Researchers believe they have found evidence that a world collided with the Earth billions of years ago to form the moon. Recent analysis of lunar rock brought back by Apollo astronauts decades ago show traces of the “planet” called Thea.
This discovery supports the theory that the Moon was created by a massive collision between Earth and Theia. This has been the accepted theory since the 1980s.
The lack of any evidence of Thea in lunar rock samples has been the main sticking point for this theory.
Early analysis of lunar rock samples showed Moon rock originated entirely from the Earth.
“It was getting to the stage where some people were suggesting that the collision had not taken place,” he told BBC News.
“But we have now discovered small differences between the Earth and the Moon. This confirms the giant impact hypothesis.”
What are these differences? Researchers measured the isotopic composition of the oxygen contained in rocks on Earth and Moon rock.
According to the results, the Moon consists of 50% Thea and 50% Earth. The scientists have said more work is needed to confirm the results, though.
Not all scientists are quick to cheer today’s news. This is the first report ever to claim a difference in oxygen isotopes.
It would be handy to have more recent lunar samples, but we aren’t planning on going back to the Moon anytime soon. Drill cores of lunar rock would give us a better understanding of the Moon’s compositions. There are too many variables that could affect surface rock such as meteor impacts.
Today’s report supports the giant impact theory, but more work needs to be done before it’s a slam dunk.