Never heard of Eris? No wonder. It was discovered just five years ago by a team at the Palomar Observatory, and named for the Greek goddess of strife and discord. It's orbiting the sun three times farther out than Pluto. Astronomers estimate it is about 2,500 kilometers in diameter, and 27 percent more massive than Pluto. That makes it the ninth largest object known to be orbiting the sun. Eris (pictured in an artist's rendering at left) has a satellite of its own, dubbed Dysnomia, the daughter of Eris and demon of lawlessness. Nice.