China's Chang'e 5 robotic craft has found evidence of water on the lunar surface, which has long been thought to be waterless.
The research team, led by Professors Lin Yangting and Lin Honglei from the Institute of Geology and Geophysics at the Chinese Academy of Sciences, found water marks on rocks that Chang'e 5 took from the moon's surface.
The findings, published in the journal Science Advances, also involved researchers from the National Space Science Center of CAS, the University of Hawaii, the Shanghai Institute of Technical Physics of CAS, and Nanjing University.
Chang'e 5 landed on a part of the moon covered in young basalt, sending rocks weighing 1,731 grams to Earth. Before being picked up and sent to Earth, the rocks were tested using the lunar mineralologic spectrometer (LMS) on board the robotic craft.
From the test results, it can be seen that there are traces of water in the rocks. Water (OH/H20) can be detected using a spectrometer at ~3 m. However, at 2 m, the emission of heat from the hot lunar layer would turn from masking the spectrometer's features.
As a result, the researchers used a thermal correction model to read the results of the spectrometer. The results of the analysis found that there was a standing water of 120 ppm where Chang'e landed.
As previously reported, Chang'e-5 was an unmanned mission that landed on the closest side of the Moon (the side facing Earth) in December 2020. The mission brought 1.7 kilograms of lunar rock to Earth. This is the first sample collected from the Moon since 1976 using the Soviet Union's Luna 24 mission.
The goal of the Chang'e-5 mission is to find evidence of some of the youngest volcanic eruptions on the Moon. Although scientists had previously been able to predict volcanic rock at this age on the Moon, by studying the number of impact craters on the lunar surface, it was still impossible to confirm this. without checking the sample.
Sample analysis was performed using a sensitive high-resolution ion microprobe (SHRIMP), at the SHRIMP Center in Beijing, China.
First, the material is sorted. The researchers manually selected several small fragments of basalt (volcanic rock), roughly 2 millimeters in size to investigate. Subsequently, laboratory analysis was carried out, building on techniques such as those developed in the 1970s for the analysis of the first Apollo samples.
