Scientists have been puzzled for along time in trying to understand why rock samples from the Moon and Earth though having similar chemical composition, are still different.
What was puzzling them, was the presence of volatiles, which are present in Earth samples, but missing in those from the Moon, like zinc and sodium for example. However recent studies at at Southwest Research Institute in Boulder, U.S.A., have finally revealed the secret.
During the formation of the moon, Earth collided with a large planet approximately 4.5 Billion years back. This resulted in massive clouds of material being thrown out, including a half moon size ball of hot material. This material had the same composition as rocks found on Earth, and gradually cooled to form the Moon’s core.
Gradually, the hot material which still circled Earth lost it’s volatiles, and cooled into pebbles and rocks, which got sucked in by Moon’s gravity, onto it’s surface, building up it’s second layer. Hence the absence of volatiles.
