For decades, scientists have hypothesized that Earth’s moon was formed more than 4.5 billion years ago by a collision between Earth and an ancient planet known as Theia. There was very little evidence to back up the theory, but now a group of scientists from Germany’s University of Georg-August-Universität Göttingen believe they have cracked the case and now have enough evidence to support the hypothesis.
The scientists aren’t necessarily working from any new collections from the moon’s surface. In fact the rock samples used come from the various Apollo missions that took place more than 4o years ago.
According to Daniel Herwartz, who led the group of scientists, a new technique was used that detected a minor chemical difference between moon rocks and Earth rocks, leading them to believe that another planetary body played a role in its formation.
While it isn’t fully confirmed, Herwartz is led to believe that Theia is responsible for about half of the moon’s rocky composition. This contrasts the previous theories that it may be either 8 percent or a much higher 90 percent.
The differences between the two planets are still hard to detect, but the group of German scientists are certain that their evidence clearly supports the Theia theory. “This means two things: Firstly, we can now be reasonably sure that the giant collision took place. Secondly, it gives us an idea of the geochemistry of Theia. Theia seems to have been similar to what we call E-type chondrites. If this is true, we can now predict the geochemical and isotopic composition of the Moon because the present Moon is a mixture of Theia and early Earth,” Herwartz stated in a statement.