For the first time, Chinese scientists and their US collaborators have been able to precisely measure the age of volcanic eruptions on the far side of the moon.
Previously this was only estimated through remote sensing observations.
Two research teams led by scientists from the Chinese Academy of Sciences, based in Beijing and Guangzhou, used radiometric dating to analyse isotope decay in basalts, a type of volcanic rock brought back to Earth by China’s Chang’e-6 mission in June.
Their studies, published on Friday in journals Nature and Science, both found that the moon’s oldest and deepest crater on its far side was volcanically active around 2.8 billion years ago.
In comparison, samples returned by the Apollo, Luna and Chang’e-5 missions – all from the near side – established that lunar volcanism occurred between 4 billion and 2 billion years ago.
The Nature paper highlighted that the 2.8 billion-year age was “surprisingly young” as volcanic activities on the far side were traditionally thought to have ended much earlier. Most volcanic eruptions were associated with the near side and believed to have ceased by around 3 billion years ago.