Pub Date : 2025-10-23DOI: 10.1016/j.pss.2025.106215
Kun Zhang , Kim-Chiu Chow , Kwing L. Chan , Jing Xiao , Tao Cai
Dust devils are small, intense, and short-lived atmospheric vortices which frequently occur on Mars. In this study, a large number of dust-devil-like vortices (referred as dust devils hereafter) have been simulated by using a computational fluid dynamics model with the approach of Large Eddy Simulation (LES). When a uniform and constant heat flux is applied at the surface of the model domain, a number of dust devils appear with cyclonic or anticyclonic rotation, and the total number increases with the magnitude of the heat flux. The simulated dust devils are not randomly distributed, but generally occur at the boundary of the relatively large convection cells. With the high-resolution large eddy simulation, the structure of the dust devils is also revealed, with warm and low-pressure features in the core region.
{"title":"A large Eddy simulation of dust-devil-like vortices on Mars: Characteristics of formation and structure","authors":"Kun Zhang , Kim-Chiu Chow , Kwing L. Chan , Jing Xiao , Tao Cai","doi":"10.1016/j.pss.2025.106215","DOIUrl":"10.1016/j.pss.2025.106215","url":null,"abstract":"<div><div>Dust devils are small, intense, and short-lived atmospheric vortices which frequently occur on Mars. In this study, a large number of dust-devil-like vortices (referred as dust devils hereafter) have been simulated by using a computational fluid dynamics model with the approach of Large Eddy Simulation (LES). When a uniform and constant heat flux is applied at the surface of the model domain, a number of dust devils appear with cyclonic or anticyclonic rotation, and the total number increases with the magnitude of the heat flux. The simulated dust devils are not randomly distributed, but generally occur at the boundary of the relatively large convection cells. With the high-resolution large eddy simulation, the structure of the dust devils is also revealed, with warm and low-pressure features in the core region.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"269 ","pages":"Article 106215"},"PeriodicalIF":1.7,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145369821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-17DOI: 10.1016/j.pss.2025.106205
Adil Murad , Muhammad Adnan , Shahida Parveen , Ikramullah , Fida Younus Khattak
<div><div>The propagation characteristics of low-frequency electrostatic waves are investigated in the magnetized plasma environment of Venus, where both ion cyclotron and ion acoustic modes are examined. The plasma is modeled as a four-component system composed of solar wind electrons, Venus-origin hydrogen (H<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span>), Venus-origin oxygen (O<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span>), and solar wind protons (SWP). The electrons are assumed to follow a superthermal <span><math><mi>κ</mi></math></span>-distribution, consistent with spacecraft observations indicating the presence of suprathermal electrons in the Venus ionosheath. Ions are treated as warm fluids, and the analysis includes the effects of an induced magnetic field through the Lorentz force. The low-frequency approximation is justified by the dominance of electrostatic structures and slow wave dynamics near the subsolar region of Venus, as observed in Pioneer Venus Orbiter (PVO) and Venus Express (VEX) missions. This approximation allows neglecting high-frequency electromagnetic components and focusing on the electrostatic behavior critical to understanding plasma transport and wave–particle interactions in the ionosheath.</div><div>A general dispersion relation is derived, solved numerically, and decoupled to reveal three ion cyclotron roots and three ion acoustic roots, each associated with the different ion species. In the nonlinear regime, a Zakharov–Kuznetsov (ZK) equation is derived using reductive perturbation theory to describe the evolution of small but finite-amplitude ion acoustic solitons. The analysis shows that superthermality significantly affects soliton properties: for hydrogen acoustic modes, low <span><math><mi>κ</mi></math></span> values yield rarefactiolitons while higher <span><math><mi>κ</mi></math></span> values support compressive structures, indicating a polarity switch linked to suprathermal electronve s populations. The amplitude and width of the solitons are further influenced by the magnetic field and solar wind proton density—higher field strength reduces width due to enhanced dispersive effects, while increased proton density decreases amplitude in oxygen modes but increases it in hydrogen modes.</div><div>A two-dimensional pulse stability analysis based on the Allen–Rowlands method reveals that both magnetic field and solar wind proton density suppress the first-order instability growth rate. Second-order instability becomes significant beyond the critical propagation angle (<span><math><mrow><mi>θ</mi><mo>></mo><mn>37</mn><mo>.</mo><msup><mrow><mn>8</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>), particularly for proton modes. These results align with observed electrostatic wave behavior and density fluctuations reported in PVO and VEX datasets, highlighting the role of multi-ion interactions and suprathermal effects in shaping Venus
{"title":"Low frequency electrostatic wave dynamics in the subsolar magnetosheath of Venus: A theoretical framework with multi-ion and suprathermal electrons","authors":"Adil Murad , Muhammad Adnan , Shahida Parveen , Ikramullah , Fida Younus Khattak","doi":"10.1016/j.pss.2025.106205","DOIUrl":"10.1016/j.pss.2025.106205","url":null,"abstract":"<div><div>The propagation characteristics of low-frequency electrostatic waves are investigated in the magnetized plasma environment of Venus, where both ion cyclotron and ion acoustic modes are examined. The plasma is modeled as a four-component system composed of solar wind electrons, Venus-origin hydrogen (H<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span>), Venus-origin oxygen (O<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span>), and solar wind protons (SWP). The electrons are assumed to follow a superthermal <span><math><mi>κ</mi></math></span>-distribution, consistent with spacecraft observations indicating the presence of suprathermal electrons in the Venus ionosheath. Ions are treated as warm fluids, and the analysis includes the effects of an induced magnetic field through the Lorentz force. The low-frequency approximation is justified by the dominance of electrostatic structures and slow wave dynamics near the subsolar region of Venus, as observed in Pioneer Venus Orbiter (PVO) and Venus Express (VEX) missions. This approximation allows neglecting high-frequency electromagnetic components and focusing on the electrostatic behavior critical to understanding plasma transport and wave–particle interactions in the ionosheath.</div><div>A general dispersion relation is derived, solved numerically, and decoupled to reveal three ion cyclotron roots and three ion acoustic roots, each associated with the different ion species. In the nonlinear regime, a Zakharov–Kuznetsov (ZK) equation is derived using reductive perturbation theory to describe the evolution of small but finite-amplitude ion acoustic solitons. The analysis shows that superthermality significantly affects soliton properties: for hydrogen acoustic modes, low <span><math><mi>κ</mi></math></span> values yield rarefactiolitons while higher <span><math><mi>κ</mi></math></span> values support compressive structures, indicating a polarity switch linked to suprathermal electronve s populations. The amplitude and width of the solitons are further influenced by the magnetic field and solar wind proton density—higher field strength reduces width due to enhanced dispersive effects, while increased proton density decreases amplitude in oxygen modes but increases it in hydrogen modes.</div><div>A two-dimensional pulse stability analysis based on the Allen–Rowlands method reveals that both magnetic field and solar wind proton density suppress the first-order instability growth rate. Second-order instability becomes significant beyond the critical propagation angle (<span><math><mrow><mi>θ</mi><mo>></mo><mn>37</mn><mo>.</mo><msup><mrow><mn>8</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>), particularly for proton modes. These results align with observed electrostatic wave behavior and density fluctuations reported in PVO and VEX datasets, highlighting the role of multi-ion interactions and suprathermal effects in shaping Venus","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106205"},"PeriodicalIF":1.7,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the geomorphology of ancient Martian Lake systems is crucial for unraveling the planet's past climate and potential habitability. This study addresses persistent gaps in basin-scale mapping by presenting the first comprehensive, high-resolution (1:25,000 scale) geomorphological map of Jezero Crater, produced from integrated CTX and HiRISE orbital datasets. The new map covers the entire crater, including previously underexplored eastern sectors, and highlights spatial relationships among fractured floor units, delta deposits, and crater rim features. These results offer new insights into the geological processes that shaped the basin.
To broaden the planetary context, we also revisited previous mapping efforts on Gale Crater and compared them with Jezero. Building on previous work, we refine Gale's geomorphological framework by incorporating additional features, enabling a crater-wide comparative synthesis of fluvial histories. Both sites were mapped using a consistent methodology and well-defined dataset selection criteria.
Our results demonstrate that Jezero experienced longer-lasting and more stable fluvial activity than Gale, highlighting the diversity of local hydrological regimes during Mars's transition from wetter to drier climates. This integrated approach advances the geomorphological context needed for interpreting in situ rover data and for guiding future exploration, and it provides a robust foundation for reconstructing early Martian paleoenvironments.
{"title":"Orbital geomorphological mapping of Jezero Crater and comparative insights from Gale Crater","authors":"Fatima-Ezzahra Jadid , Hasnaa Chennaoui Aoudjehane , Cristian Carli , Beatrice Baschetti , Riccardo Pozzobon","doi":"10.1016/j.pss.2025.106207","DOIUrl":"10.1016/j.pss.2025.106207","url":null,"abstract":"<div><div>Understanding the geomorphology of ancient Martian Lake systems is crucial for unraveling the planet's past climate and potential habitability. This study addresses persistent gaps in basin-scale mapping by presenting the first comprehensive, high-resolution (1:25,000 scale) geomorphological map of Jezero Crater, produced from integrated CTX and HiRISE orbital datasets. The new map covers the entire crater, including previously underexplored eastern sectors, and highlights spatial relationships among fractured floor units, delta deposits, and crater rim features. These results offer new insights into the geological processes that shaped the basin.</div><div>To broaden the planetary context, we also revisited previous mapping efforts on Gale Crater and compared them with Jezero. Building on previous work, we refine Gale's geomorphological framework by incorporating additional features, enabling a crater-wide comparative synthesis of fluvial histories. Both sites were mapped using a consistent methodology and well-defined dataset selection criteria.</div><div>Our results demonstrate that Jezero experienced longer-lasting and more stable fluvial activity than Gale, highlighting the diversity of local hydrological regimes during Mars's transition from wetter to drier climates. This integrated approach advances the geomorphological context needed for interpreting in situ rover data and for guiding future exploration, and it provides a robust foundation for reconstructing early Martian paleoenvironments.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106207"},"PeriodicalIF":1.7,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-10DOI: 10.1016/j.pss.2025.106204
C.R. Neeraja, S Arivazhagan, P Abishek
The Apollo basin, within the South Pole-Aitken (SPA) basin on the far side of the Moon, is a notable geological feature that offers an understanding of the Moon's history and evolution and showcases a complex geological history influenced by impact processes and volcanic activity. The present study focused on delineating the basaltic flows of the basin along with age determination and lithological discrimination. The current research utilized Chandrayaan-1 Moon Mineralogy Mapper (M3), Chandrayaan-2 Imaging Infra-Red Spectrometer (IIRS), Lunar Reconnaissance Orbiter Camera (LROC) - Wide Angle Camera (WAC), Kaguya Terrain Camera (TC) and Kaguya Multiband Imager (MI) derived maps. The FeO weight percent map, Mg # map generated from Kaguya MI data, and the TiO2 abundance map from LROC WAC data are used for the compositional analysis. The mare is classified into eight distinct units by comparing these parameters with an Integrated Band Depth (IBD) color composite image. Spectral studies are done to identify the pyroxene mineralogy of each unit. By analyzing the pyroxene thermometry plot generated by analyzing the spectral data, two distinct crystallization trends are observed, starting with pigeonite and sub-calcic augite to ferro-augite. The other trend progresses from augite to diopside boundary. The ages of the mare units were estimated using the Crater Size Frequency Distribution (CSFD) method. The study suggests that mare volcanism commenced at approximately 3.5 Ga and progressed to a younger phase between 2.0 and 1.8 Ga. The units A2 and A4 exhibit the highest average model age (AMA) of 3.5 Ga and dominantly exhibit higher calcium content, while unit A8 represents the youngest unit with an age of 1.8 Ga with relatively lower calcium content. Mare volcanism was initiated at the periphery of the basin, particularly in the southern and southeastern regions, and subsequently progressed westward and towards the basin's center. Magmas with diverse chemical compositions derived from varied source regions erupted in the Apollo basin between the Imbrian and Eratosthenian periods.
{"title":"Decoding the Apollo basin: Insights into volcanism, compositional diversity and crustal evolution","authors":"C.R. Neeraja, S Arivazhagan, P Abishek","doi":"10.1016/j.pss.2025.106204","DOIUrl":"10.1016/j.pss.2025.106204","url":null,"abstract":"<div><div>The Apollo basin, within the South Pole-Aitken (SPA) basin on the far side of the Moon, is a notable geological feature that offers an understanding of the Moon's history and evolution and showcases a complex geological history influenced by impact processes and volcanic activity. The present study focused on delineating the basaltic flows of the basin along with age determination and lithological discrimination. The current research utilized Chandrayaan-1 Moon Mineralogy Mapper (M<sup>3</sup>), Chandrayaan-2 Imaging Infra-Red Spectrometer (IIRS), Lunar Reconnaissance Orbiter Camera (LROC) - Wide Angle Camera (WAC), Kaguya Terrain Camera (TC) and Kaguya Multiband Imager (MI) derived maps. The FeO weight percent map, Mg # map generated from Kaguya MI data, and the TiO<sub>2</sub> abundance map from LROC WAC data are used for the compositional analysis. The mare is classified into eight distinct units by comparing these parameters with an Integrated Band Depth (IBD) color composite image. Spectral studies are done to identify the pyroxene mineralogy of each unit. By analyzing the pyroxene thermometry plot generated by analyzing the spectral data, two distinct crystallization trends are observed, starting with pigeonite and sub-calcic augite to ferro-augite. The other trend progresses from augite to diopside boundary. The ages of the mare units were estimated using the Crater Size Frequency Distribution (CSFD) method. The study suggests that mare volcanism commenced at approximately 3.5 Ga and progressed to a younger phase between 2.0 and 1.8 Ga. The units A2 and A4 exhibit the highest average model age (AMA) of 3.5 Ga and dominantly exhibit higher calcium content, while unit A8 represents the youngest unit with an age of 1.8 Ga with relatively lower calcium content. Mare volcanism was initiated at the periphery of the basin, particularly in the southern and southeastern regions, and subsequently progressed westward and towards the basin's center. Magmas with diverse chemical compositions derived from varied source regions erupted in the Apollo basin between the Imbrian and Eratosthenian periods.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106204"},"PeriodicalIF":1.7,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-27DOI: 10.1016/j.pss.2025.106190
Joel Patzwald , Ferry Schiperski , Hannah Fisher , Thomas Neumann , Enrico Stoll
To support sustainable solar system exploration, humans must harness resources from celestial bodies like the Moon to build infrastructure and obtain essential consumables, including water and oxygen. Lunar regolith, a loose rock layer covering the Moon’s surface, is a key resource for in-situ resource utilisation (ISRU) technologies. Developing and testing these technologies on Earth relies on the use of accurate simulant materials. In prior studies, the LX lunar regolith simulant system was developed and the base simulants LX-T100 (anorthosite) and LX-M100 (basalt) were thoroughly characterised in terms of their bulk mineralogical and bulk chemical composition, particle size distribution, particle morphology, density, void ratio and porosity, adsorption and BET-specific surface area, compressibility, flow, magnetic and optical properties. This work focuses on the LX high-fidelity simulants, specifically their mineralogy and chemistry. The high-fidelity simulants are composed of four source rocks, namely the anorthosite of LX-T100, the basalt of LX-M100, as well as a harzburgite as a source for olivine and pyroxene and an ilmenite ore as a source for ilmenite. The bulk mineralogy and chemistry of the harzburgite and ilmenite ore, as well as the crystal chemistry of all four source rocks, were analysed and the results were compared with the lunar samples from the Apollo and Luna missions. Finally, a deviation analysis was carried out in which the bulk chemistry of the LX high-fidelity simulants and 13 other relevant simulants from research and industry were compared with the chemical composition of the lunar soil at the landing sites of the Apollo, Luna and Chang’e 5 missions. It was shown that of all simulants, the LX high-fidelity simulants can on average best mimic the chemical composition of the lunar soil. The findings from these investigations deepen the understanding of the LX lunar regolith simulants, increasing their reliability for scientific research.
{"title":"The chemistry and mineralogy of the LX high-fidelity lunar regolith simulants","authors":"Joel Patzwald , Ferry Schiperski , Hannah Fisher , Thomas Neumann , Enrico Stoll","doi":"10.1016/j.pss.2025.106190","DOIUrl":"10.1016/j.pss.2025.106190","url":null,"abstract":"<div><div>To support sustainable solar system exploration, humans must harness resources from celestial bodies like the Moon to build infrastructure and obtain essential consumables, including water and oxygen. Lunar regolith, a loose rock layer covering the Moon’s surface, is a key resource for in-situ resource utilisation (ISRU) technologies. Developing and testing these technologies on Earth relies on the use of accurate simulant materials. In prior studies, the LX lunar regolith simulant system was developed and the base simulants LX-T100 (anorthosite) and LX-M100 (basalt) were thoroughly characterised in terms of their bulk mineralogical and bulk chemical composition, particle size distribution, particle morphology, density, void ratio and porosity, adsorption and BET-specific surface area, compressibility, flow, magnetic and optical properties. This work focuses on the LX high-fidelity simulants, specifically their mineralogy and chemistry. The high-fidelity simulants are composed of four source rocks, namely the anorthosite of LX-T100, the basalt of LX-M100, as well as a harzburgite as a source for olivine and pyroxene and an ilmenite ore as a source for ilmenite. The bulk mineralogy and chemistry of the harzburgite and ilmenite ore, as well as the crystal chemistry of all four source rocks, were analysed and the results were compared with the lunar samples from the Apollo and Luna missions. Finally, a deviation analysis was carried out in which the bulk chemistry of the LX high-fidelity simulants and 13 other relevant simulants from research and industry were compared with the chemical composition of the lunar soil at the landing sites of the Apollo, Luna and Chang’e 5 missions. It was shown that of all simulants, the LX high-fidelity simulants can on average best mimic the chemical composition of the lunar soil. The findings from these investigations deepen the understanding of the LX lunar regolith simulants, increasing their reliability for scientific research.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106190"},"PeriodicalIF":1.7,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-24DOI: 10.1016/j.pss.2025.106203
A. Ettehadi , M. Radonjic , M. Mokhtari , R.C. Anderson
Mars sample collection is often hindered by the mechanical fragility of calcium sulfate-filled fractures, which are prone to fragmentation under drilling-induced stress. This study presents a coupled mineralogical and nano-mechanical investigation of such fracture systems in terrestrial Martian analog rocks, aiming to inform Mars Sample Return (MSR) drilling strategies. X-ray diffraction (XRD), scanning electron microscopy in backscattered mode (SEM-BSE), and energy-dispersive spectroscopy (EDS) reveal that gypsum is the dominant fracture-filling phase, exhibiting spatial continuity but considerable heterogeneity at vein–matrix interfaces. The host matrix consists primarily of quartz, albite, and dolomite, creating stark mineralogical contrasts that control fracture evolution and mechanical response. Nano-indentation testing was conducted across gypsum, matrix, and interfacial regions, revealing significant differences in mechanical properties. Gypsum zones show pronounced plasticity and low elastic modulus (E ≈ 10–20 GPa), while matrix minerals such as quartz exhibit higher stiffness (E > 100 GPa) and hardness. Critically, vein–matrix interfaces display intermediate properties and increased indentation depths, indicating weak interfacial bonding and stress localization. These mechanically vulnerable zones are likely to fracture or delaminate during coring operations. By integrating mineralogical heterogeneity with mechanical behavior, this study identifies key failure mechanisms in sulfate-rich terrains and formulates drilling and coring recommendations tailored to mitigate damage. The findings provide essential guidance for tool design, load control strategies, and sample targeting, ultimately improving the reliability of core recovery and scientific return in future Mars exploration missions.
{"title":"Coupled mineralogical and nano-mechanical characterization of calcium sulfate veins in Martian analog rocks: Implications for Mars sample return drilling strategies","authors":"A. Ettehadi , M. Radonjic , M. Mokhtari , R.C. Anderson","doi":"10.1016/j.pss.2025.106203","DOIUrl":"10.1016/j.pss.2025.106203","url":null,"abstract":"<div><div>Mars sample collection is often hindered by the mechanical fragility of calcium sulfate-filled fractures, which are prone to fragmentation under drilling-induced stress. This study presents a coupled mineralogical and nano-mechanical investigation of such fracture systems in terrestrial Martian analog rocks, aiming to inform Mars Sample Return (MSR) drilling strategies. X-ray diffraction (XRD), scanning electron microscopy in backscattered mode (SEM-BSE), and energy-dispersive spectroscopy (EDS) reveal that gypsum is the dominant fracture-filling phase, exhibiting spatial continuity but considerable heterogeneity at vein–matrix interfaces. The host matrix consists primarily of quartz, albite, and dolomite, creating stark mineralogical contrasts that control fracture evolution and mechanical response. Nano-indentation testing was conducted across gypsum, matrix, and interfacial regions, revealing significant differences in mechanical properties. Gypsum zones show pronounced plasticity and low elastic modulus (E ≈ 10–20 GPa), while matrix minerals such as quartz exhibit higher stiffness (E > 100 GPa) and hardness. Critically, vein–matrix interfaces display intermediate properties and increased indentation depths, indicating weak interfacial bonding and stress localization. These mechanically vulnerable zones are likely to fracture or delaminate during coring operations. By integrating mineralogical heterogeneity with mechanical behavior, this study identifies key failure mechanisms in sulfate-rich terrains and formulates drilling and coring recommendations tailored to mitigate damage. The findings provide essential guidance for tool design, load control strategies, and sample targeting, ultimately improving the reliability of core recovery and scientific return in future Mars exploration missions.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106203"},"PeriodicalIF":1.7,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-22DOI: 10.1016/j.pss.2025.106202
S. Gopalakrishnan, X. Wang, H.-W. Hsu, M. Horányi
The secondary electron yield (SEY) from sub-keV ion and neutral particle impacts on a stainless steel surface has been investigated in the laboratory. Sub-keV ions were generated using a large Kauffman ion source and energetic neutral particles (ENPs) were generated from ion-neutral charge-exchange collisions. It is found that the SEY from ion impacts increases with the ion kinetic energy, reaching the yield of 0.25-0.4 by the 1000 eV ion impact, depending on the surface cleanliness. The SEY from neutral impacts is about an order of magnitude lower than from ion impacts, indicating that the electrostatic potential energy plays a bigger role in generating secondary electrons than the kinetic energy in this energy range. It is shown that the SEY is higher for impacts by lighter ion species. The effect of surface cleanliness is investigated, showing an increase in the SEY for a contaminated surface. Our results show that secondary electrons generated from sub-keV ion impacts are non-negligible and may play a more pronounced role in determining the surface charge in various space environments, such as permanently shadowed regions (PSRs) on airless bodies. The SEY measured from sub-keV ENP impacts is useful for determining the surface charge of a spacecraft moving through dense planetary atmospheres.
{"title":"Secondary electron generation by sub-keV ion and energetic neutral particle impacts on a surface","authors":"S. Gopalakrishnan, X. Wang, H.-W. Hsu, M. Horányi","doi":"10.1016/j.pss.2025.106202","DOIUrl":"10.1016/j.pss.2025.106202","url":null,"abstract":"<div><div>The secondary electron yield (SEY) from sub-keV ion and neutral particle impacts on a stainless steel surface has been investigated in the laboratory. Sub-keV ions were generated using a large Kauffman ion source and energetic neutral particles (ENPs) were generated from ion-neutral charge-exchange collisions. It is found that the SEY from ion impacts increases with the ion kinetic energy, reaching the yield of <span><math><mo>∼</mo></math></span>0.25-0.4 by the 1000 eV ion impact, depending on the surface cleanliness. The SEY from neutral impacts is about an order of magnitude lower than from ion impacts, indicating that the electrostatic potential energy plays a bigger role in generating secondary electrons than the kinetic energy in this energy range. It is shown that the SEY is higher for impacts by lighter ion species. The effect of surface cleanliness is investigated, showing an increase in the SEY for a contaminated surface. Our results show that secondary electrons generated from sub-keV ion impacts are non-negligible and may play a more pronounced role in determining the surface charge in various space environments, such as permanently shadowed regions (PSRs) on airless bodies. The SEY measured from sub-keV ENP impacts is useful for determining the surface charge of a spacecraft moving through dense planetary atmospheres.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106202"},"PeriodicalIF":1.7,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-18DOI: 10.1016/j.pss.2025.106201
Gurpreet Kaur Bhatia, Sumit Sankhyan
Understanding a planet's early thermal evolution and differentiation is crucial to comprehending the distribution of volatiles in its different reservoirs. Mercury is now known as a volatile rich planet. It has carbon saturated core, deeply buried volatile rich layers, a diamond layer at the core-mantle boundary and graphite floating at the crust. For carbon saturation, Mercury is believed to have accreted from Enstatite/CB chondrite rich building blocks. In the present work, we studied the early thermal evolution and core formation in the interior of Mercury by considering its accretion from water rich Enstatite chondrites prior to the dispersal of solar nebula. The heat sources for the melting and differentiation of Mercury include the decay energy of SLR 26Al and the blanketing effect of the impact generated H2O+CO+H2 along with primordial atmosphere. The results suggest the complete core formation with lowest assumed water content in the building blocks Mercury for accretion timescales ≤1.5 Myr after the formation of CAIs. The longer accretion timescales, it needed higher abundance of water to cause significant blanketing effect at the surface. During differentiation process, the volatiles dissolved in the magma ocean under the pressure of overlying atmosphere, could partition into the core. Hence, the outcomes of present study have implications to explain the distribution of volatile in the interior of Mercury. Conversely, under the strong blanketing effect, the surface silicate could vaporize and dissolve in the steam atmosphere.
{"title":"Mercury's early thermal evolution and core formation in the presence of impact-generated atmosphere during accretion","authors":"Gurpreet Kaur Bhatia, Sumit Sankhyan","doi":"10.1016/j.pss.2025.106201","DOIUrl":"10.1016/j.pss.2025.106201","url":null,"abstract":"<div><div>Understanding a planet's early thermal evolution and differentiation is crucial to comprehending the distribution of volatiles in its different reservoirs. Mercury is now known as a volatile rich planet. It has carbon saturated core, deeply buried volatile rich layers, a diamond layer at the core-mantle boundary and graphite floating at the crust. For carbon saturation, Mercury is believed to have accreted from Enstatite/CB chondrite rich building blocks. In the present work, we studied the early thermal evolution and core formation in the interior of Mercury by considering its accretion from water rich Enstatite chondrites prior to the dispersal of solar nebula. The heat sources for the melting and differentiation of Mercury include the decay energy of SLR <sup>26</sup>Al and the blanketing effect of the impact generated H<sub>2</sub>O+CO+H<sub>2</sub> along with primordial atmosphere. The results suggest the complete core formation with lowest assumed water content in the building blocks Mercury for accretion timescales ≤1.5 Myr after the formation of CAIs. The longer accretion timescales, it needed higher abundance of water to cause significant blanketing effect at the surface. During differentiation process, the volatiles dissolved in the magma ocean under the pressure of overlying atmosphere, could partition into the core. Hence, the outcomes of present study have implications to explain the distribution of volatile in the interior of Mercury. Conversely, under the strong blanketing effect, the surface silicate could vaporize and dissolve in the steam atmosphere.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106201"},"PeriodicalIF":1.7,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-12DOI: 10.1016/j.pss.2025.106198
Tabaré Gallardo, Rodrigo Cabral
The dynamics of small bodies perturbed by an eccentric planet was done mostly under the assumption of well separated orbits using analytical approximations appropriate for the hierarchical case. In this work we study the dynamics of small bodies in a wide range of eccentricities and inclinations perturbed by a giant planet with , in the non-hierarchical case. We consider small bodies both interior and exterior to the planet. We apply semi-analytical models for the study of resonances and the properties of the secular disturbing function. We perform a frequency analysis of numerical integration of the exact equations of motion to obtain the proper frequencies and corresponding dynamical secular paths. We study the dependence of proper frequencies with the initial mutual inclination and we find a critical inclination around 30 degrees for which the pericenter proper frequency vanishes giving rise to the increase of small bodies eccentricities followed by unstable dynamics. This happens for both interior and exterior small bodies and constitutes a stability barrier in the inclination. For greater inclinations the ZLK mechanism dominates both populations. By means of numerical integration of thousands of small bodies we reproduce the well known pericenter shepherding, but for the exterior populations with low inclinations we also find concentrations of the longitude of the ascending node in the direction of the planetary line of apsides.
{"title":"Dynamical regimes of small bodies perturbed by an eccentric giant planet","authors":"Tabaré Gallardo, Rodrigo Cabral","doi":"10.1016/j.pss.2025.106198","DOIUrl":"10.1016/j.pss.2025.106198","url":null,"abstract":"<div><div>The dynamics of small bodies perturbed by an eccentric planet was done mostly under the assumption of well separated orbits using analytical approximations appropriate for the hierarchical case. In this work we study the dynamics of small bodies in a wide range of eccentricities and inclinations perturbed by a giant planet with <span><math><mrow><msub><mrow><mi>e</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>4</mn></mrow></math></span>, in the non-hierarchical case. We consider small bodies both interior and exterior to the planet. We apply semi-analytical models for the study of resonances and the properties of the secular disturbing function. We perform a frequency analysis of numerical integration of the exact equations of motion to obtain the proper frequencies and corresponding dynamical secular paths. We study the dependence of proper frequencies with the initial mutual inclination and we find a critical inclination around 30 degrees for which the pericenter proper frequency vanishes giving rise to the increase of small bodies eccentricities followed by unstable dynamics. This happens for both interior and exterior small bodies and constitutes a stability barrier in the inclination. For greater inclinations the ZLK mechanism dominates both populations. By means of numerical integration of thousands of small bodies we reproduce the well known pericenter shepherding, but for the exterior populations with low inclinations we also find concentrations of the longitude of the ascending node in the direction of the planetary line of apsides.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106198"},"PeriodicalIF":1.7,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145060814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-11DOI: 10.1016/j.pss.2025.106200
C. Pacelli , A. Cassaro , L. Cocola , A. Cordone , M. Del Bianco , M. Esposito , F. Ferranti , M. Ferrara , D. Giovannelli , L. Manfrin , L. Parca , L. Poletto , L. Tonietti , A. Zinzi
The exploration of icy moons in the solar system marks a new chapter in the search for extraterrestrial life, with next-generation missions targeting these promising environments. Cassini's flybys of Enceladus revealed a global subsurface ocean containing organic compounds and biologically available nitrogen, suggesting potential conditions for life as we know it. Other moons with subsurface oceans, such as Europa, Titan, Ganymede, and Callisto, are now considered more common in the cosmos than once believed. Enceladus thus provides a critical platform for advancing astrobiological research and technology.
Given the challenges of space exploration, Earth-based (both in-situ and laboratory) experiments are crucial for interpreting remote data and understanding icy moon processes. Terrestrial hydrothermal sites, similar to those expected on Enceladus, shed light on the origins and preservation of life, expanding our knowledge of the habitability concept. Microbial extremophiles thriving in these environments allow to refine life's boundaries and support the search for life elsewhere.
In this context, the MICROICY project aims to: (i) study microbial communities in the Strýtan alkaline shallow-water hydrothermal vents in Iceland, analogues to Enceladus' hydrothermal vents; (ii) assess the adaptation mechanisms of extremophiles under Enceladus-like conditions; and (iii) detect gas biosignatures of microbial activity using a mass spectrometry detector. These findings will support the use of gas biosignatures in next-generation astrobiology missions, advancing the exploration of Enceladus and other icy moons.
{"title":"MICROorganisms under simulated ICY moon environments: supporting solar system exploration (MICRO ICY project)","authors":"C. Pacelli , A. Cassaro , L. Cocola , A. Cordone , M. Del Bianco , M. Esposito , F. Ferranti , M. Ferrara , D. Giovannelli , L. Manfrin , L. Parca , L. Poletto , L. Tonietti , A. Zinzi","doi":"10.1016/j.pss.2025.106200","DOIUrl":"10.1016/j.pss.2025.106200","url":null,"abstract":"<div><div>The exploration of icy moons in the solar system marks a new chapter in the search for extraterrestrial life, with next-generation missions targeting these promising environments. Cassini's flybys of Enceladus revealed a global subsurface ocean containing organic compounds and biologically available nitrogen, suggesting potential conditions for life as we know it. Other moons with subsurface oceans, such as Europa, Titan, Ganymede, and Callisto, are now considered more common in the cosmos than once believed. Enceladus thus provides a critical platform for advancing astrobiological research and technology.</div><div>Given the challenges of space exploration, Earth-based (both in-situ and laboratory) experiments are crucial for interpreting remote data and understanding icy moon processes. Terrestrial hydrothermal sites, similar to those expected on Enceladus, shed light on the origins and preservation of life, expanding our knowledge of the habitability concept. Microbial extremophiles thriving in these environments allow to refine life's boundaries and support the search for life elsewhere.</div><div>In this context, the MICROICY project aims to: (i) study microbial communities in the Strýtan alkaline shallow-water hydrothermal vents in Iceland, analogues to Enceladus' hydrothermal vents; (ii) assess the adaptation mechanisms of extremophiles under Enceladus-like conditions; and (iii) detect gas biosignatures of microbial activity using a mass spectrometry detector. These findings will support the use of gas biosignatures in next-generation astrobiology missions, advancing the exploration of Enceladus and other icy moons.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106200"},"PeriodicalIF":1.7,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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