Add Yahoo as a preferred source to see more of our stories on Google. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far ...

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 ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

The Solar System is a weird place filled with incredible physics and geological oddities that often break down in human terms ...