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

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

Think you know Pluto? From icy plains to planetary debates, this quiz dives deep into the mysteries of our solar system’s most controversial—and captivating—dwarf planet.

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

A planet far, far away A possible dwarf planet, like Pluto, has been observed in our solar system, according to a preprint published in arXiv. The area of space where this planet was found was ...

The unusual orbit of a possible dwarf planet, known as 2017 OF201, makes it less likely that our solar system contains a hidden ninth “Planet X” ...

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.

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 ...

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 ...