The latest findings from the Chang'e-6 mission have rewritten a chapter in lunar history. Chinese scientists, led by Chen Yi of the Institute of Geology and Geophysics at the Chinese Academy of Sciences, have directly dated the South Pole-Aitken (SPA) basin— the moon's largest and oldest impact crater—to 4.25 billion years ago.
Previously, indirect estimates of the SPA basin's age ranged between 4.26 and 4.35 billion years. However, through meticulous analysis of roughly 1,600 fragments from just five grams of lunar samples, the research team identified key norite clasts that carried the signature of an ancient impact melt sheet. Using precise lead-lead dating techniques on zirconium-bearing minerals, the team distinguished two separate impact events, with the older marking the formation of the SPA basin itself.
This breakthrough came from samples retrieved from the Apollo Basin area within the SPA region—a site that has undergone multiple impact events and basaltic eruptions over billions of years. As a result, the Chang'e-6 samples not only offer a direct timeframe for the colossal asteroid bombardment that shaped much of the early solar system, but also provide a critical anchor for refining the lunar cratering chronology.
Launched on May 3, 2024, and returning on June 25, 2024, the Chang'e-6 mission stands as a testament to the power of modern scientific exploration. The study’s insights pave the way for a deeper understanding of planetary evolution, merging cutting-edge research with humanity’s eternal curiosity about the cosmos.
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Chang'e-6 samples date moon's oldest impact crater to 4.25b years ago
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