On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered 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 ...

There's a new object in the distant reaches of our solar system, and it might just offer clues to a long-standing cosmic mystery. Astronomers have cataloged a frozen minor planet called 2017 OF201, ...

PHOENIX — Arizona State University is searching for the ninth planet in the solar system, and they want you to help find it. Astronomer Adam Schneider with the university’s School of Earth and Space ...

In the race to discover a proposed ninth planet in our Solar System, Carnegie’s Scott Sheppard and Chadwick Trujillo of Northern Arizona University have observed several never-before-seen objects at ...

Scientists have been on the hunt for a true ninth planet since 2014, and a pair of new studies provide more evidence that such an object exists. Share on Facebook (opens in a new window) Share on X ...

Astronomers believe there is evidence for a large distant planet in our solar system that hasn't been spotted yet. Konstantin Batygin and Michael E. Brown of the California Institute of Technology ...

Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the distant solar system. The object, which the researchers have nicknamed Planet Nine, has a ...