Is there a ninth planet? After Pluto's demotion as a planet, we have currently eight planets in our solar system. But Sun's gravitational pull can be felt well beyond Pluto, so is it possible to have a ninth planet beyond Pluto? I asked this question because we have Kuiper belt beyond Pluto, so there might be some Kuiper belt object which may qualified to be a ninth planet, isn't it possible?
According to Caltech there is possibly a planet 10 times the mass of earth in a 15-20 thousand year orbit at an odd angle. It hasn't been observed yet. There's a search for it ongoing.