Astronomers propose a new hypothetical planet, Planet Y, beyond Neptune, based on observed orbital anomalies in the Kuiper ...

First trans-Neptunian object (TNO) found in a rare 10:1 orbital resonance with Neptune; Object orbits the Sun once every ~800 years, while Neptune makes ten orbits; L ...

As far as we know Neptune is the furthest full-size planet in our Solar System, orbiting the Sun some 2.69 billion miles away ...

Planet Nine was previously suggested as a possible explanation for distant orbital clustering. It was thought to be ten times Earth’s mass, orbiting far beyond Neptune.

Astronomers have picked up evidence of an Earth-sized world, distinct from the previously hypothesised Planet Nine and Planet ...

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

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

Astronomers using the James Webb Space Telescope have found an unknown moon orbiting Uranus, bringing the planet’s total to ...

A Neptune-sized planet closely orbiting its host star has just been discovered, making it only the fourth object of its kind ever identified. Scientists detected the planet, designated TOI-3261 b ...

Over millions of years, Uranus’s inner moons may have collided and spread out into rings. As the material in the rings ...