Journal of Geophysical Research: Planets最新文献

{"title":"Coupling Seismic, Gravity and Magnetic Surveys for the Investigation of Planetary Lava Tubes: A Terrestrial Analog Case Study in Lanzarote (Spain)","authors":"A. Ghirotto,&nbsp;I. Barone,&nbsp;F. Santoro De Vico,&nbsp;G. Melchiori,&nbsp;A. Zunino,&nbsp;E. Armadillo,&nbsp;A. Mittelholz,&nbsp;F. Sauro,&nbsp;M. Massironi","doi":"10.1029/2026JE009802","DOIUrl":"https://doi.org/10.1029/2026JE009802","url":null,"abstract":"<p>Lava tubes are subsurface volcanic conduits formed during effusive basaltic eruptions and are considered key targets for planetary exploration. Orbital remote sensing on the Moon and Mars has identified numerous collapse pits interpreted as possible surface expressions of underlying lava tube systems. However, the limited resolution of current orbital data sets severely restricts our ability to determine their three-dimensional geometry, internal structure, continuity, and in some cases even their existence. With upcoming planetary missions planning to deploy ground-based geophysical instruments, robust and transferable strategies for subsurface lava tube detection and characterization are urgently needed. Terrestrial lava tubes represent valuable analogs for developing and testing such approaches. Previous investigations have often relied on single geophysical methods, resulting in ambiguous interpretations. Here we present a multi-method geophysical study of the “Cueva de Los Naturalistas,” a well-preserved lava tube located in the UNESCO Global Geopark of Lanzarote (Canary Islands), an excellent analog for extraterrestrial volcanic environments. We conducted high-resolution, profile-based, active and passive seismic surveys integrated with gravity and magnetic measurements. Seismic anomalies above the cavity correlate with negative gravity and magnetic signatures, while upward continuation of magnetic data reveals the tube's subsurface continuity. Joint 2.5D Hamiltonian Monte Carlo inversion of magnetic and gravity data, combined with 3D structural modeling, constrains the tube's geometry and structure, demonstrating the effectiveness of an integrated geophysical approach for lava tube exploration and characterization. The proposed geophysical workflow could be easily adapted to future robotic and human exploration of other celestial bodies.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JE009802","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148943644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lunar Regolith Evolution From Thermal Conductivity: A New Maturity Indicator","authors":"Ziwei Tian,&nbsp;Hanyu Wang,&nbsp;Guanghui Liu,&nbsp;Yiwei Liu,&nbsp;Shijing He,&nbsp;Songzheng Yu,&nbsp;Quan Zheng,&nbsp;Xin Liu,&nbsp;Yang Li,&nbsp;Jie Zheng,&nbsp;Haidong Wang,&nbsp;Guang Zhang","doi":"10.1029/2026JE009847","DOIUrl":"https://doi.org/10.1029/2026JE009847","url":null,"abstract":"<p>Building upon an original data set that couples particle-scale voxel features with the intrinsic thermal properties of lunar regolith particles, this study establishes a framework for predict thermal conductivity under multi-scale parameter constraints. Within a Gaussian process regression framework, physically constrained kernel functions explicitly distinguish the different roles of temperature and microstructural factors in heat conduction, enabling reliable prediction of the intrinsic thermal conductivity of individual lunar regolith particles. The particle-scale predictions are subsequently incorporated, together with the sample-based measurements of average macroscopic packing characteristics, into a parameterized thermal-resistance network model to quantitatively characterize the equivalent macroscopic thermal conductivity of the lunar surface regolith under different geological settings. Furthermore, the systematic variation of thermal conductivity with regolith weathering maturity is analyzed, and a method for assessing lunar regolith maturity based on the relative magnitude of macroscopic thermal conductivity is proposed. Based on the thermal resistance network model, a calculated equivalent macroscopic thermal conductivity, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>κ</mi>\u0000 </mrow>\u0000 <annotation> $kappa $</annotation>\u0000 </semantics></math>, greater than 1.20 × 10⁻³ W m⁻¹ K⁻¹ suggests relatively immature regolith, whereas <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>κ</mi>\u0000 </mrow>\u0000 <annotation> $kappa $</annotation>\u0000 </semantics></math> below 0.60 × 10⁻³ W m⁻¹ K⁻¹ may indicate a highly mature state. Comparisons with thermal conductivity derived from remote-sensing inversions and with magnetic-resonance-based maturity measurements provide support for the feasibility of the proposed approach as a complementary indicator for characterizing lunar regolith maturity. The results further suggest that the regolith at the Chang'e-5 landing site is likely immature, while the Chang'e-6 landing site exhibits a higher degree of maturity relative to Chang'e-5.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rheology and Structure of Fe-Mg-Ca Enriched Silicate Melt: Benchmarking Viscosity Models for an Exotic Planetary Composition","authors":"Fabrizio Di Fiore,&nbsp;Michele Cassetta","doi":"10.1029/2026JE009904","DOIUrl":"https://doi.org/10.1029/2026JE009904","url":null,"abstract":"<p>Silicate melt viscosity plays a pivotal role in the evolution of rocky bodies within the Solar System, exerting first-order control on mantle differentiation and stratification, while dictating the metal-silicate separation and the subsequent volcanic activity. Thus, predicting the viscosity of planetary compositions is essential to model and better understand their thermomechanical evolution. Notably, the chemical signatures of primordial planetary magmas, marked by extreme Fe, Mg, and Ca enrichment, drive a highly depolymerized and fragile rheological regimes that frequently fall beyond the calibration data sets used to model the viscosity. In this study, we characterize the effect on viscosity by doping a basalt with iron, magnesium, and calcium to resemble an exotic planetary composition. By integrating high- and low-temperature viscometry with Raman spectroscopy and ultrasonic data, we show that this chemical enrichment significantly impacts the rheology, elasticity and the structural organization of the doped melt. In particular, viscosity decreases ∼2 times at high temperatures compared to the original basalt. This behavior is driven by the extreme depolymerization of the melt, and it is reflected in a shift toward <i>Q</i>² and <i>Q</i>¹ structural units. Vibrational analysis via the Boson Peak confirms a highly fragile state characterized by noticeably small correlation lengths. We tested several widely used semi-empirical models and found that while traditional empirical formulations struggle to accurately predict the viscosity of these exotic compositions, spectroscopy-based frameworks provide significantly better accuracy. This performance highlights the fundamental link between atomic-scale vibrational properties and melt-scale dynamics.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JE009904","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing Monte Carlo Models of Impact Alteration of Planetary Atmospheres","authors":"M. R. Huffman,&nbsp;D. A. Brain,&nbsp;K. N. Singer,&nbsp;J. C. Johnston,&nbsp;C. A. Caldwell","doi":"10.1029/2025JE009581","DOIUrl":"https://doi.org/10.1029/2025JE009581","url":null,"abstract":"&lt;p&gt;One process that affects atmospheric surface pressure is impact bombardment. The evolution of a planet's atmosphere under impact bombardment is an open question. We use a Monte Carlo method to evolve a range (0.006–92.5 bar) of initial atmospheres at Mars, Earth, and Venus under bombardment of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;5&lt;/mn&gt;\u0000 &lt;mo&gt;×&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;msup&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mn&gt;6&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $5times 1{0}^{6}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; impactors using seven individual models. Since these seven models are best suited for specific impactor size regimes, we also combine these models into a composite model and compare it to other existing composites. Alterations to the existing models are required to apply to broad initial conditions. If we use each component model for every impactor, starting from present-day atmospheric pressure, we find about two or three orders of magnitude spread in the final atmospheric pressure for low initial pressures. For high initial pressures, we see a spread of about fourteen orders of magnitude. Given these differences, we suggest that the use of any one model to determine atmospheric change due to impact bombardment is risky. Most models and starting parameters result in net growth between &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;mn&gt;0.01&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${Delta }P=+0.01$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;mn&gt;100&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${+}100$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; bar for low initial pressures. For high initial pressures, the net change in atmospheric pressure can vary between about ΔP = −100 and +100 bar. Our composite model shows that the atmospheres of Venus, Earth, and Mars tend to grow under bombardment, with Earth's atmosphere growing most quickly. For an early Martian (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${P}_{0}=1$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; bar) and an early terrestrial (with an initial pressure of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 ","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JE009581","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diamond-Like-Carbon, Microdiamonds, Titanium Spherules and New UHT Minerals in Impact Debris From the SW Egypt Regolith: Possible Relations to the Extraterrestrial Carbonaceous Pebble “Hypatia” and the Libyan Desert Glass","authors":"Marco A. G. Andreoli,&nbsp;Rudolph Erasmus,&nbsp;Jasper Knight,&nbsp;Vittoria Pischedda,&nbsp;George Belyanin,&nbsp;Chiara Elmi,&nbsp;Hassina Mouri,&nbsp;Simo Huotari,&nbsp;Aki Kallonen,&nbsp;Mpho Lekgoathi,&nbsp;Romano Serra,&nbsp;Roger Gibson,&nbsp;John M. Saul,&nbsp;Mario Di Martino","doi":"10.1029/2026JE009901","DOIUrl":"https://doi.org/10.1029/2026JE009901","url":null,"abstract":"<p>In this paper we report the discovery, in the Gilf Kebir Plateau of southwest Egypt, of the first natural occurrence of Diamond-Like-Carbon, of microdiamonds, and new ultra-high T (≥1300°C) silicates, phosphates in boulders and pebbles of a mullite and magnetite melt rock. We also report, in the regolith of the Libyan Desert Glass (LDG) strewn field, comparable mullite-magnetite pebbles and, in paleosols, Diamond-Like-Carbon, N-rich amorphous carbon, aliphatic hydrocarbons, moissanite, and metallic spherules and grains of native Ti. These findings point to a ∼350 km, south to north strewnfield of melt rocks and their related disaggregated debris formed by the impact of a carbonaceous meteorite in the Jebel Uweinat, near the Egypt-Sudan border. At the northern end of their fluvial depository, the reworked debris co-mingled with the LDG strewnfield, likely originated from a second impact in the Gilf Kebir. The date of the diamonds-forming mullite impact melt is undetermined but tentatively linked to the 29 Ma event of the LDG, because disordered carbon + aliphatic compounds were found in a glass and in the, extraterrestrial (extrasolar) “Hypatia” from the same areas. The latter is considered as relic of the original, parent impactor.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148943606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aluminum Phyllosilicate and Jarosite Formation Through Alteration of Reworked Al/Si-Rich Volcaniclastic Sediments in Nili Fossae, Mars","authors":"S. R. Baker,&nbsp;B. L. Ehlmann","doi":"10.1029/2025JE009605","DOIUrl":"https://doi.org/10.1029/2025JE009605","url":null,"abstract":"<p>Aluminum phyllosilicates occur in 1–10s of km² exposures of Noachian (∼3.7 Ga) rock across Mars and typically appear stratigraphically above Fe/Mg-phyllosilicates. These units have been proposed to represent pedogenic basalt weathering sequences. We examine Al-phyllosilicates in the Nili Fossae region, combining mineral maps generated from imaging spectroscopy with digital elevation models and high-resolution imagery to determine mineral assemblages, their geologic relationships, and their history of formation. We find that the Al-phyllosilicate is dominantly kaolinite and lacks associated Fe oxide. The Al-phyllosilicates typically have a distinct texture relative to Fe/Mg-phyllosilicate units, indicating an unconformity, and two different protoliths rather than formation as a pedogenic weathering sequence. Layers in some kaolinite deposits and their preferential association with sedimentary basins suggest reworked sedimentary material. The most plausible source is an Al/Si-enriched (non-basaltic) airfall volcanic deposit. We detect sparse jarosite closely associated with kaolinite but not Fe/Mg-phyllosilicate. We interpret that the jarosite, which is metastable under present surface conditions, formed from reaction between Fe-enriched fluids and S that is found sufficiently only within the kaolinite-bearing protolith. Collectively, these observations suggest less intense near-surface oxidative weathering than the basalt pedogenesis hypothesis, namely, an upper bound of several million cumulative years of aqueous activity in Nili Fossae that largely ended after the formation of jarosite. Detection of Al-phyllosilicate-bearing float rocks in nearby Jezero Crater by the Perseverance Rover shows that sample return has potential to conclusively determine processes and environmental conditions forming Nili Fossae's distinctive Al-phyllosilicates.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JE009605","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early Water on Mars Hindered Subduction-Driven Plate Tectonics","authors":"Subhendu Pramanik,&nbsp;David Hernández-Uribe,&nbsp;Andrew J. Dombard","doi":"10.1029/2026JE009718","DOIUrl":"https://doi.org/10.1029/2026JE009718","url":null,"abstract":"<p>Mars lacks subduction-driven plate tectonics, and the reason for this is poorly known. Here, we investigate whether early water on Mars inhibited long-term sustained subduction by lowering the crustal density during metamorphism. We use numerical and thermodynamic modeling to estimate the subduction potential of the variably hydrated Martian crust. Our reference model, representative of the Hesperian (3.7–3.0 Ga) to early Amazonian (3.0–∼2.0 Ga), shows that hydration stabilized low-density hydrous assemblages, driving the density contrast toward values that hindered subduction. In dry scenarios, subduction is predicted along cool Martian geotherms, contrasting with the lack of subduction-driven tectonics on Mars. However, our wet models show that subduction was suppressed by minimal hydration (&gt;0.45 wt% H₂O). We propose that the presence of water early in Mars history explains the lack of subduction-driven plate tectonics. Our conclusions remain valid even when accounting for variations in crustal thickness between the northern and southern hemispheres as currently observed, as well as for the presence of a lithosphere comparable in thickness to the crust, as inferred for the Noachian (4.1–3.7 Ga). Our work reconciles Mars's tectonic quiescence with its hydrologically active past.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148848761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subsurface Habitability Clues in Northern Chryse Planitia, Mars: Implications for Tianwen-3 Landing Site Selection","authors":"Gang Bao,&nbsp;Kai Zhu,&nbsp;Xiaojia Zeng,&nbsp;Erbin Shi,&nbsp;Jianzhong Liu","doi":"10.1029/2025JE009450","DOIUrl":"https://doi.org/10.1029/2025JE009450","url":null,"abstract":"<p>China plans to launch its Tianwen-3 Mars sample return mission in 2028. Within the designated candidate landing zone, this study characterizes a geologically and compositionally diverse region (26°N–30°N, 28°W–36°W) shaped by the interplay of fluvial, periglacial, tectonic, and volatile-related processes. Through integrated geomorphological, mineralogical, and thermophysical analyses, we identify several key features, including widespread olivine exposures within crater floors, walls, and ejecta; conical landforms potentially associated with subsurface sediment mobilization, possibly involving mud-volcanic processes; erosion-resistant mesa units; and polygonal terrains consistent with contractional cracking associated with volatile loss. The spatial arrangement and stratigraphic relationships among coarse-grained residual units, ridge systems, trough networks, and elevated mesas indicate a prolonged and multi-stage geomorphic evolution involving resurfacing, structural deformation, and erosion. Crater size–frequency distribution measurements suggest that a major resurfacing event occurred during the Middle Amazonian, approximately 600–800 million years ago, representing one of the latest resurfacing phases in the region. Collectively, geomorphological, mineralogical, and thermophysical evidence indicates a history of volatile redistribution, structural modification, and subsurface material exposure relevant to understanding the geological evolution and subsurface habitability potential of northern Chryse Planitia. Given its geomorphic diversity, exposed stratigraphy, and evidence of subsurface processes, this region represents a scientifically valuable target for future exploration, including the Tianwen-3 mission.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Lunar Rotation on Antipodal Ejecta Deposition","authors":"S. Wakita,&nbsp;B. C. Johnson","doi":"10.1029/2026JE009799","DOIUrl":"https://doi.org/10.1029/2026JE009799","url":null,"abstract":"<p>The Moon's crust exhibits strong magnetic anomalies that likely record ancient magnetic fields produced by a core dynamo. Lunar materials have low magnetic susceptibility, but impactor material with high susceptibility may record the Moon's ancient dynamo. Some magnetic anomalies are antipodal to lunar basins and it is hypothesized that impact ejecta accumulates at the basin antipode and records the ancient lunar magnetic field. Previous impact simulations, which ignored the rotation of the Moon, support this hypothesis. Here, we reevaluate the deposition of antipodal ejecta by considering the rotation of the Moon. Assuming that the rotational period of the Moon is the same as the current day, we find that the rotation of the Moon does not strongly affect the deposition of the antipodal ejecta if impacts occur near the poles. In contrast, rotation has a considerable effect on antipodal deposits for impacts occurring near the equator. An eastward impact at a 45° incidence angle results in almost no antipodal ejecta, however, an eastward impact with a 30° incidence angle accumulates more antipodal ejecta than the non-rotating case. It is hard to determine the impactor's direction and location, for basins without an ellipsoidal shape and/or an asymmetric ejecta blanket. Nevertheless, our work demonstrates that care must be taken in interpreting the magnetic anomalies antipodal to lunar basins and that the effect of rotation should not be ignored.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JE009799","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Space Weathering-Induced Mechanical Evolution of Lunar Minerals: Micromechanical Evidence From Chang'e-5 Lunar Regolith Particles and the Laâyoune 002 Feldspathic Breccia Meteorite","authors":"Shixin Zhang,&nbsp;Yachen Xie,&nbsp;Yifei Liu,&nbsp;Dongzhan Wu,&nbsp;Bowen Liu,&nbsp;Wei Liu,&nbsp;Hongtao Wang,&nbsp;Yanyan Li,&nbsp;Cunbao Li,&nbsp;Heping Xie","doi":"10.1029/2026JE009932","DOIUrl":"https://doi.org/10.1029/2026JE009932","url":null,"abstract":"<p>Deep-space exploration requires reliable mechanical constraints for lunar materials; however, the scarcity of samples limits destructive macroscale testing. Here, we combine automated mineralogical analysis and nanoindentation to investigate the mineral-scale mechanical behavior of two Chang'e-5 regolith particles and a Laâyoune 002 feldspathic breccia comparison sample. Rather than treating these materials as bulk proxies for all mare and highland regolith regions, we compare analogous mineral domains using an identical testing protocol. Minerals in the Chang'e-5 particles generally show lower elastic modulus and hardness, greater indentation depth and creep displacement, and higher plastic work ratios than analogous minerals measured in the interior polished section of Laâyoune 002. The strongest contrast occurs in ilmenite, where more plastic, energy-dissipative deformation is observed. These measured contrasts document micromechanical differences among analogous minerals in the analyzed lunar samples. Their interpretation considers lithology, mineral chemistry, local microstructure, and impact history, with regolith processes and space-weathering overprint as plausible contributors to the Chang'e-5 response. First-order homogenization of the analyzed particle-scale assemblages yields equivalent elastic moduli of about 54 GPa for the Chang'e-5 assemblage and about 78 GPa for the Laâyoune 002 assemblage. These results provide mineral-resolved mechanical constraints for interpreting lunar material evolution and for designing better simulants, experiments, and multiscale engineering assessments.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148848760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}