A Chinese lunar rover makes an unexpected discovery on the other side of the moon

As the first mission to successfully land on the other side of the moonChinese Chang & # 39; e 4 was almost expected to make enchanting discoveries. The analysis of the lunar crust, however, found that the mission was also unexpected.

In a study published in the journal Nature on May 16, scientists from the National Astronomical Observatory of the Chinese Academy of Sciences revealed that the composition of the lunar surface of the South-Aitken Pole Basin was slightly different from what they expected.

A fundamental theory postulates that the moon was not as cold and dead as today. Instead, it probably started as a giant, molten marble covered with magmatic oceans. These oceans have gradually cooled, depositing heavy minerals such as green olivine or low calcium pyroxene deeper into the lunar mantle. Less dense minerals floated upward, giving the moon a series of obvious geological layers like a cosmic onion. The crust, the highest layer, is composed mainly of aluminum silicate or plagioclase.

"Understanding the composition of the lunar mantle is essential to verify whether an ocean of magma has ever existed, as supposed," said co-author Li Chunlai in a press release. "It also helps us better understand the thermal and magmatic evolution of the moon."

Understanding the composition of the mantle gives planetary scientists a clearer idea of ​​how the interiors of other planetary bodies, including the Earth, might evolve.

The LG Chang & # 39; e 4 landed originally in the crater Von Kármán, which rests on the ground of the South Pole-Aitken Basin in January. The lander then sent a rover, Yutu-2, equipped with a spectrometer that measures reflected light. By studying the light reflected from the surface as the rover rolled along Von Kármán, scientists were able to detect minerals and determine their chemical composition. Rather than seeing a lot of plagioclase, the robot detects a dominance of olivine and pyroxene.

As these elements are expected much deeper into the mantle, the authors suggest that they were ejected from an impact event caused by a meteor striking the lunar surface. The rover explores nearly 72 km of crater Finsen. It is possible that the minerals were sprayed on the surface during the creation of this crater.

Although NASA's Apollo missions landed humans on the moon and Russia made concerted efforts to recover lunar samples in the 1970s, no studies of the lunar mantle had yet been conducted. This makes the mission of China particularly important, but due to the complexity of studying the moon's minerals on a planetary body located hundreds of thousands of kilometers away, it will be necessary to continue the work to better understand the coat composition.