Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system ...

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

The Kepler telescope has looked up in perfect silence at the stars and found more than 1,200 new worlds. NASA said Tuesday that Kepler, constantly searching the cosmos for "exoplanets" circling other ...