Any More Planets out There?

If the solar system had a 10th planet (well actually, a 9th since Pluto has been demoted) beyond Pluto's orbit, would astromers have already discovered it since long? I mean, if we are able to detect exosolar planets, it seems very improbable to me that we have still large bodies undiscovered in our solar system. I ask you this because I'm getting tired of Nibiru and all of that 2012 new age pseudoscience bullsh**.
- Anonymous

I agree with your comment about Mr. Nibiru.  But he is in the business of selling books not science.   The outer solar system, Kuiper-belt and all, has been pretty well searched although Eris, nee Xena, was only discovered in 2003.   Asteroids are more sneaky however and some of them with extreme eccentric orbits might give us a surprise. 

LeeH

(published on 08/18/2011)