Permanent Human Settlement of the Earth, Space and Ocean Frontiers

Wednesday, August 16, 2006

A Real Planetary Mess

The proposal to identify what is defined as a “planet” has leaked:

"A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet."

I have cut and pasted part of the article here. Otherwise, you can click to and read it in detail on their site.

The final plan it seems is riddled with odd inconsistencies and contradictions to logic. Oh well – who said you could run a universe by committee anyway? When you do, then you get what you get.

======= From

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 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.

Brown and other another expert said the proposal, to be put forth Wednesday at the IAU General Assembly meeting in Prague, is not logical. For example, Brown said, it does not make sense to consider Ceres and Charon planets and not call our Moon (which is bigger than both) a planet.

IAU members will vote on the proposal Thursday, Aug. 24. Its fate is far from clear.