The Universe Season 6 Episode 2 explores Nemesis Theory with its author, Richard Muller. Nemesis is thought to be a hard-to-spot red dwarf, a postulated companion to our Sun in a binary star system. Many scientists feel it's almost a certainty there's another large body out there, given the circumstances of our Solar System. Mike Brown of Cal Tech discovered a moon- sized planetoid, in 2003, Sedna. The planetoid orbits at three times the distance from our Sun as Pluto. Brown believes Sedna's extreme elliptical orbit, can be ex- plained, by the gravitational pull of another large body. The episode also considers a lite version of Nemesis, known as Tyche, a smaller and more planet-like body. Nemesis, is speculated, to return every 26,000,000 million years, to displace comets from the Oort Cloud into our inner system, and possibly explain, coincidence of regular extinction events here on Earth. The theories are interesting, Muller first theorizing in the eighties on Nemesis' presence in his book, "Nemesis: The Death Star."