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.

Researchers found the object named 2017 OF201 while searching for "Planet Nine" - a hypothetical planet thought to exist ...

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

A sweeping new ICE operation shows how Donald Trump’s focus on immigration is reshaping federal law enforcement.

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

As a result of the International Astronomical Union’s 2006 demotion of Pluto from planet to dwarf planet, our solar system ...

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 ...

A possible new dwarf planet has been discovered at the edge of our solar system, so far-flung that it takes around 25,000 years to complete one orbit around the sun. The object, known as 2017 ...

Now, a US-based trio hunting this elusive world has instead stumbled on what appears to be a new dwarf planet in the solar system's outer reaches. And the existence of this new kid on the block ...

With its low density and unusually cool, methane-rich atmosphere, this planet offers a rare window into giant planet ...

A giant conundrum has been found orbiting a teeny tiny red dwarf star just a fifth of the size of the Sun. Such small stars ...