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

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

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

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

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

The object, known as 2017 OF201, was found by researchers at the Institute for Advanced Study and Princeton University who were searching for “Planet Nine,” a hypothetical planet larger than ...

A newly detected planet beyond Pluto is not just expanding our understanding of the Solar System, it might be quietly rewriting it. Astronomers from the University of Taiwan recen ...

Less than 1% of this dwarf planet candidate's orbit is close enough to detect, which means astronomers are lucky to have ...

They said: ‘The discovery of 2017 OF201 is significant because it’s found in a region of the Solar System thought to be empty ...

Some astronomers say the strange, clustered orbits of icy rocks beyond Neptune indicate that something big is out there, ...