INTRODUCTION The Chang'e-6 mission recently returned the first sample from the lunar farside. The sampling site was located on a flat basaltic maria that was emplaced at ~2.8 Ga in the Apollo Basin(Zhang Q W L et ...INTRODUCTION The Chang'e-6 mission recently returned the first sample from the lunar farside. The sampling site was located on a flat basaltic maria that was emplaced at ~2.8 Ga in the Apollo Basin(Zhang Q W L et al., 2025;Cui et al., 2024), which formed in the northeastern portion of the South Pole-Aitken(SPA) Basin.展开更多
The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources.Oxygen,crucial for supporting human life on the Moon,can be extract...The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources.Oxygen,crucial for supporting human life on the Moon,can be extracted from lunar regolith,which is highly rich in oxygen and contains polymetallic oxides.This oxygen and metal extraction can be achieved using existing metallurgical techniques.Furthermore,the ample reserves of water ice on the Moon offer another means for oxygen production.This paper offers a detailed overview of the leading technologies for achieving oxygen production on the Moon,drawing from an analysis of lunar resources and environmental conditions.It delves into the principles,processes,advantages,and drawbacks of water-ice electrolysis,two-step oxygen production from lunar regolith,and one-step oxygen production from lunar regolith.The two-step methods involve hydrogen reduction,carbothermal reduction,and hydrometallurgy,while the one-step methods encompass fluorination/chlorination,high-temperature decomposition,molten salt electrolysis,and molten regolith electrolysis(MOE).Following a thorough comparison of raw materials,equipment,technology,and economic viability,MOE is identified as the most promising approach for future in-situ oxygen production on the Moon.Considering the corrosion characteristics of molten lunar regolith at high temperatures,along with the Moon's low-gravity environment,the development of inexpensive and stable inert anodes and electrolysis devices that can easily collect oxygen is critical for promoting MOE technology on the Moon.This review significantly contributes to our understanding of in-situ oxygen production technologies on the Moon and supports upcoming lunar exploration initiatives.展开更多
0 INTRODUCTION The lunar surface lacks an atmosphere and is continuously subjected to a combination of space weathering factors such as cosmic rays,solar wind,and micrometeorite impacts,forming a several-meter-thick l...0 INTRODUCTION The lunar surface lacks an atmosphere and is continuously subjected to a combination of space weathering factors such as cosmic rays,solar wind,and micrometeorite impacts,forming a several-meter-thick lunar regolith(Sorokin et al.,2020).展开更多
The study presents the results of over 30,000 numerical analyses on the stability of lava tubes under lunar conditions.The research considered random irregularities in cave geometry and their impact on stability,with ...The study presents the results of over 30,000 numerical analyses on the stability of lava tubes under lunar conditions.The research considered random irregularities in cave geometry and their impact on stability,with a particular focus on the geometric characteristics of identified collapses.We propose a procedure for extracting the collapse areas and integrating it into the stability analysis results.The results were examined to assess the possibility of describing the geometry characteristics of collapses using commonly applied probability density distributions,such as normal or lognormal distribution.Our aim is to facilitate future risk assessment of lunar caves.Such an assessment will be essential prior to robotically exploring caves beneath the lunar surface and can be extended to be used for planetary caves beyond the Moon.Our findings indicate that several collapse characteristics can be represented by unimodal probability density distributions,which could significantly simplify the candidate selection process.Based on our results,we also highlight several key directions for future research and suggested implications related to their future exploration.展开更多
The utilization of lunar resources is critical for the long-term sustainability of China's lunar exploration missions.In-situ manufacturing and construction using lunar regolith as the primary feedstock can provid...The utilization of lunar resources is critical for the long-term sustainability of China's lunar exploration missions.In-situ manufacturing and construction using lunar regolith as the primary feedstock can provide essential support for establishing,operating,and maintaining lunar bases.This paper presents a comprehensive review of current lunar regolith forming technologies.These methods fall into two main categories,depending on whether Earth-based additives are required during the forming process.Direct forming technologies rely entirely on local materials and require minimal or no external input.In contrast,indirect forming technologies depend on additional binders or components transported from Earth.The advantages and limitations of each approach are analyzed across several dimensions,including technical principles,forming speed,forming precision,forming quality,environmental adaptability,energy consumption,and process simplicity.This paper evaluates the application potential of each method in two key lunar use cases:large-scale infrastructure construction and flexible manufacturing of fine-structured components.Based on this analysis,development trends and strategic recommendations are proposed to support the optimization and deployment of in-situ resource utilization-based lunar regolith forming technologies for diverse lunar surface applications.展开更多
Lunar Laser Ranging has extremely high requirements for the pointing accuracy of the telescopes used.To improve its pointing accuracy and solve the problem of insufficiently accurate telescope pointing correction achi...Lunar Laser Ranging has extremely high requirements for the pointing accuracy of the telescopes used.To improve its pointing accuracy and solve the problem of insufficiently accurate telescope pointing correction achieved by tracking stars in the all-sky region,we propose a processing scheme to select larger-sized lunar craters near the Lunar Corner Cube Retroreflector as reference features for telescope pointing bias computation.Accurately determining the position of the craters in the images is crucial for calculating the pointing bias;therefore,we propose a method for accurately calculating the crater position based on lunar surface feature matching.This method uses matched feature points obtained from image feature matching,using a deep learning method to solve the image transformation matrix.The known position of a crater in a reference image is mapped using this matrix to calculate the crater position in the target image.We validate this method using craters near the Lunar Corner Cube Retroreflectors of Apollo 15 and Luna 17 and find that the calculated position of a crater on the target image falls on the center of the crater,even for image features with large distortion near the lunar limb.The maximum image matching error is approximately 1″,and the minimum is only 0.47″,which meets the pointing requirements of Lunar Laser Ranging.This method provides a new technical means for the high-precision pointing bias calculation of the Lunar Laser Ranging system.展开更多
Building a lunar human base is one of the important goals of human lunar exploration.This paper proposes a method for the production of oxygen by combining photothermal synergistic water decomposition with high-temper...Building a lunar human base is one of the important goals of human lunar exploration.This paper proposes a method for the production of oxygen by combining photothermal synergistic water decomposition with high-temperature carbon dioxide electrolysis,utilizing the full solar spectrum.The optimal oxygen production rates under different solid oxide electrolysis cell inlet temperatures T_(e),ultraviolet(UV)separation wavelengths λ_(2),infrared(IR)separation wavelengths,and photovoltaic cell materials were explored.The results indicate that the inlet temperature of the solid oxide electrolysis cell should be as high as possible so that more carbon dioxide can be converted into carbon monoxide and oxygen.Furthermore,when the ultraviolet separation wavelength is approximately 385 nm,the proportion of solar energy allocated to the photoreaction and electrolysis cell is optimal,and the oxygen production rate is highest at 2.754×10^(-4) mol/s.Moreover,the infrared separation wavelength should be increased as much as possible within the allowable range to increase the amount of solar radiation allocated to the electrolysis cell to improve the rate of oxygen generation.In addition,copper indium gallium selenide(CIGS)has a relatively large separation wavelength,which can result in a high oxygen production rate of 3.560×10^(-4) mol/s.The proposed integrated oxygen production method can provide a feasible solution for supplying oxygen to a lunar human base.展开更多
NWA 6950 is a type of cumulate gabbro meteorite that displays features indicating a lunar origin.Specifically,the Fe/Mn values of olivines and pyroxenes in the meteorite suggest a lunar origin,as does the presence of ...NWA 6950 is a type of cumulate gabbro meteorite that displays features indicating a lunar origin.Specifically,the Fe/Mn values of olivines and pyroxenes in the meteorite suggest a lunar origin,as does the presence of Fe-Ni metal.The meteorite has also undergone intense shock metamorphism,which is evidenced by the presence of ringwoodite,tuite,and xieite(a type of chromite with a CaTi_(2)O_(4)structure)within the shock melt veins(SMVs).The texture,mineral modal abundances,and bulk compositions(measured from the SMVs)of NWA 6950 are similar to those of the NWA 773 clan,as are the concentrations and patterns of rare-earth-elements in olivine,pyroxene,plagioclase,and phosphate.In-situ U-Pb dating of baddeleyite and phosphate in NWA 6950 has determined its crystallization age to be 3133±11 and 3129±23 Ma,which is consistent with age data provided by Shaulis et al.(2017).Further,the chronology of the NWA 773 clan appears to be at least bimodal when considering the age of NWA 3333(3038±20 Ma;Merle et al.,2020).The tight range of ages for the NWA 773 clan at approximately 3.1 Ga coincides with a change in the eruption flux and style on the Moon.This suggests that lunar volcanism may have shifted from extrusivedominated to intrusive-dominated at approximately 3.1 Ga,resulting in the widespread distribution of gabbro lithologies on the Moon.展开更多
Landing spacecraft experience significant impact forces during landing,resulting in large deformation and failure in the soil surface,which severely affects landing safety and stability.This paper establishes a smooth...Landing spacecraft experience significant impact forces during landing,resulting in large deformation and failure in the soil surface,which severely affects landing safety and stability.This paper establishes a smoothed particle hydrodynamics(SPH)model based on the theory of soil elastoplastic constitutive relations to describe the process of a lander’s footpad impacting lunar regolith vertically.The model can provide engineering indices such as impact load and penetration depth,and illustrate the large deformation and crater characteristics of the regolith.A detailed analysis of the response of the footpad and lunar regolith during landing reveals that the process can be broadly divided into two stages of rapid penetration and oscillatory attenuation.Furthermore,there are significant similarities in the landing process under different landing velocities and footpad masses.The research investigates the large deformation and crater characteristics of the lunar regolith bed.The results demonstrate two failure modes in the regolith.Under the impact of a footpad with a smaller mass,the final failure surface of the regolith exhibits a bowl-shaped profile with a uniformly open mouth.In contrast,under the impact of a footpad with a larger mass,the final failure surface of the regolith presents an urn-shaped profile with a large abdomen and a small opening.However,the impact craters in both scenarios show a bowl-like distribution.In cases of high-velocity impacts,the impact crater exhibits obvious blocky spalling on its sides.The SPH model developed in this study can be applied to predict the large deformation and failure response of lunar soil under the impact of rigid structures as well as the impact load and penetration depth.It effectively predicts the dynamic response of the landing process,which is expected to provide a reference for engineering design.展开更多
The utilization of lunar regolith for construction on the lunar surface presents a critical challenge in-situ resource utilization.This study proposes a lunar regolith manufacturing method that uses a high-performance...The utilization of lunar regolith for construction on the lunar surface presents a critical challenge in-situ resource utilization.This study proposes a lunar regolith manufacturing method that uses a high-performance resin binder characterized by a high regolith content and strong forming capabilities.A combined resin material with both thermosetting and photosetting properties was developed and mixed with lunar regolith to create a slurry.This slurry can be directly molded or additively extruded into green bodies with specific structures.These green bodies can self-cure under the high temperatures and ultraviolet radiation experienced during the lunar day,reducing energy consumption and fulfilling the requirements of lunar construction.The material-forming processes and effects of various additive types and concentrations,regolith mass ratios,and processing parameters on the properties of the slurry and the formed specimens were thoroughly investigated.The mechanical performance and microstructure of the fabricated samples were analyzed.The lunar regolith mass ratio reached 90 wt%(approximately 79 vol%),with the highest compressive strengths exceeding 60 MPa for cast specimens and 30 MPa for printed samples.This technology shows significant potential for enabling in-situ lunar regolith-based construction in future lunar missions.展开更多
A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This pape...A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This paper investigates the thermal processing capability of lunar regolith without the addition of binders,with a focus on large-scale applications for the construction of lunar habitats and infrastructure.The study used a simulant of lunar regolith found on the Schr?dinger Basin in the South Pole region.This regolith simulant consists of20 wt%basalt and 80 wt%anorthosite.Experiments were conducted using a high power CO_(2)laser to sinter and melt the regolith in a 80 mm diameter laser spot to evaluate the effectiveness of direct large area thermal processing.Results indicated that sintering begins at approximately 1180℃and reaches full melt at temperatures above 1360℃.Sintering experiments with this material revealed the formation of dense samples up to 11 mm thick,while melting experiments successfully produced larger samples by overlapping molten layers and additive manufacturing up to 50 mm thick.The energy efficiency of the sintering and melting processes was compared.The melting process was about 10 times more energy efficient than sintering in terms of material consolidation,demonstrating the promising potential of laser melting technologies of anorthosite-rich regolith for the production of structural elements.展开更多
The mechanical properties of minerals in planetary materials are not only interesting from a fundamental point of view but also critical to the development of future space missions.Here we present nanoindentation expe...The mechanical properties of minerals in planetary materials are not only interesting from a fundamental point of view but also critical to the development of future space missions.Here we present nanoindentation experiments to evaluate the hardness and reduced elastic modulus of olivine,(Mg,Fe)_(2)SiO_(4),in meteorite NWA 12008,a lunar basalt.Our experiments suggest that the olivine grains in this lunaite are softer and more elastic than their terrestrial counterparts.Also,we have performed synchrotron-based high-pressure X-ray diffraction(HP-XRD)measurements to probe the compressibility properties of olivine in this meteorite and,for comparison purposes,of three ordinary chondrites.The HP-XRD results suggest that the axial compressibility of the orthorhombic b lattice parameter of olivine relative to terrestrial olivine is higher in NWA 12008 and also in the highly-shocked Chelyabinsk meteorite.The origin of the observed differences is discussed.A simple model combining the results of both our nanoindentation and HP-XRD measurements allows us to describe the contribution of macroscopic and chemical-bond related effects,both of which are necessary to reproduce the observed elastic modulus softening.Such joint analysis of the mechanical and elastic properties of meteorites and returned samples opens up a new avenue for characterizing these highly interesting materials.展开更多
In order to increase the sustainability of future lunar missions,techniques for in-situ resource utilization(ISRU)must be developed.In this context,the local melting of lunar dust(regolith)by laser radiation for the p...In order to increase the sustainability of future lunar missions,techniques for in-situ resource utilization(ISRU)must be developed.In this context,the local melting of lunar dust(regolith)by laser radiation for the production of parts and larger structures was investigated in detail.With different experimental setups in normal and microgravity,laser spots with diameters from 5 mm to 100 mm were realized to melt the regolith simulant EAC-1A and an 80%/20%mixture of TUBS-T and TUBS-M,which are used as a substitute for the actual lunar soil.In the experiments performed,the critical parameters are the size of the laser spot,the velocity of the laser spot on the surface of the powder bed,the gravity and the wettability of the powder bed by the melt.The stability of the melt pool as a function of these parameters was investigated and it was found that the formation of a stable melt pool is determined by gravity for large melt pool sizes in the range of 50 mm and by surface tension for small melt pool sizes in the range of a few mm.展开更多
Lunar in-situ construction using additive manufacturing(AM)technology has emerged as a critical pathway for sustainable extraterrestrial exploration.This review systematically evaluates two dominant AM paradigms for l...Lunar in-situ construction using additive manufacturing(AM)technology has emerged as a critical pathway for sustainable extraterrestrial exploration.This review systematically evaluates two dominant AM paradigms for lunar regolith processing:low-temperature deposition forming(material extrusion and binder jetting),and high-energy beam additive manufacturing(powder bed fusion and directed energy deposition).Low-temperature methods achieve moderate compressive strength with low energy consumption but face challenges such as binder dependency and vacuum instability.By contrast,high-energy beam techniques enable binder-free fabrication with better compatibility for in-situ resource utilization,though they suffer from porosity,high energy intensity,and geometric limitations.In the context of lunar in-situ resource utilization(ISRU),low-temperature methods offer near-term feasibility for small-scale infrastructure,while high-energy approaches show promise for large-scale,autonomous construction by leveraging solar energy and raw regolith.Future advancements will hinge on hybrid systems that integrate material efficiency,energy sustainability,and robotic adaptability to overcome extreme environmental challenges.This review consolidates technological progress,identifies interdisciplinary synergies,and provides strategic insights into guiding the transition from Earth-dependent prototypes to self-sufficient lunar habitats,ultimately advancing the capability of humanity for a long-term extraterrestrial presence.展开更多
The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP...The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP(a.k.a.urKREEP)has never been identified in previous lunar samples or meteorites.The Moon is the focus of many countries’and agencies’space exploration plans,and with the advancement of technology,crewed missions have been proposed.We propose two candidate landing sites,located respectively in the northwest(9.5°W,0.9°S)and southeast(11.1°W,6.2°S)of Lalande crater(8.6°W,4.5°S),for future crewed missions,with the primary goal of sampling the speculated urKREEP.Both sites are situated on the Th-(a critical marker of KREEP)and silica-rich Lalande ejecta in the Mare Insularum and Mare Nubium,respectively.Their geolocations at the low latitude on the lunar nearside,the flat surface,and the low rock abundance suggest the sites are safe for landing and meet the needs of real-time Earth-Moon communication.The astronauts could perform many extravehicular activities,such as collecting KREEP-rich samples,screening clast samples,and drilling regolith cores,to gather a variety of samples,such as Lalande ejecta,basalts,Copernicus ejecta,and regolith.The returned samples are valuable to explore the speculated urKREEP,to reveal the relationship between heat-producing elements and volcanism,to refine the lunar cratering chronology function,and to investigate volatiles in the regolith.展开更多
Acquiring pristine deep lunar regolith cores with appropriate drilling tools is crucial for deciphering the lunar geological history.Conventional thick-walled drill bits are inherently limited in obtaining deep lunar ...Acquiring pristine deep lunar regolith cores with appropriate drilling tools is crucial for deciphering the lunar geological history.Conventional thick-walled drill bits are inherently limited in obtaining deep lunar regolith samples,whereas thin-walled coring bits offer a promising solution for lunar deep drilling.To support future lunar deep exploration missions,this study systematically investigates the failure mechanisms of lunar regolith induced by thin-walled drilling tools.Firstly,five thin-walled bit configurations were designed and evaluated based on drilling load,coring efficiency,and disturbance minimization,with Bit D demonstrating optimal overall performance.And the interaction mechanisms between differently configured coring bits and large-particle lunar regolith were elucidated.Coring experiments under critical drilling parameters revealed an operational window for the feed-to-rotation ratio(FRR of 2.0–2.5),effectively balancing drilling load and core recovery rate.Furthermore,a novel theoretical framework was developed to characterize dynamic drilling load parameters,supported by experimental validation.Based on these findings,practical strategies are proposed to mitigate drilling-induced disturbances,including parameter optimization and bit structural improvements.This research could provide valuable insights for designing advanced lunar deep drilling tools and developing drilling procedures.展开更多
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
Lunar core samples are the key materials for accurately assessing and developing lunar resources.However,the difficulty of maintaining borehole stability in the lunar coring process limits the depth of lunar coring.He...Lunar core samples are the key materials for accurately assessing and developing lunar resources.However,the difficulty of maintaining borehole stability in the lunar coring process limits the depth of lunar coring.Here,a strategy of using a reinforcement fluid that undergoes a phase transition spontaneously in a vacuum environment to reinforce the borehole is proposed.Based on this strategy,a reinforcement liquid suitable for a wide temperature range and a high vacuum environment was developed.A feasibility study on reinforcing the borehole with the reinforcement liquid was carried out,and it is found that the cohesion of the simulated lunar soil can be increased from 2 to 800 kPa after using the reinforcement liquid.Further,a series of coring experiments are conducted using a selfdeveloped high vacuum(vacuum degree of 5 Pa)and low-temperature(between-30 and 50℃)simulation platform.It is confirmed that the high-boiling-point reinforcement liquid pre-placed in the drill pipe can be released spontaneously during the drilling process and finally complete the reinforcement of the borehole.The reinforcement effect of the borehole is better when the solute concentration is between0.15 and 0.25 g/mL.展开更多
As we look ahead to future lunar exploration missions, such as crewed lunar exploration and establishing lunar scientific research stations, the lunar rovers will need to cover vast distances. These distances could ra...As we look ahead to future lunar exploration missions, such as crewed lunar exploration and establishing lunar scientific research stations, the lunar rovers will need to cover vast distances. These distances could range from kilometers to tens of kilometers, and even hundreds and thousands of kilometers. Therefore, it is crucial to develop effective long-range path planning for lunar rovers to meet the demands of lunar patrol exploration. This paper presents a hierarchical map model path planning method that utilizes the existing high-resolution images, digital elevation models and mineral abundance maps. The objective is to address the issue of the construction of lunar rover travel costs in the absence of large-scale, high-resolution digital elevation models. This method models the reference and semantic layers using the middle- and low-resolution remote sensing data. The multi-scale obstacles on the lunar surface are extracted by combining the deep learning algorithm on the high-resolution image, and the obstacle avoidance layer is modeled. A two-stage exploratory path planning decision is employed for long-distance driving path planning on a global–local scale. The proposed method analyzes the long-distance accessibility of various areas of scientific significance, such as Rima Bode. A high-precision digital elevation model is created using stereo images to validate the method. Based on the findings, it can be observed that the entire route spans a distance of 930.32 km. The route demonstrates an impressive ability to avoid meter-level impact craters and linear structures while maintaining an average slope of less than 8°. This paper explores scientific research by traversing at least seven basalt units, uncovering the secrets of lunar volcanic activities, and establishing ‘golden spike’ reference points for lunar stratigraphy. The final result of path planning can serve as a valuable reference for the design, mission demonstration, and subsequent project implementation of the new manned lunar rover.展开更多
The size of basalt fragments in Chang’E-5(CE-5)regolith are small(<6 mm^(2)),resulting in large variation on the estimated bulk composition of CE-5 basalt.For example,the estimated TiO_(2) content of CE-5 basalt r...The size of basalt fragments in Chang’E-5(CE-5)regolith are small(<6 mm^(2)),resulting in large variation on the estimated bulk composition of CE-5 basalt.For example,the estimated TiO_(2) content of CE-5 basalt ranges from 3.7 wt% to 12.7 wt% and the Mg#(molar percentage of Mg/[Mg+Fe])also shows a wide range(26.2-42.4).Preliminary experimental studies have shown that these geochemical characteristics of CE-5 basalt are critical for investigating the crystallization sequence and formation mechanism of its parent magma.This study presents new experimental data on the distribution coefficient of titanium between pyroxene and lunar basaltic magma(D_(Ti)^(Px/melt)).Combining with available literature data,we confirm that D_(Ti)Px/melt is affected by crystallization conditions such as pressure and temperature,but it is mainly controlled by the CaO content of pyroxene.Comparing with previous experimental results under similar conditions,we parameterized the effect as D_(Ti)^(Px/Melt)=D_(Ti)^(Px/Melt)=-0.0005X_(Cao)^(2)+0.0218X_(CaO)+0.0425(R^(2)=0.82),where X_(CaO) is the CaO content in pyroxene in weight percentage.The new experimental results suggest that pyroxene with high TiO_(2) content(>2.5 wt%)in CE-5 basalt is not a product of equilibrium crystallization,and the CaO content in pyroxene is also affected by cooling rate of its parent magma.The TiO_(2) content in the CE-5 parent magma is estimated to be about 5 wt% based on the Mg# of pyroxene and its calculated CaO content,which is consistent with those estimated from olivine grains.展开更多
基金supported by the Natural Science Foundation of China (Nos. 42241108, 42273040, 42473049, 42203047)the Guangdong Basic and Applied Basic Research Foundation (No. 2024A1515011311)。
文摘INTRODUCTION The Chang'e-6 mission recently returned the first sample from the lunar farside. The sampling site was located on a flat basaltic maria that was emplaced at ~2.8 Ga in the Apollo Basin(Zhang Q W L et al., 2025;Cui et al., 2024), which formed in the northeastern portion of the South Pole-Aitken(SPA) Basin.
基金financially supported by the National Natural Science Foundation of China(Nos.52404328,52274412,and 52374418)the China Postdoctoral Science Foundation(No.2024M753248)。
文摘The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources.Oxygen,crucial for supporting human life on the Moon,can be extracted from lunar regolith,which is highly rich in oxygen and contains polymetallic oxides.This oxygen and metal extraction can be achieved using existing metallurgical techniques.Furthermore,the ample reserves of water ice on the Moon offer another means for oxygen production.This paper offers a detailed overview of the leading technologies for achieving oxygen production on the Moon,drawing from an analysis of lunar resources and environmental conditions.It delves into the principles,processes,advantages,and drawbacks of water-ice electrolysis,two-step oxygen production from lunar regolith,and one-step oxygen production from lunar regolith.The two-step methods involve hydrogen reduction,carbothermal reduction,and hydrometallurgy,while the one-step methods encompass fluorination/chlorination,high-temperature decomposition,molten salt electrolysis,and molten regolith electrolysis(MOE).Following a thorough comparison of raw materials,equipment,technology,and economic viability,MOE is identified as the most promising approach for future in-situ oxygen production on the Moon.Considering the corrosion characteristics of molten lunar regolith at high temperatures,along with the Moon's low-gravity environment,the development of inexpensive and stable inert anodes and electrolysis devices that can easily collect oxygen is critical for promoting MOE technology on the Moon.This review significantly contributes to our understanding of in-situ oxygen production technologies on the Moon and supports upcoming lunar exploration initiatives.
基金supported by the National Major Scientific and Technological Infrastructure Project“Space Environment Simulation and Research Infrastructure”financially supported in part by the National Natural Science Foundation of China(No.52275241)the Fund for National Key Laboratory of Space Environment and Matter Behaviors(No.2023059)。
文摘0 INTRODUCTION The lunar surface lacks an atmosphere and is continuously subjected to a combination of space weathering factors such as cosmic rays,solar wind,and micrometeorite impacts,forming a several-meter-thick lunar regolith(Sorokin et al.,2020).
基金The work was performed based on the research project no.2023/51/D/ST10/01956,financed by the National Science Center,Poland.
文摘The study presents the results of over 30,000 numerical analyses on the stability of lava tubes under lunar conditions.The research considered random irregularities in cave geometry and their impact on stability,with a particular focus on the geometric characteristics of identified collapses.We propose a procedure for extracting the collapse areas and integrating it into the stability analysis results.The results were examined to assess the possibility of describing the geometry characteristics of collapses using commonly applied probability density distributions,such as normal or lognormal distribution.Our aim is to facilitate future risk assessment of lunar caves.Such an assessment will be essential prior to robotically exploring caves beneath the lunar surface and can be extended to be used for planetary caves beyond the Moon.Our findings indicate that several collapse characteristics can be represented by unimodal probability density distributions,which could significantly simplify the candidate selection process.Based on our results,we also highlight several key directions for future research and suggested implications related to their future exploration.
基金supported by International Partnership Program of the Chinese Academy of Sciences(Grant No.310GJH2024010GC)National Natural Science Foundation of China(Grant No.52005479),China Building Materials Federation(Grant No.2023JBGS0401)+1 种基金Beijing Municipal Natural Science Foundation(Grant No.2244111)Director’s Fund of Technology and Engineering Center for Space Utilization(Grant No.CAS T4035711XY)。
文摘The utilization of lunar resources is critical for the long-term sustainability of China's lunar exploration missions.In-situ manufacturing and construction using lunar regolith as the primary feedstock can provide essential support for establishing,operating,and maintaining lunar bases.This paper presents a comprehensive review of current lunar regolith forming technologies.These methods fall into two main categories,depending on whether Earth-based additives are required during the forming process.Direct forming technologies rely entirely on local materials and require minimal or no external input.In contrast,indirect forming technologies depend on additional binders or components transported from Earth.The advantages and limitations of each approach are analyzed across several dimensions,including technical principles,forming speed,forming precision,forming quality,environmental adaptability,energy consumption,and process simplicity.This paper evaluates the application potential of each method in two key lunar use cases:large-scale infrastructure construction and flexible manufacturing of fine-structured components.Based on this analysis,development trends and strategic recommendations are proposed to support the optimization and deployment of in-situ resource utilization-based lunar regolith forming technologies for diverse lunar surface applications.
基金funded by Natural Science Foundation of Jilin Province(20220101125JC)the National Natural Science Foundation of China(12273079).
文摘Lunar Laser Ranging has extremely high requirements for the pointing accuracy of the telescopes used.To improve its pointing accuracy and solve the problem of insufficiently accurate telescope pointing correction achieved by tracking stars in the all-sky region,we propose a processing scheme to select larger-sized lunar craters near the Lunar Corner Cube Retroreflector as reference features for telescope pointing bias computation.Accurately determining the position of the craters in the images is crucial for calculating the pointing bias;therefore,we propose a method for accurately calculating the crater position based on lunar surface feature matching.This method uses matched feature points obtained from image feature matching,using a deep learning method to solve the image transformation matrix.The known position of a crater in a reference image is mapped using this matrix to calculate the crater position in the target image.We validate this method using craters near the Lunar Corner Cube Retroreflectors of Apollo 15 and Luna 17 and find that the calculated position of a crater on the target image falls on the center of the crater,even for image features with large distortion near the lunar limb.The maximum image matching error is approximately 1″,and the minimum is only 0.47″,which meets the pointing requirements of Lunar Laser Ranging.This method provides a new technical means for the high-precision pointing bias calculation of the Lunar Laser Ranging system.
基金supported by the National Natural Science Foundation of China(52106276 and 52130601).
文摘Building a lunar human base is one of the important goals of human lunar exploration.This paper proposes a method for the production of oxygen by combining photothermal synergistic water decomposition with high-temperature carbon dioxide electrolysis,utilizing the full solar spectrum.The optimal oxygen production rates under different solid oxide electrolysis cell inlet temperatures T_(e),ultraviolet(UV)separation wavelengths λ_(2),infrared(IR)separation wavelengths,and photovoltaic cell materials were explored.The results indicate that the inlet temperature of the solid oxide electrolysis cell should be as high as possible so that more carbon dioxide can be converted into carbon monoxide and oxygen.Furthermore,when the ultraviolet separation wavelength is approximately 385 nm,the proportion of solar energy allocated to the photoreaction and electrolysis cell is optimal,and the oxygen production rate is highest at 2.754×10^(-4) mol/s.Moreover,the infrared separation wavelength should be increased as much as possible within the allowable range to increase the amount of solar radiation allocated to the electrolysis cell to improve the rate of oxygen generation.In addition,copper indium gallium selenide(CIGS)has a relatively large separation wavelength,which can result in a high oxygen production rate of 3.560×10^(-4) mol/s.The proposed integrated oxygen production method can provide a feasible solution for supplying oxygen to a lunar human base.
基金supported by a pre-research project on Civil Aerospace Technologies funded by CNSA(No.D020205)the Natural Science Foundation of China(Nos.42241156)+1 种基金the CUG outstanding youth team project(No.G1323523042)the Central Public-interest Scientific Institution Basal Research Fund for Institute of Geology,CAGS(No.J1904)。
文摘NWA 6950 is a type of cumulate gabbro meteorite that displays features indicating a lunar origin.Specifically,the Fe/Mn values of olivines and pyroxenes in the meteorite suggest a lunar origin,as does the presence of Fe-Ni metal.The meteorite has also undergone intense shock metamorphism,which is evidenced by the presence of ringwoodite,tuite,and xieite(a type of chromite with a CaTi_(2)O_(4)structure)within the shock melt veins(SMVs).The texture,mineral modal abundances,and bulk compositions(measured from the SMVs)of NWA 6950 are similar to those of the NWA 773 clan,as are the concentrations and patterns of rare-earth-elements in olivine,pyroxene,plagioclase,and phosphate.In-situ U-Pb dating of baddeleyite and phosphate in NWA 6950 has determined its crystallization age to be 3133±11 and 3129±23 Ma,which is consistent with age data provided by Shaulis et al.(2017).Further,the chronology of the NWA 773 clan appears to be at least bimodal when considering the age of NWA 3333(3038±20 Ma;Merle et al.,2020).The tight range of ages for the NWA 773 clan at approximately 3.1 Ga coincides with a change in the eruption flux and style on the Moon.This suggests that lunar volcanism may have shifted from extrusivedominated to intrusive-dominated at approximately 3.1 Ga,resulting in the widespread distribution of gabbro lithologies on the Moon.
基金funded by the National Natural Science Foundation of China(Nos.12172057 and 12032005).
文摘Landing spacecraft experience significant impact forces during landing,resulting in large deformation and failure in the soil surface,which severely affects landing safety and stability.This paper establishes a smoothed particle hydrodynamics(SPH)model based on the theory of soil elastoplastic constitutive relations to describe the process of a lander’s footpad impacting lunar regolith vertically.The model can provide engineering indices such as impact load and penetration depth,and illustrate the large deformation and crater characteristics of the regolith.A detailed analysis of the response of the footpad and lunar regolith during landing reveals that the process can be broadly divided into two stages of rapid penetration and oscillatory attenuation.Furthermore,there are significant similarities in the landing process under different landing velocities and footpad masses.The research investigates the large deformation and crater characteristics of the lunar regolith bed.The results demonstrate two failure modes in the regolith.Under the impact of a footpad with a smaller mass,the final failure surface of the regolith exhibits a bowl-shaped profile with a uniformly open mouth.In contrast,under the impact of a footpad with a larger mass,the final failure surface of the regolith presents an urn-shaped profile with a large abdomen and a small opening.However,the impact craters in both scenarios show a bowl-like distribution.In cases of high-velocity impacts,the impact crater exhibits obvious blocky spalling on its sides.The SPH model developed in this study can be applied to predict the large deformation and failure response of lunar soil under the impact of rigid structures as well as the impact load and penetration depth.It effectively predicts the dynamic response of the landing process,which is expected to provide a reference for engineering design.
基金supported by International Partnership Program of the Chinese Academy of Sciences(Grant No.310GJH2024010GC)National Natural Science Foundation of China(Grant No.52005479)the China Building Materials Federation(Grant No.2023JBGS0401)。
文摘The utilization of lunar regolith for construction on the lunar surface presents a critical challenge in-situ resource utilization.This study proposes a lunar regolith manufacturing method that uses a high-performance resin binder characterized by a high regolith content and strong forming capabilities.A combined resin material with both thermosetting and photosetting properties was developed and mixed with lunar regolith to create a slurry.This slurry can be directly molded or additively extruded into green bodies with specific structures.These green bodies can self-cure under the high temperatures and ultraviolet radiation experienced during the lunar day,reducing energy consumption and fulfilling the requirements of lunar construction.The material-forming processes and effects of various additive types and concentrations,regolith mass ratios,and processing parameters on the properties of the slurry and the formed specimens were thoroughly investigated.The mechanical performance and microstructure of the fabricated samples were analyzed.The lunar regolith mass ratio reached 90 wt%(approximately 79 vol%),with the highest compressive strengths exceeding 60 MPa for cast specimens and 30 MPa for printed samples.This technology shows significant potential for enabling in-situ lunar regolith-based construction in future lunar missions.
文摘A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This paper investigates the thermal processing capability of lunar regolith without the addition of binders,with a focus on large-scale applications for the construction of lunar habitats and infrastructure.The study used a simulant of lunar regolith found on the Schr?dinger Basin in the South Pole region.This regolith simulant consists of20 wt%basalt and 80 wt%anorthosite.Experiments were conducted using a high power CO_(2)laser to sinter and melt the regolith in a 80 mm diameter laser spot to evaluate the effectiveness of direct large area thermal processing.Results indicated that sintering begins at approximately 1180℃and reaches full melt at temperatures above 1360℃.Sintering experiments with this material revealed the formation of dense samples up to 11 mm thick,while melting experiments successfully produced larger samples by overlapping molten layers and additive manufacturing up to 50 mm thick.The energy efficiency of the sintering and melting processes was compared.The melting process was about 10 times more energy efficient than sintering in terms of material consolidation,demonstrating the promising potential of laser melting technologies of anorthosite-rich regolith for the production of structural elements.
基金Financial support from the project PID2021-128062NB-I00 funded by the Spanish Ministerio de Ciencia,Innovación y Universidades MCIU(doi:10.13039/501100011033)is acknowledged,as well as the Spanish program Unidad de Excelencia María de Maeztu CEX2020-001058-M.The ALBA-CELLS synchrotron is acknowledged for granting beamtime at the MSPD beamline under projects 2021095390 and 2022025734.PG-T acknowledges the financial support from the Spanish MCIU through the FPI predoctoral fellowship PRE2022-104624.JS acknowledges the financial support from projects 2021-SGR-00651 and PID2020-116844RB-C21.EP-A acknowledges financial support from the LUMIO project funded by the Agenzia Spaziale Italiana(2024-6-HH.0).DE thanks the financial support from Spanish MCIU under projects PID2022-138076NB-C41 and RED2022-134388-T from Generalitat Valenciana(GVA)through grants CIPROM/2021/075 and MFA/2022/007,which are part of the Advanced Materials program and is supported with funding from the European Union Next Generation EU(PRTR-C17.I1).RT and DE(PB and DE)thank GVA for the Postdoctoral Fellowship CIAPOS/2021/20(CIAPOS/2023/406).JS-M thanks the Spanish MCIU for the PRE2020-092198 fellowship.NWA 12008 has been studied within the framework of an international European consortium led by IFP.Special acknowledge to I.Weber for providing the NWA 12008 meteorite thin section.This work is part of the doctoral thesis of PG-T(Doctoral Program in Physics at Universitat Autònoma de Barcelona).
文摘The mechanical properties of minerals in planetary materials are not only interesting from a fundamental point of view but also critical to the development of future space missions.Here we present nanoindentation experiments to evaluate the hardness and reduced elastic modulus of olivine,(Mg,Fe)_(2)SiO_(4),in meteorite NWA 12008,a lunar basalt.Our experiments suggest that the olivine grains in this lunaite are softer and more elastic than their terrestrial counterparts.Also,we have performed synchrotron-based high-pressure X-ray diffraction(HP-XRD)measurements to probe the compressibility properties of olivine in this meteorite and,for comparison purposes,of three ordinary chondrites.The HP-XRD results suggest that the axial compressibility of the orthorhombic b lattice parameter of olivine relative to terrestrial olivine is higher in NWA 12008 and also in the highly-shocked Chelyabinsk meteorite.The origin of the observed differences is discussed.A simple model combining the results of both our nanoindentation and HP-XRD measurements allows us to describe the contribution of macroscopic and chemical-bond related effects,both of which are necessary to reproduce the observed elastic modulus softening.Such joint analysis of the mechanical and elastic properties of meteorites and returned samples opens up a new avenue for characterizing these highly interesting materials.
基金supported by 40th DLR Parabolic Flight Campaign and within the project"Powder based Additive Manufacturing at reduced Gravitation"(Grant No.FKZ:50WM2068)European Space Agency,OSIP Off-Earth Manufacturing and Construction Campaign(Grant No.4000134280/21/NL/GLC/mk)。
文摘In order to increase the sustainability of future lunar missions,techniques for in-situ resource utilization(ISRU)must be developed.In this context,the local melting of lunar dust(regolith)by laser radiation for the production of parts and larger structures was investigated in detail.With different experimental setups in normal and microgravity,laser spots with diameters from 5 mm to 100 mm were realized to melt the regolith simulant EAC-1A and an 80%/20%mixture of TUBS-T and TUBS-M,which are used as a substitute for the actual lunar soil.In the experiments performed,the critical parameters are the size of the laser spot,the velocity of the laser spot on the surface of the powder bed,the gravity and the wettability of the powder bed by the melt.The stability of the melt pool as a function of these parameters was investigated and it was found that the formation of a stable melt pool is determined by gravity for large melt pool sizes in the range of 50 mm and by surface tension for small melt pool sizes in the range of a few mm.
基金supported by National Key Research and Development Program of China(Grant Nos.2023YFB3711300,2021YFF0500300)Space Application System of China Manned Space ProgramStrategic Research and Consulting Project of the Chinese Academy of Engineering(Grant No.2023-JB-09-10)。
文摘Lunar in-situ construction using additive manufacturing(AM)technology has emerged as a critical pathway for sustainable extraterrestrial exploration.This review systematically evaluates two dominant AM paradigms for lunar regolith processing:low-temperature deposition forming(material extrusion and binder jetting),and high-energy beam additive manufacturing(powder bed fusion and directed energy deposition).Low-temperature methods achieve moderate compressive strength with low energy consumption but face challenges such as binder dependency and vacuum instability.By contrast,high-energy beam techniques enable binder-free fabrication with better compatibility for in-situ resource utilization,though they suffer from porosity,high energy intensity,and geometric limitations.In the context of lunar in-situ resource utilization(ISRU),low-temperature methods offer near-term feasibility for small-scale infrastructure,while high-energy approaches show promise for large-scale,autonomous construction by leveraging solar energy and raw regolith.Future advancements will hinge on hybrid systems that integrate material efficiency,energy sustainability,and robotic adaptability to overcome extreme environmental challenges.This review consolidates technological progress,identifies interdisciplinary synergies,and provides strategic insights into guiding the transition from Earth-dependent prototypes to self-sufficient lunar habitats,ultimately advancing the capability of humanity for a long-term extraterrestrial presence.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0503104)the National Natural Science Foundation of China(Grant Nos.42241111,62227901,and 42441826)+1 种基金the Macao Young Scholars Program(Grant No.AM201902)the Key Research Program of the Institute of Geology and Geophysics,Chinese Academy of Sciences(Grant No.IGGCAS-202401).
文摘The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP(a.k.a.urKREEP)has never been identified in previous lunar samples or meteorites.The Moon is the focus of many countries’and agencies’space exploration plans,and with the advancement of technology,crewed missions have been proposed.We propose two candidate landing sites,located respectively in the northwest(9.5°W,0.9°S)and southeast(11.1°W,6.2°S)of Lalande crater(8.6°W,4.5°S),for future crewed missions,with the primary goal of sampling the speculated urKREEP.Both sites are situated on the Th-(a critical marker of KREEP)and silica-rich Lalande ejecta in the Mare Insularum and Mare Nubium,respectively.Their geolocations at the low latitude on the lunar nearside,the flat surface,and the low rock abundance suggest the sites are safe for landing and meet the needs of real-time Earth-Moon communication.The astronauts could perform many extravehicular activities,such as collecting KREEP-rich samples,screening clast samples,and drilling regolith cores,to gather a variety of samples,such as Lalande ejecta,basalts,Copernicus ejecta,and regolith.The returned samples are valuable to explore the speculated urKREEP,to reveal the relationship between heat-producing elements and volcanism,to refine the lunar cratering chronology function,and to investigate volatiles in the regolith.
基金supported by the National Natural Science Foundation of China(Nos.52225403,52434004,and 52404365)the National Key Research and Development Program of China(No.2023YFF0615404)the Scientific Instrument Developing Project of Shenzhen University.
文摘Acquiring pristine deep lunar regolith cores with appropriate drilling tools is crucial for deciphering the lunar geological history.Conventional thick-walled drill bits are inherently limited in obtaining deep lunar regolith samples,whereas thin-walled coring bits offer a promising solution for lunar deep drilling.To support future lunar deep exploration missions,this study systematically investigates the failure mechanisms of lunar regolith induced by thin-walled drilling tools.Firstly,five thin-walled bit configurations were designed and evaluated based on drilling load,coring efficiency,and disturbance minimization,with Bit D demonstrating optimal overall performance.And the interaction mechanisms between differently configured coring bits and large-particle lunar regolith were elucidated.Coring experiments under critical drilling parameters revealed an operational window for the feed-to-rotation ratio(FRR of 2.0–2.5),effectively balancing drilling load and core recovery rate.Furthermore,a novel theoretical framework was developed to characterize dynamic drilling load parameters,supported by experimental validation.Based on these findings,practical strategies are proposed to mitigate drilling-induced disturbances,including parameter optimization and bit structural improvements.This research could provide valuable insights for designing advanced lunar deep drilling tools and developing drilling procedures.
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National Natural Science Foundation of China (Nos.U2013603,51827901,and 52403383)Program for Guangdong Introducing Innovative and Entrepreneurial Teams (No.2019ZT08G315)+1 种基金Institute of New Energy and Low-Carbon Technology (Sichuan University)State Key Laboratory of Coal Mine Disaster Dynamics and Control of Chongqing University。
文摘Lunar core samples are the key materials for accurately assessing and developing lunar resources.However,the difficulty of maintaining borehole stability in the lunar coring process limits the depth of lunar coring.Here,a strategy of using a reinforcement fluid that undergoes a phase transition spontaneously in a vacuum environment to reinforce the borehole is proposed.Based on this strategy,a reinforcement liquid suitable for a wide temperature range and a high vacuum environment was developed.A feasibility study on reinforcing the borehole with the reinforcement liquid was carried out,and it is found that the cohesion of the simulated lunar soil can be increased from 2 to 800 kPa after using the reinforcement liquid.Further,a series of coring experiments are conducted using a selfdeveloped high vacuum(vacuum degree of 5 Pa)and low-temperature(between-30 and 50℃)simulation platform.It is confirmed that the high-boiling-point reinforcement liquid pre-placed in the drill pipe can be released spontaneously during the drilling process and finally complete the reinforcement of the borehole.The reinforcement effect of the borehole is better when the solute concentration is between0.15 and 0.25 g/mL.
基金co-supported by the National Key Research and Development Program of China(No.2022YFF0503100)the Youth Innovation Project of Pandeng Program of National Space Science Center,Chinese Academy of Sciences(No.E3PD40012S).
文摘As we look ahead to future lunar exploration missions, such as crewed lunar exploration and establishing lunar scientific research stations, the lunar rovers will need to cover vast distances. These distances could range from kilometers to tens of kilometers, and even hundreds and thousands of kilometers. Therefore, it is crucial to develop effective long-range path planning for lunar rovers to meet the demands of lunar patrol exploration. This paper presents a hierarchical map model path planning method that utilizes the existing high-resolution images, digital elevation models and mineral abundance maps. The objective is to address the issue of the construction of lunar rover travel costs in the absence of large-scale, high-resolution digital elevation models. This method models the reference and semantic layers using the middle- and low-resolution remote sensing data. The multi-scale obstacles on the lunar surface are extracted by combining the deep learning algorithm on the high-resolution image, and the obstacle avoidance layer is modeled. A two-stage exploratory path planning decision is employed for long-distance driving path planning on a global–local scale. The proposed method analyzes the long-distance accessibility of various areas of scientific significance, such as Rima Bode. A high-precision digital elevation model is created using stereo images to validate the method. Based on the findings, it can be observed that the entire route spans a distance of 930.32 km. The route demonstrates an impressive ability to avoid meter-level impact craters and linear structures while maintaining an average slope of less than 8°. This paper explores scientific research by traversing at least seven basalt units, uncovering the secrets of lunar volcanic activities, and establishing ‘golden spike’ reference points for lunar stratigraphy. The final result of path planning can serve as a valuable reference for the design, mission demonstration, and subsequent project implementation of the new manned lunar rover.
基金funded by National natural Science Foundation of China(41973058 and 42473052)the B-type Strategic Priority Research Program of Chinese Academy of Sciences(XDB41020305)National Key and Development Program of China(2024YFF0807500).
文摘The size of basalt fragments in Chang’E-5(CE-5)regolith are small(<6 mm^(2)),resulting in large variation on the estimated bulk composition of CE-5 basalt.For example,the estimated TiO_(2) content of CE-5 basalt ranges from 3.7 wt% to 12.7 wt% and the Mg#(molar percentage of Mg/[Mg+Fe])also shows a wide range(26.2-42.4).Preliminary experimental studies have shown that these geochemical characteristics of CE-5 basalt are critical for investigating the crystallization sequence and formation mechanism of its parent magma.This study presents new experimental data on the distribution coefficient of titanium between pyroxene and lunar basaltic magma(D_(Ti)^(Px/melt)).Combining with available literature data,we confirm that D_(Ti)Px/melt is affected by crystallization conditions such as pressure and temperature,but it is mainly controlled by the CaO content of pyroxene.Comparing with previous experimental results under similar conditions,we parameterized the effect as D_(Ti)^(Px/Melt)=D_(Ti)^(Px/Melt)=-0.0005X_(Cao)^(2)+0.0218X_(CaO)+0.0425(R^(2)=0.82),where X_(CaO) is the CaO content in pyroxene in weight percentage.The new experimental results suggest that pyroxene with high TiO_(2) content(>2.5 wt%)in CE-5 basalt is not a product of equilibrium crystallization,and the CaO content in pyroxene is also affected by cooling rate of its parent magma.The TiO_(2) content in the CE-5 parent magma is estimated to be about 5 wt% based on the Mg# of pyroxene and its calculated CaO content,which is consistent with those estimated from olivine grains.
