Did you know our solar system might have had an extra planet? Scientists believe a mysterious ninth planet once existed but ...

A 9th planet in our solar system might be found — and no, it’s not Pluto - Is there another planet out there? Researchers say ...

A new study, however, identifies a possible candidate. A separate team of astronomers compared 1983 data from the Infrared ...

Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

A ninth planet the size of Neptune may be hidden in the far reaches of the solar system, but the evidence has left some experts skeptical.

Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner ...

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

Astronomers may have found a candidate for Planet Nine. This planet is beyond Neptune. The finding could be the first ...

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

The ongoing search for an additional planet at the solar system's edge has identified a new candidate, potentially ...

Astronomers claim to have discovered a new ninth planet in our Solar System. Planet Nine, also known as Planet X, is a hypothetical celestial object that would distantly orbit our Sun – but ...