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In situ geologic context mapping based on rover and helicopter observations provides documentation of a nearly continuous record of geology and exposed surface structure over a 120 m‐wide corridor along the traverse of the Mars 2020/Perseverance rover. The results record the geologic context of Mars 2020 campaign sites and sample sites, including the local extent of bedrock outcrops, stratigraphy, attitude, and structure from imaging and rover‐based remote sensing, and outcrop lithology based on in situ proximity science. Mapping identifies a sequence of igneous lithologies including (a) early mafic, possibly intrusive, rocks; (b) pervasively fractured and deeply altered massive bedrock of undetermined protolith; (c) buried and exhumed lava flows with pahoehoe and aa textures; (d) several varieties of regolith; and (e) small impact craters. Plain Language Summary: Reconnaissance‐type geologic mapping along the traverse of Perseverance on the Jezero Crater floor is adapted from field geologic methods used on Earth and modified to account for the geometry of rover‐based imaging. The final field geologic map records bedrock and surficial geology, contacts, and structures over a 120‐m wide strip along the traverse. Most of the lithologies are igneous, including possible intrusive mafic rocks, deeply weathered massive rocks of unknown original lithology, and lava flows. Stratigraphy determined from mapping together with the observed inclination of layers identifies either uplift or draping of the section centered in the elevated older terrain. The final map information provides ground‐truth geologic context for the first eight samples collected for return to Earth. Key Points: In situ mapping from the rover observations on Mars uses field geologic mapping methodsDocuments the geologic context of samples and the crater floor traverse of PerseveranceDevelops methods applicable to future robotic and human traverses on planetary surfaces [ABSTRACT FROM AUTHOR]

Nonlinear orbit control with the use of low-thrust propulsion is proposed as an effective strategy for autonomous guidance of a space vehicle directed toward the Moon. Orbital motion is described in an ephemeris model, with the inclusion of the most relevant perturbations. Unfavorable initial conditions, associated with weak, temporary lunar capture, are considered, as representative conditions that may be encountered in real mission scenarios. These may occur when the spacecraft is released in nonnominal flight conditions, which would naturally lead it to impact the Moon or escape the lunar gravitational attraction. To avoid this, low-thrust propulsion, in conjunction with nonlinear orbit control, is employed, to drive the space vehicle toward two different, prescribed, low-altitude lunar orbits. Nonlinear orbit control leads to identifying a saturated feedback law (for the low-thrust magnitude and direction) that is proven to enjoy global stability properties. The guidance strategy at hand is successfully tested on three different mission scenarios. Then, the capture region is identified, and includes a large set of initial conditions for which nonlinear orbit control with low-thrust propulsion is effective to achieve lunar capture and final orbit acquisition. For the purpose of achieving lunar capture, low-thrust propulsion is shown to be more effective if ignited at aposelenium. [ABSTRACT FROM AUTHOR]

A recent letter studied cratering during collisions between rocky bodies and primordial black holes. Hydrodynamic simulations in that work showed that ejecta blankets from these collisions are steeper because the black holes completely penetrate the target, potentially making these craters distinguishable from traditional point-like impactors. This may allow us to use lunar craters to constrain primordial black holes in the asteroid-mass window, about 1017–1019 g. In this work, we calculate the lunar dark matter flux from the Galactic halo and several models for a dark disc. We consider several effects that may enhance the dark matter flux, such as gravitational focusing on the Solar system and historical modulations due to the Solar system's galactic orbit. We find that non-detection of novel craters on the Moon can constrain relativistic compact MACHO dark matter up to 1017 g at 95 per cent confidence, motivating a detailed search through lunar surface scans. In addition, we show that fluxes near Earth from dark discs may be significantly enhanced by gravitational focusing and that the relative velocity between the disc and the Sun can result in annual modulations out of phase with the annual modulations from the halo. [ABSTRACT FROM AUTHOR]

We study the satellite plane problem of the Milky Way (MW) by using the recently published simulation data of TNG50-1. Here, we only consider the satellite plane consisting of the brightest 14 MW satellites (11 classical satellites plus Canes Venatici I, Crater II, and Antlia II). One halo (haloID = 395, at z = 0, hereafter halo395) of 231 MW-like candidates possesses a satellite plane as spatially thin and kinematically coherent as the observed one has been found. Halo395 resembles the MW in a number of intriguing ways: it hosts a spiral central galaxy, and its satellite plane is almost (∼87°) perpendicular to the central stellar disk. In addition, halo395 is embedded in a sheet plane, with a void on the top and bottom, similar to the local environment of MW. More interestingly, we found that 11 of the 14 of the satellites on the plane of halo395 arise precisely from the peculiar geometry of its large-scale environment (e.g., sheet and voids). The remaining three members appeared at the right place with the right velocity by chance at z = 0. Our results support previous studies wherein the satellite plane problem is not seen as a serious challenge to the ΛCDM model and its formation is ascribed to the peculiarities of our environment. [ABSTRACT FROM AUTHOR]

The surface of the Moon and planets have been covered with loose soil called regolith, and there is a risk that the rovers may stack, so it is necessary for them to recognize the traveling state such as its posture, slip behavior, and sinkage. There are several methods for recognizing the traveling state such as a system using cameras and Lidar, and they are used in real exploration missions like Mars Exploration Rovers of NASA/JPL. When a rover travels and travels across loose soil with steep slopes like a side wall of a crater on the lunar surface, the rover has side slipping. It means that its behavior makes the rover slip down to the valley direction. Even if this detection uses sensors like a camera and Lidar or other controlling systems like SLAM (Simultaneous Localization and Mapping), it would be too difficult for the rover to avoid slipping down to valley direction, because it is not able to detect the traction or resistance given from ground by individual wheel of the rover, as the traction of individual wheel of the rover is not clear. This means that the movement of the rover appeared by integrating the traction of all wheels mounted on the rover. Even if the localization by sensors is carried out, the location would be the location after slipping down. This is because when traveling on unstable ground, the driving force of each individual wheel cannot be accurately predicted, and the sum of the driving force of all wheels is the motion of the rover, which is detected after the position changes. Therefore, if the rover obtains information on the traction of each wheel, its maneuver to change its posture would work sooner and it would be able to travel more efficiently than in a state without that information. Because the onboard computer of rovers can identify their location and state from the information of the traction of each wheel, they can decide the next work carefully and in detail. From these tasks, we focused on the intrinsic sensation of a biological function like a human body and aimed to develop a system that recognizes the traveling state (slip condition) from the shape deformation of the chassis. In this study, we experimentally verified the relationship between the change in strain, which is the amount of deformation acting on the chassis, and the traveling state while the wheel is traveling. From the experimental results, we confirmed that the strain in the chassis was displaced dynamically and that the strain changed oscillatory while the wheel was traveling. In addition, based on the function of muscle spindles as mechanoreceptors, we discussed two methods of analyzing strain change: nuclear chain fiber analysis and nuclear bag fiber analysis. These analyses mean that the raw data of the strain are updated to detect the characteristic strain elements of a chassis while the wheel is traveling through loose soil. Eventually, the slipping state could be estimated by updating the data of a lot of strain raw data, and it was confirmed that the traveling state could be detected. [ABSTRACT FROM AUTHOR]

Craters on the lunar surface are the most direct method for the study of geological processes and are of great significance to the study of lunar evolution. In order to fill the research gap on small craters (diameter less than 3 m), we focus on the small craters around the moving path of the Yutu-2 lunar rover and carry out a 3D reconstruction and geometrical morphology analysis on them. First, a self-calibration model with multiple feature constraints is used to calibrate the navigation camera and obtain the internal and external parameters. Then, the sequence images with overlapping regions from neighboring stations are used to obtain the precise position of the rover through the bundle adjustment (BA) method. After that, a cross-scale cost aggregation for a stereo matching network is proposed to obtain a parallax map, which can further obtain 3D point clouds of the lunar surface. Finally, the indexes of the craters are extracted (diameter D, depth d, and depth–diameter ratio dr), and the different indicators are fitted and analyzed. The results suggest that CscaNet has an anomaly percentage value of 1.73% in the KITTI2015 dataset, and an EPE of 0.74 px in the SceneFlow dataset, both of which are superior to GC-Net, DispNet, and PSMnet, and have higher reconstruction accuracy. The correlation between D and d is high and exhibits a positive correlation, while the correlation between D and dr is low. The geometric morphology expressions of small craters fitted by using D and d are significantly different from the expressions proposed by other scholars for large craters. This study provides a priori knowledge for the subsequent Von Karmen crater survey mission in the SPA Basin. [ABSTRACT FROM AUTHOR]

The Lonar impact crater in the Deccan Volcanic Province of India is an excellent analogue for impact-induced structures on the Moon and other terrestrial planets. We present a detailed architecture of the crater using a high-resolution 3-D seismic velocity image to a depth of 1.5 km through the inversion of high-frequency ambient noise data recorded over 20 broad-band seismographs operating around the crater. The ambient noise waveform is dominated by cultural noise in the 1–10 Hz band. The shear wave velocity (Vs) model is created from Rayleigh wave group velocity data with a horizontal resolution of 0.5–1 km in the period range of 0.1–1.2 s. A key feature of the model is a velocity reduction of 10–15 per cent below the crater compared to outside the ejecta zone. The low-velocity zone below the crater is nearly circular and extends to a depth of ∼500 m. This estimated crater's depth is consistent with global depth–diameter scaling relations for simple craters. The basement, with a Vs of more than 2.5 km s−1, lies beneath the Deccan basalt, which has a Vs of ∼2.4 km s−1. These results are consistent with laboratory-measured data from the Lonar crater and borehole data in the western Deccan trap. This study opens a new window for exploring impact craters and sub-basalt structures using high-frequency ambient noise tomography. [ABSTRACT FROM AUTHOR]

Crater mapping using neural networks and other automated methods has increased recently with automated Crater Detection Algorithms (CDAs) applied to planetary bodies throughout the solar system. A recent publication by Benedix et al. (2020, https://doi.org/10.1029/2019ea001005) showed high performance at small scales compared to similar automated CDAs but with a net positive diameter bias in many crater candidates. I compare the publicly available catalogs from Benedix et al. (2020, https://doi.org/10.1029/2019ea001005) and Lee and Hogan (2021, https://doi.org/10.1016/j.cageo.2020.104645) and show that the reported performance is sensitive to the metrics used to test the catalogs. I show how the more permissive comparison methods indicate a higher CDA performance by allowing worse candidate craters to match ground‐truth craters. I show that the Benedix et al. (2020, https://doi.org/10.1029/2019ea001005) catalog has a substantial performance loss with increasing latitude and identify an image projection issue that might cause this loss. Finally, I suggest future applications of neural networks in generating large scientific datasets be validated using secondary networks with independent data sources or training methods. Plain Language Summary: I have compared two computer programs that use neural networks to identify craters on solar system bodies. The crater catalogs created by these programs have been previously compared against an existing human‐made catalog to measure their performance, but each comparison used a different method making it challenging to understand the difference between the catalogs. In this paper, I use the comparison methods from these two independent papers, discuss where the catalogs agree and disagree, and suggest why they disagree. I emphasize the need for more accurate and consistent methods to validate automatic crater‐mapping programs, especially when it is impractical for humans to check the craters found by automated methods. Key Points: The apparent performance of automatic crater detection algorithms is sensitive to the choice of metric used to gauge the performanceFeature Detection Algorithms trained to find spatial features should be used with appropriately projected images where possibleAs neural networks extend crater detection beyond practical human limits, validating their results with a independent networks is critical [ABSTRACT FROM AUTHOR]

Thermal moonquakes are recurring seismic signals detected on the lunar surface that are temporally correlated with the lunar day‐night cycle, although their precise mechanism is not known. The Lunar Seismic Profiling Experiment (LSPE) was a deployment of four geophones during the Apollo 17 mission to characterize the near‐surface structure of the landing site using explosive shots. The array was reactivated in passive recording mode several times after the mission was completed and recorded thousands of thermal moonquakes. In this study, we expand on an initial detection catalog and determine waveform parameters and source information for the seismic signals. We used a spectrogram‐based approach to obtain fine‐tuned arrival times, quantify the envelope length using emergence, and compute peak‐ground‐velocity. We obtain the incident azimuth direction by applying stochastic gradient descent to a travel‐time misfit equation. We found that thermal moonquakes are split into two main classes: (a) impulsive, high‐amplitude events that are produced by the lunar module descent vehicle located east of the LSPE array in response to rapid temperature transitions during sunrise and sunset and (b) emergent events, that are natural responses to incident sunlight whose duration is directly linked to the temperature of the regolith. We hypothesize that the correlation between temperature and emergence could be due to changes in regolith scattering or higher energy daytime events occurring further away. Plain Language Summary: Thermal moonquakes are a frequent seismic activity on the moon. We know that the quantity of these events is linked with the 30‐day lunar day‐night cycle, but a mechanism that explains how these vibrations are generated is not known. These signals are important because they provide clues on lunar surface processes including crater deformation and lunar soil production. Thousands of these signals were recorded during an 8‐month span from 1976 to 1977 on four seismometers deployed during the Apollo 17 Lunar Seismic Profiling Experiment, but the poor quality of data makes analysis difficult. We developed algorithms to accurately determine the arrival timing of the waves, measure the strength of the seismic signal, and find the direction of the moonquake source. We found that impulsive moonquakes are not due to natural processes, but are vibrations generated from the lunar module descent vehicle left by the astronauts in 1972. The duration of the non‐impulsive events is correlated with temperature: the hotter the temperature, the longer the seismogram. We think that this behavior might be due to changes in regolith properties or stronger events during the day. Key Points: Thermal moonquakes from the Apollo 17 Lunar Seismic Profiling Experiment were assessed for parameters including emergence, peak‐ground‐velocity, and incident azimuthWe found two classes of seismic signals: impulsive and emergent events produced by the lunar module and regolith processes respectivelyThe rise time of emergent moonquakes correlates with temperature, suggesting a regolith or source property change [ABSTRACT FROM AUTHOR]

The document is a citation for Peter Schultz, the 2004 Barringer Medal winner, highlighting his contributions to impact cratering and planetary science. Schultz's career includes significant research on impact-generated magnetic fields, atmospheric effects on ejecta emplacement, and oblique impacts. He is recognized for his observational talents, experiments, and fieldwork, as well as his teaching and community involvement. Schultz has received numerous awards and is known for his creativity and dedication to advancing the field of planetary science. [Extracted from the article]

This article is an editorial that discusses the future of planetary exploration and the next generation of planetary missions. It highlights the importance of recent missions in reshaping our understanding of the Solar System and looks ahead to upcoming missions that have the potential to deepen our insights. The article also emphasizes the impact of these missions in inspiring the next generation of scientists and engineers. It mentions specific research topics covered in the article, including exploratory data analysis, planetary protection, artificial intelligence in remote sensing, radiative transfer in planetary atmospheres, and upcoming missions to Venus. Overall, the article provides valuable insights into the evolving landscape of planetary exploration. [Extracted from the article]

Planetary geomorphological maps over a wide range of spatial and temporal scales provide important information on landforms and their evolution. The process of producing a geomorphological map is extremely time-consuming and maps are often difficult to reproduce. The success of deep learning and machine learning promises to drastically reduce the cost of producing these maps and also to increase their reproducibility. However, deep learning methods strongly rely on having sufficient ground truth data to recognize the wanted surface features. In this study, we investigate the results from an artificial intelligence (AI)–based workflow to recognize lunar boulders on images taken from a lunar orbiter to produce a global lunar map showing all boulders that have left a track in the lunar regolith. We compare the findings from the AI study with the results found by a human analyst (HA) who was handed an identical database of images to identify boulders with tracks on the images. The comparison involved 181 lunar craters from all over the lunar surface. Our results show that the AI workflow used grossly underestimates the number of identified boulders on the images that were used. The AI approach found less than one fifth of all boulders identified by the HA. The purpose of this work is not to quantify the absolute sensitivities of the two approaches but to identify the cause and origin for the differences that the two approaches deliver and make recommendations as to how the machine learning approach under the given constraints can be improved. Our research makes the case that despite the increasing ease with which deep learning methods can be applied to existing data sets, a more thorough and critical assessment of the AI results is required to ensure that future network architectures can produce the reliable geomorphological maps that these methods are capable of delivering.

Detecting impact craters on the Martian surface is a critical component of studying Martian geomorphology and planetary evolution. Accurately determining impact crater boundaries, which are distinguishable geomorphic units, is important work in geological and geomorphological mapping. The Martian topography is more complex than that of the Moon, making the accurate detection of impact crater boundaries challenging. Currently, most techniques concentrate on replacing impact craters with circles or points. Accurate boundaries are more challenging to identify than simple circles. Therefore, a boundary delineator for Martian crater instances (BDMCI) using fusion data is proposed. First, the optical image, digital elevation model (DEM), and slope of elevation difference after filling the DEM (called slope of EL_Diff to highlight the boundaries of craters) were used in combination. Second, a benchmark dataset with annotations for accurate impact crater boundaries was created, and sample regions were chosen using prior geospatial knowledge and an optimization strategy for the proposed BDMCI framework. Third, the multiple models were fused to train at various scales using deep learning. To repair patch junction fractures, several postprocessing methods were devised. The proposed BDMCI framework was also used to expand the catalog of Martian impact craters between 65°S and 65°N. This study provides a reference for identifying terrain features and demonstrates the potential of deep learning algorithms in planetary science research. [ABSTRACT FROM AUTHOR]

Microwave radiometer (MRM) is one of the important payloads on the Chang'e-2 (CE-2) Lunar satellite. In the Chang'e satellite's observation of the microwave radiation brightness temperature (TB) on the lunar surface, there are some "cold spots" of microwave thermal radiation at night containing the Jackson crater. In order to compare the diurnal radiation TB differences of "cold spots" on the lunar surface, two typical craters at similar latitudes on the northern hemisphere on the lunar farside were selected: Jackson, which represents the new craters with a large number of discrete rocks on their surfaces; and Morse, which no longer has a large number of rocks after long-term meteorite impact and lunar evolution. In this paper, the diurnal variation of CE-2 MRM data in the two craters is presented, and a comparative analysis is made with the (FeO + TiO 2 ) abundance (FTA) obtained by Clementine UV-VIS data and the rock abundance (RA) data of LRO Diviner. We find that the variation of the "cold spots" of lunar surface thermal radiation is closely related to the RA distribution in the newly formed craters on the lunar surface, and also has a certain correlation with the FTA. [ABSTRACT FROM AUTHOR]

The Lonar crater (India) is the best preserved and most studied on Earth, formed in basalts, which makes it possible to conduct a comparative study with impact transformations of mineral matter on the Moon and other planets of the Solar System. Comparative studies have shown that impactor material, both on the Earth and on the Moon, is present in impactites not only in a geochemically dispersed form, as previously thought, but also in the form of individual submicron particles distributed in the molten target material. These are particles of native nickel, taenite, and high-nickel kamacite, which, apparently, are the transformed material of the impactor. High-nickel submicron metal inclusions are widespread in the impactites of the Lonar crater, as they were found in all studied preparations made from materials collected from different points along the rim of the crater. The high-nickel particles found in this study are an additional argument in favor of the previously stated assumption about the chondrite type of impactor. [ABSTRACT FROM AUTHOR]

The production, distribution, and evolution of lunar regolith are critical in deciphering the lunar bombardment history and comprehending the transport of materials across the lunar surface, which are still not well understood. In this study, we conducted a comprehensive investigation of factors influencing the production and distribution of lunar regolith by individual simple craters. Combining our results for the impact‐generated regolith volume with a lunar production function, we developed an analytical model to describe the regolith growth process. We found that the strength of bedrock significantly affects the crater size and hence the volume of regolith produced especially for subdecameter impactors. The regolith volume produced by an individual impact crater is quantitatively characterized as a function of crater diameter and preimpact regolith thickness. This regolith production is primarily determined by how much bedrock is shattered, followed by the impact‐induced volume change of target material and lastly by the regolith volume created by secondary cratering processes. When a single crater forms, preimpact regolith thickness greatly affects the regolith distribution pattern; a larger fraction of the regolith will be distributed outside the crater rim for a deeper preimpact regolith layer. Our regolith evolution model can serve as a good first‐order estimation of the regolith growth process that provides better constraints on the regolith buffering trend than previous studies. This model also suggests that, when ignoring the contribution from large, distant impacts, the regolith growth process is dominated by impact craters at scales from a meter to a few hectometers. Plain Language Summary: Lunar regolith refers to the fine‐grained surficial layer of fragmental debris on the Moon that is primarily formed by continuous impact events. Knowledge of regolith production, distribution and evolution is important for revealing the impact history of the Moon and the mixing and transport processes of materials on the lunar surface. In this study, we investigated how individual impact craters produce and distribute regolith and developed an analytical regolith evolution model to describe the process of regolith growth. We found that the strength of bedrock greatly affects the regolith production especially for subhectometer craters. The regolith volume is mainly determined by how much bedrock is shattered by impact cratering, but it also depends upon the impact‐induced volume change of target material and secondary cratering processes. The results also show that the distribution of postimpact regolith is greatly influenced by the preimpact regolith layer, with more regolith distributed outside the crater rim with increasing preimpact regolith thickness. Compared with previous studies, our analytical regolith evolution model better describes how preimpact regolith protects bedrock from bombardment, hence suppressing regolith production. The model also suggests that the local regolith growth process is primarily controlled by meter‐ to hectometer‐scale impact craters. Key Points: We conducted a comprehensive study of the factors influencing regolith production and distribution by individual lunar simple cratersAn analytical regolith evolution model is developed based on regolith volume produced by individual craters and lunar production functionOur model suggests that regolith growth process is dominated by impact craters at scales smaller than a few hectometers [ABSTRACT FROM AUTHOR]

Rocks of the lunar granulite suite are the product of high‐temperature metamorphism within the Moon's crust. However, to date, their formation conditions have few constraints. Here, we combine Ti‐in‐pyroxene element diffusion modeling and two‐pyroxene thermometry with thermal modeling of the lunar crust in order to assess potential heat sources that could generate granulite metamorphism within the lunar highland crust. For the samples investigated in this study, the pyroxene crystals experienced peak metamorphic temperatures between ∼1,027 and 1,091°C over timescales ranging from ∼153 years to ∼15.1 Kyrs. To best satisfy these temperature and timescale constraints, hot (∼2,300°C) impact melt sheets with thickness ranging from 350 m to 3.35 km—equating to impact crater diameters between ∼60 and 280 km—have the potential to heat the underlying anorthositic crust. Deep (>20 km) igneous bodies, such as the large (>10 km thick) sills observed by the GRAIL mission near the base of the lunar crust, also have the potential to generate the required peak metamorphic temperatures; however, the thermal equilibration timescales in this scenario are modeled to be much larger (>100 Kyrs) than was witnessed by the granulites investigated. Our modeling highlights that while lunar granulites are only a minor component within the Apollo and meteorite collection, they are likely an important and ubiquitous lithology within the lunar highland crust. Plain Language Summary: Granulites are a suite of metamorphic rocks that are the result of high‐temperature recrystallization within the crust. Conditions within the crust that result in this style of metamorphism are generally well understood on Earth, but this is not the case for the Moon. The chemistry of minerals that make up granulites reflects the pressure and temperature regime they have experienced over geological time. Mineral chemistry can be used to estimate the highest crustal temperatures that the host rock experienced (interpreted to reflect the temperature at which metamorphism occurred) and how long minerals were held as these temperatures. Granulites investigated here were formed at temperatures between ∼1,027 and 1,091°C over timescales ranging from ∼153 years to ∼15.1 Kyrs. Using these parameters, we can constrain the potential heat sources that resulted in metamorphism. For the samples investigated here, impact melt‐sheets associated with craters >60 km in diameter best satisfy the thermal regime indicated by the mineral chemistry. Igneous bodies such as sills/dykes at the base of the lunar crust can also create the thermal conditions needed to form granulites; however, the surrounding crustal rocks would be held at higher temperatures for much longer that indicated by the granulites investigated here. Key Points: Granulites experienced peak metamorphic temperatures of ∼1,027–1,091°C, equilibrating on timescales ranging from ∼0.15 to ∼15.1 KyrsImpact melt sheets within impact craters >60 km can heat the surrounding crust to best satisfy these temperature and timescale constraintsGranulites can form next to igneous bodies in the lower crust, but would undergo longer equilibration times than those recorded by our granulite samples [ABSTRACT FROM AUTHOR]

We revealed the layered structure of the upper three hundred meters of the lunar surface in the South Pole‐Aitken Basin by using the measurements from the Lunar Penetrating Radar (LPR) onboard the Chang'E‐4 rover. The result shows that five large strata are identified by the LPR 60‐MHz channel below the depth of 90 m, with thicknesses ranging from 20 m to larger than 70 m. We speculate that at least three strata are basalt flows, while the shallowest stratum is composed of multiple thin lava flows. The thickness of the strata decreases with the decreasing depth, suggesting a progressively smaller lava effusion rate over time. To evaluate the reliability of the result, a comparison was made between Chang'E‐4, Chang'E‐3, and ground test low‐frequency data. The LPR 500‐MHz channel unveiled the structure of weathered material in the top ∼40 m, revealing several layers as well as a buried paleo crater and its ejecta blanket in the regolith. Plain Language Summary: The Chang'E‐4 rover is exploring the Moon with a two‐channel ground penetrating radar (GPR). The GPR sends electromagnetic pulses into the lunar interior and receives echoes from subsurface layers. We use the high‐frequency channel data to detect the structure of the upper 40 m along the rover's path, primarily consisting of rock debris and soil. This analysis reveals several layers and a buried crater. The low‐frequency channel has the capability to penetrate deeper into the Moon, allowing us to search for large‐scale layered structures such as lava flows. Through this investigation, we have discovered multiple layers in the upper 300 m, which likely indicate a series of basalt eruptions that occurred billions of years ago. The thickness variation of these lava flows suggests a decrease in eruption scale over time. By combining data from both channels, we are able to depict the overall structure of the Moon's upper several hundred meters. Key Points: We examined the long‐term accumulated low‐frequency data of Chang'E‐4 Lunar Penetrating Radar and identified several strata at depths below 90 mThe thickness of the strata increases with depth, implying that the lava effusion rate may have progressively decreased over timeThe stratigraphy of the upper ∼300 m of the Moon is unveiled through the combination of low‐frequency and high‐frequency data [ABSTRACT FROM AUTHOR]

The first samples collected by the Perseverance rover on the Mars 2020 mission were from the Maaz formation, a lava plain that covers most of the floor of Jezero crater. Laboratory analysis of these samples back on Earth would provide important constraints on the petrologic history, aqueous processes, and timing of key events in Jezero crater. However, interpreting these samples requires a detailed understanding of the emplacement and modification history of the Maaz formation. Here we synthesize rover and orbital remote sensing data to link outcrop‐scale interpretations to the broader history of the crater, including Mastcam‐Z mosaics and multispectral images, SuperCam chemistry and reflectance point spectra, Radar Imager for Mars' subsurface eXperiment ground penetrating radar, and orbital hyperspectral reflectance and high‐resolution images. We show that the Maaz formation is composed of a series of distinct members corresponding to basaltic to basaltic‐andesite lava flows. The members exhibit variable spectral signatures dominated by high‐Ca pyroxene, Fe‐bearing feldspar, and hematite, which can be tied directly to igneous grains and altered matrix in abrasion patches. Spectral variations correlate with morphological variations, from recessive layers that produce a regolith lag in lower Maaz, to weathered polygonally fractured paleosurfaces and crater‐retaining massive blocky hummocks in upper Maaz. The Maaz members were likely separated by one or more extended periods of time, and were subjected to variable erosion, burial, exhumation, weathering, and tectonic modification. The two unique samples from the Maaz formation are representative of this diversity, and together will provide an important geochronological framework for the history of Jezero crater. Plain Language Summary: The Perseverance rover on the Mars 2020 mission is collecting samples from Jezero crater for potential return to Earth via Mars Sample Return, and the first samples collected by the rover were from the Maaz formation, a lava plain that covers much of the crater floor. These igneous samples can be used to date when the lavas crystallized and to better understand their subsequent interactions with water, both of which will be important for reconstructing the history of habitable environments in Jezero crater. In this study we use images and reflectance spectra from the rover and orbiters, along with ground penetrating radar from the rover, to determine the history of the Maaz formation lavas. We find evidence for significant erosion and weathering in between successive flows, suggesting that they were emplaced over a long period of time. Some of the lavas underlie the Jezero delta, and so their age will provide limits on the timing of lake activity in Jezero crater, while others retain craters, so their age will help to better understand crater density‐based age estimates for surfaces across Mars. Key Points: The Maaz formation is a series of pyroxene‐ and plagioclase‐dominated lava flows on the Jezero crater floor with variable morphologiesSignificant erosion and tectonism occurred during at least one flow hiatus, suggesting emplacement over an extended period of timeThe crystallization ages of Maaz formation samples will help constrain the timing of delta activity and the global cratering chronology [ABSTRACT FROM AUTHOR]

The scattering properties of terrestrial planetary bodies can provide valuable insights into their shallow seismic structure, meteoritic impact history, and geological activity. Scattering properties of the shallow crusts of Earth, Mars, and the Moon are investigated by constructing P‐wave receiver functions (PRFs) from teleseismic waveforms with high signal‐to‐noise ratios. The authors' analysis reveals that strong coda waves lead to significant variations in the PRF waveforms calculated using different time windows, and the stability of the PRF is primarily influenced by the fractional velocity fluctuation. Synthetic PRFs for various scattering media confirm these observations. Comparing the observed and synthetic PRFs, it is found that the fractional velocity fluctuation in the shallow crust is greater than ∼0.2 for the Moon but less than ∼0.2 for Earth and Mars. The authors further discuss possible mechanisms that could have affected the fractional velocity fluctuation and suggest that the distinct fractional velocity fluctuation between the Moon and Earth/Mars is mainly due to differences in the water content of the crustal rocks of the three planetary bodies. Plain Language Summary: Coda waves follow direct P or S waves and comprise scattered waves generated when seismic waves travel through a heterogeneous medium. These incoherent coda waves may interfere with seismic waves from coherent structures and complicate the interpretation of seismic structures. The authors compute P‐wave receiver functions (PRFs) of Earth, Mars, and the Moon using teleseismic waveforms with high signal‐to‐noise ratios. It is found that the PRFs of Earth and Mars are reliable and that the crustal converted waves can be effectively recovered. However, the PRF of the Moon calculated using different time windows is unstable even for direct P waves. The authors demonstrate that the stability of the PRF can be used to characterize the strength of the seismic scattering. Increased scattering by the medium leads to the degradation of the PRF stability. The PRF stability is mainly affected by the fractional velocity fluctuation of the shallow crust, which is larger on the Moon than on Earth and Mars. The fractional velocity fluctuation of the shallow crust is smaller on Earth and Mars because their shallow crusts are hydrous, whereas the shallow crust of the Moon is anhydrous. Key Points: The stability of a P‐wave receiver function degrades with increasing fractional velocity fluctuation of the shallow crustThe fractional velocity fluctuation of the shallow crust is larger on the Moon than on Earth and MarsThe water content of the crustal rocks is the main factor responsible for the different fractional velocity fluctuations [ABSTRACT FROM AUTHOR]

Nighttime Lyman Alpha Mapping Project (LAMP) observations are used to investigate condensed volatiles at the south polar region of the Moon. This study incorporates LAMP data from the first ∼7 years of the mission and Diviner annual maximum temperatures to search for volatile signatures associated with H2O, NH3, and CO2. Other stable potential species, for example, SO2 and H2S, are not identifiable with the ultraviolet ratio‐temperature techniques and are not directly addressed in this study. We confidently detect a ∼20% increase in normalized Off‐band (175–190 nm) to On‐band (148–162 nm) albedo ratios (consistent with condensed surface volatiles) at temperatures below ∼115 K. Elevated normalized ratios extend to temperatures capable of supporting pure aforementioned ices over geologically long time scales. Although ∼115 K is consistent with H2O lifetimes of ∼1‐Myr, the presence of CO2 and NH3 are not uniquely delineated by the data trends with temperature. Future spectral modeling to appropriately identify the composition and abundance of these condensed volatiles remains necessary. Normalized albedo ratios are further analyzed for candidate species via maximum temperatures to inform the likelihood of ice signatures: H2O (70 K < T ≤ 115 K), NH3 + H2O (60 K < T ≤ 70 K), and CO2 + NH3 + H2O (T ≤ 60 K). We compare normalized albedo ratios across seven regions of interest (ROI), including Faustini, Shoemaker, Haworth, Cabeus, Amundsen, Nobile, and an unnamed region. Such comparisons allow for characterization of relative abundances of volatiles across the ROI important for their utilization in future crewed and robotic missions to the Moon. Plain Language Summary: Spectra taken by the Lyman Alpha Mapping Project ultraviolet spectrograph and surface temperature inferred from the Diviner radiometer (both onboard the Lunar Reconnaissance Orbiter) are used to investigate the presence of ices within craters at the Moon's south pole. We analyze spectral features at temperatures where H2O, NH3, and CO2 ice are stable. We find signatures consistent with condensed surface volatiles at temperatures below the H2O ice stability temperature, but are unable to confidently delineate NH3 and CO2 signatures. We further find that normalized signatures can be used to estimate the relative abundance of ice species across regions of interest. Volatile studies, such as the one presented here, are important for resource utilization in future crewed and robotic missions to the Moon. Key Points: Cold traps may support volatile reserves, which may be useful for resource utilization and for determining the origin of lunar volatilesAn increase in volatile signatures where H2O is thermodynamically stable is found; CO2, and NH3 are not confidently delineatedNormalized albedo differences provide insight on relative volatile species abundances between cold traps of interest [ABSTRACT FROM AUTHOR]

Mars' surface is characterized by a weathered layer of regolith and exposed rock exposures that are the results of long‐term geological processes. The Mars Rover Penetrating Radar (RoPeR) on board the Zhurong rover of China's first Mars mission (Tianwen‐1) has been investigating the fine structure and dielectric properties of the martian regolith in the southern Utopia Planitia. The permittivity of the regolith within 5 m of the landing zone is 3.6−2.0+3.1 ${3.6}_{-2.0}^{+3.1}$, and the average loss tangent is 0.0174−0.0053+0.0053 ${0.0174}_{-0.0053}^{+0.0053}$. The high lossy parameter suggests the possible cause for the missing subsurface reflectors in the landing region detected by either in‐situ radar or orbiter radars. The permittivity distribution map has been derived to show permittivity varying with depth and location. The high dispersion of both permittivity and loss tangent values along the traverse path indicates relatively heterogeneous material distribution on the landing site compared to an airless body such as the Moon. Plain Language Summary: A layer of regolith covers the surface of Mars, which is the result of geologic processes that occurred over millions to billions of years. Compared to the observations from satellites, the Zhurong rover of China's first Mars mission (Tianwen‐1) had a closer look at the properties of the regolith layer in the explored region within southern Utopia Planitia. There is evidence that the exposed materials might be related to aqueous activities. Local landforms on the surface suggest the possible presence of buried volatiles, like water ice. The radar instrument (RoPeR) on board the rover can expose subsurface structures and the dielectric properties of the regolith layer at high‐resolution, to assess their composition. The loss tangent results suggest that water ice is not the main component of the local martian regolith at some depth. The scattering distribution of radar profile along the traveling path and heterogeneous subsurface features show more diverse surface processes and weaker space weathering effects on Mars than those on the airless Moon. Key Points: The dielectric properties of martian regolith at the Tianwen‐1 landing site suggest that water ice is not the dominant componentThe radar image and permittivity and loss tangent distribution maps show a high heterogeneity of subsurface materialsCompared to the lunar regolith, the martian regolith shows more diverse surface processes and weaker space weathering effects [ABSTRACT FROM AUTHOR]

Such thematic mapping depends on the quality of foundational data products which comprise image data mosaics, terrain model mosaics, and potentially other data sources. In contrast to map making, planetary mapping is rather closely related to the systematic acquisition of data, while cartography consists of turning spatial data into advanced visualizations. Cartography is traditionally associated with map making and the visualization of spatial information. [Extracted from the article]

• Experimental determination of H 2 O(v) transport through packed beds of Lunar Highland and Lunar Mare Simulants. • Piecewise model developed to predict H 2 O(v) transport in slip and Knudsen flow regimes. • Diffusion and viscous flow permeability dependent on simulant particle size distribution. H 2 O(v) transport through packed beds of lunar mare and lunar highland simulants was examined for relevant in-situ resource utilization conditions to inform volatile H 2 O extraction from the lunar surface. Experiments were conducted with different packed beds at average bed pressures of 105 and 3,960 Pa at ∼ 350 K for different flow regimes in the range of 0.47 < Kn ¯ < 20.7. A piecewise model was used to describe the transition between the advective flow regime and the Knudsen flow regime. Non-linear regression was used to determine a tortuosity shape factor of 2.6175 ± 0.0092 and 0.0937 ± 0.0008, a transition Knudsen number of 1.5984 and 4.0995, and a viscous flow permeability of 0.8238 ± 0.0010 × 10-12 m2 and 5.4805 ± 0.0061 × 10-12 m2 for the lunar mare and lunar highland simulants, respectively. The resulting Knudsen diffusivities were 6.6530 ± 0.0018 cm2·s−1 and 18.9008 ± 0.0100 cm2·s−1, respectively. These results are necessary for informing the development of in-situ resource utilization technologies for the thermal extraction of H 2 O. [ABSTRACT FROM AUTHOR]

The article focuses on the history of Earth's atmospheric thermal tide, its composition, and mean temperature. It mentions the study explores the hypothesis that an atmospheric oscillation resonated with the Solar driving around 600 million years ago, affecting the length of the day. It highlight ny using global circulation models and geologic data, the researchers find evidence supporting the resonance hypothesis and provide insights into the Earth-Moon system's history.

During landing, the plume from the lander erodes the regolith on the lunar surface, thus destroying the nature of this surface. Landing also provides an opportunity to extract the mechanical properties of the lunar regolith in situ and to study wind erosion on airless bodies such as the Moon. Our goal in this study is to quantify the interparticle force of the lunar regolith, the erosion depth, and other parameters and to test the reliability of the plume erosion model. The erosion depth provides the necessary reference information for the precise interpretation of scientific results obtained from returned samples. We measure the total mass of the lunar regolith mobilized by the plume during the Moon landing. This information is also helpful for future lunar missions. With high-quality data from the Chang'E-5 (CE-5) and Chang'E-4 (CE-4) missions, we measure the erosion depth and the total mass and combine the results with computational fluid dynamics (CFD) to extract the interparticle force. We then test the plume erosion model according to the results from image measurement and CFD and propose a new formula with which to calculate the threshold friction velocity at which plume erosion is initiated. This calculation shows that the interparticle force for a 4- μ m-diameter particle is 3.38–16.1 nN. The results also show that the CE-5 landing plume stripped away a 1.2-cm-deep layer of regolith, creating a ≈ 10-m-diameter crater on the lunar surface, and dispersed ≈ 441 kg of lunar regolith. Any analysis of a CE-5 drilling sample that is sensitive to the regolith depth must consider this 1.2-cm-thick eroded layer. When a plume erodes the lunar surface, the minimum shear stress required is much less than that predicted by the erosion model, which can no longer be used to predict whether erosion will occur. • A new formula of threshold velocity is proposed for plume erosion. • The interparticle force on a typical 4- μ m-diameter particle is 3.38–16.1 nN. • The depths of the Chang'E-5 scooping and drilling samples are ≥ 0.3 and ≥ 1.2 cm, respectively. [ABSTRACT FROM AUTHOR]

Volatiles including water on the Moon has been one of the most interesting scientific objects for decades. In this study, we systematically introduced a concept for China's Chang'E−7 (CE-7) lunar polar exploration mission which consists of five elements, the orbiter, lander, rover, and leaper, and one relay satellite. The orbiter will provide a high-resolution image preparing for landing site selection. We also proposed three phases for in-situ investigation after landing. (1) The rover and leaper will jointly investigate the sunlit area; (2) the leaper will explore cold traps; and (3) the leaper will fly back to the sunlit area and continue an extended exploration mission. An experimental penetrator launched by the lander will penetrate permanently shadowed crater walls for water ice detection. Data will be transmitted to Earth through the relay satellite due to the limited Earth visibility. We also calculated the illumination rate within a 15 × 15 km area that partially covers the Shackleton crater at a high spatial resolution of 20 m/pixel during lunar southern summer. Specifically, we compared two potential landing sites with accumulated illumination at different altitude levels, slopes, and distances to the target. We found that one part of the Shackleton crater rim can be a primary landing site for CE-7's both sunlit areas and cold trap explorations. • We introduce a concept design of China's Chang'E−7 lunar polar exploration mission. • The mission element leaper is newly designed to explore water ice at cold traps. • We calculate illumination rates near the Moon's south pole during southern summer. • Engineering safety and scientific goals constrain polar landing site selection. [ABSTRACT FROM AUTHOR]

Uniformitarian scientists were surprised to discover channels on Mars like the Channeled Scablands of eastern Washington. Climate models indicate that large-scale Martian floods are impossible. This paper will describe what appear to be flood features on Mars. Three types of channels on Mars are described in this paper: valley networks, outflow channels, and gullies. Like the Solar System's other solid bodies that have not been resurfaced by debris and volcanism, Mars possesses numerous impact craters, some very large, which provide a framework for the planet's history. Secular uniformitarian scientists divide the geologic history of Mars into four main periods which span 4.5 billion years. [ABSTRACT FROM AUTHOR]

The results of studies on lunar soil science and current problems of lunar soil amelioration engineering are presented. [ABSTRACT FROM AUTHOR]

Dating young lunar surfaces, such as impact ejecta blankets and terrains associated with recent volcanic activities, provides critical information on the recent events that shaped the surface of the Moon. Model age derivation of young or small areas using a crater chronology is typically achieved through manual counting, which requires a lot of small impact craters to be tediously mapped. In this study, we present the use of a Crater Detection Algorithm (CDA) to extract crater populations on Lunar Reconnaissance Orbiter—Narrow Angle Camera (LRO‐NAC) and Kaguya Terrain Camera images. We applied our algorithm to images covering the ejecta blankets of four Copernican impact craters and across four young mare terrains, where manually derived model ages were already published. Across the eight areas, 10 model ages were derived. We assessed the reproducibility of our model using two populations for each site: (a) an unprocessed population and (b) a population adjusted to remove contaminations of secondary and buried craters. The results showed that unprocessed detections led to overestimating crater densities by 12%–48%, but "adjusted" populations produced consistent results within <20% of published values in 80% of cases. Regarding the discrepancies observed, we found no significant error in our detections that could explain the differences with crater densities manually measured. With careful processing, we conclude that a CDA can be used to determine model ages and crater densities for the Moon. We also emphasize that automated crater datasets need to be processed, interpreted and used carefully, in unity with geologic reasoning. The presented approach can offer a consistent and reproducible way to derive model ages. Plain Language Summary: Studying young lunar surfaces, such as impacted areas or volcanic activity, helps us understand recent events that have shaped the Moon's surface. Determining the model age of these areas generally involves manually counting small craters, which is time‐consuming and variable. This study presents a machine‐learning approach to detect craters on images acquired by the Lunar Reconnaissance Orbiter‐Narrow Angle Camera and the Kaguya Terrain Camera. Four impact craters and four young mare terrains were analyzed, where model ages had already been determined manually. When comparing our automatic counts to the manual counts, we observed that our results became more consistent with the published surface ages when we excluded secondary or buried craters from our crater populations. We also outline that automatic crater detection methods can be used to determine the age of lunar surfaces in a reliable and consistent manner when used correctly. Key Points: Automatic crater counting of the Moon was achieved using a Convolutional Neural Network architecture and applied to LRO‐NAC and Kaguya Terrain Camera imagesTesting of the automatic counts against manual counts across the same count areas is required to provide confidence in the resultsSurface ages resulting from automatic crater counts are within acceptable error of model ages for the same area found using manual counts [ABSTRACT FROM AUTHOR]

Lunar collapse pits and possible caves have been suggested as ideal locations for the storage and protection of lunar water ice deposits, due to their potential to create permanently shadowed regions (PSRs) at high latitudes and ability to protect ice from destructive surface processes. However, the thermal environments of these features have not been investigated at high latitudes, and it remains unclear what effects pit latitude and geometry would have on interior temperatures and ice stability. We create a 3D thermal and volatile transport model and use it to characterize the thermal environments and volatile‐trapping potential within lunar collapse pits and caves. We model the thermal behavior of lunar pits as it varies with latitude for several different pit geometries. We then apply the thermal model results to the volatile transport model and calculate water loss rates to space given an initial ice deposit. The model shows that in general, high‐latitude pits make poor cold traps for ice because their enclosed geometry increases the ability of multiple‐scattered infrared radiation to elevate pit interior temperatures. Although, the enclosed geometry of a cave might help trap volatiles in theory, in practice ice stability within pits and caves is primarily controlled by temperature and not geometric effects. We find that ice loss rates are higher within pits and caves than within PSRs of craters at similar latitudes. Nevertheless, some specific situations arise where pits can act as effective cold traps, such as when pits lie within PSRs created by exterior topography. Plain Language Summary: In light of NASA's upcoming Artemis program and related missions, interest in lunar water ice as both a science objective and a resource target is at a high. Lunar pits are collapse features characterized by steep walls that could be connected to caves, and have been suggested as ideal locations for the storage and protection of ice. However, the thermal environments of these features have not been investigated at high latitudes, and it is unclear what effects pit latitude and geometry would have on interior temperatures and ice stability. In this work, we create a 3D thermal model to investigate the thermal behavior of lunar pits as it varies with latitude and geometry. The results of the thermal model are then applied to a water transport model that assesses the stability of ice in these environments. The model shows that in general, high‐latitude pits make poor cold traps for ice because their enclosed geometry makes them less efficient at losing heat to space. This makes them warmer than craters at similar latitudes. However, there are some specific cases in which ice could be stable in lunar pits, such as when pit openings are shadowed by larger features outside. Key Points: Multiple‐scattering of infrared radiation elevates pit temperatures, making high latitude pits and caves poor cold traps relative to cratersIce loss rates are higher within pits and caves than within permanent shadows of craters at similar latitudesIf pit‐cave systems are shadowed by exterior topography, they can make effective cold traps [ABSTRACT FROM AUTHOR]

The volcanic parent rock ("protolith") composing the lunar maria is likely to have developed diverse mechanical properties upon emplacement. The abundance of rocks ejected by impacts may be sensitive to protolith properties. We investigate the relationship between the possible diversity of mare protoliths and the abundance of rocks excavated and emplaced by impacts employing cumulative size‐frequency distributions (SFDs) of rocky craters in the maria. The SFDs of 15 mare units were calculated through varying degrees of Lunar Reconnaissance Orbiter Diviner‐derived rock abundance within crater ejecta blankets. By inspecting the frequency of high rock abundance craters, we find that the age of a surface does not control an impactor's ability to excavate rocks. Through analysis of SFDs, we find that differences in SFD behavior may act as probes for the mechanical strength of the protolith and the thickness of buried lava flows. Generally, regions with SFDs that have shallower slopes with increasing rockiness may be associated with thick, competent flow types, and regions with SFDs that have unchanging slopes with increasing rockiness may be associated with stacked, thin flows that are possibly more friable. The greater frequency of high rock abundance craters and the converging behavior of SFDs at two units within Mare Humorum and Oceanus Procellarum suggest that the surfaces are underlain by thick, competent lava flows. Finally, SFD slope analysis suggests that secondary impact craters are relatively ineffective at excavating rocks and the SFDs of rocky craters may reflect primary cratering populations. Plain Language Summary: When ancient lunar lava flows cooled and hardened into rock, they likely developed different properties depending on the conditions of eruption. The variations in these now‐buried volcanic rocks can be probed using impacts, which break up and eject material from the subsurface. Ejected pieces of lava flow can be measured in terms of their abundance, which we use to infer lava flow properties in this study. By inspecting the populations of craters with a high abundance of rocks in their ejecta, we determine that age does not control the frequency of highly rocky craters. Further, we determine the size‐distribution of craters with rocks in their ejecta and find different relationships between the rock‐free crater populations and the rocky crater populations. We find that changes in the rock‐free and rocky crater populations may represent variations in lava flow properties. Finally, secondary impact craters that are formed from high‐velocity debris made by primary impacts are ordinarily difficult to discern from the primary impact population; however, we determine that by inspecting the slightly rockier crater population, secondaries may be filtered out. Key Points: Rock excavating impact populations are probes of mare protolith propertiesSurface age does not control an impactor's ability to excavate rockThe size‐frequency distributions of rocky crater populations exhibit behaviors reflective of substrate competence [ABSTRACT FROM AUTHOR]

China's first Mars rover, Zhurong, has carried out an exploration mission in southern Utopian Planitia. As rocks and their three‐dimensional (3D) morphology are essential for studying the geological characteristics of the Martian surface, this paper presents an approach for automatically extracting 3D rocks from stereo rover images. With our approach, 6,185 cm‐scale rocks are extracted using the Zhurong NaTeCam images, with the F1‐score achieving 91.86%. Approximate 3D morphological features are then calculated for each rock, and the statistical result shows that small rocks in centimeters make up the majority. Comparative morphological analyses of rocks in different areas show that landscape type affects the number of rocks but has no clear relationship to the proportions of rocks of different sizes. The outcrops of sedimentary rocks, the predominant type of rocks in the Zhurong landing area, and the float rocks are distributed differently regarding all morphological features, making the size‐frequency distribution of rocks around craters significantly different from other areas. Further comparative analysis with the Bonneville crater ejecta rocks extracted from the Spirit rover data is also conducted. Some similarities between the Zhurong outcrop rocks and the Bonneville crater ejecta rocks are found in 2D compactness. Meanwhile, the Bonneville crater ejecta rocks have a more scattered distribution in sphericity than both the float and outcrop rocks in the Zhurong landing area, indicating that the shapes of the Bonneville crater ejecta rocks may be more diverse. In addition, the sphericity is found to converge with height for rocks in both landing areas. Plain Language Summary: Rocks on the Martian surface and their three‐dimensional (3D) morphology record the geological evolution of Mars and its interaction history with outer space. Currently, China's Zhurong Mars rover has traveled nearly 2 km on Mars and collected a wealth of images, allowing the fine‐scale measurement and 3D morphological analysis of Martian rocks with statistical significance. We therefore propose an automatic approach for extracting individual 3D rocks from the stereo images and apply it to the Zhurong NaTeCam images to facilitate fine‐scale morphological analyses of the Martian rocks in the Zhurong landing area. Our morphological analyses lead to several remarkable findings about the interior relations between Martian rocks and geomorphology, giving new clues about the topographical and geomorphic evolution of Mars. Key Points: We extracted 6,185 three‐dimensional rocks at centimeter‐scale in the Zhurong landing area and computed their morphological featuresWe analyzed the morphology of the rocks and revealed the relationships between the rocks and landscape type of the Martian surfaceCompared to the rocks from the Spirit data, we found morphological similarity and difference for the outcrop and float rocks, respectively [ABSTRACT FROM AUTHOR]

Séítah is the stratigraphically lowest formation visited by Perseverance in the Jezero crater floor. We present the data obtained by SuperCam: texture by imagery, chemistry by Laser‐Induced Breakdown Spectroscopy, and mineralogy by Supercam Visible and Infrared reflectance and Raman spectroscopy. The Séítah formation consists of igneous, weakly altered rocks dominated by millimeter‐sized grains of olivine with the presence of low‐Ca and high‐Ca pyroxenes, and other primary minerals (e.g., plagioclase, Cr‐Fe‐Ti oxides, phosphates). Along a ∼140 m long section in Séítah, SuperCam analyses showed evidence of geochemical and mineralogical variations, from the contact with the overlying Máaz formation, going deeper in the formation. Bulk rock and olivine Mg#, grain size, olivine content increase gradually further from the contact. Along the section, olivine Mg# is not in equilibrium with the bulk rock Mg#, indicating local olivine accumulation. These observations are consistent with Séítah being the deep ultramafic member of a cumulate series derived from the fractional crystallization and slow cooling of the parent magma at depth. Possible magmatic processes and exhumation mechanisms of Séítah are discussed. Séítah rocks show some affinity with some rocks at Gusev crater, and with some Martian meteorites suggesting that such rocks are not rare on the surface of Mars. Séítah is part of the Nili Fossae regional olivine‐carbonate unit observed from orbit. Future exploration of Perseverance on the rim and outside of the crater will help determine if the observations from the crater floor can be extrapolated to the whole unit or if this unit is composed of distinct sub‐units with various origins. Plain Language Summary: The Mars 2020 Perseverance rover landed on Mars in the Jezero crater on 18 February 2021. An important goal of this mission is to constrain the geology of the Jezero crater and its delta, and to sample rocks to return to Earth. Here, we study the deepest rock formation observed close to the landing site on the crater floor, named the Séitah formation. We conclude that this formation is igneous with rocks consisting in the accumulation of dominant millimeter‐sized olivine crystals with pyroxenes and other minerals. Such rocks form at depth by slow cooling of the magma, and the first mineral to crystallize (olivine) settles down by gravity in the magma. Such rocks bear similarity to other Martian rocks found in the Gusev crater by the Opportunity rover, and also to some Martian meteorites. These rocks will be studied in Earth‐based laboratories and will allow us to better understand magmatic processes on Mars. Key Points: The Séítah formation consists of an olivine cumulate series, weakly altered, preserving the igneous texture and mineralogyEmplacement of the Séítah formation required fractional crystallization and slow cooling of the parent magma at depth and erosionThe Séítah formation could be a particular member of the Nili Fossae regional olivine‐carbonate unit observed from orbit [ABSTRACT FROM AUTHOR]

According to the big impact hypothesis, the moon should be very dry. However, more and more evidence from the remote sensing of the moon in recent years indicates that there is a lot of water in the moon's polar regions. Researching the source and distribution of volatiles such as water can provide a key constraint on the formation and evolution of the moon. If there is a large amount of a volatile such as water ice in the polar area of the moon, it can be used as a further resource. Regrettably, there are no detectors in place to detect the amount and presence of water to date. In the new wave of lunar exploration, polar water has become one of the main tasks of NASA, ESA and RKA. The Chang'e-7 spacecraft of China's fourth lunar exploration phase has also used the Water Molecular Analyzer and the Lunar Soil Volatile Measuring Instrument to detect water content in the lunar polar region. This paper introduces a set of methods and principles for analyzing water content via the heat flux method according to the characteristics of the Lunar Soil Volatile Measuring Instrument that was deployed on the lunar surface. According to the current design, the water content of 0.008~0.17% can be analyzed. [ABSTRACT FROM AUTHOR]

To provide reliable input information for the load design and extraction of lunar soil water ice samples, it is necessary to study the water content distribution and water migration of simulated lunar soil water ice samples. On this basis, the temperature field model and the hydrothermal coupling relationship are proposed. The temperature field model was constructed by combining energy conservation and Fourier's heat transfer law. The coupling relationship was established, and the hydrothermal coupling model was obtained by testing the unfrozen water content using the nuclear magnetic resonance method. Finite element software was used to solve the model numerically, and the water migration rule of the soil water ice samples at different ambient temperatures were analyzed. Thin-wall drilling tests were carried out on the simulated lunar soil water ice samples to obtain water content data for different locations, and the simulation results were verified. Due to the migration effect of the cold end of the water, the closer we tested to the edge of the sample, the higher the water content was. The higher the ambient temperature was, the more pronounced the water migration phenomenon of the whole sample was. These research results provide a basis for sampling scheme design. [ABSTRACT FROM AUTHOR]

The lunar polar regions are key areas for future exploration due to the long-term continuous illumination and persistently shadowed regions that can cold trap abundant water and other volatiles. However, the complex terrain, dynamic lighting, and solar wind-induced electric-field environment present multiple challenges for polar investigation and sampling missions. China's Chang'E-7 (CE-7) will explore the Moon's south polar region in 2026. One of the scientific goals is to drill samples in a wide area with a rover for in situ analysis. This study analyzes the engineering constraints of the polar illumination condition, slopes, and electric field for landing and sampling-site selection. Then, we create a 3D model of CE-7's lunar rover in three operating environments by employing the Spacecraft Plasma Interaction Software, with the rover sampling (i) on a flat surface, (ii) in a shadow, and (iii) near a meter-scale crater under different solar altitude angles. The results show that the rover can be charged to different potentials under the combined effects of solar wind incident angles and surrounding terrains. We find that a favorable traversing and/or sampling site of the rover for future polar exploration is in the upwind direction of a bulge (positively elevated terrains, such as the lander or boulders) or crater, which will cause a minimum charging effect on the rover. Our results have important implications for minimizing the risk of charging effects and guiding the lunar polar region exploration. [ABSTRACT FROM AUTHOR]

The history of mare volcanism critically informs the thermal evolution of the Moon. However, young volcanic eruptions are poorly constrained by remote observations and limited samples, hindering an understanding of mare eruption flux over time. The Chang'e-5 mission returned the youngest lunar basalts thus far, offering a window into the Moon's late-stage evolution. Here, we investigate the mineralogy and geochemistry of 42 olivine and pyroxene crystals from the Chang'e-5 basalts. We find that almost all of them are normally zoned, suggesting limited magma recharge or shallow-level assimilation. Most olivine grains record a short timescale of cooling. Thermal modeling used to estimate the thickness and volume of the volcanism sampled by Chang'e-5 reveals enhanced magmatic flux ~2 billion years ago, suggesting that while overall lunar volcanic activity may decrease over time, episodic eruptions at the final stage could exhibit above average eruptive fluxes, thus revising models of lunar thermal evolution. This work estimates the eruption volume of the young Chang'e-5 lunar samples using diffusion chronology and thermodynamic simulations, and finds that there was an increase in volcanic eruption flux about 2.0 billion years ago. [ABSTRACT FROM AUTHOR]

Wireless power transfer (WPT) using magnetically coupled resonators is being integrated into space vehicles destined for the lunar surface. The dusty soil on the Moon, called lunar regolith, is known to adhere to surfaces and is also known to contain iron, including iron oxides and metallic iron. Regolith samples are limited, and lunar soil simulants are commonly used in space science research for efforts in surface vehicle navigation, in-situ resource utilization, and power infrastructure. However, most simulants contain no metallic iron, and research involving electromagnetic field interactions with regolith would benefit from incorporating metallic iron into test samples. This work presents experimental results from tests using WPT with magnetically coupled resonators in the presence of various standard lunar simulants, plus a new iron-enriched simulant and metallic iron powders. Results for power transfer efficiency, thermal response, and frequency response are presented and demonstrate that the presence of metallic iron and its particle size are critical factors affecting the coupling of the incident magnetic field with lunar simulants and iron powder samples. The importance of particle size-to-skin depth ratio is discussed. Attenuation constants for various iron powders are estimated from experimental data and compared to those of lunar regolith and simulants. [ABSTRACT FROM AUTHOR]

Mountains are an important research object for surveying, mapping, cartography, space science, and ecological remote sensing. Automatic mountain segmentation is one of the most critical techniques in large-scale mountain analyses. However, several factors limit the segmentation accuracy, such as the complexity of mountains, the noise of geospatial data, and the confusion in distinguishing non-mountainous objects with similar features. In order to improve the accuracy of mountain segmentation against these limiting factors, we impose the cloth constraint over the digital elevation model (DEM) with the underlying assumption that the mountain has a sizeable relative elevation and slope. We propose a robust mountain segmentation method with the cloth simulation constraint. The core algorithm extracts the relative elevation of the region using a cloth simulation filtering algorithm by transforming the mountain segmentation problem into an optimization problem based on the global energy function consisting of the relative elevation and slope. Experiments on a wide range of Earth and lunar elevation datasets with some of the aforementioned limitations show that the proposed method can extract complex mountain baselines, avoid the misclassification of lunar craters, and significantly improve the robustness and accuracy of mountain segmentation. Compared to three state-of-the-art methods (the Lunar Mountain Detection Method, the Landform Mask Method in SNAP™ from European Space Agency (located in Paris, France), and the Multiscale Segmentation Method in eCognition™ from Definiens Imaging (located in Munich, Germany), the F1 and IoU improved by 14.70% and 20.46% on average and 29.07% and 38.94% at most, respectively, which validates that the proposed method has a better all-around performance. [ABSTRACT FROM AUTHOR]