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

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

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

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

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

Discovery of 2017OF201, a large trans-Neptune Object, challenges previous beliefs about the Kuiper Belt and hints at the ...

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

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

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 ...

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