The Earth’s moon was formed thanks to a violent collision about 4.5 billion years ago. The collision, between Earth and Theia, a planet that was estimated to be between the size of Mars and the size of Earth. A new report put out by Edward Young, a geologist who works at UCLA says he found evidence of this collision by looking at lunar rocks that were actually found here on our planet. This report is actually further evidence to back up earlier assertions that the collision between Theia and the Earth are how our moon was formed.
The study takes into account that there are lunar rocks, procured from various Apollo landings have the same kind isotopes as those found in rocks on the Earth. Scientists say the mixing required in order to have these kind of identical isotopes was likely done thanks to the collision which formed the moon. It should be pointed out that the Earth itself was largely molten that far back in the Universe’s history and there were not yet anything close to what we would have considered life on the planet.
One of the interesting aspects of this report is this collision between Earth and Theia wasn’t a glancing blow but had apparently had to be a head-on collision. Researchers say that if the collision had in fact been a glancing blow the oxygen isotope signatures of the rocks they studied would have been slightly different. Because they are identical this type of crash is the best explanation.
The collision forced Theia to partially incorporate into the Earth while other portions of that planet became the moon. The study was partially funded by NASA and was carried out using some new high tech equipment that is housed at UCLA. In particular, a brand new mass spectrometer was used when looking at the various lunar rocks.