Researchers have found more evidence that there is an unknown planet in our solar system. Astronomers have been searching for proof that Planet Nine — also known as Planet X — exists for years ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

Currently, our solar system recognizes 8 planets, with Pluto being demoted to a dwarf planet floating in the Kuiper Belt in 2006. Planet Nine's gravitational pull may explain what keeps the icy ...

Scientists say they have found evidence of an unknown planet in our solar system. New findings represent the ‘strongest statistical evidence yet’ that Planet 9 exists, researcher says .

Did you know our solar system might have had an extra planet? ... sending it drifting into the unknown. If this planet is still out there, it could be wandering somewhere far beyond our reach.

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system. The object—which orbits out beyond Neptune—has been named "2017 OF201" by the ...

The Vera C. Rubin Observatory is expected to find millions of unknown objects in our solar system, and perhaps even a ...

Close stellar encounters could change the structure of our planetary system, potentially dooming Earth or other worlds to ...

(CNN) — Astronomers have discovered three previously unknown moons around Uranus and Neptune, the most distant planets in our solar system. The find includes one moon spotted orbiting Uranus ...

Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, researchers say. ABC News. Video. Live. Shows. Shop. Log In. Stream on.