A fresh study of the Kuiper Belt’s structure has revived that far-out question, pointing to a possible Earth-sized ...

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

Our solar system now, once again, officially consists of only eight planets. Although largely debunked, speculation continued of the existence of a large unseen planet, referred to simply as Planet X, ...

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 dubbed ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

Is there a massive undiscovered planet on the outer reaches of the Solar System? The idea has been around since before the discovery of Pluto in the 1930s. Labelled as planet X, prominent astronomers ...

A SpaceX Falcon 9 rocket sends Amazon’s Project Kuiper satellites into space. (SpaceX / Amazon via LinkedIn) In a case of strange space bedfellows, SpaceX launched 24 satellites for Amazon’s Project ...

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 ...

The recent identification and reports of the comet 3I/ATLAS has sparked widespread interest among astronomers, space agencies ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...