The most accepted theory about origin of the Moon is that of the giant impact. This hypothesis says that about 4.42 billion years ago, a species of protoplanet the size of Mars collided with the Earth with such impressive force that an enormous amount of our world was expelled, to generate what we know today as our natural satellite.
The composition of the Moon is similar to that of the Earth’s crust, suggesting that it formed from material from the Earth. So, until some stronger theory appears, we will continue to believe in that.
But as time progresses, some things in this theory may change. For example, the true age of the Moon. A recent NASA study, which cites The Spanishfinds that these events were recorded much earlier than previously thought.
The North American space agency indicates that using remains of lunar dust collected by the Apollo 17 mission in 1972, the data was analyzed and they found that this impact was generated 4.46 billion years ago, that is, 40 million years ago than previously thought.
“When matter was melted that way, zircon crystals could not form and survive. Therefore, any crystals found on the surface had to appear when this lunar magma ocean began to cool. Otherwise, they would have melted and their chemical signatures would have been erased,” explained Philipp Heck, a researcher at the University of Chicago and the Field Museum.
Based on this theory, scientists detail that the exact date of crystal formation is determined using something called atomic probe tomography technique.
“We started by sharpening a fragment of the lunar sample by focusing it with an ion beam microscope, until we achieved a very fine point, almost like a very fancy pencil sharpener. We then use ultraviolet rays to evaporate the atoms from the surface of the tip. These atoms will travel through a mass spectrometer. The speed at which they move will tell us what their weight is, and that will tell us in turn what they are made of,” the researchers said.
This is an impressive study that analyzes atom by atom, to be able to indicate how many suffered radioactive decay.