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As Chinese scientists analyzed the soil samples brought back from the moon by their lunar probe, they realized something new: Water was found along with minerals in the soil.
Finding water on the moon alone is nothing new. NASA and Indian spacecraft have seen what they believe to be water on the surface of the moon, and Chinese scientists last year found water trapped in glass beads scattered across the moon.
But this latest discovery, according to scientists, is the first time water has been found in its molecular form, H2O, in physical samples – and, more importantly, it was found from a part of the moon where they thought water existed in that form. before this. could not be there.
Researchers closely examined samples collected by China’s Chang’e-5 probe, which landed on the moon’s surface in 2020, and found “transparent plate-like prismatic crystals” – about the width of a human hair – that were actually “an unknown lunar mineral” called ULM-1, according to the study, published July 16 in the journal Nature Astronomy.
The ULM-1 crystal (with the chemical formula (NH4)MgCl3·6H2O) is made up of about 41% water, with bits of ammonia that keep the H2O molecules stable despite wild temperature swings on the moon, according to the study.
This type of water could be a “lunar habitable resource,” the scientists wrote in their study.
The discovery is the latest result of China’s growing push to become a dominant space power – with big ambitions to build a research base on the moon. Chinese social media users praised the study, which highlighted the space program as a matter of national pride.
“The discovery of hydrated minerals at the Chang’e-5 landing site is extremely interesting and will improve our understanding of rock vapor reactions in the lunar crust and lunar surface,” said David A. Kring, chief scientist at the Center. Lunar and Planetary Institute in Texas, who were not involved in the study.
Difficult to remove
There are three types of water that can exist on the moon, according to Yuqi Qian, a planetary geologist at the University of Hong Kong, who was not involved in the study.
It contains water molecules, the compound known as H2O; its frozen form, ice; and a molecular compound called hydroxyl, a close chemical relative.
Previous discoveries have indicated that there was water on the moon when volcanoes erupted in the past – and that moonwater came from those volcanoes, meaning that it came from the moon and has been there since the moon was there early.
But people didn’t always know there was water on the moon, even though scientists have had theories about its existence for centuries. Researchers sometimes believed that the moon was dry, especially after initially finding no water in the samples collected by NASA’s Apollo missions and the Soviet Union’s Luna missions.
It is only in recent years that scientists have discovered water, ice and mostly water molecules at the dark and cold lunar poles where the sun does not reach. A recent study also suggested that water or hydroxyl may be trapped in glass beads scattered across the lunar surface, and that solar winds may change hydroxyl (chemical formula OH) to form water, or H2O.
But the lunar poles are difficult to navigate because of the rocky terrain, making them challenging sites for humans to extract water from. And the molecular water is “not stable in other regions of the moon,” evaporating at lower latitudes where temperatures can exceed 100 degrees Celsius (212 Fahrenheit), Qian said.
This new study changes that.
The samples, retrieved by China’s Chang’e-5 probe, came from the mid-latitude part of the moon, at 43.1 degrees latitude — an area that is “normally not stable for molecular water,” Qian said. Ammonium was found in the samples, which acted as a stabilizer for the water molecules, he explained.
This mechanism also corroborates NASA’s results from 2020, when its SOFIA telescope detected a signature of water on the moon’s surface – although scientists could not verify this result with physical samples at the time, or explain exactly how the t -water staying on the hot surface.
“I think there are a lot of possibilities, with this new finding that we can extract molecular water directly from lunar soils,” Qian said. “I think this is a new mechanism for making molecular water stable on the surface of the moon.”
Kring, of the Lunar and Planetary Institute, said that although the sample was collected from a mid-latitude area, “it was not clear whether it was created there. Impact processes can redistribute rock across the lunar surface.”
China’s space ambitions
A growing number of countries, including the United States, are looking at the strategic and scientific benefits of increased lunar exploration.
China has made rapid progress in recent years, reflecting leader Xi Jinping’s “eternal dream” of building the country into a space power.
In 2013, China became the first country to achieve a robotic lunar landing in nearly four decades. Then in 2019, it became the first and only country to land on the side of the moon. Three years later, China completed its latest orbital space station, the Tiangong.
And he has more planned, aiming to land astronauts on the moon by 2030 and build a research base at the south pole.
Understanding how water is stored on the moon is useful, experts previously told CNN, because it could point future lunar astronauts to potential resources that could one day be converted into drinking water or even rocket fuel.
After the latest study, many Weibo users raised the possibility of growing plants or crops on the moon using the molecular water found in the soil. But, Qian said, it is too early to draw these kinds of conclusions. Any growth on the moon would depend on factors such as how abundant water is – something that requires more research to confirm.
However, he said, “this new phenomenon, this new mechanism … will open the door to (finding) new water in this new form.”
Kring similarly cautioned that “the results so far have no significant implications for exploration mission architectures, although it does show that discoveries await those willing and able to explore the Moon.”
China’s rapid progress has caught NASA’s attention. The space agency has not been allowed to work with its Chinese counterparts since 2011, when Congress passed the Wolf Amendment citing espionage concerns.
But last August, China opened access to the Chang’e-5 samples to the international community.
“We are currently going through the process with our scientists and our lawyers to make sure that the directives and safeguards that the Chinese are demanding do not violate the law, the Wolf Amendment,” said NASA Administrator Bill Nelson with CNN recently. . “As of this moment, I don’t see a violation.”
But such issues have left China barred from the International Space Station (ISS), prompting its efforts to build the Tiangong – which has become a US competitor, especially as the ISS prepares to go retired in 2031.
These limitations on its international space cooperation, and the rise of China itself, have some Chinese social media users feeling vindicated by the latest discovery – with online comments and state media coverage suggesting a move to heads of the national space program.
“This is a demonstration of the scientific and technological strength of our country!” one user posted on Chinese social media site Weibo, where a hashtag about the discovery has been viewed 35 million times.
Another user thanked the country’s space program, writing: “We are a world leader in lunar scientific research.”
Others on Weibo suggested better cooperation for the benefit of humanity, pointing out that the study was published in an international journal peer-reviewed by experts from different nations.
“We cannot work behind closed doors – it would be better to lure all their scientists to China,” wrote one.
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