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

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

If the object really is Planet Nine, it would be larger than Neptune and exist 700 times further from the sun than Earth.

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

The solar system is our cosmic neighborhood ... Neptune and then the possible Planet Nine. It's a dynamic system shaped by gravity and time, and while we've learned a lot, it still holds plenty ...

Using two infrared space telescopes and a 23-year gap, scientists may have spotted a mysterious, slow-moving object beyond ...

Researchers have found a candidate for the hypothetical Planet Nine, which could be an undiscovered giant planet way out in ...

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 have detected a promising sign of a ninth planet lurking at the the farthest reaches of the Solar System.

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

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

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.