The simulation of the Solar System that came the closest to the observation was the presence of a small planet, between the ...

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

Since Pluto was relegated to dwarf planet status, almost everyone has agreed that there are eight planets in our solar system ...

Planet 9 may exist 42 billion miles away, influencing objects in the Kuiper Belt, and could be discovered with modern ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study ...

Amir Siraj and team propose Planet Y, a possible unseen planet influencing Kuiper Belt object orbits. Vera C. Rubin ...

An alien comet passing through our solar system made its closest approach to Mars recently, and two European robotic ...

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

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 dubbed ...

A mysterious space object named 2023 KQ14, nicknamed “Ammonite,” challenges theories about the mysterious and possible Planet ...

On October 6 1995, at a scientific meeting in Florence, Italy, two Swiss astronomers made an announcement that would transform our understanding of the universe beyond our solar system. Michel Mayor ...

Pluto's unusual eccentricity and tilt is likely due to its interactions with neighboring Neptune and other giant planets, ...