A high-profile event in 2024 for the science community and the public as well,the Chang’e-6(CE-6)mission repeatedly hit headlines from March to June 2024.First in March 2024,the launching of the Queqiao-2,a relay sat...A high-profile event in 2024 for the science community and the public as well,the Chang’e-6(CE-6)mission repeatedly hit headlines from March to June 2024.First in March 2024,the launching of the Queqiao-2,a relay satellite for communication support necessary for farside tasks,heralded the journey.On June 2,2024,the lander-ascender complex of CE-6 successfully touched down in the South Pole-Aitken(SPA)basin on the lunar farside to scoop,drill and collect samples;later,on June 25,2024,the CE-6 returner brought the 1,935.3 grams of samples home safe and sound.For the first time ever,human beings obtained samples from the lunar farside,marking a significant milestone in lunar exploration.展开更多
月球南极-艾特肯盆地是太阳系最大的撞击盆地之一,也是月球上最大、最古老的撞击盆地.南极-艾特肯盆地是研究早期大型撞击事件的重要窗口,而小型撞击坑的识别与计数定年是研究南极-艾特肯盆地演化史的基础.由于撞击坑直径和数量符合幂...月球南极-艾特肯盆地是太阳系最大的撞击盆地之一,也是月球上最大、最古老的撞击盆地.南极-艾特肯盆地是研究早期大型撞击事件的重要窗口,而小型撞击坑的识别与计数定年是研究南极-艾特肯盆地演化史的基础.由于撞击坑直径和数量符合幂次定律,数量众多的小型撞击坑难以单纯依靠人力进行识别.近年来,计算机算力的提升使得训练复杂的卷积神经网络成为可能.采用已有的专家标注训练神经网络,进而实现图像特征的自动提取,能够在保证准确率的同时极大地提高识别效率.采用基于卷积神经网络算法的You Only Look Once Version5(YOLO V5)目标探测系统来自动识别月球南极-艾特肯盆地直径为2~15 km的小型撞击坑.在训练神经网络时,使用融合了SELENE和LRO数据的数字高程模型SLDEM2015和最新的专家标记撞击坑数据库.训练好的网络在测试集上的结果与专家标记的撞击坑数据库相比,识别结果的准确率(Precision)为0.96,召回率(Recall)为0.95,F1值为0.95.通过对与专家标注不符的识别结果进行可视化,识别出至少十个专家误标记的撞击坑,证明撞击坑自动识别方法可以用于检验专家标注的可靠性.基于南极-艾特肯盆地的撞击坑自动识别结果,确定了南极-艾特肯盆地四个典型中型撞击坑的绝对模式年龄,并与已有的定年结果对比,进一步验证了自动识别结果的可靠性,也显示了提出的方法在利用自动识别的撞击坑进行中型撞击坑定年方面的潜力.提出的撞击坑自动识别方法有望进一步拓展到更小撞击坑的识别,并迁移到月球其他地质单元乃至其他行星的研究中.展开更多
Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulti...Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulties of Change＇4 are introduced and the probe＇s general design, including the aspects of landing site selection, relay communication, trajectory design of relay satellite is explained. Besides, four key technologies, namely safe landing strategy on complex terrain, orbit design and control of libration point 2, relay communication on L2, radioisotope thermoelectric generator （RTG） and electric-thermal utilization, as well as how to realize them are also discussed. Finally the prospect of the prominent technological breakthrough of Change＇4 is described.展开更多
The evolution of the Moon is driven by both endogenic(e.g.,magmatism)and exogenic processes(e.g.,impact).The lunar surface can be divided into 3 first-order tectonic units based on differences in geochemistry,crustal ...The evolution of the Moon is driven by both endogenic(e.g.,magmatism)and exogenic processes(e.g.,impact).The lunar surface can be divided into 3 first-order tectonic units based on differences in geochemistry,crustal thickness,topography,and distribution of structures.However,the interpreted boundaries demarcated by different features varied widely.As research progresses,the understanding of the lunar structure is continuously improving,and new types of structures are constantly being discovered.The previous structural classification system needs to be updated.According to the major geological events and dynamic evolution,the evolutionary history of the Moon can be divided into 3 stages and 1 pivotal event.The first stage(4.52 to 4.3 Ga)is the evolution of the magmatic ocean,and it was dominated by endogenic processes.The formation of South Pole-Aitken(SPA)basin(~4.3 Ga)is the pivotal event of crustal evolution and indicates that the lunar crust had cooled and consolidated to sufficient rigidity to preserve structures.Both endogenic and exogenic processes were active in the second stage(4.3 to 3.0 Ga),which results in numerous impact basins,mare basalt flooding,and different types of associated structures.The last stage(3.0 Ga to the present)is late neotectonic activity,which has weak modification of the tectonic framework.Response of tectonic framework and structure to lunar major geological events had been organized and discussed in this paper,and key scientific issues are summarized.This study can provide reference and support for implementation of subsequent lunar exploration projects.展开更多
文摘A high-profile event in 2024 for the science community and the public as well,the Chang’e-6(CE-6)mission repeatedly hit headlines from March to June 2024.First in March 2024,the launching of the Queqiao-2,a relay satellite for communication support necessary for farside tasks,heralded the journey.On June 2,2024,the lander-ascender complex of CE-6 successfully touched down in the South Pole-Aitken(SPA)basin on the lunar farside to scoop,drill and collect samples;later,on June 25,2024,the CE-6 returner brought the 1,935.3 grams of samples home safe and sound.For the first time ever,human beings obtained samples from the lunar farside,marking a significant milestone in lunar exploration.
基金中国科学院B类先导科技专项培育项目(XDB18000000)国家自然科学基金面上项目(41373068,41773065)+2 种基金国家自然科学基金重大项目(41490634)科技部科技基础性工作专项(2015FY210500)Brown University,Office of Vice President for Research SEED grant"Engaging the Chinese Lunar Exploration Program"(CLEP)
文摘月球南极-艾特肯盆地是太阳系最大的撞击盆地之一,也是月球上最大、最古老的撞击盆地.南极-艾特肯盆地是研究早期大型撞击事件的重要窗口,而小型撞击坑的识别与计数定年是研究南极-艾特肯盆地演化史的基础.由于撞击坑直径和数量符合幂次定律,数量众多的小型撞击坑难以单纯依靠人力进行识别.近年来,计算机算力的提升使得训练复杂的卷积神经网络成为可能.采用已有的专家标注训练神经网络,进而实现图像特征的自动提取,能够在保证准确率的同时极大地提高识别效率.采用基于卷积神经网络算法的You Only Look Once Version5(YOLO V5)目标探测系统来自动识别月球南极-艾特肯盆地直径为2~15 km的小型撞击坑.在训练神经网络时,使用融合了SELENE和LRO数据的数字高程模型SLDEM2015和最新的专家标记撞击坑数据库.训练好的网络在测试集上的结果与专家标记的撞击坑数据库相比,识别结果的准确率(Precision)为0.96,召回率(Recall)为0.95,F1值为0.95.通过对与专家标注不符的识别结果进行可视化,识别出至少十个专家误标记的撞击坑,证明撞击坑自动识别方法可以用于检验专家标注的可靠性.基于南极-艾特肯盆地的撞击坑自动识别结果,确定了南极-艾特肯盆地四个典型中型撞击坑的绝对模式年龄,并与已有的定年结果对比,进一步验证了自动识别结果的可靠性,也显示了提出的方法在利用自动识别的撞击坑进行中型撞击坑定年方面的潜力.提出的撞击坑自动识别方法有望进一步拓展到更小撞击坑的识别,并迁移到月球其他地质单元乃至其他行星的研究中.
文摘Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulties of Change＇4 are introduced and the probe＇s general design, including the aspects of landing site selection, relay communication, trajectory design of relay satellite is explained. Besides, four key technologies, namely safe landing strategy on complex terrain, orbit design and control of libration point 2, relay communication on L2, radioisotope thermoelectric generator （RTG） and electric-thermal utilization, as well as how to realize them are also discussed. Finally the prospect of the prominent technological breakthrough of Change＇4 is described.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0503100)the National Natural Science Foundation of China(Grant No.42202264)+2 种基金the National Natural Science Foundation of China-Academic Divisions of Chinese Academy of Sciences Frontier Interdisciplinary Research Strategic Research Joint Funding Project(Grant No.L2224032,XK2022DXC004)the Key Research Program of the Chinese Academy of Sciences,(Grant No.KGFZD-145-2023-15)Guizhou Provincial Science and Technology Projects(Grant No.[QKHJC-ZK(2023)-478]).
文摘The evolution of the Moon is driven by both endogenic(e.g.,magmatism)and exogenic processes(e.g.,impact).The lunar surface can be divided into 3 first-order tectonic units based on differences in geochemistry,crustal thickness,topography,and distribution of structures.However,the interpreted boundaries demarcated by different features varied widely.As research progresses,the understanding of the lunar structure is continuously improving,and new types of structures are constantly being discovered.The previous structural classification system needs to be updated.According to the major geological events and dynamic evolution,the evolutionary history of the Moon can be divided into 3 stages and 1 pivotal event.The first stage(4.52 to 4.3 Ga)is the evolution of the magmatic ocean,and it was dominated by endogenic processes.The formation of South Pole-Aitken(SPA)basin(~4.3 Ga)is the pivotal event of crustal evolution and indicates that the lunar crust had cooled and consolidated to sufficient rigidity to preserve structures.Both endogenic and exogenic processes were active in the second stage(4.3 to 3.0 Ga),which results in numerous impact basins,mare basalt flooding,and different types of associated structures.The last stage(3.0 Ga to the present)is late neotectonic activity,which has weak modification of the tectonic framework.Response of tectonic framework and structure to lunar major geological events had been organized and discussed in this paper,and key scientific issues are summarized.This study can provide reference and support for implementation of subsequent lunar exploration projects.
