CANADA: Scientists in the United States have proposed a new theoretical model that could explain the origin of some of the geochemical differences between the Earth and Moon, according to a study published Monday by Nature Geoscience magazine.
Experts at the Southwest Research Institute in Colorado have combined dynamic, thermal and chemical models on the formation of the Moon to find out why its rocks contain a relatively smaller number of so-called “volatile” elements than do Earth rocks.
In many regards, lunar rocks seem a lot like those on Earth, but on the Moon there are considerably fewer volatile elements such as potassium, sodium and zinc, which tend to have lower boiling points and vaporize rapidly.
The reason for the relatively scanty presence of such volatiles on the Moon has been a longstanding mystery and solving it is key to explaining how the Earth-Moon system formed, said Robin Canup, associate vice president of the SwRI Engineering and Science Division, in a communique.
The scientific community says that the Moon formed from a hot ring or disk of gas and material thrown out from the enormous impact that occurred between the Earth and another celestial body about as big as Mars some 4.5 billion years ago.
Until recently, some experts felt that the volatile elements vaporized in that impact could have escaped from the accreting Moon before it had fully formed.
