Our solar system may have gotten a bit bigger. Scientists at the California Institute of Technology say they've found a true "ninth planet."

FOX's Eben Brown reports from Miami:

With Pluto demoted we've been saying our solar system has only eight planets. But evidence suggests yet another.

Cal-Tech scientists found a bunch of space bodies way out there being kept in a moving pattern:

(Brown) "It shouldn't happen that way. They should all be randomly distributed in the sky. And the only way you can keep them lined up that was is something pushing them around, or pulling them around into those particular orbits."

Doctor Michael Brown, whose team made the discovery:

(Brown) "The only thing that works is to have a planet, a big planet, something that's ten times the mass of the Earth, that's actually swinging off in the opposite direction."

Such a planet, he says, would resemble Neptune.

In Miami, Eben Brown, FOX News.