Chinese scientists have made a groundbreaking discovery in lunar science, revealing a unified timeline of the Moon's impact history. A research team led by the Chinese Academy of Sciences has successfully revised the decades-old lunar impact crater chronology model, thanks to the Chang'e-6 mission's samples from the Moon's far side.
The study, published in Science Advances, analyzed remote sensing images and identified two key rock types: young basalt aged 2.807 billion years and ancient norite formed 4.25 billion years ago. The norite, in particular, is linked to the South Pole-Aitken Basin, the Moon's largest and oldest impact structure. This discovery provides a critical anchor point for understanding the Moon's early geological evolution.
For decades, scientists estimated the age of unsampled regions by counting impact craters, with a higher density indicating an older surface. However, the existing crater chronology method relied solely on samples from the Moon's near side, limiting the accuracy of lunar age estimates. The Chang'e-6 mission's samples from the far side have now bridged this gap, offering a more comprehensive understanding of the Moon's impact history.
The research team mapped crater densities across the Chang'e-6 landing area and the broader South Pole-Aitken Basin using high-resolution remote sensing imagery. By integrating this new data with historical samples from the Apollo, Luna, and Chang'e-5 missions, they constructed a new lunar impact chronology model. The results show that the far-side crater density data aligns perfectly with the near-side-derived model, indicating a homogeneous impact flux across the entire Moon.
This breakthrough has significant implications for lunar science and planetary dating. The refined chronology will serve as a more accurate reference for understanding the Moon's geological evolution and dating the surfaces of other planetary bodies in the solar system. As Yue Zongyu, the study's lead author, noted, this discovery advances our understanding of lunar impact history and highlights the scientific value of the Chang'e-6 samples.
