Over the past century, astronomers have speculated about the existence of a mysterious 9th planet lurking in the outer ...

In the paper from 2024, the team looked at long-period objects that crossed the path of Neptune's orbit, finding that their ...

Astronomers used a telescope in Hawaii to find a new object on the outer edges of our solar system, helping to fuel evidence of a long-standing theory about Planet Nine, or Planet X. For years, ...

This video explores the ongoing search for Planet X, a hypothetical world beyond Neptune that could explain the strange ...

Despite the lack of a dedicated mission to the planet, scientists have learned plenty through ground observations and space telescopes Shi En Kim | Reporter A photo of Neptune, taken by the Voyager 2 ...

Neptune, long believed to be dark blue, is actually very pale like Uranus, scientists say. They used modern telescopes to re-assess artificially enhanced images taken by NASA's Voyager 2 probe. We can ...