<p>A violent, head-on collision between the Earth and a forming planet 4.5 billion years ago created the Moon, claim researchers from the University of California-Los Angeles (UCLA), suggesting that this massive crash likely resulted in bsimilar chemical composition of both the Earth and the Moon.<br /><br />Scientists know about this high-speed crash but many thought the Earth collided with the forming planet called "Theia" at an angle of 45 degrees or more -- a powerful side-swipe.<br /><br />In 2014, a team of German scientists reported that the moon also has its own unique ratio of oxygen isotopes, different from Earth's. The new research finds that is not the case.<br /><br />"We don't see any difference between the Earth's and the moon's oxygen isotopes; they're indistinguishable," said Edward Young, lead author and a UCLA professor of geochemistry and cosmochemistry.<br /><br />The researchers analysed seven rocks brought to the Earth from the moon by the Apollo 12, 15 and 17 missions, as well as six volcanic rocks from the Earth's mantle -- five from Hawaii and one from Arizona.<br /><br />The key to reconstructing the giant impact was a chemical signature revealed in the rocks' oxygen atoms.<br /><br />The team used state-of-the-art technology and techniques to make extraordinarily precise and careful measurements, and verified them with UCLA's new mass spectrometer.</p>.<p><br />"The fact that oxygen in rocks on the Earth and our moon share chemical signatures was very telling," Young said.<br /><br />Had the Earth and Theia collided in a glancing side blow, the vast majority of the moon would have been made mainly of "Theia" and the Earth and moon should have different oxygen isotopes.<br /><br />A head-on collision, however, likely would have resulted in similar chemical composition of both the Earth and the Moon.<br /><br />"Theia was thoroughly mixed into both the Earth and the Moon and evenly dispersed between them," Young said. <br /><br />"This explains why we don't see a different signature of Theia in the moon versus the Earth."</p>.<p><br />"Theia, which did not survive the collision (except that it now makes up large parts of the Earth and the moon) was growing and probably would have become a planet if the crash had not occurred," Young added.<br /><br />Young and some other scientists believe the planet was approximately the same size as the Earth; others believe it was smaller, perhaps more similar in size to Mars.<br /></p>
<p>A violent, head-on collision between the Earth and a forming planet 4.5 billion years ago created the Moon, claim researchers from the University of California-Los Angeles (UCLA), suggesting that this massive crash likely resulted in bsimilar chemical composition of both the Earth and the Moon.<br /><br />Scientists know about this high-speed crash but many thought the Earth collided with the forming planet called "Theia" at an angle of 45 degrees or more -- a powerful side-swipe.<br /><br />In 2014, a team of German scientists reported that the moon also has its own unique ratio of oxygen isotopes, different from Earth's. The new research finds that is not the case.<br /><br />"We don't see any difference between the Earth's and the moon's oxygen isotopes; they're indistinguishable," said Edward Young, lead author and a UCLA professor of geochemistry and cosmochemistry.<br /><br />The researchers analysed seven rocks brought to the Earth from the moon by the Apollo 12, 15 and 17 missions, as well as six volcanic rocks from the Earth's mantle -- five from Hawaii and one from Arizona.<br /><br />The key to reconstructing the giant impact was a chemical signature revealed in the rocks' oxygen atoms.<br /><br />The team used state-of-the-art technology and techniques to make extraordinarily precise and careful measurements, and verified them with UCLA's new mass spectrometer.</p>.<p><br />"The fact that oxygen in rocks on the Earth and our moon share chemical signatures was very telling," Young said.<br /><br />Had the Earth and Theia collided in a glancing side blow, the vast majority of the moon would have been made mainly of "Theia" and the Earth and moon should have different oxygen isotopes.<br /><br />A head-on collision, however, likely would have resulted in similar chemical composition of both the Earth and the Moon.<br /><br />"Theia was thoroughly mixed into both the Earth and the Moon and evenly dispersed between them," Young said. <br /><br />"This explains why we don't see a different signature of Theia in the moon versus the Earth."</p>.<p><br />"Theia, which did not survive the collision (except that it now makes up large parts of the Earth and the moon) was growing and probably would have become a planet if the crash had not occurred," Young added.<br /><br />Young and some other scientists believe the planet was approximately the same size as the Earth; others believe it was smaller, perhaps more similar in size to Mars.<br /></p>