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

NASA’s New Horizons mission has taken humanity closer than ever to understanding the mysterious dwarf planet, Pluto. In 2015, ...

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 ...

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

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system.

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 ...

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

As explained in a pre-press paper [PDF] titled “Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201” ...

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

Less than 1% of this dwarf planet candidate's orbit is close enough to detect, which means astronomers are lucky to have ...