China's Chang'e 6 reveals moon's volcanic history

China's Chang'e 6 mission has revealed new details about the moon's far side. The mission, which launched in May 2024, successfully landed in the South Pole-Aitken region and returned nearly 4.3 pounds of lunar samples to Earth in June. Scientists from the Chinese Academy of Geological Sciences analyzed these samples and published their findings in the journal Science. They support the idea that the moon was once covered by a global ocean of liquid magma shortly after it formed. This magma ocean likely lasted for tens to hundreds of millions of years. The analysis showed that basalt fragments from the moon's far side share similar characteristics to basalts collected from the near side during NASA's Apollo missions. This link helps scientists understand the volcanic history of the moon better. However, the Chang'e 6 samples also showed differences. Some isotopes of Uranium and Lead in the samples varied compared to those from the Apollo missions. Researchers suggest this might be due to a massive impact that created the South Pole-Aitken basin around 4.2 billion years ago. This event may have changed the properties of the moon's mantle in that area. Chang'e 6 is China's second mission to bring back lunar samples, following the Chang'e 5 mission in 2020. Preliminary analysis indicates that far side samples differ from those on the near side in terms of density and chemical composition. Future studies could lead to new theories about the moon's origin and evolution.