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

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

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

Astronomers have long speculated about an unseen planet lurking in the solar system's outer edge. This hypothetical world, ...

For years, astronomers have toyed with the idea that the Sun hides an extra planet so distant and dim that even the best ...

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

NASA analyzed 40 years of satellite data to discover mysterious ninth planet at the edge of our solar system, potentially ...

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

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

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 ...

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