The Intruder That Knocked Our Planets Askew

Billions of years ago, a rogue planet eight times more massive than Jupiter tore through our Solar System, passing closer to the Sun than Mars orbits today. That single violent encounter may explain why our giant planets don’t orbit in perfect circles like formation theories predict and new simulations suggest there was roughly a one in 9,000 chance it happened at all. The discovery reveals that near misses with interstellar wanderers might be more important in shaping planetary systems than anyone realised.