When you buy through links on our articles, Future and its syndication partners may earn a commission. Planet Nine is a hypothesized massive planet, first proposed in 2014, that is speculated to orbit ...

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

A mysterious new world may be hiding in the outer reaches of our solar system. According to arecent study published on arXiv by Amir Siraj of Princeton University and colleagues, a previously unknown ...

Planet formation used to sound straightforward: dust clumps into rocks, rocks grow into worlds, and the rest is detail. A cluster of recent discoveries has shattered that tidy picture, revealing ...

There has been a lot of back and forth about the existence of a mysterious ninth planet, often referred to as "Planet Nine" or even "Planet X." Now, though, researchers say there is likely at least a ...

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 ...

If the solar system does have a Planet Nine, it is a world that was bullied by its larger siblings, exiled to the far reaches of space and only rescued from oblivion thanks to the intervention of ...

In the cold, dark outskirts of planetary systems far beyond the reach of the known planets, mysterious gas giants and planetary masses silently orbit their stars — sometimes thousands of astronomical ...