Return to the Moon:New perspectives on lunar exploration

Lunar exploration is deemed crucial for uncovering the origins of the Earth-Moon system and is the first step for advancing humanity’s exploration of deep space.Over the past decade,the Chinese Lunar Exploration Program(CLEP),also known as the Chang’e(CE)Project,has achieved remarkable milestones.It has successfully developed and demonstrated the engineering capability required to reach and return from the lunar surface.Notably,the CE Project has made historic firsts with the landing and on-site exploration of the far side of the Moon,along with the collection of the youngest volcanic samples from the Procellarum KREEP Terrane.These achievements have significantly enhanced our understanding of lunar evolution.Building on this success,China has proposed an ambitious crewed lunar exploration strategy,aiming to return to the Moon for scientific exploration and utilization.This plan encompasses two primary phases:the first crewed lunar landing and exploration,followed by a thousand-kilometer scale scientific expedition to construct a geological cross-section across the lunar surface.Recognizing the limitations of current lunar exploration efforts and China’s engineering and technical capabilities,this paper explores the benefits of crewed lunar exploration while leveraging synergies with robotic exploration.The study refines fundamental lunar scientific questions that could lead to significant breakthroughs,considering the respective engineering and technological requirements.This research lays a crucial foundation for defining the objectives of future lunar exploration,emphasizing the importance of crewed missions and offering insights into potential advancements in lunar science.

A lunar time scale from the perspective of the Moon’s dynamic evolution

A geologic time scale is a chronological system that separates the geological strata of a planetary body into different units in temporal sequence and shows its progressive evolution.The time scale of the Moon was established a half-century ago during the telescopic-early Apollo exploration era,using data with limited spatial coverage and resolution.The past decades have seen a wide array of studies,which have significantly extended our understanding of global lunar geologic evolution.Based on a comprehensive review of lunar evolution with respect to the dynamical changes,we propose two major updates to the current lunar time scale paradigm to include the evolution of both endogenic and exogenic dynamic forces now known to have influenced early lunar history.Firstly,based on the temporal interplay of exogenic and endogenic processes in altering the Moon,we defined three Eon/Eonothem-level units to represent three dynamical evolutionary phases.Secondly,the pre-Nectarian System is redefined and divided as the magma ocean-era Magma-oceanian System and the following Aitkenian System beginning with the South Pole-Aitken basin.The ejecta of this basin,Das Formation,was deposited on the primordial lunar crust as the oldest stratum produced from exogenic processes.The updated lunar time scale,facilitated by the post-Apollo exploration and research advances,provides an integrated framework to depict the evolution of the Moon and has important implications for the geologic study of other terrestrial planets.

The 1:2,500,000-scale geologic map of the global Moon

月球地质图系统表达了月壳表面地层、构造、岩性和年代学等地质方面的信息,反映了月球岩浆作用、撞击作用和火山活动等地质过程的演化.20世纪90年代以来,人类对月球的探索取得了巨大成就,深刻地拓展了我们对月球的认识.基于月球动力学演化历史,充分利用国内外探月数据和研究结果,世界第一幅全月1:250万地质图编制完成.在新的月球地质图中,基于月球动力学演化的认识更新了月球地质年表,表达了不同时代的撞击坑物质和盆地建造,以及17种岩石类型和14类构造要素.此图可为月球科学研究、探测规划和着陆点选址等提供重要的基础资料,为其他行星地质图的编制提供参考.

Digital and global lithologic mapping of the Moon at a 1:2,500,000 scale

Scientific knowledge of lunar lithologies was first acquired in the 1960s-1970s.The space race between the United States(U.S.)and Soviet Union has promoted numerous manned and robotic lunar exploration missions.Utilizing datasets from these missions,the first series of lunar geologic maps was prepared and published by the U.S.Geological Survey(USGS)The definition of lunar geological features in these maps was mostly based on morphological characteristics but lacked lithological constraints owing to the incompleteness of the compositional datasets avail-able.After two decades of silence,a new era of lunar exploration began in the 1990s when the Galileo spacecraft flew by the Moon during its gravity-assisted maneuvers.The very successful orbital missions,the Clementine and Lunar Prospector(LP),provided the first global geochemical and mineralogical(multispectral,gamma ray,neutron,etc.)datasets of the lunar surface.