Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

Caroline Delbert is a writer, avid reader, and contributing editor at Pop Mech. She's also an enthusiast of just about ...

Astronomers have detected a promising sign of a ninth planet lurking at the the farthest reaches of the Solar System.

Astronomers may have found a candidate for Planet Nine. This planet is beyond Neptune. The finding could be the first ...

The presence of another planet in the solar system could explain the odd movements of some of the bodies in the Kuiper Belt.

A new look through decades-old data has unveiled some of the most compelling evidence yet of a hidden ninth planet in the far ...

The solar system also includes the Kuiper Belt and Oort Cloud, which are distant regions filled with small icy bodies and long-period comets. Related: 10 incredible volcanoes in our solar system ...