A ninth planet may exist beyond Neptune in the Kuiper Belt, a region populated by icy bodies that orbit the Sun.

The search for Planet Nine has been on for years. Mysterious pulls in the Kuiper Belt have led scientists to believe a hidden ...

In 2016, scientists Michael Brown and Konstantin Batygin suggested that an unseen Planet Nine could explain the unusual orbits of some Kuiper Belt objects, sparking interest in its possible existence ...

The search for Planet Nine, a hidden world beyond Neptune, is heating up as scientists prepare to use a powerful new telescope.

It would take between 10,000 and 20,000 Earth years to make one full orbit around the Sun. If it exists, this planet could help explain the unique orbits of some smaller objects in the distant Kuiper ...