Research by scientists at the German Aerospace Center (DLR) and University of Mnster, also in Germany, indicates that the Moon may be much younger than we think, and that its origin coincides with a crucial event in the formation of our planet.
The most accepted theory for the formation of the Moon is that it results from the collision of our planet, still in formation, with another celestial body the size of Mars, called Theia. The moon would have been created by consolidating the debris ejected during the collision.
There are several issues that are not explained by this theory, such as the difference in the amount of metal between the surfaces of the Earth and the Moon. One point of discretion when this primary impact happened, with the prevailing opinion being that it was 4.51 million years ago. years.
But a new model developed by German scientists suggests that this impact occurred much later, 4.425 billion years ago, with a margin of error of 25 million years more or less. That is, a difference of 85 million years.
“The results of our most recent models suggest that a young Earth was hit by a protoplanet about 140 million years after the birth of the solar system. According to our calculations, this happened 4.425 billion years ago, with an uncertainty of 25 millions of years “.
“Earthrise”, photo showing the Earth rising over the lunar surface, taken by the Apollo 8 crew in 1968. Photo: Nasa
During the formation of the Moon, the energy gained as material was added caused it to be covered by an ocean of magma up to 1,000 km deep. Over time this magma crystallized and solidified, and until now scientists have been unable to determine how long it took. Therefore, they could not accurately determine the age of the Moon.
To find out how long this ocean of magma lasted, scientists used a new computer model that, for the first time, considered all the processes involved in the solidification of magma. “The results of this model show that the magma ocean on the Moon was long-lived, and took almost 200 million years to completely solidify into rock,” says Maxime Maurice, a PhD student at DLR who led the study.
“This time scale is much longer than that calculated in previous studies, says Nicola Tosi, according to the study’s author and advisor to Maurice’s PhD thesis.” Previous models showed a solidification period of only 35 million years. “
The calculated age, 4.425 billion years, coincides with the period of the formation of the metallic nucleus of the Earth, an event that completed the emergence of our planet. “This is the first time that the age of the Moon can be directly linked to an event that occurred at the end of the formation of the Earth, the formation of the nucleus,” says Throsten Kleine, of the Institute of Planetology at the University of Mnster.