Ancient Planetary Upheaval: How Uranus' Moons Reveal the Solar System's Lost Planets

The structure and characteristics of Uranus' moons provide compelling evidence that our early solar system contained more giant planets than exist today. A new study analyzing 122 simulations shows that the chaotic history preserved in Uranus' moon system can only be explained if rogue planets were ejected into space during a period of extreme instability—solving long-standing puzzles about planetary migration that current models cannot fully account for.