I wish I coudl take credit for that line, but it was from Colbert.
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UB313 is larger than Pluto, and farther out in orbit.
I kinda liked the idea of calling Pluto and Charon a “dual planet,” as Charon is so large that it was somewhat unfair to say that it orbits Pluto, but they aren’t going to do that.
Ceres is the largest asteroid in the Asteroid Belt but because it hasn’t swept the area clear of other asteroids (and I guess it never will b/c of its close proximity to Jupiter) it will never meet the new definition of a planet:
“a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a nearly round shape, and has cleared the neighborhood around its orbit.”