Recently, a research team in our country conducted high-precision geochronological studies on the lunar soil samples from Chang'e-6 and for the first time accurately determined that the Apollo Basin on the Moon was formed 4.16 billion years ago. This discovery precisely limited the time of the basin's formation, pushing back the starting point of the "impact storm" on the Moon by at least 1 billion years, which helps promote a new understanding of the evolution of the Earth-Moon system. The findings were published in the international academic journal "Nature Astronomy" on August 20.
In this research work, the research team led by Academician Xu Yigang from the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, discovered three special rock fragments in 3.5 grams of lunar soil, with sizes ranging from 150 micrometers to 350 micrometers. These rock fragments are impact-melted rocks generated during the formation of the Apollo Basin and are the ideal "rock clocks" for recording impact events. The research team accurately determined the age of the rock fragments and, by integrating multi-source information such as remote sensing images and geochemical data, finally confirmed that the 4.16 billion years recorded by the fragments correspond to the formation age of the Apollo Basin.
Impact rock fragments identified in the Chang'e-6 lunar soil
The lunar surface is covered with giant impact basins, most of which are remnants of small celestial bodies in the solar system that impacted the Moon about 3.8 billion years ago. The scientific community has long debated whether this "impact storm" in the solar system gradually weakened or experienced a sudden intensification between 4 billion and 3.8 billion years ago. This decades-long debate stems from the lack of precise age data for key impact basins on the Moon. The Apollo Basin, where the Chang'e-6 sampling site is located, is inside the South Pole-Aitken Basin and is the largest secondary impact structure in the region. Its formation age may mark the start of the Moon's late impact events.
In summary, the research conducted by our country's scientific team pushed back the starting point of the Moon's "impact storm" by at least 1 billion years. Moreover, through analysis, it revealed that the intensity of the Moon's "impact storm" showed a gradual decline rather than a sudden increase. This study will help promote a new understanding of the evolution of the Earth-Moon system.
Source | CCTV Finance
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