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

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

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

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

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

Cheng discovered the object as part of an ongoing research project to identify TNOs and possible new planets in the outer ...

A recently discovered celestial body is rewriting our knowledge of the Kuiper Belt and maybe challenging the existence of the ...

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 new dwarf planet discovery in the outer solar system is challenging the long-standing theory of a hidden giant planet ...

A US-based trio hunting this elusive world has stumbled on what appears to be a new dwarf planet in the solar system's outer ...