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Itongadol.- New research by an Israeli-French team marks another small step for mankind, advancing the theory that the moon was formed from a collision between Earth and a massive object of similar composition.
The research helps explain why rocks from the Earth and moon are of almost identical make-up, unlike the other planets of the solar system.
Scientists from the Technion and the University of Bordeaux carried out a modeling study that simulated the conditions of the formation of the early solar system, when the proto-Earth would have been battered by numerous collisions with other would-be planets. The debris from one such major collision is believed to have formed the moon.
Previously, it had been widely thought that the lighter body in that moon-forming collision was very different in composition from the Earth. The new research indicates that it was not.
“If the impactor had a different composition from the Earth, we should expect the Moon to have a different composition,” one of the study’s authors, The Technion’s Dr. Hagai Perets, told the Nature podcast. In fact, however, “They are almost identical.”
Hence, the scientists explained, the relatively small differences between rocks on Earth and on the moon.
“In terms of composition, the Earth and moon are almost twins, their compositions differing by at most few parts in a million,” the study’s lead author, Technion astrophysicist Alessandra Mastrobuono-Battisti told Space.com.
“The most exciting and surprising thing was to find out that we can shed new light on a 30-year-old mystery,” added Perets, also an astrophysicist. “Compositionally similar planet-impactor pairs are not rare at all.”
Earth is believed to have come into being about 4.5 billion years ago, and the moon soon after.
“This finding suggests that the similar compositions of the Earth and moon could be a natural consequence of a giant impact,” Space.com reported. “This theory also explains why their compositions differ from that of other bodies in the solar system, the researchers say.”
Along with colleague Sean Raymond, of the University of Bordeaux, the two Technion scientists detailed their findings in the April 9 issue of Nature.