images

Moon capture theory - Illustration

by

Don Dixon/Novapix

Reference

t-glb99-91020

Date

2009-05-22

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).