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

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

Scientists have discovered a colossal object approximately 435 miles wide in the frigid outer reaches of our solar system, ...

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

A small team led by Sihao Cheng, Martin A. and Helen Chooljian Member in the Institute for Advanced Study's School of Natural ...

Astronomers have discovered a mysterious dwarf planet, 2017 OF201, far beyond Pluto. This discovery challenges existing ...

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

The International Astronomical Union’s Minor Planet Center, which catalogs new moons and other small bodies in the solar ...

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

Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a highly ...