There is evidence of OH on the Moon. H2O is a chemical cousin of Hydroxyl. OH has been detected on the Moon before, but this is the first time it has been detected by a mission on the lunar surface.
The sample return mission brought a sample of lunar regolith back to Earth in December of 2020. The Chang'e-5 landers used instruments on board to look at the area around the landing site. Scientists were able to use data from a panoramic camera, lunar mineralogical spectrometer, and lunar penetrating radar to look for evidence of water.
The rock near the landing site contained the most hydroxyl, almost twice as much as the surrounding regolith. The regolith has less water than the rock.
There are images and water at the landing site. LIN Honglei has the image.
The team wrote in their paper that the spectrum of CE5-Rock exhibits a strong absorption of water's signature because of OH/H2O. Most of the lunar regolith at the landing site have no absorptions at all.
A group of scientists from around the world published a paper in the journal Science Advances.
Water was first detected on the Moon in 2009. In September of that year, scientists from three different space missions announced they had detected widespread water on the Moon. In November of 2009, the LCROSS science team held a press briefing to announce they had detected buckets of water inside the crater, where the LCROSS impactor blasted material from inside.
The water on the Moon arrives through a process called solar wind implantation, which is largely accepted by the scientific community. The hydrogen atoms on the lunar surface are formed by the charged particles from the sun. The LCROSS discovery could mean underground water ice, since the process of creating water molecule that exist diffusely in low concentrations across the Moon creates water molecule that are hydroxyl or water molecule.
The scientists think the lunar rock with a higher water content could have been blasted from under the Moon.
According to a press release from the Chinese Academy of Sciences, the rock may have been excavated from an older basaltic unit and ejected to the landing site of Chang'e-5. The lower water content of the soil, as compared to the higher water content of the rock fragment, suggests that degassing of the mantle reservoir beneath the Chang'E-5 landing site took place.
This finding will help the team in their studies of the Chang'e-5 returned samples.
Chang'e-5's sample return capsule sits amidst the snows of Inner Mongolia with a Chinese flag nearby. The image was taken via the CCTV.