- The number of impact craters on both sides of the Moon is nearly the same
- Scientists updated the lunar crater model using remote sensing images
- Impacts decreased gradually rather than in sudden major changes
For many years, scientists have tried to understand how old different parts of the moon are and how its surface changed over time. Now, for the first time, researchers have confirmed that the number of impact craters on the near and far sides of the moon is almost the same, reported CGTN.
This important finding helps scientists build a single, reliable timeline for the moon's history. According to a report in Science and Technology Daily, this new discovery lays a strong foundation for developing a uniform lunar chronology for the entire Moon.
New Research Improves Old Model
A team of scientists led by the Institute of Geology and Geophysics of the Chinese Academy of Sciences analyzed remote sensing images of the Moon. Based on this information, they updated the lunar impact crater model that had been in use for decades.
The research, published Thursday in Science Advances, shows that impacts occurred at approximately the same rate on both sides of the Moon.
The results also revealed that the initial impacts gradually decreased, rather than with sudden, major changes, as some scientists previously believed.
Knowing the age of the Moon's surface is considered crucial to understanding its long-term evolution.
For a long time, scientists have been estimating the age of different regions of the Moon by counting impact craters, or depressions, present there.
Generally, the surface with more craters is considered older. However, the previous approach relied solely on samples from the near side of the Moon. Even the oldest of those samples were no older than 4 billion years.
This limited information led to a long-standing debate about the Moon's early history, with theories such as the "Late Heavy Bombardment" being proposed.
A major breakthrough occurred in June 2024 when China's Chang'e-6 mission delivered 1,935 grams of lunar samples from the Apollo Basin to Earth. This region lies within the South Pole-Aitken Basin on the far side of the Moon.
In these samples, scientists found two major types of rocks. One was relatively young basalt, estimated to be 2.807 billion years old. The other was extremely old norite, formed approximately 4.25 billion years ago.
This norite was formed from magma that cooled after the massive collision that created the South Pole-Aitken Basin. This basin is considered the Moon's largest and oldest impact-forming structure.
These samples provided a strong foundation for re-understanding the Moon's early history.
Using high-quality remote sensing images, researchers created a detailed map of the number of craters in the Chang'e-6 landing area and throughout the South Pole-Aitken Basin. This new data was then combined with information from older samples obtained from the Apollo, Luna, and Chang'e-5 missions.
Based on this information, scientists developed a new and more comprehensive lunar impact chronology model. The results showed that data on craters on the Moon's far side fully matched the model based on the near side, within the limits of the model.
