For over a century, scientists have been arguing about how the Moon Month has formed. But scientists from Yale and Japan say they may have an answer.
Many theorists believe that the Mars-sized object crashed into the early Earth, and the material extracted from this collision formed the basis of the Moon. When this idea was tested in computer simulations, it turned out that the Moon would be created primarily from the incident object. But the opposite is true; We know that from the analysis of rocks brought from Apollo missions, the Moon is mainly made of Earth material.
A new study published on April 29 in Nature Geoscience, co-author of the geophysical Yale Shun-ichiro Karato, offers explanations.
The key is, as Karato says, that early, proto-Earth – about 50 million years after the creation of the Sun – was covered by the sea of hot magma, while the incident object was probably made of solid material. Karato and his co-workers decided to test a new model based on a proto-Earth collision covered with magma ocean and a solid incident object.
The model showed that after the collision, the magma heats much more than the solids from the incident object. Magma then spreads and goes in orbit to create a moon, scientists say. This explains why there is much more Earth material in the Moon's makeup. Previous models did not take into account the different degree of heating between silicate and earth silicate.
"In our model, about 80% of the month is made of proto-Earth materials," Karato said, conducting extensive research on the chemical properties of proto-Earth's magma. “In most previous models, about 80% of the moon is made of the impactor. That is a big difference. "
Karato said the new model confirms previous theories about how the moon was shaped without the need to design unconventional conflict conditions – something that theorists have to do so far.
For the Karato study, research led to the compression of molten silicate. The Tokyo Institute of Technology and RIKEN Center for Computational Science have developed a computational model that predicts how material from the collision has become a moon.
The first author of the study is Natsuki Hosono from RIKEN. Other co-authors are Junichiro Makino and Takayuki Saitoh.
Publications: Natsuki Hosono et al., "The Earth's Magmatic Origin of the Moon", Nature Geoscience (2019)