The huge reserves of water recently found on the Moon could have accumulated on its surface in the first moments of the life of the Earth's companion, when it still had its own atmosphere, geologists say in an article published in the journal EPS Letters.
“At the time the lunar basalts began to form, they threw out about the same amount of water into the moon's atmosphere as any large lake on the Earth's surface contains. Most of this water escaped into space, but even if only 0.1 percent of it remained in the soil, this is enough to explain the origin of all the water reserves at the poles of the moon, - said Debra Needham of the NASA Marshall Space Flight Center. (USA).
It is believed that the Moon was formed as a result of the collision of Theia, a protoplanetary body, with the "embryo" of the Earth. The collision led to the ejection of the matter of Theia and the proto-Earth into space, from which the Moon was "molded". This cataclysm was considered the reason why its bowels and surface are practically devoid of water. This hypothesis was challenged in February 2012 when scientists discovered an unexpectedly high concentration of water in lunar igneous rocks.
There are two major controversies - where this water came from and where it is hiding. Some astronomers assume that comets were the main source of water, while others attribute this role to asteroids, and there is evidence in favor of either theory.
In addition, scientists recently found large deposits of water on almost the entire surface of the Moon, which made these spores even hotter, and the reason for the appearance of water even more mysterious. Needham and her colleague David Kring of the Institute for the Study of the Moon and Planets in Tucson (USA) found the answer to this question by studying what happened in the bowels of the young Earth companion immediately after its formation.
Researchers carried out similar calculations based on samples of the lunar igneous rocks, delivered to Earth by the Apollo 15 and Apollo 17 expeditions. These data, as well as a detailed computer model of the bowels of the newborn satellite of the Earth, helped American geologists to find out that in the first moments of its life the Moon was covered with a kind of atmosphere, consisting of water vapor, hydrogen, carbon dioxide and a number of other gases.
The source of this atmosphere was the future "seas" of the Moon, which arose during the outpouring of basaltic magma onto its surface. In total, they emitted about 20 trillion tons of carbon dioxide and 260 billion tons of water, which would be enough to fill several lakes or rivers and form an atmosphere similar in density and properties to the air shell of Mars.
This atmosphere, as the calculations of scientists show, should have existed for a rather long time, about 70 million years, during which part of these reserves of water and carbon dioxide could settle in dark craters at the poles, where it was relatively cold and dark compared to the zones of volcanism in the equatorial and temperate latitudes of the moon.
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Even if a similar fate befell a vanishingly small fraction of the water contained in the moon's atmosphere - less than one percent or even 0.1 percent, these ice reserves, according to the researchers, will be quite enough to explain the data obtained by the LRO and "Chandrayan-1" in the study of craters and subpolar plains of the Moon.