Pub Date : 2025-11-12DOI: 10.1016/j.icarus.2025.116882
Courteney S. Monchinski, Hidenori Genda, Shigeru Ida
The origins of the Martian moons, Phobos and Deimos, are still heavily debated. There are currently two leading theories surrounding their origin: giant impact or asteroid capture. Previous studies focused on the giant impact theory showed that circum-Mars debris disks formed post-impact were hot enough to alter any primitive materials the moons are thought to consist of. This study proposes that the use of a water-ice dominated impactor may be able to protect primitive materials through the vaporization of water. Using Smoothed Particle Hydrodynamics (SPH), we simulate giant impacts of Mars and an impactor of varying water-ice to rock compositions. We show that the water content of the impactor was found to decrease disk temperatures, allowing for primitive materials to survive relatively unaltered for impactors initially containing 10% ice or more.
{"title":"Icy-impactor origins of the Martian moons","authors":"Courteney S. Monchinski, Hidenori Genda, Shigeru Ida","doi":"10.1016/j.icarus.2025.116882","DOIUrl":"10.1016/j.icarus.2025.116882","url":null,"abstract":"<div><div>The origins of the Martian moons, Phobos and Deimos, are still heavily debated. There are currently two leading theories surrounding their origin: giant impact or asteroid capture. Previous studies focused on the giant impact theory showed that circum-Mars debris disks formed post-impact were hot enough to alter any primitive materials the moons are thought to consist of. This study proposes that the use of a water-ice dominated impactor may be able to protect primitive materials through the vaporization of water. Using Smoothed Particle Hydrodynamics (SPH), we simulate giant impacts of Mars and an impactor of varying water-ice to rock compositions. We show that the water content of the impactor was found to decrease disk temperatures, allowing for primitive materials to survive relatively unaltered for impactors initially containing 10% ice or more.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"446 ","pages":"Article 116882"},"PeriodicalIF":3.0,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-06DOI: 10.1016/j.icarus.2025.116875
Silvia Pagnoscin , Jost von Hardenberg , John Robert Brucato , Antonello Provenzale
The main reservoirs of liquid water in the Solar System are hidden beneath the icy shells of some of the “icy moons” orbiting the gas giants Jupiter and Saturn. Although these moons lie well outside the traditional habitable zone, tidal forces exerted by their parent planet and internal radiogenic heating can sustain subsurface oceans of liquid water. These environments may offer the necessary conditions for life, making icy moons key targets in the search for extraterrestrial biospheres. Unfortunately, direct exploration of these oceans remains out of reach by current space mission technology, which is limited to surface observations. However, surface activity observed on several of these moons suggests that internal processes may be coupled with surface dynamics, potentially enabling surface-subsurface interactions. Previous global models have shown that large-scale fluid motions within the oceans may lead to latitude-dependent variations in heat flux at the ice-ocean boundary. In this study, we investigate intermediate-scale, localized convective dynamics within the subsurface oceans of icy moons, showing that these oceans can be dominated by intense thermal convection which can generate differential heat fluxes and local interactions at the ice-water interface. To explore this issue, we numerically integrate a simplified turbulent convective fluid model, coupled with a linear approximation for the freeze-melt processes of the overtopping ice layer. We observe that the resulting spatial variability in basal melting and freezing rates could induce thickness variations of the ice shell. These predictions can be tested by upcoming missions such as ESA's JUpiter ICy moons Explorer through gravity and altimetry measurements, offering new insights into the physical coupling between surface and interior also at small spatial scales.
{"title":"Convection in the subsurface ocean of icy moons and response of the upper ice layer","authors":"Silvia Pagnoscin , Jost von Hardenberg , John Robert Brucato , Antonello Provenzale","doi":"10.1016/j.icarus.2025.116875","DOIUrl":"10.1016/j.icarus.2025.116875","url":null,"abstract":"<div><div>The main reservoirs of liquid water in the Solar System are hidden beneath the icy shells of some of the “icy moons” orbiting the gas giants Jupiter and Saturn. Although these moons lie well outside the traditional habitable zone, tidal forces exerted by their parent planet and internal radiogenic heating can sustain subsurface oceans of liquid water. These environments may offer the necessary conditions for life, making icy moons key targets in the search for extraterrestrial biospheres. Unfortunately, direct exploration of these oceans remains out of reach by current space mission technology, which is limited to surface observations. However, surface activity observed on several of these moons suggests that internal processes may be coupled with surface dynamics, potentially enabling surface-subsurface interactions. Previous global models have shown that large-scale fluid motions within the oceans may lead to latitude-dependent variations in heat flux at the ice-ocean boundary. In this study, we investigate intermediate-scale, localized convective dynamics within the subsurface oceans of icy moons, showing that these oceans can be dominated by intense thermal convection which can generate differential heat fluxes and local interactions at the ice-water interface. To explore this issue, we numerically integrate a simplified turbulent convective fluid model, coupled with a linear approximation for the freeze-melt processes of the overtopping ice layer. We observe that the resulting spatial variability in basal melting and freezing rates could induce thickness variations of the ice shell. These predictions can be tested by upcoming missions such as ESA's JUpiter ICy moons Explorer through gravity and altimetry measurements, offering new insights into the physical coupling between surface and interior also at small spatial scales.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"446 ","pages":"Article 116875"},"PeriodicalIF":3.0,"publicationDate":"2025-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-05DOI: 10.1016/j.icarus.2025.116874
Kenji Kurosaki , Masahiko Arakawa
Impact cratering plays a crucial role in shaping the surfaces of small bodies, satellites, and planets, providing insights into their formation and the history of the Solar System. Small bodies are often covered with low-cohesion regolith. Using sand as a model of regolith, we constructed a numerical model for simulating impact on a sand target to investigate the mechanisms of crater formation and impact-induced seismic waves. Soda-lime glass and quartz sand targets were used for comparison. The developed sand model successfully reproduced the sound velocity measured in an experimental study. Using the new sand model, the crater formation was simulated using Smoothed Particle Hydrodynamics with a material strength parameter. The crater radius and -scaling law derived from the numerical simulation were consistent with the experimental study. The vertical acceleration around the surface of the crater was consistent with the experimentally measured acceleration for the impact-induced seismic wave. The developed model can provide insight for predicting the size of craters on unknown small bodies.
{"title":"Numerical simulation of impact cratering and induced seismic waves in sand targets","authors":"Kenji Kurosaki , Masahiko Arakawa","doi":"10.1016/j.icarus.2025.116874","DOIUrl":"10.1016/j.icarus.2025.116874","url":null,"abstract":"<div><div>Impact cratering plays a crucial role in shaping the surfaces of small bodies, satellites, and planets, providing insights into their formation and the history of the Solar System. Small bodies are often covered with low-cohesion regolith. Using sand as a model of regolith, we constructed a numerical model for simulating impact on a sand target to investigate the mechanisms of crater formation and impact-induced seismic waves. Soda-lime glass and quartz sand targets were used for comparison. The developed sand model successfully reproduced the sound velocity measured in an experimental study. Using the new sand model, the crater formation was simulated using Smoothed Particle Hydrodynamics with a material strength parameter. The crater radius and <span><math><mi>π</mi></math></span>-scaling law derived from the numerical simulation were consistent with the experimental study. The vertical acceleration around the surface of the crater was consistent with the experimentally measured acceleration for the impact-induced seismic wave. The developed model can provide insight for predicting the size of craters on unknown small bodies.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"446 ","pages":"Article 116874"},"PeriodicalIF":3.0,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145464746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-05DOI: 10.1016/j.icarus.2025.116871
R. Keerthana , R. Annadurai , K.N. Kusuma
This study investigates the morphology, mineralogy, and chronology of the Briggs crater (37 km diameter), situated west of the Oceanus Procellarum, employing high-resolution data from recent lunar missions. Lunar Reconnaissance Orbiter (LRO) images, Terrain Mapping Camera (TMC) Ortho images, and Digital Elevation Models (DEMs) from both the Chandrayaan-2 and Kaguya were employed to study the morphology of the crater. The morphological investigation identified distinct features in Briggs Crater, including a well-preserved crater rim, terraced walls, a convex floor indicative of subsurface uplift, an uplifted central peak, mounds, and prominent NE-SW and N-S trending concentric and radial fractures. Additionally, a fresh impact crater and localized slumping along the crater walls suggest ongoing surface modifications. Briggs Crater exhibits characteristics of a Class-2 Floor-Fractured Crater (FFC), including an uplifted floor and prominent concentric fractures, consistent with previously established classifications. The presence of radial and concentric fractures on the Briggs Crater floor suggests a combination of brittle and ductile deformation. Variations in fracture dimensions indicate differential stress distribution during floor uplift, likely influenced by subsurface magmatic intrusion or impact-induced processes. Integrated Band Depth (IBD) and Mineral indices-based color composite images were generated using M3 datasets to better understand mineralogy. These images enable the extraction of spectral signatures for mineralogical investigation and highlight the diversity of lithological composition. Spectral absorption analysis, IBD mapping, and mineral indices collectively confirm that the central peak exposes fresh High-Calcium Pyroxene (HCP) from deeper crustal levels, while the floor, rim, wall, and ejecta show weaker, mixed, and weathered pyroxene signatures. Integrating morphology and mineralogy with Crater Size-Frequency Distributions (CSFD)-based chronology, it has been suggested that Briggs Crater formed during the late Imbrian period (3.6 Ga). The N-S trending concentric fractures on the Briggs crater floor likely represent tectonic or magmatic activity that occurred between ∼310 Ma and ∼ 270 Ma during the Eratosthenian period, significantly after the initial crater formation.
{"title":"Morphological, mineralogical, and chronological mapping of Briggs floor fractured crater using lunar remote sensing datasets","authors":"R. Keerthana , R. Annadurai , K.N. Kusuma","doi":"10.1016/j.icarus.2025.116871","DOIUrl":"10.1016/j.icarus.2025.116871","url":null,"abstract":"<div><div>This study investigates the morphology, mineralogy, and chronology of the Briggs crater (37 km diameter), situated west of the Oceanus Procellarum, employing high-resolution data from recent lunar missions. Lunar Reconnaissance Orbiter (LRO) images, Terrain Mapping Camera (TMC) Ortho images, and Digital Elevation Models (DEMs) from both the Chandrayaan-2 and Kaguya were employed to study the morphology of the crater. The morphological investigation identified distinct features in Briggs Crater, including a well-preserved crater rim, terraced walls, a convex floor indicative of subsurface uplift, an uplifted central peak, mounds, and prominent NE-SW and N-S trending concentric and radial fractures. Additionally, a fresh impact crater and localized slumping along the crater walls suggest ongoing surface modifications. Briggs Crater exhibits characteristics of a Class-2 Floor-Fractured Crater (FFC), including an uplifted floor and prominent concentric fractures, consistent with previously established classifications. The presence of radial and concentric fractures on the Briggs Crater floor suggests a combination of brittle and ductile deformation. Variations in fracture dimensions indicate differential stress distribution during floor uplift, likely influenced by subsurface magmatic intrusion or impact-induced processes. Integrated Band Depth (IBD) and Mineral indices-based color composite images were generated using M<sup>3</sup> datasets to better understand mineralogy. These images enable the extraction of spectral signatures for mineralogical investigation and highlight the diversity of lithological composition. Spectral absorption analysis, IBD mapping, and mineral indices collectively confirm that the central peak exposes fresh High-Calcium Pyroxene (HCP) from deeper crustal levels, while the floor, rim, wall, and ejecta show weaker, mixed, and weathered pyroxene signatures. Integrating morphology and mineralogy with Crater Size-Frequency Distributions (CSFD)-based chronology, it has been suggested that Briggs Crater formed during the late Imbrian period (3.6 Ga). The N-S trending concentric fractures on the Briggs crater floor likely represent tectonic or magmatic activity that occurred between ∼310 Ma and ∼ 270 Ma during the Eratosthenian period, significantly after the initial crater formation.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"445 ","pages":"Article 116871"},"PeriodicalIF":3.0,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
The Mg-suite lithologies, particularly pink spinel-bearing rocks, provide critical insights into the Moon's crust-mantle interactions and impact metamorphism. However, discrepancies persist between remote sensing interpretations and laboratory analyses regarding the petrological characteristics of pink spinel anorthosite (PSA) or pink spinel troctolite (PST). The unbrecciated lunar meteorite NWA 12279, identified as a pink spinel-bearing troctolitic anorthosite (PSTA), offers a pristine record with well-preserved igneous textures, minimal shock metamorphism (S1–S2), and low terrestrial weathering (W0–1) affecting its mafic minerals and spinels. Combined petrological, mineral chemical, Visible-Near Infrared (VNIR) spectroscopy, and Raman spectroscopic analyses reveal a homogeneous composition dominated by anorthite (81.8 ± 0.1 vol%, An = ∼97.2), olivine (11.7 ± 1.3 vol%, Fo = ∼76.8), augite-dominated pyroxene (4.75 ± 0.45 vol%, En = ∼57.4), and Mg-spinel (0.96 ± 0.48 vol%, Mg# = ∼82.4). Reflectance spectra from six selected profiles across the sample section show diagnostic absorptions at 1050 nm (olivine), 1950 nm (Mg-spinel), and 2300–2350 nm (high-Ca pyroxene), with spectral contrasts that correlate directly with the spatial distribution of spinel. Regions enriched in spinel display a notably stronger absorption depth at 1950 nm. Furthermore, we establish well-defined linear correlations (R2 ≥ 0.971) under low-shock conditions (<4 GPa) that enable robust in-situ composition prediction. These quantitative models—olivine Fo from Peak A (∼820 cm−1; y = 3.050× – 2430), spinel Mg# from Peak B (∼670 cm−1; y = 0.0461× + 50.82), and pyroxene En from Peaks C (∼661 cm−1; y = 2.635× – 1701.5) and D (∼1007 cm−1; y = 2.547× – 2522.4). These quantitative models help resolve orbital detection discrepancies for Mg-spinel-rich lithologies and provide essential ground truth for lunar mineralogy. Our findings demonstrate that even modest Mg-spinel abundances of ∼1.0 vol% can produce detectable spectral signatures, challenging existing genetic models for lunar crustal evolution. This study underscores the value of Raman spectroscopy for future lunar missions and indicates a need to recalibrate orbital interpretations of Mg-suite lithologies.
{"title":"Lunar spinel-bearing troctolitic anorthosite NWA 12279 meteorite: Linking petrology, mineralogy and spectroscopy","authors":"Hongyi Chen , Jiankai Zhou , Lanfang Xie , Jinyu Zhang , Zhipeng Xia","doi":"10.1016/j.icarus.2025.116873","DOIUrl":"10.1016/j.icarus.2025.116873","url":null,"abstract":"<div><div>The Mg-suite lithologies, particularly pink spinel-bearing rocks, provide critical insights into the Moon's crust-mantle interactions and impact metamorphism. However, discrepancies persist between remote sensing interpretations and laboratory analyses regarding the petrological characteristics of pink spinel anorthosite (PSA) or pink spinel troctolite (PST). The unbrecciated lunar meteorite NWA 12279, identified as a pink spinel-bearing troctolitic anorthosite (PSTA), offers a pristine record with well-preserved igneous textures, minimal shock metamorphism (S1–S2), and low terrestrial weathering (W0–1) affecting its mafic minerals and spinels. Combined petrological, mineral chemical, Visible-Near Infrared (VNIR) spectroscopy, and Raman spectroscopic analyses reveal a homogeneous composition dominated by anorthite (81.8 ± 0.1 vol%, An = ∼97.2), olivine (11.7 ± 1.3 vol%, Fo = ∼76.8), augite-dominated pyroxene (4.75 ± 0.45 vol%, En = ∼57.4), and Mg-spinel (0.96 ± 0.48 vol%, Mg# = ∼82.4). Reflectance spectra from six selected profiles across the sample section show diagnostic absorptions at 1050 nm (olivine), 1950 nm (Mg-spinel), and 2300–2350 nm (high-Ca pyroxene), with spectral contrasts that correlate directly with the spatial distribution of spinel. Regions enriched in spinel display a notably stronger absorption depth at 1950 nm. Furthermore, we establish well-defined linear correlations (R<sup>2</sup> ≥ 0.971) under low-shock conditions (<4 GPa) that enable robust in-situ composition prediction. These quantitative models—olivine Fo from Peak A (∼820 cm<sup>−1</sup>; <em>y</em> = 3.050<em>×</em> – 2430), spinel Mg# from Peak B (∼670 cm<sup>−1</sup>; <em>y</em> = 0.0461<em>×</em> + 50.82), and pyroxene En from Peaks C (∼661 cm<sup>−1</sup>; <em>y</em> = 2.635<em>×</em> – 1701.5) and D (∼1007 cm<sup>−1</sup>; <em>y</em> = 2.547<em>×</em> – 2522.4). These quantitative models help resolve orbital detection discrepancies for Mg-spinel-rich lithologies and provide essential ground truth for lunar mineralogy. Our findings demonstrate that even modest Mg-spinel abundances of ∼1.0 vol% can produce detectable spectral signatures, challenging existing genetic models for lunar crustal evolution. This study underscores the value of Raman spectroscopy for future lunar missions and indicates a need to recalibrate orbital interpretations of Mg-suite lithologies.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"445 ","pages":"Article 116873"},"PeriodicalIF":3.0,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-03DOI: 10.1016/j.icarus.2025.116870
Bartosz Pieterek , Thomas J. Jones , Chiedozie C. Ogbuagu
Detailed volcanological studies continue to enhance our understanding of Martian eruptive styles and their associated volcanic products. Growing evidence points to the involvement of mildly explosive eruptions as one of the eruption styles that contributed to the formation of distributed volcanic edifices in the volcanic province, Tharsis. This highlights a complex and dynamic eruptive evolution that occurred during the late Amazonian volcanism. Therefore, here, we report on the presence of small-scale, conical-shaped volcanic edifices located at the edge of Ceraunius Fossae in Tharsis. The association of the N-S aligned cones with a rough-surfaced lava flow enabled us to constrain the minimum age of their volcanic activity at ca. 48 Ma. Although they superficially resemble Martian scoria cones, their morphometric parameters indicate that they have a distinct and separate origin. They comprise coarser pyroclastic material such as spatter, and display an accumulation of likely volcanic bombs on the cones' slopes and at their bases, observable in the high-resolution images. Combining the sizes and distribution of the mapped individual volcanic bombs with a ballistic emplacement model enables us to calculate the exit velocity and maximum height for a given bomb density at a given launch angle. This provides a means to improve our understanding of ballistic trajectories and distances over which the pyroclastic material can be transported on Mars. Moreover, we argue that the portfolio of Martian volcanic edifices is more diverse than currently recognized. The use of high-resolution remotely sensed volcanological mapping could provide critical information about volcanic products and, consequently, the magma fragmentation, which depends on the eruptivity, controlled by magma composition and volatile contents.
{"title":"Late Amazonian-aged volcanic cones of explosive origin in Ceraunius Fossae, Tharsis, Mars","authors":"Bartosz Pieterek , Thomas J. Jones , Chiedozie C. Ogbuagu","doi":"10.1016/j.icarus.2025.116870","DOIUrl":"10.1016/j.icarus.2025.116870","url":null,"abstract":"<div><div>Detailed volcanological studies continue to enhance our understanding of Martian eruptive styles and their associated volcanic products. Growing evidence points to the involvement of mildly explosive eruptions as one of the eruption styles that contributed to the formation of distributed volcanic edifices in the volcanic province, Tharsis. This highlights a complex and dynamic eruptive evolution that occurred during the late Amazonian volcanism. Therefore, here, we report on the presence of small-scale, conical-shaped volcanic edifices located at the edge of Ceraunius Fossae in Tharsis. The association of the N-S aligned cones with a rough-surfaced lava flow enabled us to constrain the minimum age of their volcanic activity at ca. 48 Ma. Although they superficially resemble Martian scoria cones, their morphometric parameters indicate that they have a distinct and separate origin. They comprise coarser pyroclastic material such as spatter, and display an accumulation of likely volcanic bombs on the cones' slopes and at their bases, observable in the high-resolution images. Combining the sizes and distribution of the mapped individual volcanic bombs with a ballistic emplacement model enables us to calculate the exit velocity and maximum height for a given bomb density at a given launch angle. This provides a means to improve our understanding of ballistic trajectories and distances over which the pyroclastic material can be transported on Mars. Moreover, we argue that the portfolio of Martian volcanic edifices is more diverse than currently recognized. The use of high-resolution remotely sensed volcanological mapping could provide critical information about volcanic products and, consequently, the magma fragmentation, which depends on the eruptivity, controlled by magma composition and volatile contents.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"445 ","pages":"Article 116870"},"PeriodicalIF":3.0,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145462683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-02DOI: 10.1016/j.icarus.2025.116866
Lauren Schwartz, Alan Whittington
Remote sensing provides invaluable data about the surfaces of planetary bodies which we have not yet visited. The micro-scale texture (e.g. crystallinity and porosity) of lava flows controls their rheology and emplacement, which in turn affects the flow surface morphology. It is currently impossible to image sub-meter scale lava flow texture or morphology on other planetary bodies except for limited areas of Mars and the Moon. A property that could potentially be used to distinguish lava morphologies is thermal inertia, which measures the resistance of a material to temperature change over time. A direct measurement of thermal inertia cannot be made remotely, and thermal modeling is difficult for bodies with thick atmospheres like Earth. Apparent thermal inertia (ATI), calculated from surface albedo and diurnal temperature difference, has been used as an approximation of thermal inertia that can be obtained entirely using remote sensing. Here we attempt to relate the surface morphology and texture of several Quaternary basaltic lava flows to their thermal inertia and ATI. The flows analyzed are Carrizozo, Paxton Springs, Bandera Crater, McCartys, and Aden Crater, all located in New Mexico. Laboratory analyses of field samples include petrography, geochemistry, density, heat capacity, and thermal diffusivity. Laboratory measurements indicate that thermal inertia is higher in dense crystalline materials and decreases with increasing glass content and porosity. Thermal inertia values greater than 2000 Jm−2K−1s-1/2 require dense crystalline materials, while values less than 1000 Jm−2K−1s-1/2 must be highly porous. However, satellite-derived ATI does not correlate with the lab-derived thermal inertia and was unable to differentiate between pahoehoe and ‘a‘ā lava flow surface morphologies. ATI shows a strong seasonal relationship with values doubling from summer to winter months, which is much larger than any morphological or chemical variations. We conclude that the macro-scale morphology and micro-scale texture of basaltic lava flows is not determinable from ATI calculated at the kilometer scale satellite spatial resolution, but that true thermal inertia values can yield mm- to cm-scale textural information including crystallinity.
{"title":"Relating thermal inertia of basaltic lavas to morphology and texture","authors":"Lauren Schwartz, Alan Whittington","doi":"10.1016/j.icarus.2025.116866","DOIUrl":"10.1016/j.icarus.2025.116866","url":null,"abstract":"<div><div>Remote sensing provides invaluable data about the surfaces of planetary bodies which we have not yet visited. The micro-scale texture (e.g. crystallinity and porosity) of lava flows controls their rheology and emplacement, which in turn affects the flow surface morphology. It is currently impossible to image sub-meter scale lava flow texture or morphology on other planetary bodies except for limited areas of Mars and the Moon. A property that could potentially be used to distinguish lava morphologies is thermal inertia, which measures the resistance of a material to temperature change over time. A direct measurement of thermal inertia cannot be made remotely, and thermal modeling is difficult for bodies with thick atmospheres like Earth. Apparent thermal inertia (ATI), calculated from surface albedo and diurnal temperature difference, has been used as an approximation of thermal inertia that can be obtained entirely using remote sensing. Here we attempt to relate the surface morphology and texture of several Quaternary basaltic lava flows to their thermal inertia and ATI. The flows analyzed are Carrizozo, Paxton Springs, Bandera Crater, McCartys, and Aden Crater, all located in New Mexico. Laboratory analyses of field samples include petrography, geochemistry, density, heat capacity, and thermal diffusivity. Laboratory measurements indicate that thermal inertia is higher in dense crystalline materials and decreases with increasing glass content and porosity. Thermal inertia values greater than 2000 Jm<sup>−2</sup>K<sup>−1</sup>s<sup>-1/2</sup> require dense crystalline materials, while values less than 1000 Jm<sup>−2</sup>K<sup>−1</sup>s<sup>-1/2</sup> must be highly porous. However, satellite-derived ATI does not correlate with the lab-derived thermal inertia and was unable to differentiate between pahoehoe and ‘a‘ā lava flow surface morphologies. ATI shows a strong seasonal relationship with values doubling from summer to winter months, which is much larger than any morphological or chemical variations. We conclude that the macro-scale morphology and micro-scale texture of basaltic lava flows is not determinable from ATI calculated at the kilometer scale satellite spatial resolution, but that true thermal inertia values can yield mm- to cm-scale textural information including crystallinity.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"445 ","pages":"Article 116866"},"PeriodicalIF":3.0,"publicationDate":"2025-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145462555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
The mechanical behavior of lunar materials holds significant engineering implications for lunar base construction and deep space exploration. However, the unique space weathering environment and complex regolith microstructure compromise the credibility of mechanical studies by terrestrial analogs, and the scarcity of returned lunar soil samples precludes repetitive macroscale laboratory testing. In this study, minimally destructive techniques—mineral identification and nanoindentation tests—were integrated to measure the microscale elastic modulus (E*) and hardness (H) of Chang'e-5 lunar soil (CE5‐054), lunar meteorite (NWA 4734), and terrestrial analog (CR-1). Results demonstrated notable variations in E* (87.1–173.2 GPa) and H (6.89–9.67 GPa) among CE5‐054 minerals, with olivine showing the highest E* and pyroxene showing the highest H. Differential mechanical responses were also observed for identical mineral group from different samples, where CE5‐054 exhibited intermediate values versus NWA 4734 and CR-1. These discrepancies probably stem from their weathering processes that lunar meteorite experienced more intense impacts than lunar soil, followed by terrestrial rock. This suggests that the significant influence of weathering processes on mechanical properties extends down to the microscale, inherently altering macroscale mechanical behavior. By characterizing the micromechanical properties of lunar soil, this study provides foundational data for lunar engineering design while advancing our understanding of mechanical property evolution through space weathering processes.
{"title":"Micromechanical properties of Chang'e-5 lunar soil minerals: Comparison with meteorite and terrestrial analogs","authors":"Sijia Qiao , Lihui Li , Beixiu Huang , Heng-Ci Tian","doi":"10.1016/j.icarus.2025.116872","DOIUrl":"10.1016/j.icarus.2025.116872","url":null,"abstract":"<div><div>The mechanical behavior of lunar materials holds significant engineering implications for lunar base construction and deep space exploration. However, the unique space weathering environment and complex regolith microstructure compromise the credibility of mechanical studies by terrestrial analogs, and the scarcity of returned lunar soil samples precludes repetitive macroscale laboratory testing. In this study, minimally destructive techniques—mineral identification and nanoindentation tests—were integrated to measure the microscale elastic modulus (<em>E</em>*) and hardness (<em>H</em>) of Chang'e-5 lunar soil (CE5‐054), lunar meteorite (NWA 4734), and terrestrial analog (CR-1). Results demonstrated notable variations in <em>E</em>* (87.1–173.2 GPa) and <em>H</em> (6.89–9.67 GPa) among CE5‐054 minerals, with olivine showing the highest <em>E</em>* and pyroxene showing the highest <em>H</em>. Differential mechanical responses were also observed for identical mineral group from different samples, where CE5‐054 exhibited intermediate values versus NWA 4734 and CR-1. These discrepancies probably stem from their weathering processes that lunar meteorite experienced more intense impacts than lunar soil, followed by terrestrial rock. This suggests that the significant influence of weathering processes on mechanical properties extends down to the microscale, inherently altering macroscale mechanical behavior. By characterizing the micromechanical properties of lunar soil, this study provides foundational data for lunar engineering design while advancing our understanding of mechanical property evolution through space weathering processes.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"445 ","pages":"Article 116872"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145462557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-01DOI: 10.1016/j.icarus.2025.116869
N. Kopacz , H.E. King , D. Campisi , A. van Silfhout , G. Delen , I.L. ten Kate
Polycyclic aromatic hydrocarbons (PAHs) are one type of meteoritic organic matter delivered to the surface of Mars. The further chemical evolution of meteoritic PAHs needs to be characterized in order to successfully differentiate between different possible sources of organic molecules detected by Mars rovers, including meteoritic, geological, and potential biological sources. In the ultraviolet regime of Mars, PAHs can be subject to metal-catalyzed degradation mechanisms in the presence of photocatalytic minerals. The efficacy of these mechanisms, however, will depend on the strength of the binding interaction between the PAH and the mineral surface. In this exploratory experimental study, we outline a protocol to characterize the force interactions between the PAH pyrene and an atomically flat mineral surface. The force regime of the adsorption was studied by functionalizing a probe and performing force curve measurements with an atomic force microscope (AFM). The distribution of pyrene on the functionalized probe was mapped with photo-induced force microscopy (PiFM). We produced atomically flat titanium dioxide pellets to obtain force information entirely attributable to the intentional modifications imposed on the probes. In addition we used density functional theory (DFT) to calculate the binding energies of pyrene and titanium dioxide to gain further insight into the nature of the chemical bonds formed in this system. Our method, though it could benefit from a more uniform distribution of pyrene at the surface of the AFM probe, revealed the binding energy between the pyrene molecules and the anatase surface in good agreement with that predicted by DFT calculations.
{"title":"Quantifying the force regime of pyrene adsorption on anatase","authors":"N. Kopacz , H.E. King , D. Campisi , A. van Silfhout , G. Delen , I.L. ten Kate","doi":"10.1016/j.icarus.2025.116869","DOIUrl":"10.1016/j.icarus.2025.116869","url":null,"abstract":"<div><div>Polycyclic aromatic hydrocarbons (PAHs) are one type of meteoritic organic matter delivered to the surface of Mars. The further chemical evolution of meteoritic PAHs needs to be characterized in order to successfully differentiate between different possible sources of organic molecules detected by Mars rovers, including meteoritic, geological, and potential biological sources. In the ultraviolet regime of Mars, PAHs can be subject to metal-catalyzed degradation mechanisms in the presence of photocatalytic minerals. The efficacy of these mechanisms, however, will depend on the strength of the binding interaction between the PAH and the mineral surface. In this exploratory experimental study, we outline a protocol to characterize the force interactions between the PAH pyrene and an atomically flat mineral surface. The force regime of the adsorption was studied by functionalizing a probe and performing force curve measurements with an atomic force microscope (AFM). The distribution of pyrene on the functionalized probe was mapped with photo-induced force microscopy (PiFM). We produced atomically flat titanium dioxide pellets to obtain force information entirely attributable to the intentional modifications imposed on the probes. In addition we used density functional theory (DFT) to calculate the binding energies of pyrene and titanium dioxide to gain further insight into the nature of the chemical bonds formed in this system. Our method, though it could benefit from a more uniform distribution of pyrene at the surface of the AFM probe, revealed the binding energy between the pyrene molecules and the anatase surface in good agreement with that predicted by DFT calculations.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"446 ","pages":"Article 116869"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145448760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-01DOI: 10.1016/j.icarus.2025.116865
Filip Matuszewski , Véronique Vuitton , Julia Shouse , Thibault Launois , Naïla Chaouche-Mechidal , Elsa Hénault , Laurène Flandinet , Èric Quirico , Rosario Brunetto , Philippe Boduch , Alicja Domaracka , Hermann Rothard , Fabien Stalport , Francois Regis Orthous Daunay , Hervé Cottin , Sarah Hörst , Roland Thissen
Complex organic molecules have been found in many space environments like meteorites and comets. There, they are subjected to various forms of radiation (photons, electrons, ions), opening the question of their behavior and chemical evolution, which may have played a crucial role in chemical processes of astrobiological interest. In this study, we investigate the irradiation of adenine (CHN) with oxygen and neon ions. The free parameters of the experiments include varying energies (30-70 keV), temperatures (150, 300 K), sample thicknesses (138-554 nm), and ion fluences (0.69-5 10 ions cm). In situ IR spectroscopy reveals the appearance of CN and N=C=N bands indicating the formation of new species. Ex situ ultra-high-resolution mass spectrometry shows the formation of new complex organic molecules that far exceed the molecular mass of adenine. These macromolecules show great chemical diversity and can be expressed as (HCN)R families, where z can reach 14 and R can be C, H, N, NH, CH or CN. In total, nearly 100 individual families have been identified, 28 of which can be found in every irradiated sample. Their aromaticity equivalent is higher than that in other N-rich samples such as Titan tholins and HCN-polymers, corresponding to polycyclic aromatic nitrogen-bearing hydrocarbons. The high amount of nitrogen in these molecules indicates a very efficient incorporation of nitrogen in the solid phase during the irradiation of adenine. The ease with which complex organic matter forms through irradiation highlights the relevance of these species in space environments.
{"title":"Ion induced formation of complex organic nitrogen molecules in solid-phase adenine","authors":"Filip Matuszewski , Véronique Vuitton , Julia Shouse , Thibault Launois , Naïla Chaouche-Mechidal , Elsa Hénault , Laurène Flandinet , Èric Quirico , Rosario Brunetto , Philippe Boduch , Alicja Domaracka , Hermann Rothard , Fabien Stalport , Francois Regis Orthous Daunay , Hervé Cottin , Sarah Hörst , Roland Thissen","doi":"10.1016/j.icarus.2025.116865","DOIUrl":"10.1016/j.icarus.2025.116865","url":null,"abstract":"<div><div>Complex organic molecules have been found in many space environments like meteorites and comets. There, they are subjected to various forms of radiation (photons, electrons, ions), opening the question of their behavior and chemical evolution, which may have played a crucial role in chemical processes of astrobiological interest. In this study, we investigate the irradiation of adenine (C<span><math><msub><mrow></mrow><mrow><mn>5</mn></mrow></msub></math></span>H<span><math><msub><mrow></mrow><mrow><mn>5</mn></mrow></msub></math></span>N<span><math><msub><mrow></mrow><mrow><mn>5</mn></mrow></msub></math></span>) with oxygen and neon ions. The free parameters of the experiments include varying energies (30-70 keV), temperatures (150, 300 K), sample thicknesses (138-554 nm), and ion fluences (0.69-5 <span><math><mo>×</mo></math></span> 10<span><math><msup><mrow></mrow><mrow><mn>15</mn></mrow></msup></math></span> ions cm<span><math><msup><mrow></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></math></span>). In situ IR spectroscopy reveals the appearance of C<span><math><mo>≡</mo></math></span>N and N=C=N bands indicating the formation of new species. Ex situ ultra-high-resolution mass spectrometry shows the formation of new complex organic molecules that far exceed the molecular mass of adenine. These macromolecules show great chemical diversity and can be expressed as (HCN)<span><math><msub><mrow></mrow><mrow><mi>z</mi></mrow></msub></math></span>R families, where z can reach 14 and R can be C<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>, H<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>, N<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>, N<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>H<span><math><msub><mrow></mrow><mrow><mi>y</mi></mrow></msub></math></span>, C<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>H<span><math><msub><mrow></mrow><mrow><mi>y</mi></mrow></msub></math></span> or C<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>N<span><math><msub><mrow></mrow><mrow><mi>y</mi></mrow></msub></math></span>. In total, nearly 100 individual families have been identified, 28 of which can be found in every irradiated sample. Their aromaticity equivalent is higher than that in other N-rich samples such as Titan tholins and HCN-polymers, corresponding to polycyclic aromatic nitrogen-bearing hydrocarbons. The high amount of nitrogen in these molecules indicates a very efficient incorporation of nitrogen in the solid phase during the irradiation of adenine. The ease with which complex organic matter forms through irradiation highlights the relevance of these species in space environments.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"445 ","pages":"Article 116865"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145462600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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