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.

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

Learn how a possible ninth planet, the theoretical Planet X, could have acquired its wide orbit in the outer Solar System - a ...

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

There’s a new object in the distant reaches of our solar system, and it might just offer clues to a long-standing cosmic ...

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

WASHINGTON: A group of scientists has found a strange new object about 435 miles wide at the far edge of the solar system. It ...

Scientists hunting for the hypothetical Planet Nine have discovered a potential new dwarf planet, 2017 OF201, in the outer ...

Astronomers find evidence of a possible ninth planet beyond Neptune, reigniting the debate about the formation of the Solar ...

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

A new member of the solar system has been detected, the second-largest of its kind, suggesting there may be more like it ...

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