Astronomers believe they have uncovered evidence of a previously unknown ninth planet lurking in the not-too-distant reaches of the solar system. This hypothetical world, dubbed "Planet Y," could be ...

A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than the hypothesized Planet Nine. According to a new measurement of the Kuiper ...

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

Twelve new Jovian moons were discovered, increasing the total known count to 79. These discoveries were a serendipitous outcome of a separate Planet Nine search. The research utilized the Blanco ...

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 ...