Last updated on April 24, 2014 at 6:16 EDT
Planet X New Member of our Solar System
327 of 516

Planet X: New Member of our Solar System

April 12, 2006
This artist's concept shows the planet catalogued as 2003UB313 at the lonely outer fringes of our solar system. Our Sun can be seen in the distance. The new planet, which is yet to be formally named, is at least as big as Pluto and about three times farther away from the Sun than Pluto. It is very cold and dark. The planet was discovered by the Samuel Oschin Telescope at the Palomar Observatory near San Diego, Calif., on Jan. 8, 2005.