China’s Chang’e 5 confirms the presence of water on the lunar surface

China's lunar lander Chang'e 5 has successfully confirmed the presence of water on the lunar surface in real time for the first time. India's Chandrayaan-1 was the first mission to detect lunar water in 2008. However, its findings were not shared in real time, but were published later in September 2009. Other missions have also mapped water on the lunar surface from orbit. However, until Chang'e 5, no mission has been able to confirm the presence of water in real time.

Now, the lander has found water — which translates as “sea of ​​storms” — an ancient Mare basalt at a landing site close to the moon's ocean. In 2020, Chang'e 5 sent a field-clear signal through airborne spectroscopic analysis, confirming moisture in basalt rocks and soil. The discovery was then verified in 2021 by laboratory analysis of samples brought by Chang'e 5.

The results of the study have now been published in Nature Communications.

“For the first time in the world, laboratory analysis of lunar return samples and spectroscopic data from in situ lunar surface surveys have been combined to examine the presence, form and quantity of ‘water' in lunar samples,” said co – national Astronomical Observatory of the Chinese Academy of Sciences (NAOC) ) author Li Chunlai.

Chang'e-5 detected about 30 parts per million of hydroxyl groups in soil and rocks on the lunar surface, the report said. Hydroxy groups contain one hydrogen and one oxygen atom, which are the main components of water. Also, it is the most common result of water reacting with other substances. Hydroxyl was first detected in 11 rock and soil samples by the Lunar Mineral Spectrometer and confirmed by five multipart laboratory analyses of 8 of the samples.

The samples were collected when the moon was hot, reaching 200 degrees Fahrenheit, and the surface was driest. This is also a period of low solar wind, which can lead to hydration at high enough power.

The hydroxyl groups collected by Chang'e 5 are mainly contained in a phosphate-rich crystalline mineral called apatite, which occurs naturally on the Moon and earth. “These excess hydroxyl groups are naturally occurring, indicating the presence of lunar-origin interior water in the Chang'e-5 lunar samples, which played an important role in the formation and crystallization of late lunar basaltic magmas,” Li said.

Li added that investigating lunar water and its sources will help unearth information about the formation and evolution of the moon and the solar system.