A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

Could a lonely planet wander aimlessly through the restless galaxy change the subtle dance of gravity within our solar system ...

Astronomers are investigating a potential hidden planet, dubbed Planet Y, far beyond Neptune. Its gravitational pull is ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than ...

While Planet Y has been not yet been directly observed, unexpected inclinations found in the orbits of roughly 50 distant ...

Astronomers have discovered new evidence that suggests the possibility of an unknown planet in our solar system's farthest ...

(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 ...

A strange tilt in the outer reaches of the Kuiper Belt has scientists wondering if the solar system is hiding a potential ...

When you look at the solar system, you might notice that the planets' orbits are tilted, and oddities in the protoplanetary ...