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

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

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

Some scientists think they discovered a new dwarf planet at the edge of the solar system, so far away that it takes around 25 ...

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 announced the discovery of a new dwarf planet in our solar system, named 2017 OF201. Located far beyond ...

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

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

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

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 ...

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

A possible new dwarf planet has been discovered at the edge of our solar system, so far-flung that it takes around 25,000 years to complete one orbit around the sun. The object, known as 2017 ...