The capture of the Moon - Moon capture theory - Infographic showing the different processes...

The capture of the Moon - Moon capture theory - Infographic showing the different processes of capturing a satellite by a planet. At the top, the developing planetary halo of gas slows down and captures a passing Celestial body. In the middle, the sphere of gravitational influence of the planet develops and attracts a celestial body. At the bottom, interactions between passing asteroids can cause one to remain in orbit around a planet. Infographic shows processes for planet to aquire a satellite. A developing planet's halo of gas expands to capture a passing body (top). Its gravitational sphere of influence expands as well (middle). Interactions between passing asteroids may cause one to fall into orbit (bottom)