The Journey of Lonely Planets: How Planet-Planet Scattering Creates Free-Floating Worlds

Planet-planet scattering can eject planets from their systems, creating free-floating planets (FFPs). Simulations reveal that 40-80% of planets are ejected, often within 100 million years, with speeds of 2-6 km/s. Collisions reduce ejections, and bound planets end up on eccentric orbits. To match observed FFPs, 5-10 planets must form per star, highlighting scattering as a key mechanism in their creation.