "I expect that in a month or two, we'll have finished everything we're going to find until New Horizons gets close." Only then will the team seriously consider what the two (or more) moons will be named. If things stay as they are, P4 and P5 will probably be named after a pair of characters with Greek underworld connections, such as Orpheus and Eurydice. (The name Orpheus is already taken, but they could go with a variant, such as Orfeo.)

As of today, Showalter says there are no other Plutonian moon candidates in sight. "Of all the things that we have looked at, that we thought might be moons, none of them has ever been convincing until this came along," he said of P5. "There is no P6 in our back pocket at this time."

The detection ... and the debate
Finding P5 was hard enough. Showalter told me that he first spotted the moon in the data on Saturday, the 7th. He and his colleagues then went back and found signs of the moon in the data gathered earlier, as well as the follow-up imagery captured on Monday. The object is just 0.001 percent as bright as Pluto, and 4 percent as bright as Nix, Showalter said. "We're really at the edge of what we can accomplish with Hubble," he said. "I don't know of any instrument that's going to be better than that."

In an IAU circular issued today, the team reports that P5's brightness is about magnitude 27, which makes it half as bright as P4. The brightness was used to estimate P5's size.

Today's announcement revived the debate over whether Pluto should be counted as a planet, period, rather than a dwarf planet. The difference, as outlined by the IAU almost six years ago, has to do with how much a celestial body has "cleared out the neighborhood of its orbit." In my book, "The Case for Pluto," I set out the argument for counting Pluto and other worlds that have a basically roundish shape as types of planets, even if they're put in the dwarf category.

"The name 'dwarf planet' really doesn't bother me," Showalter said. "When you think of a bonsai tree, it's still a tree, and what's interesting about it is that it's really, really small. I think of Pluto the same way. ... It only gets more interesting with each one of these discoveries that comes along. If you don't like the term 'dwarf planet,' call it a 'bonsai planet.'"

I like that approach. But what about you? Feel free to weigh in below with your comments on Pluto, P5, or your suggestions for the names of the bonsai planet's newest moons.

More about Pluto:

• Final push for Pluto's postage stamp
• Scientists spot Pluto's fourth moon
• Carbon monoxide found in Pluto's air
• Pluto debate is about more than one little world
• Cosmic Log archive on Pluto 

Last updated 4:30 p.m. ET.

In addition to Showalter, Weaver and Stern, members of the discovery team include A.J. Steffl and M.W. Buie.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Revelations about the solar system's icy frontier, carbon-based nanostructures and the neurological basis of perception and decision have brought global recognition to seven researchers who are sharing in this year's three $1 million Kavli Prizes.

The prizes have been awarded every other year since 2008 for pioneering work in three areas of research: astrophysics, nanoscience and neuroscience. The program is a partnership involving the Norwegian Academy of Science and Letters, the Kavli Foundation and the Norwegian Ministry of Education and Research.

The Norwegian academy receives nominations from their colleagues in other countries and forwards them on to prize committees who recommend the winners. Much of the money for the awards is put up by the foundation, created by Norwegian-born industrialist/philanthropist Fred Kavli.

Here are the winners of this year's prizes, announced on Thursday:

Astrophysics
Planetary scientists David Jewitt, Jane Luu and Mike Brown share the $1 million astrophysics prize "for discovering and characterizing the Kuiper Belt and its largest members, work that led to a major advance in the understanding of the history of our planetary system." The Kuiper Belt is an icy ring of material on the outskirts of the solar system, between 30 and 50 AU. (One AU, or astronomical unit, equals the distance from Earth to the sun.) UCLA's Jewitt and MIT's Luu found the first Kuiper Belt object beyond Pluto in 1992. Caltech's Brown led a team that found numerous large Kuiper Belt objects, including one that's more massive than Pluto. Brown's discovery of the world now known as Eris led to Pluto's reclassification as a dwarf planet in 2006, but I don't hold that against him.

Kavli Prize

Winners of the Kavli Prize for Astrophysics: UCLA's David Jewitt, MIT's Jane Luu, Caltech's Mike Brown.

Earlier in the week, Jewitt and Luu were awarded the $1 million Shaw Prize in Astronomy for their study of trans-Neptunian bodies. Jewitt told Physics World it was "very flattering" to receive such rich honors from two independent prize committees almost simultaneously.

Kavli Prize

MIT's Mildred Dresselhaus

Nanoscience
MIT physicist Mildred Dresselhaus will receive the nanoscience prize "for her pioneering contributions to the study of phonons, electron-phonon interactions, and thermal transport in nanostructures." Over the course of five decades, Dresselhaus has come up with a steady stream of insights revealing how the properties of materials at the nanometer scale can be radically different from their properties at larger scales. Her early work on carbon fibers and materials known as graphite intercalation compounds laid the foundation for later discoveries relating to buckyballs, carbon nanotubes and graphene. (Graphene was the focus of a Nobel Prize awarded in 2010.)

Kavli Prize

The 2012 Kavli Prize in Neuroscience goes to Rockefeller University's Cornelia Bargmann, Winfried Denk of the Max Planck Institute for Medical Research and MIT's Ann Graybiel.

Neuroscience
Cornelia Bargmann, Winfried Denk and Ann Graybiel share the neuroscience prize "for elucidating basic neuronal mechanisms underlying perception and decision." Rockefeller University's Bargmann used nematode worms to study the molecular controls for animal behavior, including the role of odorant receptors, sensory neurons and the neurotransmitters involved in behavioral adaptation following experience. Denk, a resercher at the Max Planck Institute for Medical Research, developed two techniques for studing how information is transmitted from the eye to the brain. MIT's Graybiel traced neural loops connecting the outer brain with an inner region known as the striatum. Such loops form the basis for linking sensory cues to actions involved in habitual behaviors.

Norway's King Harald V will present the prizes to the laureates during a Sept. 4 ceremony in Oslo.

Update for 10 p.m. ET June 2: The prize announcement was made during a webcast from the Norwegian Academy of Letters and Science in Oslo that was beamed to the World Science Festival in New York. One of the laureates, Cornelia Bargmann, was in attendance for the announcement. Check out the archived video of the event, and if you're in New York this weekend, check out the festivities at the science festival. It's also worth noting that on the other side of the country, a month-long science fest is just starting up in Seattle.

More about scientific prizes:

• Nobel laureates say we must fund dark energy research
• Three scientists win Nobel for discovering cosmic speedup
• Vindicated! Ridiculed Israeli chemist wins Nobel Prize

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Dan Durda / SwRI

This concept art for a 2015 stamp celebrates NASA's New Horizons mission to Pluto.

More than 11,000 people have signed an online petition to honor NASA's mission to Pluto and other denizens of the solar system's icy rim with a commemorative U.S. postage stamp — which is a fine way to celebrate the 82nd anniversary of Pluto's planetary coming-out party.

"I'm pretty happy," said Alan Stern, a planetary scientist at the Southwest Research Institute who is the principal investigator for NASA's New Horizons mission. New Horizons is due to fly by the dwarf planet in 2015, and Stern is among the leading supporters of the stamp campaign.

"A lot of stamps get 1,000 petition names, and they're very happy with that," Stern told me. "Still, I'd rather have 12,000 than 11,000."

Tuesday marks the 82nd anniversary of the announcement of Pluto's discovery by Clyde Tombaugh at the Lowell Observatory in Arizona, and it also marks a turning point for the petition drive. Stern said he and his colleagues are now turning their attention to the preparation of a formal proposal that will be submitted to the Citizen Stamp Advisory Committee next month.

Years-long process
Back in 1991, the U.S. Postal Service issued a set of stamps honoring NASA's interplanetary missions — but the set included a stamp picturing Pluto, with the legend "Not Yet Explored." The $700 million New Horizons mission aims to cancel that earlier stamp's sentiment, and Stern is hoping that a brand-new New Horizons stamp will provide a stickable way to set the record straight.

The half-ton, piano-sized New Horizons probe was launched in 2006 and has made its way well beyond the orbit of Uranus, but it'll probably be another three years before most people sit up and truly take notice of the mission, Stern said. New Horizons' view of Pluto's surface features should match the resolution of the Hubble Space Telescope around April 2015.

Why start so early on the stamp? That's just the way things are done: Proposals for commemorative stamps are considered by the advisory panel, and recommendations are then forwarded to the postmaster general for a final decision. "I don't think we're going to hear anything for two to three years," Stern said.

That time frame sounds about right to Robert Z. Pearlman, editor of the CollectSpace online publication and an expert on space history and memorabilia. "We'll probably know if it's a success in mid-2014," he said. Pearlman based that estimate on the circumstances surrounding the stamp that commemorated NASA's Messenger mission to Mercury. In Messenger's case, postal officials announced in August 2010 that the stamp would be part of its lineup. That was followed by its issuance in May 2011.

Spacecraft in semi-slumber
The New Horizons spacecraft has been rousing itself from hibernation every week to transmit status signals confirming that it's still on course and healthy (the so-called "green beacon"). Stern said the spacecraft is due to wake up fully on April 30 for "a very intensive couple of months of activities," aimed at rehearsing the procedures that will be used for the flyby of Pluto and its largest moon, Charon, in July 2015.

Pluto has been the subject of a lot of discussion since New Horizons was launched: In August 2006, the International Astronomical Union voted to classify the icy world as a "dwarf planet" rather than a major planet — a move that was widely seen as a demotion. March 13, the date on which Pluto's discovery was announced in 1930, has become known in some circles as "Pluto Day." It's a day to draw attention to the little guys of the solar system, and as the author of "The Case for Pluto," I can't help but keep it on my holiday calendar.

Glenn Fleishman via Twitpic

Tim Lloyd hoists a protest sign during a Pluto Day rally in Seattle on Saturday.

Over the weekend, I was among about 30 grown-ups and kids who attended an early Pluto Day rally at the Greenwood Space Travel Supply Co. in Seattle. At the appointed time, we raised our protest signs, marched down the sidewalk and shouted good-natured chants ("Can't stop the power, the power of the Pluto, 'cause the power of the Pluto don't stop") as well as edgier ones ("Hey, hey, ho, ho, the IAU has got to go"). My favorite placard read, "Keep your laws off my icy body."

At the end of the block-long march (on both sides of the street), we gathered at a local coffee shop for a teach-in about dwarf planets. The climax was a rock-paper-scissors contest to decide whether or not Pluto was an honest-to-goodness planet. I'm happy to report that I triumphed in a two-out-of-three match against University of Washington astronomer Toby Smith.

I'm also happy to report that two Cosmic Log correspondents have won 3-D glasses in last week's "Where in the Cosmos" contest on the Cosmic Log Facebook page, which had a Pluto-stamp theme. Congratulations to Allison Rae Hannigan and Jacob Smith! Pluto lives!

More about Pluto and other dwarfs:

• Scientists spot Pluto's fourth moon
• Carbon monoxide found in Pluto's air
• Join the search for icy worlds
• Interactive: The new solar system
• More about Pluto on Cosmic Log
• More about 'The Case for Pluto'

This concept art for a 2015 stamp celebrates NASA's New Horizons mission to Pluto.

The next three years just might be prime time for poor little Pluto, thanks to NASA's New Horizons mission — and if the leaders of that mission are successful, a brand-new Pluto postage stamp will be part of the celebration. But they need your help.

Today marks the start of an online petition campaign at Change.org, calling for the creation of a stamp commemorating the $700 million mission and its 2015 Pluto flyby. It would mark only the second time the dwarf planet has appeared on a U.S. postage stamp. The first time was in 1991, when a 29-cent stamp labeled Pluto as "Not Yet Explored."

Back then, some planetary scientists saw that stamp as a challenge — and that gave an early boost to the efforts that eventually led to New Horizons' launch in 2006. The mission's principal investigator, Alan Stern of the Southwest Research Institute, even included one of the old stamps as a pint-sized payload on the spacecraft. Now the postal connection is coming full circle, just in time to render that "Not Yet Explored" label obsolete.

"We're asking people to sign the petition because the post office considers not just the merits of a new stamp proposal, but also whether it is supported by a significant number of people," Stern said in today's kickoff announcement. "This is a chance for us all to celebrate what American space exploration can achieve through hard work, technical excellence, the spirit of scientific inquiry and the uniquely human drive to explore."

USPS

The 1991 stamp was part of a solar-system set.

The petition, along with the formal stamp proposal, would be sent to the U.S. Postal Service's Citizens' Stamp Advisory Committee, which sifts through thousands of suggestions and recommends which subjects should be transformed into commemorative stamps. Last year, for example, one set of stamps paid tribute to Mercury astronaut Alan Shepard's history-making flight in 1961, as well as the Messenger mission to Mercury.

It takes about three years to move from the submission of a proposal to the issuance of a new stamp — which is why Stern and his colleagues are making a big push now for a stamp that would be unveiled in 2015. The more signatures they can get, the better the chances of winning the approval of the committee and the postmaster general.

"If we get 10,000 signatures, we'll get a stamp — that's the impression I get," Stern told me. "But we're aiming for 100,000."

Stern said he'd like to turn in the signatures as well as the stamp proposal during the week of March 13, which marks the 82nd anniversary of the announcement of Pluto's discovery. That's not entirely out of the question, even though the International Astronomical Union reclassified Pluto as a dwarf planet in 2006. After all, how many other celestial bodies have been the subject of letter-writing campaigns, legislative action, street protests and petitions by planetary scientists?

Dan Durda, an artist and space scientist at the Southwest Research Institute whose works appear on the New Horizons website and in many other places (including my book, "The Case for Pluto"), has drawn up a concept for the Pluto stamp — but if the stamp proposal is approved, the stamp's design may well be out of his hands.

"Stamp designing is an unusual art form requiring exacting skill in portraying a subject within very small dimensions," the Postal Service says. "Due to the demands of stamp design and reproduction requirements, it is our policy not to review nor accept unsolicited artwork."

The design isn't uppermost in Stern's mind right now. "You know, I'm sure it will turn out fine," he told me. "Our goal is to commemorate the historic nature of the mission and celebrate U.S. leadership in space exploration. And involve the public."

That's where you come in.

"Sign the petition, and mention it on Facebook," Stern said. "Let's see how high we can drive the numbers for Pluto and for space exploration."

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.