Summary of the United States on Chang'e-6 of China!

Four discoveries explain why the far side of the Moon is so strange.

On July 15, the U.S. publication "Space News" published an article by expert Keith Cooper.

The samples brought back by Chang'e 6 from the far side of the Moon recorded ancient volcanic activity, the magnetic field of the Earth, and the lack of important elements and a dry mantle.

The samples returned by the Chinese Chang'e-6 mission from the South Pole-Aitken (SPA) basin have brought new discoveries, bringing us closer to solving the origin of the strange differences between the near and far sides of the Moon.

The near side of the Moon is familiar to us because it is the only side we can see from Earth.

Although we have many samples from the near side of the Moon, we do not have samples from the far side to test theories.

Then, in June 2024, China's Chang'e 6 mission landed in the SPA basin and brought back a total of 1,935.3 grams of samples.

This provides a unique opportunity to develop models that can explain the differences between the two hemispheres of the Moon.

Therefore, after analyzing the samples, the team from the Chinese Academy of Sciences announced four findings.

The first is that these samples contain basaltic volcanic rocks, which come from two different periods of volcanic eruptions on the far side of the Moon, one about 4.2 billion years ago, and the other about 2.8 billion years ago.

The evolution of the lunar magma ocean is key to forming the lunar mantle, and it is the center of the next discovery.

The second is that geochemical analysis of the rock samples shows that the lunar mantle is a source deep below the lunar surface, especially elements such as thorium are severely depleted.

It is unknown whether this depleted mantle exists only beneath the SPA basin or is more widely present throughout the entire Moon.

"Honestly, we don't know," said Yang.

To find out, we need to collect more samples from the far side of the Moon, especially from areas outside the SPA.

The third finding is our unexpected discovery on the Moon: water.

However, what we're talking about is a content of one part per million - Apollo samples are considered "dry," and the mantle of the far side of the Moon seems to be even drier.

"The water content of this mantle is lower than that of all basalts on the near side of the Moon," said Yang.

The fourth discovery is related to the Moon's magnetic field. The Earth's natural satellite currently does not have a global magnetic field, but retains magnetic traces in some anomalous regions known as lunar swirls.

However, in the distant past, it did have a global magnetic field.

The Moon's magnetic field was restored 2.8 billion years ago, perhaps when the outer core of the Moon had started convection and upwelling of hot material.

Not only could this trigger volcanic eruptions, but the upward-moving material may have been sufficient to vaporize most of the water in the mantle, making the mantle dry.

If the formation of the SPA basin was the main cause of all this, then its impact goes far beyond the Moon.

Larger impact features have also been seen on other celestial bodies, particularly Mercury and Mars.

We may have underestimated the role of these large impacts in planetary internal evolution.

The research results of Chang'e 6 were divided into four papers and recently published in the journal Nature.

Original: https://www.toutiao.com/article/1837843440374792/

Statement: This article represents the views of the author.