【人民日报】嫦娥六号玄武岩为揭示月球地质演化历史提供关键线索

Core Insights - The research team from the Chinese Academy of Sciences has conducted high-precision potassium isotope analysis on samples collected by the Chang'e 6 mission, revealing the impact of the South Pole-Aitken basin collision on the loss of moderately volatile elements in the lunar mantle, which is crucial for understanding the evolution of the Moon and the reasons behind its dichotomy [1][2]. Group 1 - The Chang'e 6 mission collected samples from the largest impact basin on the Moon, the South Pole-Aitken basin, providing key samples for studying the effects of this large-scale impact event [1]. - High-precision isotope analysis can capture minute changes in isotope ratios, which are essential for understanding the temperature, energy, and material sources during the impact event [1]. - The isotopic system of moderately volatile elements (such as potassium, zinc, and gallium) is particularly valuable, as these elements are prone to volatilization and fractionation under high-temperature conditions generated by impacts [1]. Group 2 - The research team performed high-precision potassium isotope analysis on milligram-level single particles of Chang'e 6 basalt, finding higher potassium-41 and potassium-39 ratios compared to Apollo samples from the Moon's near side [2]. - The study confirmed that the impact event altered the potassium isotope composition of the lunar mantle, leading to potassium loss and elevated isotope ratios [2]. - During the high-temperature and high-pressure conditions of the impact, lighter isotopes (like potassium-39) tend to escape first, resulting in higher ratios in the remaining material, which may have suppressed volcanic activity on the Moon's far side, providing critical insights into the geological evolution history of the Moon [2].