According to some theories, many billions of years ago, cosmic body the size of Mars (some sources indicated as "Tay") etched in our young planet and only a miracle it did not destroy. Earth survived this collision, but the fragments formed upon impact formed the Moon - natural satellite of our planet. And despite the fact that this encounter happened long ago, astronomers believe they have finally found traces of evidence once existed "Thea" in lunar samples brought back to Earth within the space missions "Apollo."
Discovered isotopes, or oxygen bonds, which scientists have studied within the last survey were not like anything on earth nor the moon, that would speak in favor of the fact that the formation of the Moon could participate another cosmic body.
"If the moon was formed from the wreckage of Thea, as suggested by the majority of modern mathematical models, the Earth and Moon must differ in their composition," - says a study.
To confirm their guesses researchers conducted a study of lunar samples collected during the execution of missions "Apollo 11", "Apollo-12" and "Apollo 16" with an electron microscope, which, of course, much more powerful than those that were available in 1960s and 1970s of the last century.
In those days the power and resolution microscopes can not detect any differences, but a new study of lunar rocks showed that in 12 cases per million they have more oxygen-17 than terrestrial rocks.
"This difference is very small and difficult to detect, but it is," - says the study's lead author Daniel Hervarts of the University of Cologne.
"It can mean two things: first, we can say with some certainty say that the collision between the Earth and other space body really took place to be; and secondly, it gives us an opportunity to look at the geochemistry of Thea."
Full results of this study were published in the latest issue of the authoritative scientific journal Science, and will be presented at the conference, which will be held in California (USA) on June 11.