Evidence Points to Mysterious 'Planet Y' Lurking in Our Solar System's Outer Regions

Oct 04, 2025 02:21 pm CST

Astronomers have discovered compelling evidence suggesting the existence of a previously unknown celestial body dubbed 'Planet Y' in the distant regions of our solar system. This hypothetical planet, likely between Mercury and Earth in size, was inferred from the unusual 15-degree tilt observed in the orbits of approximately 50 Kuiper Belt objects beyond Neptune. While not yet directly observed, researchers believe Planet Y could coexist with the previously hypothesized Planet Nine, with the Vera C. Rubin Observatory potentially providing definitive evidence in its upcoming survey.