Far beyond Neptune, something heavy appears to be tugging on the outer solar system, bending the paths of distant icy worlds ...

Planet Nine is a theoretical planet in the outer solar system that has proved to be extremely hard to find. | Credit: Shutterstock Some experts believe that we could be just a few years away from ...

FILE - Artist's concept of a hypothetical planet orbiting far from the Sun. Nicknamed "Planet Nine," researchers said that the most recent data shows something big is able to pull objects from outer ...

Astronomers studying the outer solar system say the unusual alignment of distant objects points to the influence of Planet 9. Mathematical models suggest the odds of this pattern occurring by chance ...

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 ...

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 ...

A powerful new observatory is the best hope yet for finding the elusive Planet 9, a large planet that some scientists say is hidden in our solar... If Planet Nine is out there, this telescope might ...

Some experts believe that the solar system's hypothetical ninth planet could be just a few years away from being discovered. If this is the case, how long would it take for humans to send probes to ...