Mars exhibits a unique hybrid magnetospheric environment, characterized by interactions between the solar wind and both the ionosphere and the localized crustal magnetic fields. This configuration renders the Martian magnetosphere highly sensitive to external influences, including solar activity and seasonal variations. Here, we present findings from the Tianwen-1 mission and the MAVEN mission, providing insights into the dynamic behavior of the Martian magnetosphere. The Tianwen-1’s MINPA instrument and MAVEN’s STATIC instrument enabled the characterization of ionospheric ion motions, revealing critical dependencies on local crustal fields, variations in solar EUV flux, and fluctuations in solar wind dynamic pressure. By integrating Tianwen-1 and MAVEN datasets, this research advances our understanding of Mars’s magnetospheric variability and its implications for atmospheric loss. These findings not only deepen our knowledge of Martian atmospheric evolution and potential habitability but also inform future exploration strategies for planetary sciences.

How to cite: Fan, K. and Wei, Y.: Seasonal variations of the Martian magnetosphere: Tianwen-1 observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11192, https://doi.org/10.5194/egusphere-egu25-11192, 2025.

China's Tianwen-1 (TW1) mission successfully entered Mars orbit in 2021. This mission provides a valuable tracking dataset for at least three more years to enhance the understanding of Mars' gravity field. The highly elliptical near-polar orbit of the TW1 orbiter offers unique sensitivity to long-wavelength gravity signals, complementing the contributions of low-altitude missions like the Mars Reconnaissance Orbiter (MRO). In this study, we first developed a new 50 degree and order Mars gravity field model using four months of TW1 radio tracking data combined with MRO data. We evaluated the improvement of gravity field determination through power spectrum analysis, gravity anomalies maps and trajectory precision assessment. The result shows significant improvements in accuracy up to degree and order 30, with an average enhancement of 38% in the zonal harmonic coefficients, as shown in Figure 1. There are obvious differences between the two gravity field models in gravity anomalies maps, as shown in Figure 2. The range of gravity anomaly errors improves after incorporating TW1 data, with the maximum error decreasing from 53.4 mGal to 46.4 mGal, and the average error improving from 8.4 mGal to 7.3 mGal. Orbit determination experiments confirm that the fused gravity field model enhances trajectory modeling for both MRO and TW1, as shown in Figure 3. Additionally, we processed all the tracking data currently accumulated by TW1 to obtain an 80th-degree Mars gravity field model, as shown in Figure 4. These findings highlight the scientific value of TW1 tracking data in advancing Mars' gravity field modeling.

Figure 1. Power spectrum of the MRO50 and MTW50 gravity field models and their error estimates, along the Kaula’s rule and power spectrum of the a priori MGS95J gravity field model

Figure 2. From (a) to (b): maps of gravity anomalies of MRO50 and MTW50 gravity field models and their differences. The maps are centered on 0°E longitude (Hammer projection) 

Figure 3. Orbit fit difference rms on the MRO RTN frame using the MRO50 and MTW50 gravity field models for MRO

Figure 4. Power spectrum of the 80-degree gravity field model obtained with and without the Kaula’s rule and their error estimates, and power spectrum of the a priori MRO120D gravity field model

How to cite: sun, S., wang, C., yan, J., and barriot, J.: Enhancing Mars Gravity Field Solutions with China’s Tianwen-1 tracking data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3135, https://doi.org/10.5194/egusphere-egu25-3135, 2025.

Mars is rich in color information, and color images can more vividly represent its surface morphology, which helps scientists accurately interpret the geomorphological and geological characteristics of Mars. However, modern telescopes and remote sensing technology still haven't provided a quantitative answer to the exact colors of the Martian surface. The Moderate Resolution Imaging Camera (MoRIC) on Tianwen-1 is a "true color" camera with red, green, and blue spectral bands matching the spectral response range of human eyes. In around 8.3 months, it obtained color images covering the entire globe of Mars. But affected by illumination and atmospheric conditions, there are conspicuous stripes along the image strip direction in the color mosaic map, and the overall tone is noticeably red. Color difference analysis reveals that in the high latitudes of the northern hemisphere, the color differences mainly stem from varying atmospheric conditions during mapping; in the middle and low latitudes, they're mainly due to different lighting conditions; while in the high latitudes of the southern hemisphere, the color differences (measured by CIEDE2000, ΔE00) are mainly caused by the changes in surface features resulting from the seasonal melting of the ice caps. In this work, we proposed a novel approach to quantified color correction and equalization for generating Mars global color image mosaics from the MoRIC images. This approach makes the image brightness and tone visually consistent under different imaging conditions and maintains global consistency in the tones of the same surface features. A significant portion (80.1%) of the overlapped regions has color differences concentrated within ΔE00≤3.0, which greatly improves the issue of color and brightness inconsistencies in the original images (Level 2C). After processing, the tone of the global color mosaic map shows the "terracotta hue" that we expect for Mars images and is a good approximation of what the human eye would see.

How to cite: Ren, X., Zhang, X., Chen, W., Yan, W., Zeng, X., Liu, D., Liu, B., Zuo, W., Fu, Q., Liu, J., and Li, C.: An Innovative Approach to Performing Color Correction and Equalization for Creating Mars Global Color Image Mosaics Using Tianwen-1 MoRIC Images, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4035, https://doi.org/10.5194/egusphere-egu25-4035, 2025.

Evidence from instruments in Mars orbit and from the Zhurong rover suggests that oceans may have existed in the northern plains of Mars. Sedimentary stratification is a key indicator for verifying the historical presence of oceans on the Martian surface. However, there is still disagreement about the formation mechanism of sedimentary stratification at the Zhurong rover landing site. In this study, three-dimensional point clouds are generated from images taken by the Zhurong rover's navigation stereo camera. These point clouds are used to perform quantitative measurements and statistical analyses of the cross-bedding angles in sediments in rocks, and these angles are then compared with sedimentary bedding angles from various terrestrial environments to infer the dynamic sedimentary processes in the Zhurong landing area. The dip angles of the rocks at the Zhurong landing site on Mars range from 18.5° to 51.5°, with a median of 33.4°. The dip angles of the rocks in Gale Crater range from 14.7° to 41.7°, with a median of 31.5°. On Earth, the dip angles of strata in humid regions range from 7.4° to 38.4°, with a median of 27°, whereas in arid regions, the dip angles of strata range from 7.6° to 38°, with a median of 22.6°. These dip ranges indicate that the cross-bedding angles of sedimentary rocks on the Martian surface are similar to those of coastal aeolian cross-bedding on Earth, which indicate that their formation mechanism was comparable to the formation mechanism of coastal dunes. The sedimentary rocks at the Zhurong landing site were concluded to have formed in a nearshore marine depositional environment. This study represents the first statistical analysis of critical information on cross-bedding in Martian surface rocks compared with that in similar terrestrial environments, providing evidence from a sedimentary dynamics perspective for the depositional evolution of the Martian Utopia Planitia and indicating the historical presence of an ancient ocean in this region.

How to cite: Hu, H., Kang, Z., Chen, H., Hu, T., Xu, X., Ye, C., Cao, Z., Shao, S., and Chen, L.: Rock Strata Inclination: Insights into the Paleo-Coastal Marine Environment at the Zhurong Landing Zone, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6768, https://doi.org/10.5194/egusphere-egu25-6768, 2025.

China’s Tianwen-1 successfully landed on Utopia Planitia in 2021, forming the deepest landing crater on Mars. The landing crater and plume-surface interaction can provide valuable insights into the mechanical properties of the nearby Martian soil. We first derived the digital elevation model (DEM) of the landing crater based on the image data from Zhurong’s NaTeCams. The depth and diameter were obtained. After that, we established numerical models for the PSI and the crater formation based on Computational Fluid Dynamics (CFD) methods. The increase in cohesion and internal friction angle leads to a decrease in erosion rate and maximum crater depth, with the cohesion having a greater impact. While the influence of the nozzle height is not clear, as it interacts with the position of the Shock Diamond to jointly control the erosion process. We categorized the evolution of landing craters into the dispersive and the concentrated erosion modes based on the morphological characteristics, and estimated the upper limits of internal friction angle and cohesion of the nearby Martian soil via the comparative case studies.

How to cite: Chen, X., Xu, T., Li, J., Li, S., Zhang, Z., Zheng, B., Sun, X., Wu, Y., Diao, Y., Hu, Y., He, J., and Li, X.: Formation of Tianwen-1 landing crater and mechanical properties of nearby Martian soil, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5320, https://doi.org/10.5194/egusphere-egu25-5320, 2025.

This research delves into the three-dimensional (3D) morphological characteristics of Martian rocks, utilizing high-resolution images captured by the NaTeCam of China's Zhurong rover and a novel 3D rock extraction approach. The morphological analysis encompasses a detailed examination of 6,185 cm-scale rocks, highlighting the prevalence of small rocks (length < 10 cm, width < 8 cm, height < 2 cm) that constitute approximately 75% of the total rock population in the study areas. This finding underscores the significance of small-scale features in the Martian landscape and suggests that these rocks may play a substantial role in the planet's surface dynamics.

A key discovery is the influence of landscape type on the distribution of rocks. The research indicates that the number of rocks varies with different landscape types, such as flat terrains, sand dunes, and crater complexes. However, the proportions of rocks of different sizes remain consistent across these varied landscapes, suggesting a uniformity in the rock size distribution that is independent of the specific geomorphological setting. Comparative morphological analyses reveal distinct differences between sedimentary rocks and float rocks. The size-frequency distribution around craters is notably different from other areas, indicating that the geological processes around craters may lead to a unique rock distribution pattern. This finding is crucial for understanding the impact of crater formation on the local geology and the subsequent redistribution of rocks.

Furthermore, the study compares the morphological features of rocks from the Zhurong landing area with those from the Bonneville crater ejecta, as documented by the Spirit rover. The analysis shows similarities in 2D compactness between the outcrop rocks of Zhurong and the Bonneville crater ejecta rocks, suggesting a commonality in the horizontal morphological characteristics. In contrast, the Bonneville crater ejecta rocks exhibit a more diverse sphericity distribution, implying a greater variety in their three-dimensional shapes. This diversity in sphericity may reflect different formation processes or subsequent erosional histories. An intriguing observation is the convergence of sphericity with height for rocks in both landing areas. As rock height increases, the sphericity values tend to stabilize, suggesting a potential relationship between rock size and shape that could be influenced by factors such as weathering and erosion.

In conclusion, this study provides a detailed and nuanced understanding of the 3D morphological features of Martian rocks. The findings not only contribute to the broader knowledge of Martian geology but also offer specific insights into the geological processes that have shaped the Martian surface over time. The analysis of cm-scale rocks, in particular, reveals the complexity and diversity of the Martian landscape, highlighting the importance of small-scale features in the overall geological picture. These results are expected to inform future Martian exploration missions and enhance our understanding of the planet's geological evolution.

How to cite: Li, Y., Zhang, W., Xiao, Z., Ma, C., and Zeng, L.: Three-dimensional Morphological Analysis of Martian Rocks Using Zhurong Rover NaTeCam Images, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5847, https://doi.org/10.5194/egusphere-egu25-5847, 2025.

China’s Tianwan-1 orbiter has recently observed the Martian South Polar Seasonal Cap (SPSC) around Ls =210°-332° in MY36 and obtained a bunch of data. The SPSC plays a crucial role in the planet's atmospheric dynamics, with its seasonal variation reflecting the Martian climate system. Although the recession of the SPSC has been observed over multiple Martian years, the asymmetry observed in this process makes it difficult to characterize. Understanding these asymmetries is essential for identifying time steps in the recession process and deepening our knowledge of Martian seasonal dynamics and climate cycles. Additionally, comparing the critical time steps of the recession process and investigating the impact of suspended dust on the SPSC will provide new insights into the relationship between the SPSC and climate, help in understanding the role of dust in shaping Martian atmospheric circulation, and offer valuable observational constraints for future climate models. In this study, we introduced a series of multi-temporal maps of the SPSC constructed from image data collected by the Moderate Resolution Imaging Camera (MoRIC) aboard the Tianwen-1 orbiter. With these maps, the dynamic changes (such as boundary, area, etc.) of the SPSC can be identified through remote sensing methods. And a dynamic recession model spanning from solar longitude (Ls) 210° to 332° would be demonstrated by incorporating a 5th-order polynomial fitting of the time-series on cap latitude. Furthermore, the influence of Martian dust activity on the SPSC during the spring and summer seasons could also be analyzed. This research could enhance our understanding of the complex interactions between Martian seasonal processes, dust activity, and the atmospheric system.

How to cite: Zeng, X., Fu, Q., Li, Z., Yan, W., Chen, W., Tan, X., Ren, X., Wen, W., Chen, Z., Zhang, Q., Li, C., and liu, J.: Characterization of the seasonal variation of the Martian south polar cap with new observation data obtained by Tianwen-1 probe, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3068, https://doi.org/10.5194/egusphere-egu25-3068, 2025.

The timing of the martian dynamo has always been an outstanding scientific issue in the evolution of Mars, as it provides the key implications for the evolution of the Martian core and the habitability. Both an early dynamo before ~ 4.1 Ga (e.g., Acuña et al., 1999), a late dynamo after 3.9 Ga (e.g., Mittelholz et al., 2020), and even a long-lived dynamo (Steele et al., 2023; 2024) have been suggested to interpret the martian magnetism at large scale by orbiting measurements and at very small scale via Martian meteorites. The dynamo status after early Hesperian (e.g., ~3.7 Ga) is still poorly constrained. Here we report surface magnetic survey in the southern Utopia basin from Zhurong rover. In addition to the extremely weak magnetic fields inside a ~ 6-km diameter ghost crater in the first 800-m track, the magnetic intensity exhibits a significant enhancement (~ 40 nT on average) in the following 600-m track at the edge and outside the crater. A magnetic source with depth of about 600-m and average magnetization of ~ 1 A/m are required to produce the measured field strength outside the crater. Such magnetic source is likely carried by Hesperian lava flows. The presence of the moderate and little magnetizations outside and inside the ghost crater indicate the martian dynamo may have persisted until mid-Hesperian but experienced a significant decrease before the ghost crater was formed.

How to cite: Du, A., Luo, H., and Ge, Y.: New constraint of the Martian dynamo from surface magnetic survey by Zhurong rover, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4970, https://doi.org/10.5194/egusphere-egu25-4970, 2025.

Aqueous activities on Mars have gradually declined since the Noachian (>3.7 Ga). During the Hesperian and Amazonian periods, records of aqueous activity are relatively fragmentary. In 2021, the Zhurong rover, part of China’s Tianwen-1 mission, successfully landed in the southern Utopia Planitia which belongs to the northern lowlands of Mars. High-quality orbital and in-situ data of the landing region have been acquired by the Tianwen-1 orbiter and the Zhurong rover, which provides unprecedent opportunities for studying the post-Noachian aqueous activities as well as testing the hypothesis of an ancient northern ocean on Mars. A series of possible water/ice-related features have been identified, such as polygons, cones, and sedimentary rocks. We analyzed their morphological characteristics, stratigraphic relationships, and possible origins. Based on these studies, we proposed the aqueous history of the southern Utopia Planitia, and provided possible evidence for the existence of an ancient ocean on Mars.

How to cite: Zhao, J., Huang, J., Wang, L., Wang, J., and Xiao, L.: Water/ice-related features in the Zhurong landing region: implications for the aqueous history of southern Utopia Planitia, Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16964, https://doi.org/10.5194/egusphere-egu25-16964, 2025.

The Martian subsurface structure archives the magmatic activity, sedimentary processes, and meteorite impact history of Mars, making it a promising region for investigating the geological evolution and ancient water activities of the planet. On 15 May 2021, China’s first Mars mission, Tianwen-1, successfully landed on the south of Utopia Planitia and released the Zhurong rover to in-situ detect the subsurface structure with the equipped ground penetrating radar (Rover Penetrating Radar, RoPeR). Using the low-frequency channel radar data recorded during the first 113 Sols, a high-precision radar imaging result of depths exceeding 80 meters beneath the surface was obtained, following effective random noise attenuation and velocity inversion. Beneath the Martian regolith layer, which is several meters thick, two fining-upward sedimentary sequences were identified at depths of about 10–30 meters and 30–80 meters. Further analysis using dielectric permittivity inversion yielded insights into the strata’s physical properties, indicating that southern Utopia Planitia underwent multiple water-related resurfacing events since the Late Hesperian period (3.5–3.2 billion years ago). Hydrological processes might have persisted until the middle and late Amazonian period (around 1.6 billion years ago). No evidence of liquid water was found within the upper 80 meters of the subsurface in this region, although the presence of saline ice cannot be ruled out.

How to cite: Li, C., Zhang, J., Chen, L., Zhang, L., and Pan, Y.: Layered subsurface in Utopia Basin of Mars revealed by Zhurong rover radar, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14497, https://doi.org/10.5194/egusphere-egu25-14497, 2025.

The erosion rate on Mars has been dwindling throughout its history and its signatures provide paleo-climatic information. Active aeolian abrasion supported by sands is a well-understood mechanism for modern Mars erosion. Abrasive sands undergoing redistribution, comminution, or deactivation can evolve toward depletion, leading to even weaker erosion condition. This complementary aspect of Mars surface processes has not been thoroughly investigated in-situ beyond early robotic missions.

Zhurong rover's landing on the southern Utopia Planitia, Mars, during the Tianwen-1 mission (14 May 2021, UTC, 109.925°E, 25.066°N) opened a new frontier in the understanding of a potential weakly abraded landscape. The rover, traversing southwards from its landing site, has witnessed a largely flat, apparently dust-covered landscape of Hesperian-Amazonian age bedrock dotted by cemented, bright dunes dated to 0.4-1.4 Ma. The encrusted surface of these dunes may have inhibited them as currently active abrasion sources. Orbital observations focusing on long-term surface feature retention also predicted a low erosion rate over the past 1.1 Ga (0.01-0.1 nm/yr).

Here, in the anticipated weakly abraded landscape visited by Zhurong, we report the existence of extensive, millimeter-thick coverings bearing abraded morphology over local blocks as observed by the Navigation and Terrain Cameras (NaTeCam) and Multispectral Camera (MSCam) onboard Zhurong. The coverings are unlike the micrometer-scale dust film usually seen on Mars in terms of their thickness and the abraded ventifact-like morphology differs from typical Martian ventifact in terms of its mechanical strength. Using the first Mars in-situ material physics analysis through laser-induced blast waves, facilitated by Zhurong’s Mars Surface Composition Detector (MarSCoDe) with laser-induced breakdown spectroscopy (LIBS) capability, we probed the cohesion of the covering (ranging from 0.4 to 18 kPa), which exceeds modelled electrostatic and van der Waals cohesion, suggesting a potential cementation from agents like perchlorate and sulfate salts. Our results and modellings suggest an unprecedented accumulation mode termed Cemented Aeolian Coverings (CAC): aeolian materials accumulate over local blocks by dustfall or aggregate saltation and are cemented by water-supported process and salt. They are preserved, thickened, and shaped into present ventifact-like form due to insufficient aeolian abrasion.

This example illustrates the active aeolian accumulation over the modern Martian surface under a limited erosion. The CAC is probably unique to Mars as well as its weakly abraded landscape due to its accumulation-cementation processes under a hyper-arid condition and the very limited erosion unavailable on Earth. It may be representative to a "terminal" phase of the modern Mars abrasion process where the abrasive sands have been depleted. The contemporary CAC forming scenario investigated by Zhurong, featuring an active cycle of grain adhesion, salt deliquescence, and aeolian erosion, may provide new insights into the activity of current surface processes and the formation of fine-scale, periodic geomorphology on Mars.

How to cite: Chen, Z., Caravaca, G., Loche, M., Chide, B., D. Pál, B., Zhang, J., Cousin, A., Forni, O., Lasue, J., Liu, J., Liu, X., Ren, X., Rapin, W., Xu, W., Zhang, Q., Zhang, Y., Shu, R., Kereszturi, Á., Maurice, S., and Li, C.: Modern aeolian accumulation and erosion processes at the Martian surface revealed by the Zhurong rover of Tianwen-1, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18467, https://doi.org/10.5194/egusphere-egu25-18467, 2025.

The Zhurong rover from the China’s Tianwen-1 mission have collected meteorological data in Utopia Planitia during Mars Year 36 (MY36). This study first utilized the column dust optical depth (CDOD) data of MY36 observed by the Mars orbiter to analyze the spatial and temporal variation of dust near the landing site of Zhurong rover in Utopia Planitia.  Moreover, the Global Open Planetary atmospheric model for Mars (GoMars) model was used to simulate the atmospheric dynamics in Utopia Planitia, further analyzing the local circulation near the landing site of Zhurong rover. Finally, the thermal and dynamical characteristics of atmosphere simulated by GoMars between the operational period and dormancy of the Zhurong rover were compared to demonstrate the evolution of dust activity in Utopia Planitia. These results can serve as a reference for the atmospheric environment analysis in future Mars exploration missions.

How to cite: Li, Y., Liu, M., Liu, J., Pu, Y., Dong, L., Liu, H., Li, J., and Liu, S.: Preliminary Analysis of Dust Activity during the Operational Period and Dormancy of Zhurong Rover in Utopia Planitia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19509, https://doi.org/10.5194/egusphere-egu25-19509, 2025.

Previous mineralogical investigations on Utopia Planitia only show sporadic hydrous minerals in localized areas, limiting the modeling of the regional aqueous activities. Although the periglacial landforms and radar observations allude to the presence of subsurface water ice in Utopia Planitia, evidence of water ice on the surface is not detected. Using a total of 330 CRSIM images covering the southern Utopia Planitia and the bordering highland, we identify widespread phyllosilicates and carbonates on the highland, and four possible water ice spectra at a midlatitude on the lowland, three of which are mixed with monohydrated sulfate. Moreover, orbital data near the landing site of Zhurong rover in southern lowland show a thick dust cover. The restriction of phyllosilicates and carbonates to the Noachian/Hesperian highland units and sulfate to the Hesperian/Amazonian lowland units suggest that the ancient water retreated from highland to lowland when the aqueous environment changed from alkaline/neutral to acidic. Spectral evidence for water ice indicates that Utopia Planitia is still a reservoir on Mars.

How to cite: Song, M., Zhong, Y., Ke, T., and Wang, X.: Spectral evidence of hydrous minerals and water ice on southern Utopia Planitia, Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5419, https://doi.org/10.5194/egusphere-egu25-5419, 2025.

In May 2021, China’s first Mars exploration mission, Tianwen-1, successfully landed its rover, Zhurong, on the southern part of Utopia Planitia, an Amazonian geological unit on Mars. Zhurong is equipped with a Shortwave Infrared Spectrometer (SWIR) capable of capturing spectra in the 0.85–2.4 μm range from the surface of landing area. Previous studies of the SWIR spectra have primarily been qualitative, suggesting evidence of hydrated activities in the region. These findings indicate that water activity during the Amazonian era may have been more active than previously thought.

The SWIR spectra obtained by Zhurong are mixed spectra comprising signals from multiple components. Through further quantitative analysis, the mineral abundances in the landing site can be determined, providing better constraints on the intensity of hydrated processes and enhancing our understanding of Amazonian hydrology on Mars.

This study selected olivine, high-calcium pyroxene, low-calcium pyroxene, plagioclase, and glass as common Martian spectral endmembers, and hydrated minerals such as gypsum as characteristic endmembers. Using the Hapke radiative transfer model combined with the Cascading Adaptive Transitional Metropolis In Parallel (CATMP) algorithm, we performed linear spectral unmixing of the SWIR data. The analysis retrieved the surface mineral abundances, grain sizes, and associated uncertainties.

The spectral unmixing results across the 2-km traversed area of the landing area were highly consistent, showing a dominance of primary minerals such as olivine, with a relatively low abundance of hydrated minerals. This suggests limited chemical weathering processes in the region. Our unmixing results enable more precise quantitative characterization of surface hydration activity, contributing to a deeper understanding of the Amazonian climate and hydrological evolution on Mars.

How to cite: Zhou, X., Wu, X., Zou, Y., and Liu, Y.: Quantitative Mineral Analysis of Zhurong Landing Area Based on In-situ SWIR Spectral Unmixing, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10183, https://doi.org/10.5194/egusphere-egu25-10183, 2025.

As Utopia Planitia might have once stored a relatively large water body, the western edge of the Qaidam Basin (a dehydrated paleolake basin featured by various Mars-like landscapes) in the northeastern Tibetan Plateau is analogous to the supposed lake shoreline of the landing site of Zhurong. As evaporation intensified, salt types in water sources and dry soils within the Qaidam Basin transformed from (bi)carbonates to sulfates and chlorides associated with decreasing biological activity, as suggested by isotopic signatures [1]. Evaporite minerals (e.g., gypsum, halite, and polyhydrated sulfates) were abundant in the western Qaidam Basin. Using the engineering qualification model of Zhurong’s MarSCoDe payload in a simulated Mars environment platform, the contents of gypsum in Qaidam soils were calibrated based on mineralogical and short-wave infrared (SWIR) spectral results. Putative signals of sulfur and chlorine in laser-induced breakdown (LIBS) spectra were additionally investigated. Semi-quantitative assessments of several evaporite minerals were performed for spectral data acquired from the Zhurong landing area. Furthermore, our findings imply that LIBS-associated statistics and suites of spectrometers can be promising tools for in situ life detection on Mars or returned sample analyses in laboratories if biotic materials were present in a small measured region even at low biomass levels [2,3]. In future Mars missions, we recommend that the life detection strategy should consider regions with mineral products of water-rock reactions as landing zones, as they could offer more habitable environments that provide life-essential elements and energy sources and preserve organic matter or even traces of life [4].

References

[1] Shen, J., Huang, T., Zhang, H., Lin, W. (2024). Hydrochemical and isotopic characteristics of water sources for biological activity across a massive evaporite basin on the Tibetan Plateau: Implications for aquatic environments on early Mars. Science of The Total Environment, 935, 173442.

[2] Shen, J., Liu, L., Chen, Y., Sun, Y., Lin, W. (2022). Geochemical and Biological Profiles of a Quartz Stone in the Qaidam Mars Analog Using LIBS: Implications for the Search for Biosignatures on Mars. ACS Earth and Space Chemistry, 6(11), 2595-2608.

[3] Shen, J., Liu, L., Chen, Y., Lin, W. (2024). A suite of spectroscopic devices as a potential tool to discriminate biotic and abiotic materials with an igneous rock. Icarus, 407, 115804.

[4] Shen, J., Liu, C., Pan, Y., Lin, W. (2024). Follow the serpentine as a comprehensive diagnostic for extraterrestrial habitability. Nature Astronomy, 8, 1230-1236.

How to cite: Shen, J., Liu, L., Zhang, H., Guo, X., Huang, C., Chen, Y., and Lin, W.: Mineral and elemental geochemistry of the arid Qaidam Basin for habitability evaluation at Zhurong landing region on Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7818, https://doi.org/10.5194/egusphere-egu25-7818, 2025.

Mn-oxides (MnO_x) usually requires highly oxidizing conditions to form under ambient conditions, and thus its occurrance has been widely interpreted as a strong sign for oxidizing atmosphere sustained by oxygenic photosynthesis. However, lack of ozone would allow direct penetration of UV radiation through the early anoxic atmospheres on the Mars and Earth, which could drive multiple photo-oxidation reactions. Here, we test the photo-reactivity of Mn(II)-bearing carbonate minerals using first principle calculations. We found that trace incorporation of Mn(II) would susbtantially lower the band gap of common carbonate minerals, enabling the anoxic photo-oxidation of Mn(II)-bearing carbonates upon 200-400 nm light. Our results imply that photo-oxidation of Mn(II) could be prevalent on the early Mars and Earth, complicating its applicability as a oxygen-barometer and biosignature for oxygenic photosynthesis.

How to cite: Hao, J., Guo, J., and Huang, F.: Photochemical Reactivity of Mn-bearing Carbonate Minerals Under Early Earth and Mars Conditions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15402, https://doi.org/10.5194/egusphere-egu25-15402, 2025.

The International Lunar Research Station (ILRS) represents a significant milestone in lunar exploration. It is a jointly - implemented, scalable, and maintainable facility with functions like power supply, communication, and scientific research. The ILRS adheres to principles such as peaceful utilization and shared benefits. Its objectives cover technological leaps, scientific research on lunar geology, and resource utilization. The implementation is divided into basic and extended models by 2035 and 2050 respectively. International cooperation engages with numerous countries, international organizations, and institutions in various aspects, including facility construction, scientific research, and data sharing. A sound cooperation mechanism has been established, with management frameworks for scientific data and lunar samples, aiming to promote global lunar exploration and space development.

How to cite: Shen, Y. and Wang, W.: The International Lunar Research Station (ILRS) , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21719, https://doi.org/10.5194/egusphere-egu25-21719, 2025.

All the lunar landings and photographic investigations show that several meter-thick regolith layers cover the lunar’s surface. The regolith layer records its space weathering and meteorite bombardment history, and understanding its formation and evolution is of great importance to lunar exploration. The Chang’E-6 (CE6) mission landed at the south of the Apollo crater inside the South Pole-Aitken (SPA) basin at the lunar’s far side. The CE6 regolith thus provides a rare opportunity to compare with near-side regolith returned from the Apollo, Luna, and Chang’E-5 (CE5) missions. Here, we conducted analyses on the chemical and Fe isotope compositions on two portions of bulk regolith and nine tiny clasts separated from the scooped CE6 regolith (CE6C0400YJFM004).

Elemental analyses show that the bulk regolith has slightly higher MgO (7.84 and 8.26 wt.%), and much higher FeO (21.01 and 19.08 wt.%) and Al₂O₃ (17.2 and 18.5 wt.%) than the previously reported values in Li et al. (2024), indicating the chemical heterogeneity in scooped CE6 regolith. EPMA analyses on agglutinate clasts show glasses with three kinds of compositions: (1) similar to pristine local basalt; (2) similar to Mg-suite rocks; (3) intermediate between local basalt and Mg-suite rocks. Based on mass-balance calculations, it indicates that the CE6 regolith contains 20-50% exotic ejecta with compositions similar to norite. These exotic materials should originate from the Chaffee S crater, which is situated approximately 100 km from the CE6 landing site.

The clasts in CE6 regolith show overall heavy Fe isotope compositions with δ⁵⁷Fe from 0.263 to 1.411‰. No correlations exist between δ⁵⁷Fe and MgO or FeO, ruling out the effect of magmatic differentiation. Instead, the δ⁵⁷Fe variation should be caused by evaporation during impact. The clasts, which have the smallest grain size, show the heaviest Fe isotope composition (1.411‰) and indicate a high energy impact. This clast may have formed through recondensation from the vapor generated by the intense impact associated with the formation of the Apollo crater.

Reference:

Li, C. et al. Nature of the lunar farside samples returned by the Chang'E-6 mission. National Science Review (2024). https://doi.org:10.1093/nsr/nwae328

How to cite: Huang, F., Kang, J., Yu, H., and Qin, L.: Impact-controlling Chang'E-6 regolith formation on the Moon’s far-side, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9610, https://doi.org/10.5194/egusphere-egu25-9610, 2025.

Impact craters are the most ubiquitous geomorphic features on the lunar surface, playing a crucial role in helping us understand lunar formation, evolution, and surface modification processes. High-resolution data from lunar orbiters, landers, and rovers have enabled detailed studies of degraded craters across multiple size ranges. However, existing research has often overlooked the combined analysis of small- and large-sized degraded craters to evaluate localized resurfacing events and refine geological unit dating.
This study focuses on the mare basalt regions at the Chang’e 3, 4, and 5 landing sites. We analyzed small degraded craters using cumulative size-frequency distribution (SFD) curves to assess impact saturation and degradation levels. For larger degraded craters, depth-to-diameter ratios were employed to derive a novel crater-based dating equation for mare basalt units.
Key findings reveal that in older regions, such as the Chang’e-4 landing area, the proportion of degraded craters decreases more significantly with increasing crater diameter compared to younger regions like the Chang’e-5 site. Geological unit ages estimated from depth-to-diameter ratios closely align with isotopic dating, with discrepancies within 0.2 Ga. Additionally, our method effectively estimates the model ages for the Chang’e-6 landing site, confirming its broader applicability. This study demonstrates the potential of integrating multi-scale degraded crater analyses to investigate localized resurfacing phenomena. The approach can be extended to future lunar and planetary landing sites, providing a robust framework for geological evolution studies.

How to cite: Cai, J., Kang, Z., Yang, Z., Yue, Z., Hiesinger, H., and H. van der Bogert, C.: Geological Evolution Studies of Chang’e Landing Sites: Multi-Scale Degraded Crater Analyses, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19968, https://doi.org/10.5194/egusphere-egu25-19968, 2025.

The Moon, as Earth's only natural satellite, provides excellent positional resources and a supportive environment for Earth observations; lunar-based Earth observation has advantages such as minimal interference, stable orbit, and broad field of view, making it an ideal platform for observing macro phenomena on Earth. China's Chang'e phase 4 lunar exploration missions will carry out large-scale and long-term Earth observations. Conducting lunar-based Earth observations can also further enhance our understanding of Earth's resource environment while enriching the connotations of lunar exploration. Shenzhen University, leading a collaboration with scientists from France and Switzerland, has proposed an international cooperative payload named MERB (Moon-based Earth Radiation Budget). This payload has successfully passed the selection process and has been officially included as an international cooperative payload on the Chang'e-7 mission. MERB aims to measure the Earth's radiation budget from the unique vantage point of the Moon, providing data that is essential for improving our understanding of Earth's climate system and its variations over time. Based on simulations, the observing geometries, observing frequency, angular coverage and solar invasion effects of Chang’e-7 Moon Orbiter-based Earth observations were analyzed, and compared with the Moon Lander-based Earth observations. Besides, the interpreting method and application potentials of deep space-based Earth observation for Earth’s Radiation budget were also explored.

How to cite: Liu, H., Zhu, P., Zhu, L., Xu, G., Cao, T., and Li, Q.: Moon-based Earth Radiation Budget Observation for Chang’e-7 Lunar Mission, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14375, https://doi.org/10.5194/egusphere-egu25-14375, 2025.

The DORN instrument is an alpha spectrometer that was deployed to the surface of the Moon aboard the Chang’E 6 spacecraft in June 2024, in the Apollo crater within the South Polar Aitken Basin, at a latitude of -41.6°S. Its purpose was to measure the concentration of radon and polonium released from the lunar regolith, to study the origin and dynamics of the lunar exosphere and the physical and thermal properties of the regolith. It consisted of 16 silicon detectors, organised in 8 Detection Units and 2 Fields of view, covering the near and far fields, and measuring charged particles in the 0.6 to 12 MeV energy range. The instrument was switched on several times during the mission. First, during the Chang’E 6 Earth-Moon transfer (for 10 hours), then in an ellipitical orbit (for 32 hours) and in a circular orbit at an altitude of ~200 km (for 111 hours), in the wake of a strong solar storm. After Chang’E 6 landing, it collected 19 hours of data and was switched off a few hours before the liftoff of the ascent module. We will present the results obtained by this instrument and compare them with previous measurements of radon and polonium made from the orbit and with simulations obtained by a global model of radon transport in the lunar subsurface and exosphere.   

How to cite: Meslin, P.-Y., He, H., Li, J., Chacartegui Rojo, Í. D. L., Qi, B., Thomas, V., Gasnault, O., Kang, Z., Wong, K. W., Baorui, L., Maurice, S., Pilleri, P., Sabot, B., Sabroux, J.-C., Girault, F., Pineau, J.-F., Lasue, J., Pinet, P., Zhang, D., and Ruihong, Y. and the DORN Team: First results from the DORN experiment onboard the Chang’E 6 mission, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14816, https://doi.org/10.5194/egusphere-egu25-14816, 2025.

Conducting experimental research using lunar regolith simulants on Earth is essential for understanding the geotechnical properties of lunar surface material and its interaction with equipment such as lunar rovers and landers, given the limited quantity of returned lunar samples. The particle size and morphology of regolith significantly influence their mechanical properties. We developed a high-fidelity lunar regolith simulant by pulverizing, desiccating, sieving, and blending natural terrestrial minerals or rocks, based on the key characteristics of the Chang’e-5 lunar samples. To evaluate the fidelity of this simulant, we used X-ray micro-computed tomography to scan both Chang’e-5 lunar regolith samples and the simulant. This technique generated high-resolution (~1 μm) grayscale images that recorded the three-dimensional geometric features of individual particles. A machine learning-based segmentation tool was used to extract the outlines of particles from a three-dimensional perspective, enabling the determination of particle morphology using the discrete Fourier transform (DFT) method. A comparative analysis of particle size and morphology was conducted, including shape indicator, roundness, and surface roughness. Results demonstrated that our simulant exhibits high geomechanical fidelity compared to the Chang’e-5 lunar regolith samples. Furthermore, the discrete element method (DEM) was applied to investigate the mechanical behaviors of the two granular materials, based on direct shear and triaxial tests. Our results indicate that the lunar regolith may have cohesion and friction angle of 0–13.5 kPa and 35.7–40.3°, respectively. Angular fine particles with a rough surface enhance the shear strength of lunar regolith. This finding underscores the potential of our simulant to facilitate experimental investigations into the technical challenges posed by lunar regolith to equipment.

How to cite: Zou, Y., Wu, H., Chai, S., Yang, W., and Zhao, Q.: Geomechanical Assessment of Chang’e-5 Lunar Regolith Using High-fidelity Simulant, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9509, https://doi.org/10.5194/egusphere-egu25-9509, 2025.

As the closest celestial body to Earth, the Moon has become a major focus of scientific research due to its unique position and environment. Although the Moon is often thought of as a 'dead' planet, in fact there is still some faint but continuous activity in its interior and on its surface. One particularly interesting phenomenon is lunar degassing, which reveals dynamic changes in its current environment. Interestingly, these degassing regions are often associated with distinctive lunar topography. Early lunar radon measurements, although made from orbits with considerable noise, showed that there were regions with enhanced radon exhalation, particularly in the Aristarchus crater region, which has been highlighted by the Apollo 15, Lunar Prospector and Kaguya-Selene missions. The recent Chang'e 6 mission successfully deployed the DORN instrument, which resulted from a collaboration between France and China, to perform both orbital and in-situ lunar surface measurement of radon and polonium. Although the Rn-222 was not detected in situ, the likely presence of faint polonium isotope peaks indicates that there was only a weak release of radon gas in the landing site region. Therefore, the primary objective of this study is to investigate the relationship between lunar degassing phenomena and topography by comparing the geomorphological features of the Aristarchus region with those of the Chang'e 6 landing site. The purpose of this study is to explore the relationship between lunar degassing phenomena and topography by comparing the morphological differences between the Aristarchus crater and the Chang'e-6 landing site. LRO WAC images are used to compare the topographic differences between the two regions, and SLDEM2015 data are used to calculate the elevation and slope differences within the regions to hypothesise the potential impact of these topographic features on radon gas release. In addition, data from the Chang'e-2 microwave radiometer are used to calculate the diurnal temperature variation at the Chang'e-6 landing site, with a detailed investigation of how temperature anomalies reflect the subsurface stratigraphy of the lunar surface. Based on the results of the data processing, We will analyse the geological environmental differences between the two regions and investigate the possible effects of these differences on the release of radon gas and the possible sources of the weak radon gas in the landing area.

How to cite: Qi, B., Kang, Z., Pierre-Yves, M., He, H., Li, J., Meng, Z., Xu, X., and Cai, J.: Comparative study on the release mechanism of lunar radon gas based on the topography of Chang'e 6 landing area and Aristarchus crater, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16824, https://doi.org/10.5194/egusphere-egu25-16824, 2025.

Lunar volcanic products are crucial for understanding the Moon’s formation and evolution. These samples not only record early lunar volcanic activity but also reveal the Moon’s internal structure and composition. In addition to igneous rocks, volcanic glasses can represent the lunar mantle. Eruptions of gas-rich magma can produce magma fountains, generating submillimeter glass beads that may be widely distributed and further transported by impacts. Such glasses could exist as trace components in lunar samples. Recent studies of hundreds of glass beads in Chang’e-5 samples found that three-fourths contain undigested clasts, indicating an impact origin. Glasses without clasts but with compositional heterogeneity are also classified as impact glasses, as their compositions often match the local regolith. For chemically homogeneous glasses free of mineral fragments, traditional major-element criteria are insufficient for classification.

Impact glasses exhibit diverse major- and trace-element compositions. Distinguishing volcanic glasses from abundant impact glasses in lunar regolith requires a multi-criteria approach. By analyzing textures, major and trace elements, and in-situ sulfur isotopes, three picritic volcanic glasses were identified among ~3,000 glasses in Chang’e-5 samples. This methodology can be applied to other lunar samples, providing data to assess the frequency of volcanic eruptions in lunar history.

Radiometric dating of the three Chang’e-5 volcanic glass beads confirms 120-million-year-old lunar volcanism, supporting remote sensing evidence of relatively young volcanic activity, such as Irregular Mare Patches (IMPs). These findings demonstrate that the Moon remained volcanically active until ~120 million years ago, offering new insights into its thermal and geological evolution.

How to cite: He, Y., Li, Q.-L., Wang, B.-W., and Zhang, Q. W. L.: Sulfur lsotope Effect and the Discovery of 120 Ma Volcanic Glasses in Chang'e-5 Samples, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17184, https://doi.org/10.5194/egusphere-egu25-17184, 2025.

In 2019, China's Chang 'e-4 mission carried out the first biological experiment on the moon, carrying six kinds of organisms, including potatoes, cotton, rape, Arabidopsis, fruit flies and yeast, to form a miniature ecosystem and cultivate two green leaves, which were evaluated by Nature and Science as the first green leaves on the human moon. Its background, creative sources, development basis and influence will be comprehensively introduced.

Numerous studies have suggested that caves are widespread on the Moon, Mars, and even across the solar system. As compared to the ground, building bases in caves on these extraterrestrial bodies have notable advantages. For this purpose, our team investigated dozens of caves with different types in Chongqing. Karst landforms are widely developed and complete in Chongqing, including skylights, ground seams, dark rivers, shafts, and other special landforms. Most of these caves are arched structures (like lava tubes) with a radius of a few meters to several tens of meters and a length of several thousand meters, or tens of thousands of meters (enough for simulation (meeting simulation needs). Caves stretch in a winding manner, with complex crisscross structures and isolated darkness inside. And we attempted to build an integrated simulation karst cave farm in Chongqing, China.

How to cite: Xie, G., Xiong, X., and Wang, R.: Plant growth experiment(s) on the Moon: from the success of Chang'e 4 to future Lunar farming, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8033, https://doi.org/10.5194/egusphere-egu25-8033, 2025.