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.

A recently discovered celestial body is rewriting our knowledge of the Kuiper Belt and maybe challenging the existence of the ...

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

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

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

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

Almost 20 years after Pluto was infamously downgraded from its status as a planet, scientists now believe they have ...

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

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

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

The first observations of Pluto by NASA's James Webb Space Telescope (JWST) reveal dramatic phenomena on its surface, like ...

The universe's vastness challenges human comprehension. It contains trillions of galaxies and countless stars. Pluto's ...