A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

See more of our trusted coverage when you search. Prefer Newsweek on Google to see more of our trusted coverage when you search. A leading scientist has told Newsweek about new evidence supporting the ...

Beyond the orbit of Neptune, in the cold and nearly empty reaches at the frontier of the solar system, astronomers suspect a ...

Add Yahoo as a preferred source to see more of our stories on Google. Scientists think there may be a ninth planet hiding in the distant reaches of the solar system — and a new telescope could finally ...

Add Yahoo as a preferred source to see more of our stories on Google. Artist rendering of what Planet Nine might look like / Credit: CBS News It's an evocative idea that has long bedeviled scientists: ...

It might be lingering bashfully on the icy outer edges of our solar system, hiding in the dark, but subtly pulling strings behind the scenes: stretching out the orbits of distant bodies, perhaps even ...

In the cold, dark outskirts of planetary systems far beyond the reach of the known planets, mysterious gas giants and planetary masses silently orbit their stars—sometimes thousands of astronomical ...

Planet Nine, the undiscovered planet at the edge of the solar system that was predicted by the work of Caltech’s Konstantin Batygin and Mike Brown in January 2016, appears to be responsible for the ...

If the solar system does have a Planet Nine, it is a world that was bullied by its larger siblings, exiled to the far reaches of space and only rescued from oblivion thanks to the intervention of ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Is there an unseen planet — a "planet X" or "Planet Nine" — ...