Icarus最新文献

{"title":"Thermal–orbital evolution of Eris","authors":"Ryunosuke Akiba,&nbsp;Francis Nimmo","doi":"10.1016/j.icarus.2025.116770","DOIUrl":"10.1016/j.icarus.2025.116770","url":null,"abstract":"<div><div>The large Kuiper Belt object (KBO) Eris is nearly as big as Pluto and has a small moon, Dysnomia. Constraints on the system’s spin and orbit characteristics were recently used to argue for a dissipative Eris, requiring a differentiated structure but not necessarily a subsurface ocean. Here, we model the thermal history of Eris coupled to its spin–orbital evolution, finding a subsurface ocean is preferred in order for Eris to be sufficiently dissipative. Spinning down Eris without an ocean is difficult, requiring a warm convecting ice shell protected by a thick insulating layer and very dissipative anelastic behavior in ice. Oceans make up 77%–100% of successful thermal–orbital evolution models, depending on the parameters assumed, which increases to <span><math><mo>&gt;</mo></math></span>98% when the Andrade <span><math><mi>β</mi></math></span> parameter for ice is restricted to <span><math><mrow><mi>β</mi><mo>≤</mo><mn>3</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>11</mn></mrow></msup></mrow></math></span> Pa⁻¹ s<span><math><msup><mrow></mrow><mrow><mo>−</mo><mn>0</mn><mo>.</mo><mn>25</mn></mrow></msup></math></span>. Oceans freeze over by the present day unless insulation (porosity, gas clathrates) or antifreeze are present.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116770"},"PeriodicalIF":3.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886481","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}

{"title":"Quantification and geological implications of manganese, barium, and copper observed by MarSCoDe LIBS at Zhurong landing site on Mars","authors":"Yuxuan Luo ,&nbsp;Zhaopeng Chen ,&nbsp;Jianjun Liu ,&nbsp;Yizhong Zhang ,&nbsp;Jingjing Zhang ,&nbsp;Zhibin Li ,&nbsp;Xin Ren ,&nbsp;Xiangfeng Liu ,&nbsp;Zhenqiang Zhang ,&nbsp;Weiming Xu ,&nbsp;Guolin Hu ,&nbsp;Shaojin Han ,&nbsp;Rong Shu","doi":"10.1016/j.icarus.2025.116781","DOIUrl":"10.1016/j.icarus.2025.116781","url":null,"abstract":"<div><div>The Mars Surface Composition Detector (MarSCoDe) onboard the Zhurong rover, China's first Mars rover, includes a laser-induced breakdown spectroscopy (LIBS) instrument that enables quantitative analysis of Martian surface elemental composition. We developed quantitative models for manganese (Mn), barium (Ba), and copper (Cu) using respective lab datasets. The optimal model for each element is selected from combinations of various multivariate regression algorithms and feature extractions. Additionally, the model's accuracy and behaviors on the onboard MarSCoDe Calibration Targets (MCCTs) were evaluated. We obtained Mn, Ba, and Cu concentrations for 36 Martian targets detected by MarSCoDe LIBS during the first 300 sols (Martian days). For MarSCoDe rock targets, Mn is primarily associated with Fe, with olivines and pyroxenes being the main source of Mn; however, the overall contents of Ba and Cu are low in MarSCoDe rock targets, and their host minerals remain unclear. Based on the current results, MarSCoDe rocks should be primarily composed of igneous minerals, with minimal alteration preserving their original composition. Additionally, an Fe-Al-Mn-bearing phase was observed in a dune target, potentially clay minerals, suggesting that external inputs may have influenced the dune's composition. This work provides new evidence for the elemental and mineral composition as well as the potential geological processes of the Zhurong landing site.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116781"},"PeriodicalIF":3.0,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867300","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}

{"title":"Reconciling Jupiter’s vertical motions with the observed cloud structure in the upper troposphere","authors":"João M. Mendonça ,&nbsp;Tapio Schneider ,&nbsp;Junjun Liu ,&nbsp;Yuan Lian","doi":"10.1016/j.icarus.2025.116766","DOIUrl":"10.1016/j.icarus.2025.116766","url":null,"abstract":"<div><div>The eddy fluxes of angular momentum in Jupiter’s upper troposphere are known to converge in prograde jets and diverge in retrograde jets. Away from the equator, this implies convergence of the Eulerian mean meridional flow in zones (anticyclonic shear) and divergence in belts (cyclonic shear). It indicates lower-tropospheric downwelling in zones and upwelling in belts because the mean meridional circulation almost certainly closes at depth. Yet the observed banded structure of Jupiter’s clouds and hazes suggests that there is upwelling in the brighter zones and downwelling in the darker belts. Here, we show that this apparent contradiction can be resolved by considering not the Eulerian but the transformed Eulerian mean circulation, which includes a Stokes drift owing to eddies and is a better approximation of the Lagrangian mean transport of tracers such as ammonia. The potential vorticity structure inferred from observations paired with mixing length arguments suggests that there is transformed Eulerian mean upwelling in zones and downwelling in belts. Simulations with a global circulation model of Jupiter’s upper atmosphere demonstrate the plausibility of these inferences and allow us to speculate on the band structure at deeper levels.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116766"},"PeriodicalIF":3.0,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144860972","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}

{"title":"Dynamics of a granular asteroid after a subsonic DART-like impact","authors":"Paul Sánchez ,&nbsp;Daniel J. Scheeres","doi":"10.1016/j.icarus.2025.116741","DOIUrl":"10.1016/j.icarus.2025.116741","url":null,"abstract":"<div><div>We carry out numerical simulations of a variety of impacts on a Dimorphos-like self-gravitating aggregate. These impacts have the same momentum, but we proportionally vary the velocity and mass of the impactor so that as velocity increases, so does its kinetic energy. This is done to explore the space of impacts on a binary secondary in order to gain insight into body deformation and energy dissipation in such a system. We use a soft-sphere discrete element method (DEM) code for this work and reach impact speeds of up to <span><math><mo>≈</mo></math></span>1.5 km/s, bordering on supersonic where the results stop being realistic. We find that the amount of ejecta, as well as the momentum enhancing factor (<span><math><mi>β</mi></math></span>) and the variation in the along-track velocity due to the impact (<span><math><mrow><mi>Δ</mi><mi>v</mi></mrow></math></span>) increase with an increasing kinetic energy showing that our results point towards the values obtained by the DART mission. Additionally, we analyse how energy is dissipated over time, months after the impact, and evaluate the quality factor <span><math><mi>Q</mi></math></span> that characterises the energy dissipation rate.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"442 ","pages":"Article 116741"},"PeriodicalIF":3.0,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810247","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}

{"title":"The effect of clay minerals on Li in martian groundwater simulant","authors":"Rachel Y. Sheppard ,&nbsp;Jessica M. Weber ,&nbsp;Laura E. Rodriguez ,&nbsp;Cathy Trejo ,&nbsp;Elisabeth M. Hausrath ,&nbsp;Laura M. Barge","doi":"10.1016/j.icarus.2025.116769","DOIUrl":"10.1016/j.icarus.2025.116769","url":null,"abstract":"<div><div>The high mobility of Li allows it to be used as a tracer for groundwater processes, recording past aqueous conditions. On Earth, a relationship has been noted in multiple field sites between clay mineral abundances and elevated Li in bedrock. Observations from the Curiosity MSL mission at Gale crater on Mars showed a high-clay mineral and high-Li area near the Vera Rubin ridge (VRR) and Glen Torridon region, suggesting Li was perhaps substituting into clay minerals as was seen in these terrestrial field settings. However, the process of this substitution has not been examined in the laboratory using non-field samples, especially not with Mars-relevant mineralogy. To investigate this open question in the laboratory using Mars-relevant regolith and clay minerals, we conducted continuous flow packed-bed reactor experiments to test whether clay minerals affect the Li concentration of Mars regolith simulant MGS-1 during aqueous alteration. The mechanism for Li sorption was also investigated by conducting experiments with clays mixed with glass beads and investigating changes in other elements alongside Li via laser-induced breakdown spectroscopy (LIBS). We tested four dioctahedral clay minerals (kaolinite, illite, nontronite, mixed layer illite/smectite) and two trioctahedral clay minerals (talc, saponite) and found that both talc and illite are capable of increasing the amount of Li sorbed compared to MGS-1 simulant when exposed to Li-bearing groundwater. For MGS-1, the glass beads, and the clay minerals (talc, illite) the primary mechanism appears to be Li substitution for Mg, Al, and K, respectively. This has implications for ongoing Mars missions as well as astrobiology, specifically relating to understanding habitability of areas on Mars and identifying aqueous environments for future mission concepts.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116769"},"PeriodicalIF":3.0,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144829401","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}

{"title":"Prediction of Apophis’s deformation-driven rotational evolution during its closest encounter to the Earth in 2029","authors":"Masatoshi Hirabayashi","doi":"10.1016/j.icarus.2025.116754","DOIUrl":"10.1016/j.icarus.2025.116754","url":null,"abstract":"<div><div>In 2029, the near-Earth asteroid (99942) Apophis approaches the Earth within six Earth radii. This opportunity is one of the rarest natural experiments that we can use to better characterize a small body through telescopic observations and space missions. Earlier geological investigations consistently suggested that major geological processes might not occur on Apophis during this closest encounter, including surface processing and interior deformation. However, minor resurfacing may occur, depending on local geological conditions. A critical finding is that the rotational evolution occurs due to the tidal effect from the Earth. The present study offers an additional perspective on the rotational evolution, which may vary due to variations in interior properties. Namely, possible deformation processes may change the spin state variation from the rigid body state, even if deformation is not measurable. The effort in this work is to explore this issue using a simplified model, motivated by earlier studies by Hirabayashi (2023) and Taylor et al. (2023). The results show that the deformation-driven spin state change may be possible, depending on Young’s modulus. If this asteroid’s Young’s modulus is <span><math><mo>∼</mo></math></span>1 MPa or higher, the spin state only deviates a few degrees from the rigid body state over one year. However, if it is <span><math><mo>∼</mo></math></span>10 kPa or less, the spin state deviation may reach a few degrees, even a few days after the closest encounter. Both telescopic observations and space missions can provide strong insights into this phenomenon.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116754"},"PeriodicalIF":3.0,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144829664","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}

{"title":"Tidal dissipation within Earth’s solidifying magma ocean: III. Effects of matrix compaction","authors":"Jun Korenaga","doi":"10.1016/j.icarus.2025.116759","DOIUrl":"10.1016/j.icarus.2025.116759","url":null,"abstract":"<div><div>Tidal dissipation in a solidifying magma ocean is crucial for understanding the early thermal and orbital evolution of the Earth–Moon system. This study examines how matrix compaction affects tidal dissipation during magma ocean solidification. Using a one-dimensional two-phase flow model, we simulate the evolution of melt fraction profiles under various mantle potential temperatures and grain sizes. Whereas matrix compaction generally lowers tidal dissipation by reducing the cumulate thickness, our results show that, during early solidification phases, it can enhance dissipation at high tide-raising frequencies by increasing the resonance frequency of the magma ocean. These findings underscore the importance of considering matrix compaction in tidal dissipation models and suggest a potentially more complex interplay between solidification dynamics and tidal response than previously understood. This work provides a framework that allows us to better explore the possible evolutionary paths of the early Earth–Moon system.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"442 ","pages":"Article 116759"},"PeriodicalIF":3.0,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749995","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}

{"title":"Tidal dissipation within Earth’s solidifying magma ocean: I. Effects of inertia and lunar orbital eccentricity","authors":"Jun Korenaga","doi":"10.1016/j.icarus.2025.116756","DOIUrl":"10.1016/j.icarus.2025.116756","url":null,"abstract":"<div><div>When modeling the early tidal evolution of the Earth–Moon system, we need to calculate tidal dissipation within Earth’s solidifying magma ocean for a wide range of tide-raising frequency. This is because some giant impact hypotheses posit an initially rapidly spinning Earth. Also, the evection resonance, which is likely to have been encountered by the early Earth–Moon system, increases lunar orbital eccentricity, which can broaden the frequency range. It is shown that the standard solution methods such as the propagator matrix method and the shooting method are insufficient to handle this wide range of frequency. As tide-raising frequency increases, the effect of inertia becomes significant, but the propagator matrix method is commonly implemented only with the governing equations without inertia. The shooting method can handle high frequencies well, but it becomes unbearably unstable toward the low frequency end. The relaxation method is found to be extremely stable over the entire frequency range considered, being able to handle huge viscosity variations over 20 orders of magnitudes. For an initially rapidly spinning Earth, the effects of inertia and lunar orbital eccentricity are considerable, warranting a careful reevaluation of various scenarios for the early lunar evolution.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"442 ","pages":"Article 116756"},"PeriodicalIF":3.0,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767110","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}

{"title":"Exploring impact vapor plume reactions from asteroidal impacts: Monte Carlo simulations and implications for biomolecules synthesis","authors":"Yoko Ochiai ,&nbsp;Shigeru Ida ,&nbsp;Daigo Shoji","doi":"10.1016/j.icarus.2025.116736","DOIUrl":"10.1016/j.icarus.2025.116736","url":null,"abstract":"<div><div>During a hypervelocity impact, both the impactor and target materials evaporate, generating an impact vapor plume with temperatures reaching several thousand K. As the plume cools through adiabatic expansion, chemical reactions are predicted to quench, leading to a non-equilibrium composition. Previous experiments simulating meteorite impacts on the early Earth have reported the formation of biomolecules such as amino acids and nucleobases, suggesting that the chemical reactions within impact vapor plumes may have contributed to the origins of the building blocks of life. However, it is still unclear how chemical reactions proceed during the cooling impact vapor plume and lead to the synthesis of such organic molecules. In this study, to investigate the evolution of chemical composition within impact vapor plumes, we conducted a Monte Carlo chemical reaction simulation for complex organic synthesis, developed in our previous work (Ochiai, Y., Ida, S., Shoji, D., [2024], Astron. Astrophys., 687, A232). In conventional kinetic model-based studies, chemical species and their associated reaction pathways are predefined to calculate the time evolution of chemical compositions using the thermodynamic data of these species and reaction rate coefficients. In contrast, our model does not rely on a predefined reaction network; instead, it utilizes imposed conditions for chemical changes and an approximate method for calculating reaction rates suited to our objectives. Additionally, we developed a new approach to couple these chemical reaction calculations with the rapid temperature and pressure decay in the vapor plume. Results show diverse organic molecule production depending on the impactor materials assumed in this study (LL, CI, and EL chondritic types). These products include important precursors to biomolecules such as amino acids, sugars, and nucleobases. On the other hand, for all impactor compositions, the abundance of biomolecules themselves remains extremely low throughout the reactions from an impact to quenching. Therefore, our results suggest that biomolecules are not directly produced in impact vapor plumes but rather synthesized through reactions of these precursor molecules in aqueous solutions, following H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O condensation as the vapor plume cools. Many of the detected organic compounds, including the precursor molecules such as imine compounds and formamide, are not included in the reaction networks of previous kinetic model simulations, and their formation has not been predicted. This demonstrates the effectiveness of our Monte Carlo simulation as a powerful tool for investigating the synthesis of low-abundance organic compounds, including biomolecules.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"442 ","pages":"Article 116736"},"PeriodicalIF":3.0,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767119","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}

{"title":"Developing a high-fidelity lunar regolith simulant based on Chang'E-5 samples and remote sensing images","authors":"Chao Wang ,&nbsp;Siji Sanlang ,&nbsp;Xiaohua Tong ,&nbsp;Kaihan Xu ,&nbsp;Lu Han ,&nbsp;Huan Xie ,&nbsp;Yongjiu Feng ,&nbsp;Xiong Xu ,&nbsp;Yanmin Jin","doi":"10.1016/j.icarus.2025.116764","DOIUrl":"10.1016/j.icarus.2025.116764","url":null,"abstract":"<div><div>The Chang'E-5 (CE-5) mission, China's pioneering endeavor to retrieve lunar samples, brings back approximately 1.7 kg of Moon samples. These CE-5 samples provide valuable material for investigating the properties of lunar regolith and help to understand the geological evolution of the Moon. In this study, we propose a framework for developing a lunar regolith simulant that closely resembles the regolith at the CE-5 landing site. Firstly, the in-situ internal friction angle of the lunar regolith where CE-5 touched down was determined based on the impact depth of the lander footpad and the lunar regolith properties, yielding an estimated range from 29.2° to 43.0°. Secondly, two CE-5 lunar samples, CE5C0300YJFM002GP and CE5C1000YJFM002GP, were analyzed using scanning electron microscopy, micro-computed tomography, and stereoscopic microscopy to investigate particle morphology and size distribution. Thirdly, according to the statistical data from the samples, a new lunar regolith simulant named Tongji University-CE5 (TJ-CE5) was developed through a process involving drying, grinding, sieving, and blending by controlling the bulk density and size distribution. Subsequently, a series of tests were conducted to characterize the properties of the TJ-CE5 simulant. The internal friction angle of TJ-CE5 was measured as 36.9°, which is consistent with the predicted in-situ value. Ultimately, the derived TJ-CE5 simulant is equivalent to the CE-5 lunar regolith in terms of density, particle morphology, particle size distribution, internal friction angle, and chemical composition. Therefore, the framework of this study can be applied to the preparation of other lunar regolith simulants with different properties specific to various landing sites. This research established a methodology for developing a simulant that replicates the characteristics of lunar regolith and provided material for ground experiments supporting lunar exploration and construction missions.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"442 ","pages":"Article 116764"},"PeriodicalIF":3.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724170","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}