For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

As it orbits the sun once every 25,000 years, the celestial body 2017 OF201 travels beyond the Kuiper Belt into a region ...

The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...

The newly discovered object, named 2017 OF201, has a 25,000-year orbit and is believed to be a large contender for dwarf ...

A possible new dwarf planet has been discovered at the edge of our solar system, so far-flung that it takes around 25,000 ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system ...

Astronomers announced the discovery of a new dwarf planet, provisionally named 2017 OF201, located in the remote outskirts of ...

There’s a new object in the distant reaches of our solar system, and it might just offer clues to a long-standing cosmic ...

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

For the unversed, "Planet Nine" is a hypothetical planet which is reportedly larger than Earth that is thought to orbit ...

A potential new dwarf planet has been discovered in the outer reaches of the solar system, and its existence poses the ...