New Insights on Lunar Volcanism from Chang'e-6 Mission Samples

The Chang'e-6 mission has yielded lunar samples that are now under study at a laboratory in Beijing, revealing fresh perspectives on the moon's geological history. Contrary to the long-standing belief that volcanic activity on the moon ceased approximately 3 billion years ago, new findings suggest that eruptions continued well into its later years, with basalt samples dated around 2 billion to 2.8 billion years old providing compelling evidence.

one type hails from over 120 kilometers deep, while the other is sourced from depths of just 60 to 80 kilometers.

By recreating the high-pressure, high-temperature conditions of the moon's interior, the scientists deduced that these two basalt types emerged from separate layers developed after the moon's early magma ocean solidified. Traditional theories have linked young lunar volcanism to factors such as water-rich sources or radioactive materials. However, the newly collected samples were found to be dry and lacking in heat-producing radioactive elements, challenging previously held assumptions.

The team posits a revised theory wherein the thinning of the moon's lithosphere, due to gradual cooling, hindered direct eruptions from deep magma. This trapped magma in the shallower layers instead conducted heat upwards, eventually leading to partial melting in the upper mantle and subsequent volcanic activity.

Further research analyzed global lunar remote sensing data, revealing that around 3 billion years ago, there was a shift in the lunar volcanic activity’s thermodynamic mechanisms. Initially characterized by diverse heat sources like tidal forces and radioactive materials, the mechanism evolved to predominantly rely on bottom-up heat transport.

Additionally, this study indicates variations in the lunar mantle's composition between the near and far sides of the moon, with the former displaying more ilmenite and the latter featuring mostly very-low-titanium basalts. Overall, the Chang'e-6 investigation contributes valuable insights into the asymmetrical evolutionary processes of the moon, underscoring its complex geological history. The mission, which launched in May 2024, returned a significant cache of 1,935.3 grams of samples from the moon's far side, further enriching our understanding of lunar geology.