'Planet Y' theory hints at hidden Earth-size world lurking in the solar system

Astronomers claim to have found evidence of "Planet Y," a hidden Earth-sized world lurking in the Kuiper Belt, much closer than the theorized "Planet Nine." Researchers studied 50 space objects whose tilted orbits can only be explained by a hidden planet's gravity, suggesting a rocky world between Mercury and Earth's size located 100-200 times farther from the sun than Earth. While some experts remain skeptical due to limited data, the new Vera C. Rubin Observatory in Chile could prove or disprove the theory within three years by detecting thousands more space objects.