As a result, mineral particles were found in the lunar soil, the very presence of which made it possible to reveal the long-standing mystery of the mysterious magnetic anomalies of the Moon.
The study is published in the journal Nature Communications, and a brief report on it can be found on the Science Alert resource. The study was carried out by a team led by geologist Zhuang Guo from the Institute of Geochemistry of the Chinese Academy of Sciences.
She analyzed regolith samples that were brought to Earth from the Moon by China’s Chang’e-5 probe in December 2020. In it, scientists found numerous particles of a mineral known as magnetite. Until now, it was thought to be very rare in lunar soil samples.
The presence of this mineral in the regolith allowed researchers to find the key to solving a long-standing mystery. For more than half a century, scientists could not reliably explain the nature of the mysterious magnetic anomalies that were recorded in the lunar crust.
The new study has provided a better understanding of the formation and distribution of magnetite on the Moon. This mechanism provided a rather simple explanation for the nature of magnetic anomalies.
The researchers explain that magnetite is essentially a highly magnetized iron ore. In this case, it was found in submicroscopic spherical grains of iron sulfide. They look like melted drops. This suggests that these drops were formed as a result of powerful impacts on the lunar surface.
As a result, scientists came to the conclusion that magnetite was formed during the bombardment of the moon by asteroids.
Previously, as part of other studies, it was found that in its early stages of existence, the Moon was regularly hit by cosmic bodies. This means that magnetite could be widely distributed in the thin layer of regolith that covers the lunar surface.
The researchers laid the data obtained in the basis of a computer model. The simulations performed showed that the lunar regolith is extremely reduced, that is, it is saturated with electrons due to the influence of the solar wind.
This condition makes it difficult for iron to combine with oxygen to form ores. In this respect, the Moon differs markedly from the Earth.
Our planet is protected from the powerful effects of the solar wind by the atmosphere. As a result, the earth’s soil does not suffer from an excess of electrons, which contributes to the appearance of iron ore.
On the Moon, a new study has shown, tiny grains of magnetite were formed under the conditions of high pressure and high temperature that are possible when hitting the surface.
During such impacts, a phase reaction occurred, when the regolith melted, turned into a gaseous mixture, which mixed with the molten particles of the asteroid.
Then all this settled on the surface and froze. Magnetite was distributed over the surface in the impact zones. Its presence in the regolith explains the mysterious magnetic anomalies of the lunar crust in certain places.
As the researchers write, “The fury of these collisions could have turned the materials into submicroscopic magnetite, making them an important source of ferromagnetic material on the lunar surface.”
In other words, magnetic anomalies occur where the most powerful impacts of asteroids on the lunar surface occurred in ancient times.
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