Chinese scientists used high-precision dating of lunar soil samples from the Chang’e VI mission to determine the first precise date of formation of the Apollo Basin on the Moon 4.16 billion years ago, the discovery provides key evidence that the moon was subjected to an“Impact storm,” a late heavy bombardment of the Solar System. The Chinese Academy of Sciences, led by Xu Yigang, an academician and researcher at the Chinese Academy of Sciences’ Guangzhou Institute of Geochemistry, was published in the international journal Nature Astronomy on Sunday.
The Moon’s surface is littered with giant impact basins, most of which are remnants of the impact of small bodies in the solar system some 3.8 billion years ago. Did this“Impact Storm” in the solar system suddenly increase in intensity or decrease in intensity some 3.8 billion to 4 billion years ago? There has been controversy in the scientific community.
“The controversy stems from the lack of accurate age data for the key impact basins on the moon,” Xu said, adding that the Apollo Basin, where Chang’e 6 was sampled, is located in the Moon’s South Pole, the Eite Ken Basin, it is the largest secondary impact structure in the region, and its formation age may mark the start time of Late Heavy bombardment events, thus becoming the key to solve the“Impact Storm” puzzle.
The team found three special rock fragments with a diameter of 150-350 microns in just 3.5 grams of lunar soil. These fragments are impact molten rock from the formation of the Apollo basin and are an ideal “Rock clock” to record impact events.
The team accurately dated the cuttings and combined remote sensing images with geochemistry data to determine that the 4.16 billion-year-old cuttings mark the age of the Apollo Basin. The study’s newly acquired age pushes the start of the heavy bombardment of the late moon back at least 100 million years, updating the start of the“Impact Storm,” The“Catastrophe theory” of lunar impact flux has been overturned, and the early dynamic evolution law has been revealed.
“The impact flux analysis in this study shows that the impact flux during the Late Heavy Bombardment of the Moon is decreasing gradually, and does not support the hypothesis of a 3.8-to-4-billion-year surge in the impact flux,” Xu said, the Chang’e 6 study will continue to drive a new understanding of the evolution of the earth-moon system.