Core Viewpoint - Recent research indicates that the Moon, previously thought to be "dormant" for 3 billion years, has experienced volcanic activity during this period, challenging existing beliefs about lunar evolution [2][3]. Group 1: Research Findings - The Chang'e 5 and Chang'e 6 missions returned basalt samples that are 2 billion and 2.8 billion years old, respectively, confirming volcanic eruptions occurred during the Moon's "dormant" phase [2]. - A systematic study of the Chang'e 6 samples revealed two types of basalt formed around 2.8 and 2.9 billion years ago, with distinct compositions and depths of origin [3]. - The study identified "ultra-low titanium basalt" from deep within the lunar mantle (over 120 kilometers) and "low titanium basalt" from shallower depths (60 to 80 kilometers) [3]. Group 2: Mechanisms of Volcanic Activity - Traditional theories suggested that late lunar volcanic activity was linked to water-rich or radioactive heat sources, but the samples from Chang'e missions disproved this, showing dry and lacking radioactive elements [3]. - A new thermal dynamic mechanism was proposed, indicating that as the Moon cooled, magma became trapped in the shallow mantle, leading to partial melting and subsequent volcanic eruptions [3]. Group 3: Implications and Future Research - Analysis of global lunar remote sensing data revealed a significant change in volcanic heat dynamics around 3 billion years ago, shifting from diverse heat sources to a dominant upward heat transfer mechanism [4]. - The chemical characteristics of late volcanic rocks on the Moon's near side are similar to those of the Chang'e 5 basalt, while the far side is more akin to the ultra-low titanium basalt from Chang'e 6, suggesting compositional differences in the lunar mantle [4]. - This research not only enhances understanding of the Moon's thermal evolution history but also provides insights into volcanic activity mechanisms on other small, airless celestial bodies [4].

Core Insights - The research reveals that the Moon, previously thought to be "dormant" for 3 billion years, has experienced volcanic activity during this period, challenging existing beliefs about lunar evolution [1][3][4] - The study, published in the journal "Science Advances," was conducted by a team from the Guangzhou Institute of Geochemistry and Hong Kong University, focusing on samples returned by China's Chang'e 5 and Chang'e 6 missions [1][4] Group 1: Volcanic Activity - The Chang'e 5 and Chang'e 6 missions returned basalt samples that are 2 billion and 2.8 billion years old, respectively, indicating that volcanic eruptions occurred during the Moon's "dormant" phase [1][3] - Two types of basalt were identified in the Chang'e 6 samples, one originating from over 120 kilometers deep in the mantle and the other from a shallower depth of 60 to 80 kilometers [3] Group 2: Thermal Dynamics - The research team proposed a new thermal dynamic mechanism where magma, trapped in the upper mantle, can transfer heat upward, leading to partial melting and volcanic eruptions [3][4] - The study found that the heat sources for lunar volcanic activity changed significantly around 3 billion years ago, shifting from a complex mix to a dominant upward heat transfer mechanism [4] Group 3: Lunar Composition and Evolution - Analysis of remote sensing data suggests differences in the composition of the lunar mantle between the near and far sides of the Moon, with the near side having more titanium-rich minerals [4] - The findings provide new insights into the asymmetric evolution of the Moon and contribute to a better understanding of volcanic activity on other small celestial bodies [4]

Core Insights - The research indicates that the Moon, previously thought to be "dormant" for 3 billion years, has experienced volcanic activity during this period, as evidenced by samples returned from the Chang'e 5 and Chang'e 6 missions [1][3][4] - The study reveals that the Moon's interior still retains some heat, challenging previous assumptions about its thermal evolution [1][4] Group 1: Research Findings - The Chang'e 6 mission identified two types of basalt formed around 2.8 and 2.9 billion years ago, with distinct compositions and depths of origin: "ultra-low titanium basalt" from over 120 kilometers deep and "low titanium basalt" from 60 to 80 kilometers [3][4] - Traditional theories suggesting that late volcanic activity was linked to water-rich or radioactive heat sources have been disproven; the samples indicate that the source regions are "dry" and lack radioactive heat elements [3][4] - A new thermal dynamic mechanism is proposed, where magma is trapped in the shallow mantle due to the thickening lithosphere, leading to partial melting and subsequent volcanic eruptions [3][4] Group 2: Implications and Future Research - Analysis of lunar remote sensing data shows a significant change in volcanic heat dynamics around 3 billion years ago, shifting from a complex heat source to a dominant upward heat transfer mechanism [4] - The chemical characteristics of late volcanic rocks on the Moon's near side are similar to those of the Chang'e 5 basalt, while the far side is more akin to the ultra-low titanium basalt from Chang'e 6, suggesting compositional differences in the lunar mantle [4] - This research not only enhances understanding of the Moon's thermal evolution but also provides insights into volcanic activity mechanisms on other small, airless celestial bodies [4]