Crash between Earth and forming planet gave birth to Moon

Washington: 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 similar chemical composition of both the Earth and the Moon.

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. 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.

"We don't see any difference between the Earth's and the moon's oxygen isotopes; they're indistinguishable," said Edward Young, lead author. 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.

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.