Astronomers say they have evidence that there may be a hidden planet in our Solar System. Named 'Planet Y', the Earth-sized ...

Beyond the familiar planets lies a fascinating frontier filled with icy worlds, mysterious orbits, and cosmic curiosities.

Even if life never took hold on Ceres, the discovery could help broaden the range of environments that could potentially be ...

Aliens may have been closer to Earth than first thought. New research from NASA reveals that Ceres, the dwarf planet in the ...

Astronomers propose a new hypothetical planet, Planet Y, beyond Neptune, based on observed orbital anomalies in the Kuiper ...

Does our Solar System have 9 planets or only 8? Astronomers have gone back and forth on that a lot, with Pluto now being ...

New research paints a picture of Ceres hosting a deep, long-lived energy source that may have maintained habitable conditions ...

WASHINGTON >> Scientists have identified an object about 435 miles wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a ...

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 ...

A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in our solar system.

The solar system has many more moons than the one we can see in the sky. But how many do we actually know about? And how many ...