A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than ...

Astronomers are investigating a potential hidden planet, dubbed Planet Y, far beyond Neptune. Its gravitational pull is ...

What do you do when you encounter a strange astronomical event, a collection of data from planets thousands of light-years away, and models that can't ...

(CNN) — 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 ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

Voyager 1 has been exploring the cosmos for decades, but when it reached the edge of the solar system, it found something ...

The European Southern Observatory said the discovery as "the first clear detection of a baby planet in a disc with multiple rings" Abigail Adams is a Human Interest Writer and Reporter for PEOPLE. She ...