Because the solar system's contents formed from a disk around the sun, we would expect the orbits of everything orbiting the sun to keep relatively close to the plane of that disk. However, some don’t ...

Artist's concept of a hypothetical planet orbiting far from the Sun. Almost a decade after astronomers proposed the existence of Planet 9, an unseen extra planet in the distant reaches of the solar ...

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is a ...

Far beyond Neptune, something heavy appears to be tugging on the outer solar system, bending the paths of distant icy worlds in ways gravity alone should be able to explain. Planet 9, still invisible ...

Researchers at the California Institute of Technology (Caltech) have found new evidence that further suggests there is a ninth planet in our solar system. Nicknamed "Planet Nine," researchers said ...

Researchers closely tracked and computationally analyzed moon and asteroid sized objects beyond Neptune and determined that a ninth planet about five times bigger than the Earth is about 16 times ...

For years, astronomers have suspected there’s a massive unseen world hiding far beyond Neptune — Planet 9. This video breaks ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...

Astronomers believe there is a Planet Nine in the outer solar system beyond Neptune. A team led by Amos Chen from the National Tsing Hua University, is searching for Planet Nine’s heat signature. When ...