Chinese researchers identify native lunar water in Chang'e-5 samples

Chinese researchers identify native lunar water in Chang’e-5 samples

A team of researchers with the Chinese Academy of Sciences (CAS) identifies domestic lunar water based on Chang’e-5 in situ spectral analysis and lab results from returned samples. The findings will be published in Nature Communications on June 14, 2022./ CAS

A team of researchers with the Chinese Academy of Sciences (CAS) identifies domestic lunar water based on Chang’e-5 in situ spectral analysis and lab results from returned samples. The findings will be published in Nature Communications on June 14, 2022./ CAS

An on-site discovery of China’s moon probe Chang’e-5 and the subsequent analysis of its returned samples revealed at least two water sources on the moon, one from the solar wind and the other from domestic sources.

The results were published in the journal Nature Communications on Tuesday.

Chang’e-5, consisting of an orbiter, a lander, an ascender and a returner, was launched in November 2020 and returned to Earth in December. It collected a total of 1,731 grams of lunar samples, mainly rocks and soil from the lunar surface.

Screenshot of the study from the website nature.com

Screenshot of the study from the website nature.com

Water detection

One of the probe’s scientific goals was to investigate the presence of lunar water, which is a key to the moon’s formation and development. It also provides significant information about the evolution of the solar system. The presence of water is expected to provide support for future human lunar resources on site.

But the sources of the moon’s water are still controversial. It has traditionally been assumed that the moon’s water was implanted by the solar wind or the result of a meteorite or comet. Minerals such as apatite that contain domestic water are also believed to be present in small amounts and unevenly distributed on the surface of the moon.

A group of researchers from the Chinese Academy of Sciences found new evidence for water on the moon’s surface based on Chang’e-5’s in situ spectral analysis and lab results from returned samples.

Their results revealed that the apatite found in the young large region where Chang’e-5 landed contained native water in the form of hydroxyl.

The Chang’e-5 landing site is located at one of the youngest extrusive lava flow areas on the moon, making apatite, the final state in the formation of these basalts, an ideal destination for searching for evidence of domestic water, according to the study.

Excess hydroxyl

Equipped with the Moon’s mineralogical spectrometer (LMS), the Chang’e-5 lander obtained spectral data for a rock and various lunar soil targets, and found that the hydroxyl content of the rock is much higher than that of the lunar earth.

The researchers said that there should be little or no foreign hydroxyl associated with impact craters or ejecta because Chang’e-5 saw at its landing site mainly local stoma material.

A subsequent laboratory analysis back on earth has shown that the returned stone fragments, with a significant amount of apatite grains, have a higher proportion of mineral content with much less glass content compared to Apollo samples.

The content of glass was considered a measure of the solar wind’s contribution to lunar water, and it is quite low in the Chang’e-5 sample, only about a third of that in the Apollo 11 sample, according to the study.

They then confirmed the presence of hydroxyl in the apatite grains.

In addition, the total hydroxyl content of lunar soil samples detected in situ is relatively low. But one of them marked 0012 stands out.

Excluding the domestic water in the mineral, the water content of Chang’e-5 soil samples should also be about one-third that of the Apollo 11 sample, according to the study. But sample 0012 shows a higher hydroxyl content than it should be.

It turns out that the researchers discovered the hydroxyapatite in the soil sample, which strongly suggests that the hydroxyl-containing apatite is likely to be an important source of the excess hydroxyl observed.

Source (s): Xinhua News Agency

#Chinese #researchers #identify #native #lunar #water #Change5 #samples

Leave a Comment

Your email address will not be published.