Researchers from Tohoku University found that the moon rock was primarily composed of moganite, which is a mineral that cannot form without the presence of water. This discovery is huge since it is the first time that moganite has ever been detected in a moon rock.
"Moganite is a crystal of silicon dioxide and is similar to quartz. It forms on Earth as a precipitate when alkaline water including SiO2 is evaporated under high-pressure conditions," said lead researcher Masahiro Kayama. "The existence of moganite strongly implies that there is water activity on the Moon."
For ages, researchers had held the belief that the moon doesn't contain any water at all. While this may be true for its surface, several studies have suggested that there is actually ice hidden somewhere in the moon's crust. So far, no researchers have ever managed to pinpoint its location, which is why the discovery of moganite in this asteroid is so exciting for the scientific community since it proves that ice is present at mid and lower lunar latitudes.
Using electron microscopy, the scientists closely inspected the chemical makeup of 13 different lunar meteorites, which were all recovered from the same African desert. They then used a technique called micro-Raman spectroscopy to identify particular mineral structures within each meteorite. Curiously, moganite was only found in one of the samples, which indicates that it could not have formed after landing on Earth.
According to Kayama, "if terrestrial weathering had produced moganite in the lunar meteorite, there should be moganite present in all the samples that fell to Earth around the same time. But this was not the case."
The team of scientists believes that the moganite was formed through evaporated water on the Moon's surface, in an area known as the Procellarum Terrane, which frequently receives strong and direct sunlight.
"For the first time, we can prove that there is water ice in the lunar material," Kayama said. "In a moganite, there is less water, because moganite forms from the evaporation of water. That's the case on the surface of the moon. But in the subsurface, much water remains as ice, because it's protected from the sunlight."
The scientists have estimated the water on the moon is roughly 0.6 weight percent. This means that future explorers should be able to extract around 6 liters per cubic meter of moon rock (roughly 1.6 gallons of water per 36 cubic feet). If this estimate turns out to be accurate, this would mean that future colonies on the moon would have more than enough water to keep them going for a very long time.
This study's biggest drawback is that the findings cannot be confirmed until further samples are retrieved from the moon itself. Thankfully, there are already a handful of lunar missions in the pipeline, and Japan's Aerospace Exploration Agency has promised to carry out two expeditions, one to search for additional sources of water, and another to bring back additional samples.
In the meantime, the team is now focusing on water that forms from volcanoes and solar wind - two distinct ways that water could have appeared on the moon. "Solar wind-induced water can give us new insight into the history of Sun activity, and volcanic water provides us with information of lunar evolution together with water," said Kayama.
Once again, all we can do is sit back and wait for further developments.