New Planet Definition Leaves Scientific Loose Ends

The controversial vote today that reduced our solar system's planet tally to eight has left a series of loose scientific ends in its wake.

Not only does it leave NASA with a robotic mission en route to an "unplanet," astronomers are wondering what names will be given to all the little round objects in the outer solar system, decisions that will force changes in textbooks and curricula.

But it's all for the good, many astronomers say.

Heading for Pluto

NASA's New Horizons robotic mission to Pluto launched in January. It's due to arrive in 2015. Several astronomers told SPACE.com that the project is now more significant and interesting than ever, because Pluto is finally recognized as what it is: part of a swarm of small things beyond Neptune.

"In fact [Pluto] becomes even more interesting to look at because it is the standard by which all future dwarf planets will be judged," said Charles Liu, a researcher at the American Museum of Natural History and a professor of astrophysics at CUNY/Staten Island.

"In a sense, it makes it more clear what this mission is about," said Caltech planet-hunter Mike Brown. "I think it's better this way."

Brown's team has discovered dozens of objects that will now be termed "dwarf planets" under the new definition from the International Astronomical Union (IAU). Back in the late 1990s, before these objects were known, one justification for going to Pluto was that it was the last planet that had not been visited.

Now New Horizons has fresh purpose, Brown said in a telephone interview.

"We really are learning about a new class of objects," he said. "Pluto is close and it's easy to get there. We'll learn a ton."

Running out of names

Brown and others say ultimately there will be dozens and perhaps hundreds of dwarf planets found. The IAU has not said how they will be named. Pluto and asteroid Ceres (also once thought to be a planet) both have classic planet names from Roman mythology. If that theme is extended to other dwarf planets, there won't be enough names, Brown points out.

"I would call that the next problem," said Louis Friedman, Executive Director of The Planetary Society. The IAU has "obviously not solved the whole problem yet." Freidman said he expects dwarf planets to get names of some sort.

Already the IAU has opened up to using other names for far-out objects. Sedna, discovered by Brown's team, is the most distant known object in the solar system and is named for the goddess of the sea for Arctic dwellers.

Another object found by Brown's team, 2003 UB313, is about the same size as Pluto. Despite reports that a name for this object is pending from the IAU, Brown said an early proposal he submitted was long ago rejected. He does not know what he will do now, name-wise. "I'm still trying to figure out what the rules are," he said today.

Sell the names

Stephen Maran, author of "Astronomy for Dummies," has a novel idea. He notes that fictitious star names are sold to anyone who wants to spend the money. Asteroids are named after John, Paul, George and Ringo and other luminaries.

"I think the IAU should consider selling the naming rights to dwarf planets, whether they're private individuals or corporate sponsors, and use that money to support education and science around the world," Maran said.

Maran and others also think the issue will stimulate interest among school children and the need for teachers to explain planets in much more defined terms than ever.

Of course, textbooks will need to be redone.

Maran has already talked to his agent about this, suggesting that the 3rd edition of his book should perhaps be put out sooner than planned.

The Debate at the IAU Meeting

• BLOG: The Right Decision
• Pluto Demoted: No Longer a Planet in Highly Controversial Definition
• 3rd Proposal 'Shot Down in Flames'
• Details Emerge on Plan to Demote Pluto
• Pluto May Get Demoted After All
• One Astronomer Says 'It's All About the Atmosphere'
• Earth's Moon Could Become a Planet
• Public Laughs and Shrugs at 12-Planet Proposal
• Astronomers Sharply Divided on New Planet Definition
• Adding Planets Means New Textbooks, Toys
• Nine Planets Become 12 with Controversial New Definition
• Image Gallery: The 12 "Planets"

Defining Moments: The Saga's History

• Pluto's Fate to be Decided by 'Scientific and Simple' Planet Definition
• JUNE: Definition of 'Planet' Expected in September
• 2005: Definition Debate: Planets May Soon Get Adjectives
• 2003: Controversial Proposal Would Boost Solar System's Planet Tally to 12
• 2000: What is a Planet? Debate Forces New Definition