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 ...

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 ...

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

The most unsettling space images are not of black holes or distant galaxies, but of stars that look eerily like our own Sun in its final moments. Astronomers can now map, almost step by step, how our ...

Scientists say studying objects like Ammonite, despite their immense distance, offers valuable insight into the solar ...

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 ...