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

The object’s aphelion—the farthest point on the orbit from the sun—is more than 1,600 times that of Earth’s orbit,” Institute ...

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

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

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.

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

Researchers discovered a new trans-Neptunian object, 2017 OF201, potentially a dwarf planet, in the outer solar system.

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

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