The solar system lost its ninth planet back when Pluto was demoted to a dwarf planet, but research might indicate that there ...

Astronomers have uncovered a massive new trans-Neptunian object, 2017 OF201, lurking at the edge of our solar system. With an ...

Astronomers have directly spotted a rare young planet, WISPIT 2b, still forming within the gap of a dusty ringed disk around ...

Astronomers may have demoted Pluto from full-fledged planet to dwarf status, but evidence suggests the solar system may still ...

New discoveries of objects in the Kuiper Belt have also presented challenges for the Planet Nine theory. The latest is known ...

Astronomers continue the search for a massive unseen planet that could reshape our understanding of the solar system.

Astronomers say they have evidence that there may be a hidden planet in our Solar System. Named 'Planet Y', the Earth-sized ...

In 2016, a pair of astronomers made an exciting announcement: There might be a hidden planet about ten times the size of Earth lurking somewhere in the most distant part of our solar system ...

This object could shoulder outer solar system sculpting responsibilities with Planet Nine, says co-author Antranik Sefilian, a doctoral candidate at Cambridge University, letting the theoretical ...

If Planet Nine really exists, it could help scientists understand the birth of the solar system, said Scott Kenyon of the Harvard-Smithsonian Center for Astrophysics.

According to a new proposal, the solar system has 12 planets instead of the familiar 9, with several dozen more to come.

Astronomers have discovered a rare in-sync solar system with six planets moving like a grand cosmic orchestra, untouched by outside forces since their birth billions of years ago.