Add Yahoo as a preferred source to see more of our stories on Google. Digital art of distant planet - Dottedhippo/Getty Images On August 24, 2006, our solar system lost a planet. It wasn't by ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. Planetary scientists are split, oscillating between two main theories that explain the order in ...

LONDON — The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper's authors have ...

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 ...