That’s an artist’s conception of Sedna, the most distant object found in solar orbit. The consensus seems to be that it’s not a planet, but rather a planetoid and, more specifically, an Oort Cloud Object. It’s out beyond even the Kuiper Belt — very far, indeed.
Man, does a single day go by anymore that I don’t go online, see some bit of planetary astronomy news, and think, “Damn, if only Carl Sagan hadn’t died just a handful of years before all this!”
(link via Jay Manifold)
