Astronomers can't seem to make up their mind.
What IS a planet?
The proposed 12 planet system
According to Space.com:
"The tally of planets in our solar system would jump instantly to a dozen under a highly controversial new definition proposed by the International Astronomical Union (IAU).
Eventually there would be hundreds as more round objects are found beyond Neptune.
The proposal, which sources tell SPACE.com is gaining broad support, tries to plug a big gap in astronomy textbooks, which have never had a definition for the word "planet." It addresses discoveries of Pluto-sized worlds that have in recent years pitched astronomers into heated debates over terminology.
The asteroid Ceres, which is round, would be recast as a dwarf planet in the new scheme.
Pluto would remain a planet and its moon Charon would be reclassified as a planet. Both would be called "plutons," however, to distinguish them from the eight "classical" planets.
A far-out Pluto-sized object known as 2003 UB313 would also be called a pluton.
That would make Caltech researcher Mike Brown, who found 2003 UB313, formally the discoverer of the 12th planet. But he thinks it's a lousy idea.
"It's flattering to be considered discoverer of the 12th planet," Brown said in a telephone interview. He applauded the committee's efforts but said the overall proposal is "a complete mess." By his count, the definition means there are already 53 known planets in our solar system with countless more to be discovered... " Read the Full Article
planets, PLUTO, Astronomy, solar system