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 ...

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 ...

Add Yahoo as a preferred source to see more of our stories on Google. Digital art of distant planet - Dottedhippo/Getty Images On August 24, 2006, our solar system lost a planet. It wasn't by ...

With the same data but a different statistical analysis, researchers have spotted two additional planets in a system that was already thought to host seven of them, giving it one more planet than our ...

In an exciting breakthrough in planetary science, a recent study has increased the likelihood of Planet Nine’s existence by up to 40%. This planet, also referred to as Planet X, has remained an ...

A leading scientist has told Newsweek about new evidence supporting the existence of a secret ninth planet lurking at the edge of our solar system. This hypothetical extra planet, often referred to as ...

Astronomers have found new evidence that a mysterious ninth planet may be hiding at the edge of the solar system - rewriting what we know about the cosmos again. An international team from Taiwan, ...

When I was a kid, the solar system was simple. There were nine planets and they all orbited in more-or-less circles around the sun. This same sun-and-a-handful-of-planets scheme repeated itself again ...

LONDON — 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 ...

Caltech professor Mike Brown (L) and assistant professor Konstanin Batygin have been working together to investigate distant objects in our solar system for more than a year and a half. The two ...

The outer solar system is a vast and mysterious place that could be harboring hidden objects we know almost nothing about — from the elusive Planet Nine and baby black holes to interstellar visitors ...