Pluto was discovered in 1930 in Arizona, but in 2006 scientists decided to cut Pluto from the planetary line up. Here is why ...

The presence of another planet in the solar system could explain the odd movements of some of the bodies in the Kuiper Belt.

Scientists think they’ve detected a new planet beyond Neptune. Find out why experts believe 'Planet X' might support alien life.

For over a century, astronomers have wondered if there's an extra planet in our Solar System that we haven't been able to see ...

A new look through decades-old data has unveiled some of the most compelling evidence yet of a hidden ninth planet in the far ...

The solar system consists of our star, the sun, and everything bound to it by gravity: the planets Mercury, Venus, Earth, ...

Once the quirky underdog of our solar system, Pluto held planetary status until 2006, when it got a cosmic demotion that still stings space fans. Discovered in 1930, Pluto was the ninth planet for ...