Astronomers have discovered icy rocks in the outer solar system that seem to defy the laws of physics, raising questions ...

Astronomers studying the outer solar system say the unusual alignment of distant objects points to the influence of Planet 9.

There may be a warp in the Kuiper Belt, possibly caused by “Planet Y” — a Mercury-to-Earth-sized world that orbits the sun way beyond the orbit of Neptune. Is there a mysterious “Planet Y” orbiting ...

A newly discovered dwarf planet called 'Ammonite' (2023 KQ14) has been spotted in the outer solar system, and it could be another nail in the coffin for the Planet Nine hypothesis. When you purchase ...

Is there a massive undiscovered planet on the outer reaches of the Solar System? The idea has been around since before the discovery of Pluto in the 1930s. Labelled as planet X, prominent astronomers ...

"It is possible that a planet once existed in the solar system but was later ejected, causing the unusual orbits we see today." When you purchase through links on our site, we may earn an affiliate ...

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London.View full profile Alfredo has a PhD in Astrophysics and a Master's in Quantum ...

Ian Whittaker does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...

Astronomers have observed a planet that in some ways behaves more like a star — including a massive growth spurt unlike anything witnessed before in a free-floating planet. The rogue planet, which ...