月球“晚年”为何还有火山喷发？中国科学家研究嫦娥六号样品揭秘

Core Insights - The research reveals that the Moon has experienced volcanic activity during its "late" period, challenging the long-held belief that it became dormant around 3 billion years ago [1][2] - The study identifies two distinct types of basalt from the Chang'e 6 samples, indicating different sources and depths of formation, which contributes to understanding the Moon's thermal evolution [2][4] Group 1: Volcanic Activity - The study confirms that volcanic eruptions occurred on the Moon even in its later stages, raising questions about the heat dynamics that sustain this activity [1][2] - Two types of basalt were identified: "ultra-low titanium basalt" from deep within the Moon's mantle (approximately 120 km from the surface) and "low titanium basalt" from a shallower depth (60-80 km) [2][4] Group 2: Thermal Mechanisms - The research proposes a new thermal mechanism where magma, trapped in the upper mantle, can transfer heat upward, leading to partial melting and subsequent volcanic eruptions [2][3] - Traditional hypotheses linking volcanic activity to water-rich or radioactive heat sources were disproven, as the identified source regions were found to be dry and lacking radioactive elements [2][4] Group 3: Asymmetrical Evolution - Analysis of lunar remote sensing data indicates a significant shift in volcanic heat sources around 3 billion years ago, transitioning from diverse sources to a dominant upward heat transfer mechanism [3][4] - The chemical characteristics of late-stage volcanic rocks on the Moon's near side are similar to those of the Chang'e 5 basalt, while the far side shows a closer resemblance to the ultra-low titanium basalt from Chang'e 6, suggesting compositional differences in the lunar mantle [4] Group 4: Implications for Lunar Studies - The findings from the Chang'e 6 samples not only enhance the understanding of the Moon's thermal evolution but also provide insights into volcanic mechanisms on other small celestial bodies [5][6] - The ongoing research is expected to uncover more mysteries about the Earth-Moon system, indicating that the Moon's geological history is more complex than previously thought [5][6]