Far beyond Neptune, something heavy appears to be tugging on the outer solar system, bending the paths of distant icy worlds in ways gravity alone should be able to explain. Planet 9, still invisible ...

Far beyond Neptune, scientists suspect a massive unseen world may be shaping the orbits of distant objects. Planet 9 remains one of the most intriguing possibilities in the outer Solar System.

Add Yahoo as a preferred source to see more of our stories on Google. Planet Nine is a theoretical planet in the outer solar system that has proved to be extremely hard to find. | Credit: Shutterstock ...

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 ...

There may be a warp in the Kuiper Belt, possibly caused by “Planet Y” — a Mercury-to-Earth-sized world that orbits the sun way beyond the orbit of Neptune. Is there a mysterious “Planet Y” orbiting ...

Add Yahoo as a preferred source to see more of our stories on Google. Planet Nine is a hypothesized massive planet, first proposed in 2014, that is speculated to orbit far out in the solar system. It ...

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 ...