The search for our solar system's ninth planet | Mike Brown

Could the strange orbits of small, distant objects in our solar system lead us to a big discovery? Planetary astronomer Mike Brown proposes the existence of a new, giant planet lurking in the far reaches of our solar system -- and shows us how traces of its presence might already be staring us in the face.
by contact@ted.com (TED) via TED Talks Daily (SD video)