In December 2020, China's Chang'e-5 lunar probe returned from the moon with about 2 kilograms of lunar samples, marking the first time in over four decades that samples were brought back from the moon's surface.

After months of study, scientists from the Chinese Academy of Sciences (CAS) recently unveiled their groundbreaking findings. The papers have been published in some of the world's leading scientific journals, including Science, Nature and China's National Science Review.

Scientists at the Institute of Geology and Geophysics at the CAS successfully dated the age of the basalt in the Chang'e-5 samples as 2 billion years old, with a mere 4-million-year margin of error.

Prior to Chang'e-5, the youngest lunar samples ever collected were from the NASA Apollo missions in the 1970s, which were dated to be 2.8 to 3 billion years old. That said, the Chinese lunar samples have extended the known duration of volcanic activity on the moon by at least 800 million years.

The groundbreaking revelation has also raised new questions about our closest neighbor in the galaxy: The moon is small and light, and it has no atmosphere and very little magnetic field, how did it manage to keep its volcanism for so long?

Scientists proposed two theories. One was the radioactive elements detected on the surface of the moon might also exist in its mantle, providing the necessary heat to turn the mantle into magma. Another theory was that the moon's mantle used to hold a lot of water, allowing the mantle to melt at a lower temperature.

Based on these hypotheses, scientists took a closer look at the Chang'e-5 lunar samples. The result: the basalt that is believed to have emerged from the moon's mantle contained very few radioactive elements or moisture, suggesting neither radioactivity nor water contributed to the prolonged volcanism of the moon.

Chinese scientists are now actively collaborating with scientists from around the world to solve the mysteries brought forward by the Chang'e-5 lunar samples. More findings are expected to emerge in the near future.