Add Yahoo as a preferred source to see more of our stories on Google. An illustration showing Planet Nine, a hypothetical, undiscovered planet in our solar system. New research now suggests the ...

For over a century, scientists have suspected there could be a hidden planet lurking far beyond Neptune—massive enough to ...

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 ...

WASHINGTON (Reuters) -Astronomers have spotted a small rocky planet that orbits perilously close to its host star disintegrating as its surface is vaporized by stellar heat, trailed by a comet-like ...

Planet Y is the latest in a series of hypothetical solar system planets that scientists have proposed in recent years, all with slightly different characteristics but collectively believed to be ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...