Chinese astronomers have updated the geochronological model of the Moon based on the dating of lunar soil samples delivered to Earth by the domestic Chang'e-5 probe. The results of the study by scientists from the Research Institute of Aerospace Information of the Chinese Academy of Sciences were recently published in the prestigious international scientific journal Nature Astronomy.
According to the updated geochronological model, most of the lunar rocks are older than previously thought. The maximum difference is about 200 million years.
A new discovery, as the authors of the article stated, is of great importance for the study of geochronology and the history of the interaction of celestial bodies in the solar system.
Geochronological models of the Moon are built by comparing the radiometric ages of samples measured in laboratories, delivered to Earth by the American Apollo spacecraft and the Soviet Luna spacecraft, with a compiled distribution of craters in these areas.
Such models have been widely used to determine the absolute age of various regions of the Moon, and have also been extended to date the surfaces of rocky planets in the inner solar system.
However, in previous samples, there is an age gap between three billion years and one billion years ago, which corresponds to almost half of the evolutionary history of the Moon.
Chinese probe Chang'e-5 brought back a sample of basalt rock from the Moon, which is about two billion years old.
By analyzing the distribution of craters by size and frequency, Chinese scientists have updated the Neukum model (1983), which is the most widely used geochronological model in planetary science.
It is expected that the updated geochronological model of the Moon will serve as the basis for the development of analogues for studying the geochronology of terrestrial planets, including Mars and Mercury.