Travel through time to witness some of the most remarkable episodes in our solar system's history, uncovering its ancient ...

New discoveries of objects in the Kuiper Belt have also presented challenges for the Planet Nine theory. The latest is known ...

A renowned physicist believes he's cracked the mystery of where a giant unidentified object hurtling through our solar system came from.

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 ...

The Oort Cloud, an expanse of icy bodies in the far reaches of our solar system, is shown here in a scene from "Encounters in the Milky Way," a show at New York City's Hayden Planetarium that ...

Astronomers using the Subaru Telescope have discovered a strange new body in a weird orbit at the edge of the solar system, which could be bad news for Planet Nine theories.