BREAKING NEWS: IAU committee proposes 12 planet solar system

The verdict is in- and the International Astronomical Union will vote on it next Thursday.

A committee of the IAU has recommended that Pluto remain a planet- and that its largest moon, Charon, also be considered a planet, in effect recognizing the solar system's only double-planet system; that 2003 UB 313 be considered a planet; and that Ceres, the largest of the asteroids, be considered a planet.

Ceres, Pluto and Charon and 2003 UB313 will be relegated to a new category: "dwarf planets."

If the proposal is adopted, according to IAU rules 2003 UB313 will be named after a deity of the underworld in some pantheon or other.

Comments

Eric Phillips said…
How can Charon be a planet and a moon at the same time? Doesn't it orbit Pluto?
Well, actually, Pluto and Charon orbit each other. The concept is explained here: http://tinyurl.com/gzsqb

While Pluto is the larger of the two, no other moon in the solar system is as relatively large with respect to its "primary" as Charon is. In fact, size is the only reason why Pluto is considered the primary, and Charon the moon.

Astrophysicists actually think this arrangement is probably rather common in other star systems. The only remotely similar situation in our own is the Earth/Moon system. Given its size, the moon would warrant serious consideration as a planet in its own right if it didn't orbit Earth, without Earth orbiting it, as in the Pluto/Charon system.

Essentially, what the IAU committee is suggesting is that instead of regarding Charon as the largest of Pluto's three moons, the Pluto-Charon system simply be considered a double planet.
The IAU committee can call Pluto a dog if they want, that doesn't make it a dog. Pluto is a planet whether they say so or not. They can go pee on a fire hydrant.

-- LouieInSeattle