How the moon formed according to isotopic research:-http://www.sciencedaily.com/releases/2012/10/121017131830.htm-Hit by a giant object the moon was knocked off the Earth-And why it is so impotant to us, the evolved:-"Without the stabilizing influence of the Moon, Earth would probably be a very different sort of place. Planetary sciences think Earth would spin more rapidly, days would be shorter, weather more violent, and climate more chaotic and extreme. In fact it might have been such a harsh world, it would have been unfit for the evolution of our favorite species: us."