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 ...

Astronomers have long been on the hunt for "Planet Nine," a hypothetical planet that lies within our solar system just beyond Neptune. Scientific evidence has alternately pointed to and against the ...

(CNN) — The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have ...

After studying thousands of computer simulations of the solar system, researchers at Rice University and the Planetary Science Institute think there’s a 40% chance an elusive “Planet Nine” or “Planet ...

For years, astronomers have searched for Planet Nine, a hypothetical world thought to lurk far beyond Neptune. Its existence ...

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 ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth than the hypothetical Planet X, which astronomers have been hunting for ...