最新刊期
卷 29 ， 期 2 ， 2025
- “在月球探测领域，嫦娥七号月SAR系统实现高分辨率成像，揭示月球表面结构与物质特性，为中国探月工程提供重要支撑。”
摘要：Synthetic Aperture Radar (SAR) is an active microwave imaging sensor that can achieve high-resolution microwave imaging of the entire lunar surface (especially permanently shadowed regions) without the limitation of lighting conditions. The penetration of SAR enables it to reveal the structure and properties of the subsurface; hence, it is indispensable in lunar exploration. Since the beginning of the 21st century, high-resolution, multipolarization, and multifrequency microwave image data obtained by lunar orbit SAR have provided important information for deepening the understanding of the structural characteristics and material composition of the lunar surface as well as clues for exploring the geological structure of the moon and the evolution of celestial bodies. However, due to the lack of intuitiveness, difficulties in registration, severe deformation distortion, and multiple inversion parameters in SAR data compared with traditional optical images, SAR has not yet widely applied in lunar scientific research. This paper first outlines the development of SAR in lunar exploration and introduces the overview of the lunar SAR system of Chang’E-7 mission in the fourth phase of China’s Lunar Exploration Project, including the frequency, polarization, resolution, and the swath of current or outcoming lunar orbit SAR systems and their scientific objectives. The interpretation and application of lunar SAR data can be divided into three levels: radar backscatter intensity analysis, polarization characteristic parameter analysis, and target physicochemical characteristic parameter inversion. Subsequently, the application of SAR data in lunar scientific research is summarized systematically from three aspects: material characteristics of lunar surface, morphological structure, and water ice detection. Lunar material characteristics are preliminary retrieved by SAR data including the permittivity, surface roughness, rock abundance, and the thickness of regolith. The morphological structures can be identified and interpreted on SAR images including the impact crater, sputtering sediments, and volcanic landforms. The present situation and existing problems in lunar water ice detection by SAR data are also analyzed. On this basis, many difficulties and trends in the application of lunar SAR data are discussed to support the design of SAR payload systems, radar data processing, and image interpretation applications in China’s future lunar exploration projects. The achievement of multifrequency, multiangle, high polarization accuracy, high sensitivity, and low ambiguity imagery under the limitation of the minimum antenna area and transmission power for SAR system in deep space is the prerequisite for obtaining multidimensional, high-precision SAR images. New systems and technologies for lunar orbit SAR imaging are required under multiple constraints including limited resources of satellite platform and complex design of radar payload. Moreover, the high-precision calibration methods for lunar orbit SAR are still lacking. Complete calibration models and high-precision calibration benchmarks are required based on precise electromagnetic scattering modeling and analysis of lunar surface materials or targets. On this basis, the interpretation methods of planetary microwave remote sensing data are expected to be studied based on the comprehensive study of the research content and method characteristics in the field of planetary geological science.关键词：synthetic aperture radar;lunar exploration;high-precision imaging;water ice detection370|126|0更新时间：2025-03-27 - “在天体研究领域，专家全面梳理了综合使用影像和数字高程模型的撞击坑检测方法，为月球及类地行星表面研究提供新方向。”
摘要：Impact craters are ubiquitous on the surface of the Moon and most planets, which are important data sources for celestial body research. The detection methods for impact craters have evolved from manual visual inspection to computer-automated detection. At present, impact crater detection methods are many, and the earliest ones are based on image data or Digital Elevation Model (DEM) alone. With the continuous enrichment of spatial exploration data, and in consideration of the complementary strengths of both image and DEM data, a trend of using images and DEMs has developed in recent years. These methods can fully leverage the advantages of both types of data, thereby enhancing the efficiency and accuracy of automatic crater extraction. Given the lack of comprehensive reviews in this domain, the existing impact crater detection methods are examined using images and DEMs, and classified into four categories in this paper: The first is the image-based DEM supplemented method, which Utilizing the high resolution and morphological texture features of images, supplemented by the three-dimensional characteristics of DEM to optimize detection results. The second is the DEM-based image supplemented method, to detect impact craters through their three-dimensional morphological characteristics, and then verification and optimization using image data. These two methods have their advantages in impact crater detection. For example, they take one data as the main data and the other as the supplemental data to optimize the impact crater detection results, and the accuracy can be improved. The third is the combined method, in which impact craters are first detected using image data and DEM separately, and then combined to generate the final results to compensate for the shortcomings of using only one data and to effectively employ the respective advantages of image data and DEM as well as enrich the impact crater data sets. The fourth is the fusion method, in which image and DEM covering the same area are used together as training samples and the samples are fused as the input to the algorithm to obtain an unified detection model. The advantages of this method are that the fusion of image data and DEM before the crater detection helps train the unified detection model, can input a single type of data to detect craters, and can meet the requirements of the transfer learning. In this paper, the representative works of these four categories are summarized, the advantages and scope of applicability of different methods are examined. The image-based DEM supplemented method and DEM-based image supplemented method enhance detection accuracy through complementary optimization. Combined method fully leverage the respective advantages of image and DEM to enrich crater datasets. While fusion methods enhance model generalization capabilities via data integration and unified model training. Finally, we identify research hotspots and future development directions in this field, with the aim of serving as a theoretical foundation for advanced crater detection research.关键词：terrestrial planet;crater detection;image data;digital elevation model;machine learning137|73|0更新时间：2025-03-27 - “在深空探测领域，行星地质图研究进展缓慢，各国制图标准差异大。美国体系完善，欧洲航天局创新，中国正形成制图标准。”
摘要：Planetary geological map is an important expression form of achievements in deep space exploration and the basic data of planetary mineral reserve estimation. The mapping system of the planetary geological map is a cartographic product system based on the geological information of a specific area, and the complex geological information is expressed through the use of graphic elements with colors and patterns. Although various countries have performed numerous planetary exploration activities, the research progress of planetary geological mapping is slow. The mapping achievements are concentrated in the last century, and the standards of planetary geological mapping vary greatly among countries. Previous planetary mapping was mostly performed manually using telescopes and observatories. The simple sketches drawn in this way are of a single type and are not conducive to updating and storage, which cannot meet the needs of people for planetary exploration. After human exploration of the moon began, scientists started using the image as the basis for geological structure interpretation and geological mapping. Especially during the Apollo mission, to meet the landing area selection and lunar surface patrol route design, National Aeronautics and Space Administration (NASA) scientists drew many lunar geological maps to support lunar exploration missions. After the 20th century, with the rapid development of computer technology, the Geographic Information System (GIS), which is powerful, user friendly, and easy to use, uses data tools to replace hand-drawn maps gradually. Today, planetary maps can be viewed and edited in a multilayered, multiprojection, multistyle GIS, WebGIS, or Web Mapping Service. Digital technology has not only changed the map interface for mapmakers and users, but also gradually altered the way map data are collected. This paper clarifies the history of planetary mapping in various stages and the planetary geological mapping systems of diverse countries. At present, the United States (US) has a perfect planetary geological mapping system. Standardized maps in the US undergo a thorough technical review to achieve scientific objectivity and cartographic standardization and meet strict cartographic standards. The European Space Agency (ESA) has formed unique nonstandard mapping products based on the US cartographic system. Compared with standardized maps, nonstandardized maps are flexible, exploratory maps that can more easily respond to data inflows and innovations. Nonstandardized maps are more focused on providing users with multilevel digital maps. China is also formulating a complete set of planetary mapping standards. At present, domestic scientists have made a large amount of research work in the field of planetary geological mapping and have obtained a series of research results for extraterrestrial bodies such as the moon and Mars. However, China has not yet built a more accurate and perfect planetary geological mapping system. How to process and analyze more deep space exploration data and form standard geological map products will be an urgent problem to be solved. Based on the planetary mapping system of NASA and ESA, and combined with the characteristics of China’s deep space exploration data, China should form a perfect planetary geological mapping system that can support the output and international promotion of high-level research results of Chinese exploration mission data.关键词：planetary mapping;mapping history;drawing system;planetary geological map;planetary cartography;planetary exploration;coloring;compilation of lunar digital geological maps87|56|0更新时间：2025-03-27
Reviews
- “最新研究揭示月球光学影像与SAR图像匹配技术，HAPCG算法表现最佳，为月球多源数据应用提供参考。”
摘要：Multimodal image matching methods have been widely applied in the registration of multisource remote sensing images of the Earth, but comparative research on the application of multimodal registration of lunar images is lacking. To facilitate high-precision alignment between high-resolution lunar optical imagery and Synthetic Aperture Radar (SAR) imagery, this paper conducts an experimental comparison across various lunar regions, including mid latitude, low latitude, the Antarctic, and the Arctic, using a suite of eight algorithms: Scale-Invariant Feature Transform (SIFT), region-based Channel Features of Orientated Gradients (CFOG), Histogram of Orientated Phase Congruency (HOPC), the structural feature-based Radiation-variation Insensitive Feature Transform (RIFT), Histogram of Absolute Phase Consistency Gradients (HAPCG), and Histogram of the Orientation of the Weighted Phase descriptor (HOWP), along with the deep learning models SuperGlue and Local Feature Transformer (LoFTR). The performance of these algorithms is evaluated through four metrics: the number of correct matches, root mean square error, repeatability, and coverage. The findings reveal that the HAPCG algorithm, which integrates anisotropic filtering with a composite feature vector, outperforms the others in terms of matching quality. The LoFTR algorithm leverages self-attention and cross-attention mechanisms, and demonstrates robust performance, particularly for lunar imagery with sparse textures. The HOWP and SuperGlue algorithms exhibit midrange performance in terms of matching efficacy. By contrast, the CFOG, HOPC, and RIFT algorithms yield the least satisfactory results, and the SIFT algorithm fails to establish any matches. The distribution of matched points is influenced by factors such as imaging illumination conditions and the extent of the overlapping regions, and matches in mid- and low-latitude areas are more successful than those in polar regions. A statistical analysis of the Stokes parameter for the HAPCG matches indicates that the mean values of the scattering characteristic parameters for points in the Mare and highland experimental areas are higher than those in polar regions, which aligns with the topographical characteristics. Scatter plots also show a correlation between the Stokes parameter of the HAPCG-matched points and the grayscale values of the optical images, which underscores the algorithm’s robustness in matching under conditions of nonlinear radiative variability between optical and SAR imagery. To improve the multimodal matching algorithms in the future, effective feature descriptors can be developed to extract the feature points and combine them with the geological knowledge of lunar images. Moreover, robust error removal models can be studied to improve the accuracy of matching feature points between lunar optical image and SAR image. In addition, public datasets of lunar optical images and SAR images for deep learning methods can be constructed to improve the generalization ability of existing machine learning models. Based on the imaging mechanism of lunar optical images and SAR images, the deep semantic information of lunar multimodal images can be determined, and a new multimodal image matching network can be constructed. This paper offers insights into the selection of appropriate matching methodologies for lunar optical and SAR imagery, and thereby enhances the utility of lunar multisource data.关键词：Moon;Multi-modal image matching;SAR images;Optical images;Stokes vector320|652|0更新时间：2025-03-27 - “在行星遥感领域，专家提出了一种TDI-CCD影像重构和RPC拟合方法，为高保真处理提供便捷方案。”
摘要：The variation in integration time between lines in planetary TDI-CCD (Time Delayed Integration) images makes it difficult to directly use the Rational Function Model (RFM) for geolocation. However, research addressing the challenges posed by variable integration time imaging in planetary TDI-CCD imaging remains limited. This scarcity of studies hinders the processing of such imagery in general photogrammetric software, as well as its joint processing with other types of imagery. To address this issue, this paper proposes a reconstruction method for planetary TDI-CCD variable integration time imagery, enabling high-precision fitting of Rational Polynomial Coefficients (RPC). The method is based on the assumption of uniform exposure time across each image line in virtual imaging scenarios. First, using the auxiliary files of the raw imagery, the start time of the first line and the integration time per line are accumulated to determine the total imaging duration of the entire scene. Each line integration time and initial imaging time of the raw imagery are then utilized to calculate the central imaging time for all original lines. Second, the total imaging duration and the number of lines in the imagery are used to compute the average integration time per line and the virtual imaging time at the center of each reconstructed line. Third, the virtual line center imaging times are compared with the original line center imaging times to identify the two lines from the raw imagery with imaging times closest to each virtual line center. Linear interpolation and resampling are then applied, based on the temporal relationship between the virtual line centers and their neighboring original lines, to reconstruct each line of the re-build image. Finally, the original satellite orbital and attitude data, sensor parameters, and virtual imaging times are utilized to establish a rigorous model for the reconstructed imagery and it’s RPC fitting accordingly. The experiment, conducted on five panchromatic multi-view stereo images from the Mars Express High Resolution Stereo Camera (HRSC) and two stereo images from the Chang’E-2 lunar mission, demonstrate that the RPC fitting accuracy and the relative accuracy between the RFM models of the reconstructed images and rigorous models of the original images both achieve a precision of 0.01 pixels. This method avoids the transformation calculations between the ray paths of the original and virtual images. It also circumvents the loss in radiometric accuracy resulting from twice resampling and the potential parallax errors stemming from topographic inaccuracies in existing methods. This paper offers a more streamlined processing approach for reconstructing TDI-CCD variable time-integral images and fitting RPCs, ensuring higher fidelity to the original image's radiometry and geometry, laying a solid foundation for large-scale adjustment, 3D reconstruction, and global mapping applications of various planetary remote sensing images.关键词：planetary photogrammetry;TDI-CCD;virtual imaging;Rigorous geometric model;RFM;lunar remote sensing mapping;mar remote sensing mapping55|46|0更新时间：2025-03-27 - “在月球探测领域，专家提出了基于多张单目影像光度法的像素级三维重建方法，有效重建月球南极高精度DEM，为月球南极探测提供数据支撑。”
摘要：Three-dimensional mapping of the lunar surface is of immense importance for lunar exploration missions and scientific research. Research in the past decades has mainly focused on laser altimetry and photogrammetry methods to generate precise DEM based on rigorous mathematical calculation. Due to the limitation of the hardware and algorithms, these methods cannot meet the requirements for exploration of the lunar south pole, which demands meter-level resolution to guarantee safe descending and traversing. Thus, photoclinometry has received much attention because it can make full use of the images to reconstruct pixel-wise-resolution DEMs from monocular images. However, the lunar south pole suffers from solar elevation angles of nearly 0 degree, and the shadow effect is severe such that effectively recovering all the terrain details using only a single image is not possible. Moreover, the loss functions established directly from multiple images in the photoclinometry algorithm may be inconsistent due to the major differences among the images caused by the varying illuminations. This limitation may cause difficulties in converging the loss and may prevent recovering the terrain. The paper presents a multiple image photoclinometry method for pixel-wise 3D reconstruction at the lunar south pole. The inputs of the method are multiple high-resolution images and corresponding low-resolution DEM, and a multi-resolution pyramid is used to optimize the DEM step by step. In terms of the loss function, this paper proposes a similarity constraint by fully considering the shadow differences between the lunar south pole images. Rather than optimizing a single DEM, the approach initializes multiple DEMs using the low-resolution DEM associated with each image. While the conventional photoclinometry constraints are established on each DEM, an encourage mechanism is then introduced to ensure the pixels cover the same region exhibit consistent elevation. With respect to the loss optimization, an adaptive learning rate optimizer is introduced to guarantee the convergence of the loss function. The gradient update information in the optimization stage could also provide a reference for the photometric quality of the image, which becomes an important index for the following DEM fusion. Two regions are selected around the Shackleton Crater at the lunar south pole for experimental analysis. Regarding the LDEM and photogrammetric DEM as the reference, the geometric accuracy of the DEMs generated from the proposed approach is about one pixel, and the terrain details (e.g., small craters and ridges) presented on the images are fully reconstructed. Rendering simulation is also conducted based on the reconstructed photoclinometry DEM for in-depth evaluation. By analyzing the DEM under various illumination conditions, the simulated images closely resemble the original NAC images, and thereby demonstrate the accuracy and precision of the photoclinometry-derived DEM. The method presented in this paper can effectively reconstruct high-resolution, high-precision DEMs from monocular images at the lunar south pole, and provide important 3D data support for future exploration missions to the lunar south pole and related scientific research.关键词：Lunar South Pole;DEM;pixel-wise 3D reconstruction;photoclinometry;photogrammetry86|50|0更新时间：2025-03-27 - “在月球表面撞击坑识别领域，专家提出了基于迁移学习的无锚深度卷积神经网络自动识别方法，有效解决了小尺度撞击坑识别难题，为月球表面年代研究提供新方案。”
摘要：Impact craters are the most typical and common geomorphic units on the lunar surface. Their morphological WU characteristics and spatial distribution record the evolution history, climate formation, and surface age of the moon. Due to the impact crater’s fuzzy edges and nested impact craters, the automatic recognition of impact craters (especially small-scale one) still faces problems such as low accuracy and difficulty in identifying small-scale within large-scale impact crater. Therefore, to address these, this paper proposes an automatic anchor-free convolutional neural network method based on transfer learning strategy to locate and identify small-scale lunar impact craters automatically.Instead of using postprocessing operations such as nonmaximum suppression, the proposed method directly locates the centers of impact craters and regresses their sizes on the high-resolution feature map generated by the stacked hourglass network; thus, it realizes the automatic recognition of different types of impact craters. Moreover, the idea of transfer learning is used for training, not from scratch, so that the model has higher reliability and robustness.This paper selects the Orthophoto image captured by the LRO WAC camera on the Lunar Reconnaissance Orbiter and the Robbins impact crater database in the Sinus Iridum and Oceanus Procellarum region to verify the reliability and robustness of the developed method. The method in this paper achieves a recall rate of up to 74.71% and an accuracy of up to 75.97%. Compared with other existing methods, the proposed method shows remarkable advantages in recognition accuracy and a high adaptability in extracting and identifying impact craters in different areas of the lunar surface. Comparing the performance and accuracy by drawing roc curves of different models reveals that transfer learning can effectively help the models converge better and improve the performance of model classification. The number of craters identified by the model is calculated and compared with the number of craters in the Robbins database. Results show that the proposed model can identify small-scale craters, and the number of craters identified in a certain diameter range is greater than that in the Robbins database. Therefore, the proposed model can provide a new tool for improving the lunar surface impact crater database.The automatic recognition model in this paper can effectively extract impact craters and can to a certain extent solve the identification of small and medium-sized impact craters within nested impact craters. The key insight behind the developed method is to improve the model recognition accuracy based on transfer learning. The proposed method does not need the non-maximum suppression operation, which would effectively identify small and medium-sized ones within nested impact craters. Although the developed method shows a superior recognition performance for the lunar impact craters, the following shortcomings must be addressed. The generalization of the model still needs to be further improved. Therefore, future work will also make full use of the similarity of impact craters in different regions to reduce the missed detection rate of impact craters on the lunar surface.关键词：Impact crater extraction;Intelligent recognition;deep learning;target recognition;Sinus Iridum region;Oceanus Procellarum region1188|485|0更新时间：2025-03-27
Planetary Data Processing
- “国际月球科研站建设，中国科学家基于多源数据分析，为选址和科考提供重要参考。”
摘要：The establishment of the International Lunar Research Station (ILRS) is an important space strategic deployment for China that conforms to the current situation. The moon is an important part of deep space scientific research that cannot be ignored. Exploration of the moon marks a country’s space capability. Cooperation in lunar exploration and utilization, and building a lunar research station is the future direction of development. China’s lunar exploration is moving from independence to mutually beneficial. Chang’e-4 has created a new situation for the first time, in which China leads in promoting multinational cooperation in joint Chinese and foreign exploration. In 2021, based on the existing Exploration of the Moon plans of China and Russia, China National Space Administration and Roscosmos jointly launched the ILRS project. To study the application of topography analysis based on multisource data in the construction of ILRS, the “ILRS plan” is divided into site selection and scientific research stages. The constraint conditions to be considered in the site selection stage of ILRS are analyzed, the application of orthophoto, lunar surface topography, multi/hyperspectral image, lunar radar, gamma rays, and other multisource data in the site selection stage is briefly described, and the multisource data of Chang’e-2 DOM, DEM, LRO diver radiometer, LOLA laser altimeter, and geological mapping are used to examine the topographic characteristics, temperature conditions, lighting conditions, earth visibility, and geological characteristics. Many factors that should be considered in the ILRS site selection stage and the regional characteristics suitable for landing site selection are proposed. To achieve the scientific goals of ILRS, the landing area should have conditions such as gentle terrain fluctuations, minimal changes, suitable lighting and temperature, and convenient water ice detection. Taking the Amundsen area as an example, three candidate landing sites are selected. Based on the best decision model and the multicriteria decision model, qualitative and quantitative decision analysis is conducted for the three candidate points proposed in this paper. Taking Shackleton, Shoemaker, de Gerlache, and Amundsen impact craters as examples, based on the analysis results of multisource data, this paper provides a reference for the planning of inspection route, the analysis of water ice detection, and the establishment of observation base stations in the ILRS scientific research phase. The shape of the impact crater in the study area affects the planning of the inspection route. When setting the inspection route, the area with complex, changeable shape of the impact crater should be avoided. The permanent shadow area in the large impact crater should be emphatically analyzed to ensure the successful realization of water ice detection and to reduce the risk and resource waste caused by misjudgment. Areas with higher visibility to the sky and ground are more suitable for establishing observation base stations to ensure the continuous, stable progress of observation tasks. The topography analysis results based on multisource data have important reference value for ILRS location and scientific research tasks.关键词：International Lunar Research Station;multi-source data;morphology analysis;site selection;scientific research242|396|0更新时间：2025-03-27 - “在火星表面研究领域，专家提出了基于视觉基础模型的火星横向风成脊零样本遥感解译方法，为火星气候历史重建提供科学依据。”
摘要：Studying the morphological characteristics of transverse aeolian ridges can help reveal the interaction between the Martian thin atmosphere and the Martian surface. In the past few decades, remote sensing exploration has greatly promoted our understanding of Martian aeolian landforms and processes. However, existing research mainly relies on the visual interpretation of remote sensing images, and the substantial amount of manual labor limits its research scope. Although several recent studies have applied deep convolutional neural networks to automatic recognition of transverse aeolian ridges, these methods cannot obtain segmentation masks for individual transverse aeolian ridges and typically rely on a large number of manually annotated training samples. Therefore, developing novel methods is of foremost importance.In response to the above issues, this paper proposes a zero-shot remote sensing interpretation method for Martian transverse aeolian ridges based on the visual foundation model. The overall framework of this method consists of three main steps: First, by leveraging the universal segmentation capability of visual foundation models, fine segmentation of Martian high-resolution images is achieved without training samples. Second, based on the geometric and spectral constraints for transverse aeolian ridges, segmentation masks of transverse aeolian ridges are robustly filtered out from all segmentation masks of the image. Finally, based on the segmentation mask of each transverse aeolian ridge, the corresponding morphological parameters are calculated.On the public dataset M-TARset, this method achieves an accuracy of 94.33%, a recall of 92.32%, and an F1-score of 0.93, and outperforms other state-of-the-art methods for transverse aeolian ridge detection. This method achieves high accuracy and recall on six different regions of test data, and differences in F1-scores obtained in different regions are observed. Compared with flat areas, the overall accuracy of this method is lower in areas with closely distributed transverse aeolian ridges and other geological structures similar to transverse aeolian ridges. In addition, large-scale statistical analysis experiments show that transverse aeolian ridges in the landing area present a generally consistent east-west orientation, and indicate that the dominant wind direction in the landing area is about 10° northeast wind. Moreover, the frequency histograms of the length, width, perimeter, and area of transverse aeolian ridges in the landing area show a right skewed pattern that generally follows a log normal distribution, which is consistent with previous research results.Remote sensing interpretation of Martian transverse aeolian ridges is a meaningful, challenging task in planetary geological surveys. In response to the shortcomings of existing research, this paper proposes a new zero-shot remote sensing interpretation method for transverse wind ridges based on the visual foundation model SAM. The performance of this method is assessed on the public dataset M-TARset and a HiRIC orthophoto map covering the landing site of Tianwen-1. The experimental results verify the effectiveness of the proposed method. In the future, the performance of this method will be further improved, and global-scale fine interpretation of Martian transverse wind ridges will be performed to provide fundamental data for reconstructing the Martian climate history and improving the Martian global climate model.关键词：Tianwen-1;transverse aeolian ridge;Remote Sensing Interpretation;visual foundation model;zero-shot generalization;instance segmentation;morphological analysis;Martian climate158|81|0更新时间：2025-03-27
Planetary Morphological Analysis
- “据最新报道，科学家在月球莫斯科盆地和史密斯海发现低亮温差异常，揭示月壳成分不均匀性，为月球撞击演化研究提供新线索。”
摘要：The thermal physical properties of lunar regolith are crucial for unraveling the moon’s thermal history, geological evolution, and viability of in-situ resource utilization, and the thermal anomaly is a key area of interest. Microwave observations can reveal subsurface characteristics about lunar regolith from centimeters to meters in depth, and remarkably enhance our understanding of these properties. The microwave radiometer (MRM) onboard Chang’E-2 (CE-2) conducted passive microwave remote sensing of the moon at frequencies of 3.0, 7.8, 19.35, and 37 GHz from 2010 to 2011. The employment of multichannel, multitemporal MRM data provides a new perspective on thermal anomalies.Considering that Brightness Temperature (TB) is strongly affected by latitude, the difference between the TB values of the same frequency generated at two dissimilar local times is introduced, named dTB, which indicates an excellent description of the thermophysical characteristics of the mare deposits in the wavelength-related penetration depth. Utilizing dTB obtained at 37 GHz, along with numerical simulations of brightness temperature, and integration with Clementine UV-VIS, LRO Diviner, and DEM data reveal the substantially low dTB at 37 GHz in the eastern and southern highlands of the Moscoviense basin. The statistical analysis of the anomalous region and the western highlands, the corresponding FeO, TiO2, rock abundance, and DEM data do not show the same trend of change. Hence, the known compositional and topographical data cannot explain the genesis of the low dTB anomaly.The existence of low dTB anomalies is confirmed in Mare Smythii. Taking the highlands at the same latitude and the Chang’e-5 landing region with normal brightness temperature differences as references, the EM unit in Mare Smythii exhibits lower dTB at 19.35 and 37 GHz. Furthermore, comparative analysis with the compositional data from Chang’e-5 landing region reveals that currently known compositions cannot account for the low dTB anomalies. The anomaly may likely be due to a component that has not yet been detected or identified.Additionally, the discovery of low dTB anomalies in the Apollo basin and Balmer region provides valuable clues for understanding these phenomena. Based on the impact cratering model, the low dTB anomaly in the Apollo basin is likely due to the rebound of deep lunar crustal materials during the impact process. The anomaly in the Balmer region corresponds with the location of the impact crater ejecta coverage, which suggests that the material causing the low dTB anomaly likely originated from the excavation of deep lunar crustal materials by impact events, which indicates vertical heterogeneity in the lunar crust’s composition.The discovery of low dTB anomaly provides a new insight for further research on the thermal radiative properties of lunar regolith, and the localized and previously undetected material offers innovative scientific views for investigating the moon’s impact evolution history and the properties of shallow crust.关键词：Low brightness temperature difference anomaly;Microwave radiometer;brightness temperature;Regolith composition;Geological significance183|535|0更新时间：2025-03-27 -
Geological characteristics of the landing area of the Zhurong Rover in the Utopia Planitia， Mars AI导读
“中国首个火星探测任务天问一号探测器成功登陆火星乌托邦平原，祝融号火星车将对撞击坑、风成脊等地貌进行探测，为研究火星地质演化提供重要数据。”
摘要：China’s first Mars exploration mission Tianwen-1 probe is composed of an orbiter, a lander, and a rover (Zhurong). The Zhurong rover successfully landed on the preselected landing area in the southern Utopia Planitia in the Martian northern hemisphere on May 15, 2021. Utopia Planitia might have an environment capable of nurturing life in the past; thus, the traversing and in-situ exploration by the Zhurong rover in this region will produce wealthy scientific outputs. To provide context for the analysis and interpretation of the in situ measured and the remotely sensed data acquired by the rover and the orbiter, this article uses available remote sensing images and products to analyze the geological characteristics within 50 km of the landing site of the Zhurong rover and produces a geological map. The main landforms in the landing area are impact craters, troughs, cones, and traverse aeolian ridges. At a baseline of 200 m, the general elevation is high in the south and low in the north, and the terrain is flat, which is very suitable for the follow-up traversing and in-situ measuring. The thermal inertia of the landing area is low, and only a few semi-buried rocks are on the surface of the regolith, which indicate the surface regolith is vulnerable to thermal disturbance. Limited by the low resolution of hyperspectral images and/or the lack of absorption features of the surface materials, the compositions and abundances of the minerals in the landing area are temporarily unknown; thus, the in-situ measurements by the rover are urgently needed to fill the current vacancy. Considering the impact-origin of the Utopian basin and the possible existence of a giant paleo-ocean and its subsequent evolution in the northern hemisphere of Mars, this paper proposes that the Utopian Planitia mainly experienced a complicated geological transformation and evolution, including formation of impact basin (Pre-Noachian), infilling of flowing water sediments (Noachian), development of typical landforms, for example, impact craters (Hesperian), and partial coverage of volcanic materials (Amazonian). This paper combines the geological characteristics of the landing area and the scientific payloads carried by the Zhurong rover, and suggests that the rover should select the traverse aeolian ridge, the trough, and the pitted cone in the southern of the landing area as the rover’s short-, mid-, and long-term priority detection targets, respectively. Their formation mechanisms or classifications may be determined through a comprehensive analysis from the viewpoint of morphology, mineralogy, stratigraphy, and climatology. The results of the in-situ measurements will greatly promote the understanding of the geological evolution of Utopia Planitia in the planetary science community and can even support a comprehensive evaluation of the possible paleo-ocean and habitable environment in the past.关键词：Mars;Tianwen-1;Zhurong Rover;Utopia Planitia;landing area;geological characteristics;priorities for exploration120|54|0更新时间：2025-03-27 - “嫦娥四号探测器成功着陆月球背面，为分析月球背面形成与演化提供科研数据。”
摘要：Chang’E-4 is the first detector that successfully landed in the Von Kármán crater on the lunar farside and released the Yutu-2 rover for in-situ scientific detection. The landing site is in the northeastern part of the South Pole-Aitken Basin, the largest impact structure of the moon, and scientific datasets obtained from the Yutu-2 rover may provide valuable clues to the formation and evolution of the lunar farside. Subsurface structures and material compositions concealed beneath the lunar surface hold valuable insights into geological history, even as meteoritic impacts and solar weathering erase surface traces. In this paper, in-situ lunar penetrating radar, orbiter optical and multispectral data, and geological map are integrated to analyze the subsurface structure, mineralogical composition, and material sources of the shallow material in the Von Kármán crater. For craters with diameter of 100 m, scientists usually determine whether the impact penetrated the regolith layer based on the presence of dark-colored bedrock material in the crater ejecta. Therefore, bright craters with small diameters may not penetrate the regolith layer. Based on Crater Helper Tools for ArcMap, 2495 bright craters were identified and the iron oxide content, optical maturity index, and the relative abundances of plagioclase, clinopyroxene, orthopyroxene, and olivine at crater centers were derived. Based on the 2495 mineral sample points obtained at different depths, the mineral composition variations at various depths were analyzed by 3D spatial interpolation using 3D Empirical Bayesian kriging. The spatial point patterns of bright craters were also used to examine crater densities, proximity distances, and positional relationships to infer ejecta source directions. Results show that the subsurface structure can be divided into a four-layer structure consisting of the regolith layer, ejecta layer, paleo-regolith layer, and basalt layer. The shallow material in the Von Kármán crater is mainly divided into endogenous material, ejecta material, and deeper materials (around the Zhinyu crater). Endogenous materials are predominantly found in the southern and western parts of the Von Karmen crater, with high abundances of orthopyroxene, olivine, and iron oxides. Ejecta materials are mainly located in the southeastern, northeastern and Mons Tai, and characterized by an enrichment of clinopyroxene and plagioclase; the southeastern ejecta is plagioclase rich, and the northeastern ejecta is clinopyroxene rich. Deeper materials are dominated by materials excavated during the formation of the Zhinyu crater, with high contents of orthopyroxene, olivine, and iron oxides. The eastern part of the Von Karmen crater is heavily affected by ejecta materials, which mainly come from the Von Kármán L crater to the southeast and the Finsen crater to the northeast. The Chang’E-4 landing area is in the overlapping area of different ejecta, and the surface material is successively covered by the Finsen ejecta and the Zhinyu ejecta.关键词：lunar shallow structure;Chang’E-4;Von Kármán crater;crater distribution;spatial statistics;mineral composition;empirical Bayesian kriging;material origin66|54|0更新时间：2025-03-27 - “最新研究揭示阿蒙森撞击坑地质特征，为月球南极探测提供重要参考。”
摘要：The Amundsen impact crater, with a diameter of about 103 km, is one of the most remarkable geomorphological features in the south polar region of the Moon. The crater floor hosts extensive plain terrains and permanent shadowed regions, with the enrichment of hydrogen elements, making it one of the most prioritized candidate landing areas for future volatile prospecting missions in the lunar south polar region. However, the detailed geological characteristics and evolution history of this region are poorly constrained. To serve future exploration needs of the lunar polar regions, investigated the geological context and characteristics of the Amundsen region are systematically using multisource high-resolution remote sensing data including topography, spectroscopy, and solar illumination conditions. The topographical signature of the Amundsen crater is well preserved and is one of the representative complex impact craters on the Moon. Over 2000 km2 of plain terrains occur on the crater floor, with an average slope less than 5°. The composition and albedo analyses reveals that these floor plains are characterized with high albedo and low iron content, which is clearly different from mare plains, and indicate that these plains probably originated from ejecta materials from distant impact craters/basins, especially the Schrodinger basin, rather than volcanic eruption. In addition, the Amundsen crater area is characterized with elevated abundance of hydrogen, which shows its enormous potential for water ice prospecting. A new, large-scale geological map of the Amundsen area is created, and the regional multistage geological evolutionary history is investigated. Comparison with the Von Kármán crater mare plain where China’s Chang’e-4 mission landed suggests that the Amundsen crater floor plain has the topographical conditions for soft landing efforts, while its special characteristics of solar illumination condition, surface temperature, and the provenance of the plains materials bring scientific opportunities and technological challenges for landing exploration missions.关键词：Amundsen crater;lunar polar region;permanently shadowed region;volatile components;morphology;geological evolution358|709|0更新时间：2025-03-27 - “据最新报道，中国计划2030年左右实施“天问三号”火星采样返回任务。专家分析火星Cerulli撞击坑区域地质特征，推断该区域可作为未来火星采样返回任务的备选着陆点。”
摘要：China plans to conduct the “Tianwen-3” Mars sample-return mission around 2030 to understand the habitability of Mars further and search for the potential signs of Martian life. Selecting a suitable landing site is crucial to ensure the successful achievement of mission objectives. In this paper, the geological characteristics of the Cerulli crater area in the northwestern Arabia Terra of Mars are studied in detail utilizing high-resolution remote sensing images and topographic data. Multiple landform types are identified within the study area, including impact craters, water-related landforms, and glacial landforms. The primary types of impact craters observed within the study area include ancient craters covered by ejecta blankets, fresh craters with central pits, typical ring-mold craters, and craters filled with ice-rich deposits. The main water-related landforms are Type-1 valley networks, which are elongated and sinuous, with narrow widths and well-defined edges. Additionally, Type-2 valley networks, which are wider and often develop at the termini of Type-1 valley networks with linear fissures visible at their floo, are observed. The Mamers Vallis, an outflow channel partially buried by the Cerulli crater and its ejecta blanket, is also identified. In addition to ring-mold craters and glacial landforms at the floo of valley networks, the glacial landforms in the study area include viscous flow features, which are concentrated around the central peaks of the craters. Furthermore, this paper conducted crater counting and compiled a geological map of the study area. The research findings indicate that the Cerulli crater formed at the Noachian/Hesperian boundary (around 3.7 Ga) and suggest that Mamers Vallis was formed during the Noachian period, prior to 3.7 Ga. At the Noachian/Hesperian transition, the Cerulli crater formed and covered parts of the Mamers Vallis outflow channel and earlier craters with its ejecta blanket. Simultaneously, water activity triggered by the impact event formed various water-related landforms within the ejecta blanket and crater. From the Hesperian to the Amazonian period, after the formation of the Cerulli crater, new craters emerged and modified the crater floor and ejecta blanket of the Cerulli crater. The region may have undergone multiple glacial activities and formed various glacial landforms such as viscous flow features and ring-mold craters within the region, and potentially new valley networks carved by glacial meltwater. The formation mechanism of the valley network in the region may be related to the release of liquid water triggered by impact events or glacial activity resulting from changes in the Martian obliquity. The complex water activity characteristics in this region provide clues for a deeper understanding of Mars’ climate and water activity history while offering conditions conducive to the formation and preservation of habitable environments and even life. Therefore, this study suggests that this region could serve as a potential landing site for future Mars sample-return missions, especially the fan-shaped deposits at the floo of the Cerulli crater and the termini of valley networks. Sampling at these locations offers remarkable advantages for understanding the duration of Martian water activity, sediment composition, climatic characteristics, and searching for signs of life.关键词：remote sensing;Mars;Cerulli crater;geological characteristics;sample-return mission;landing site selection64|49|0更新时间：2025-03-27 - “最新研究揭示月球底部破裂撞击坑成因，证实岩浆侵入观点，为月球热演化历史研究提供新支撑。”
摘要：The formation mechanisms and evolutionary history of lunar Floor-Fractured Craters (FFCs) have been a popular topic of research in lunar science. FFCs are characterized by shallow, often plate-like floors and contain radial, concentric and/or polygonal fractures; additional interior features may include ridges, pits of mare material, and dark-haloed pits associated with volcanic activities. Current studies of FFCs are based on visible data, gravity data, radar data, and numerical simulations based on observational data. The penetration depth of visible and infrared radiation in the lunar weathering layer is limited to a few microns. At this limited depth, the lunar weathering layer is easily contaminated by surrounding impact ejecta. The main mechanisms of formation are currently classified into two views, namely, viscous relaxation and magmatic intrusion, and the major difference between these two mechanisms is the presence or absence of dikes in the deeper part of the impact crater. Therefore, based on the Chang’E-2 microwave radiometer data, which have a certain penetration depth and can reflect the thermophysical properties of the material, eight representative FFCs with a diameter greater than 80 km and with center coordinates within 60 degrees north–south latitude are selected, according to the following criteria: (1) To improve the display of the bright temperature characteristics inside the impact crater, the FFCs whose brightness temperature characteristics are less affected by the material outside the crater, that is, no substantial amount of basaltic material outside the crater, are selected. (2) To study the thermophysical properties of the crater, FFCs whose surfaces are less affected by impact events are selected. (3) Impact craters with larger diameters are selected to represent the similar behaviors of FFCs. Based on the 24 h brightness temperature (TB) mapping, normalized brightness temperature (nTB) mapping and brightness temperature difference (dTB) mapping methods and combined with the exposure of surface basalt, the microwave thermal radiation characteristics of lunar FFCs are systematically studied. The main findings are as follows: (1) The dTB behaviors show regions with high dTB values in all four channels, and the surface fractures in these regions are well developed. (2) In the FFCs with basalt exposed on the surface, microwave thermal emission anomalies are observed in the basalt exposed areas, which indicate that the dike forms the surface volcanic features. (3) In the FFCs with no basalt exposed on the surface, microwave thermal emission anomalies are on the bottom of the craters, which indicate that the dike exists in the deep part of the craters. These results confirm that the lunar FFCs are caused by magma intrusion from the perspective of microwave thermal emission, and provide important novel support for the study of the thermal evolution history of the moon.关键词：remote sensing;Chang’E-2 microwave radiometer data;Floor-Fractured Crater;Lunar magmatic activities;Moon335|385|0更新时间：2025-03-27
Remote Sensing Geological Interpretation
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1∶2500000 geological map compilation and research of the Nectaris Quadrangle （LQ-20） on the Moon AI导读
“中国科学院地球化学研究所团队编制了全月地质图，包括LQ-20酒海幅，涵盖12类岩石、8个盆地、260个撞击坑和16类构造形迹，揭示了月球地质演化历史。”
摘要：Based on the Chang’E lunar exploration data and other lunar geological data, the team led by the Institute of Geochemistry of the Chinese Academy of Sciences has compiled a series of lunar global geological maps. These maps include a 1∶2500000-scale global geologic map, a digital global lithologic map, and a global tectonic map. Thirty lunar quadrangle geological maps are also compiled, including the LQ-20 Nectaris Quadrangle map. The LQ-20 map is eye-catching because it depicts the impact event of the Mare Nectaris Basin, which divided the Nectarian and Aitkenian periods, during the Nectarium classic formation event.This article provides a detailed overview of the development history of lunar geological mapping and discusses the various geological features observed in the LQ-20, including rock types, impact basins, crater materials, and structural characteristics：12 rock types, basin formations on eight impact basins, crater materials from 260 impact craters, and 16 types of structural characteristics, which cover geological information in the sixth periods.Finally, this article discusses the regional geological evolution history of the LQ-20 map from the Magmatic Oceanic Period to the Copernican Period. This article also compares the expression of geological features in the LQ-20 map with that of the USGS lunar geological map and highlights the differences and advantages: The fundamental distinction in conveying geological information lies in the comprehensive establishment and systematic representation of the overall lunar geological processes as an integrated geological system. This approach involves providing a clear explanation of the geological causes for each unit and ensuring that each geological feature conveys its origin. Furthermore, each region is characterized by a distinct hierarchy of geological units arranged in chronological order. This project would provide lunar geological background information for lunar exploration, scientific research, and related endeavors, and will benefit not only China but also the global communities.关键词：remote sensing;lunar geological map;LQ-20;Mare Nectaris;Remote Sensing Interpretation;Geological Evolution History135|469|0更新时间：2025-03-27 - “在月球极区形貌可视化领域，专家结合高精度激光测高数据，通过晕渲可视化方法制作晕渲地图，有效表现月球极区地貌，为月球极区科学研究提供直观、详细、全面的可视化地图。”
摘要：Due to its special geographic location and topographic features, the lunar polar regions have low solar altitude angles and insufficient illuminations, and numerous Permanently Shadowed Regions (PSR) lack direct solar illumination all the time. Therefore, these sites may contain enormous amounts of water ice and are of scientific importance and utilization. Visible-band imagery is often used to visualize the topography of the lunar mid- and low-latitude regions, but this method is poorly effective in the lunar polar regions. The shadow range of the existing image data is huge, which leads to incomplete topographic representation and poor human understanding. If the planetary topography of the lunar polar region is directly represented from the elevation data, problems such as unnatural color and light effects and lack of topographic details will occur. Human’s intuitive perceptions of the lunar surface mainly come from naked-eye optical observation, telescope optical photography, and remote sensing images from orbiting satellites, which largely shape the geospatial knowledge of the lunar landscape. Migrating these mature geospatial cognitions of the moon to the lunar polar regions can effectively reduce the cost of understanding the lunar morphology. Therefore, to improve the scientific exploration of the lunar polar regions, a set of comprehensive, efficient, and human-cognitive-habit-suitable visualization mapping methods of the lunar polar regions is needed. In this paper, high-precision laser altimetry data are combined with the shading visualization method to create illumination maps, which effectively represent the impact craters, crater chains, rilles, and other landforms in the lunar polar regions, and have the characteristics of intuition, detail, and comprehensiveness. When visualization operation is performed, the undulation of complex planetary landforms such as impact craters is comprehensively considered, and the topography is appropriately exaggerated so that the absolute and relative elevations of the terrain can be reasonably expressed in the shading map. Such a planetary topographic map has a powerful sense of three-dimensionality in the visual sense with a clear light-shadow relationship and the elevation expression has a better display effect even in the polar regions, without losing the details of the terrain, which can realize a more satisfactory effect of displaying the terrain features. The large-scale topographic maps and local topographic details of the lunar polar regions are created by this method and compared with the corresponding remote sensing images. Moreover, further processes overlaying the PSRs on the corresponding shading map can obtain a clearer thematic map. Orthorectified aerial view maps based on the grayscale coloring of the elevation not only restore the real planetary topography but also express the relationship between its absolute elevations and its relative height. Enhanced visualization of the lunar polar region aligns with human geospatial cognitions and can depict the topography of the lunar surface objectively and realistically. This enhances visualization and strengthens the suitable geospatial planetary cognition of map users following human intentions and minds, improving the display effects of large-scale topography and small-scale terrain details. The topographic shading maps provide support for landing site selection, rover path planning, and results display in the lunar polar regions.关键词：planetary cartography;lunar exploration;lunar polar region;shading map;Visualization415|652|0更新时间：2025-03-27
Planetary Mapping
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