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 was touted more than a century ago.

There's good news for those who were annoyed when Pluto was knocked off the list of planets. According to a pair of scientists at Caltech, there may actually be nine planets in the Solar System ...

Scientists confirm existence of 1,284 more Milky Way planets, including 9 that could be Earth-like By Amina Khan Staff Writer May 10, 2016 6:36 PM PT ...

IAU members will vote on the proposal Thursday, Aug. 24. Its fate is far from clear. Q&A on the Proposal / Gallery: The 12 "Planets" / Read the Draft Resolution The definition The definition ...

About 45 minutes before sunrise all this week until Sunday, September 9 it's possible to see Mercury. It was the highest it ever gets above the eastern horizon in the pre-dawn sky on August 26 ...

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 was touted more than a century ago. But ...