The Chinese mission is revealing new clues to the Moon's ancient past

The dusty surface of the Moon, immortalized in the images of the Apollo astronauts' lunar footprints, was formed as a result of asteroid impacts and the harsh environment of space that crumbles rock over millions of years. An ancient layer of this material, covered by periodic lava flows and now buried beneath the lunar surface, could provide new insight into the Moon's deep past, according to a team of scientists.

“Using careful processing of data, we found interesting new evidence that this buried layer, called paleoregolalite, may be much thicker than previously predicted, ”said Tieyuan Zhu, assistant professor of geophysics at Penn State. "These layers have been undisturbed since their formation and could be important records for determining the early impact of asteroids and the volcanic history of the moon."

Researchers have identified a thick layer of paleoregolite, about 5 -9 meters, sandwiched between two layers of lava rock which are believed to be 2.3 and 3.6 billion years old. The results suggest that palaeoregolite formed much faster than previous estimates of about 2 meters per billion years, according to the scientists.

Photo: depositphotos

The moon has experienced volcanic activity throughout its history, depositing lava rock on the surface. Over time, the rock turned into dust and soil, called regolith, with repeated asteroid impacts and space weather, only to be buried by successive lava flows. Previous studies have looked at the dataset, created when the Yutu rover sent electromagnetic pulses into the lunar subsurface and then examined the echoes. Zhu explained that his team developed a four-step data processing stream to enhance the signal and suppress noise in the data. Scientists observed polarity changes as electromagnetic pulses traveled downward through dense lava rock and paleoregolite, allowing the team to distinguish between the different layers. According to the team, the findings could indicate increased meteoric activity in the solar system billions of years ago, reporting their recent findings in the journal Geophysical Research Letters.

Zhu explained that these same data processing tools could be used to interpret similar data obtained during future missions to the Moon, Mars or elsewhere in the solar system. Her team is now working with machine learning technology to further improve outcomes.