Planetary and Space Science最新文献

{"title":"In situ plasma and neutral gas observation time windows during a comet flyby: Application to the Comet Interceptor mission","authors":"J. De Keyser ,&nbsp;N.J.T. Edberg ,&nbsp;P. Henri ,&nbsp;H.-U. Auster ,&nbsp;M. Galand ,&nbsp;M. Rubin ,&nbsp;H. Nilsson ,&nbsp;J. Soucek ,&nbsp;N. André ,&nbsp;V. Della Corte ,&nbsp;H. Rothkaehl ,&nbsp;R. Funase ,&nbsp;S. Kasahara ,&nbsp;C. Corral Van Damme","doi":"10.1016/j.pss.2024.105878","DOIUrl":"https://doi.org/10.1016/j.pss.2024.105878","url":null,"abstract":"<div><p>A comet flyby, like the one planned for ESA’s Comet Interceptor mission, places stringent requirements on spacecraft resources. To plan the time line of in situ plasma and neutral gas observations during the flyby, the size of the comet magnetosphere and neutral coma must be estimated well. For given solar irradiance and solar wind conditions, comet composition, and neutral gas expansion speed, the size of gas coma and magnetosphere during the flyby can be estimated from the gas production rate and the flyby geometry. Combined with flyby velocity, the time spent in these regions can be inferred and a data acquisition plan can be elaborated for each instrument, compatible with the limited data storage capacity. The sizes of magnetosphere and gas coma are found from a statistical analysis based on the probability distributions of gas production rate, flyby velocity, and solar wind conditions. The size of the magnetosphere as measured by bow shock standoff distance is <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup></mrow></math></span>–<span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>6</mn></mrow></msup></mrow></math></span> <!--> <!-->km near 1<!--> <!-->au in the unlikely case of a Halley-type target comet, down to a nonexistent bow shock for targets with low activity. This translates into durations up to <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span>–<span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> seconds. These estimates can be narrowed down when a target is identified far from the Sun, and even more so as its activity can be predicted more reliably closer to the Sun. Plasma and neutral gas instruments on the Comet Interceptor main spacecraft can monitor the entire flyby by using an adaptive data acquisition strategy in the context of a record-and-playback scenario. For probes released from the main spacecraft, the inter-satellite communication link limits the data return. For a slow flyby of an active comet, the probes may not yet be released during the inbound bow shock crossing.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"244 ","pages":"Article 105878"},"PeriodicalIF":2.4,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0032063324000424/pdfft?md5=bd969ce9776cc77c8587cf73d1da5f9f&pid=1-s2.0-S0032063324000424-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140112984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geological history of the Atira Mons large shield volcano, Beta Regio, Venus.","authors":"C.H.G. Braga ,&nbsp;E.G. Antropova ,&nbsp;R.E. Ernst ,&nbsp;H. El Bilali ,&nbsp;J.W. Head ,&nbsp;K.L. Buchan","doi":"10.1016/j.pss.2024.105879","DOIUrl":"10.1016/j.pss.2024.105879","url":null,"abstract":"<div><p>Atira Mons is a large (∼300,000 km²) low-relief (1.8 km) shield volcano, with individual flows extending up to ∼700 km from the central caldera. It is located about 3000 km NW from the major plume center Beta Regio. Detailed mapping of the flows (at 1:500,000 scale, 10x more detailed than previous mapping) has identified fifty-three flow units which are grouped into eleven packages. Flow units are distinguished based on radar brightness, topography, morphology, continuity, structural modification, and sources, while flow packages group flows with clear stratigraphic relationship affinity.</p><p>Cross-cutting relationships indicate a complex and multi-episodic eruption history with provisional identification of six mapped stages. The most voluminous flows are concentrated in the early stages, while the younger pulses, with a few exceptions, are shorter and less voluminous. A central caldera hosts the youngest volcanism with flows breaching its eastern side. Multiple stages of caldera collapse are indicated.</p><p>The volume of the volcano is estimated using various methods and yields values range from ∼47,000 to ∼270,000 km³. The larger estimates are consistent with that of the magma volume of Large Igneous Provinces (LIP) on Earth. An appropriate terrestrial analogue is the Benham Rise Oceanic LIP in the western margin of the Philippine Sea, and particularly the Apolaki Caldera, which is the world's largest known basaltic caldera with a diameter of ∼150 km.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"244 ","pages":"Article 105879"},"PeriodicalIF":2.4,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0032063324000436/pdfft?md5=0115db2e50dbda8d76aee90f7fe434be&pid=1-s2.0-S0032063324000436-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applying machine learning to a nonlinear spectral mixing model for mapping lunar soils composition using CHANDRAYAAN-1 M3 data","authors":"Viktor Korokhin ,&nbsp;Yehor Surkov ,&nbsp;Urs Mall ,&nbsp;Vadym Kaydash ,&nbsp;Sergey Velichko ,&nbsp;Yuri Velikodsky ,&nbsp;Oksana Shalygina","doi":"10.1016/j.pss.2024.105870","DOIUrl":"10.1016/j.pss.2024.105870","url":null,"abstract":"<div><p>We present a newly developed method which combines the nonlinear spectral mixing model of Shkuratov et al. (1999) with a machine learning algorithm to map the lunar regolith composition using spectral data. The new method performs orders of magnitude faster than the traditionally used numerical optimization approaches, allowing the mapping of regolith properties (including mineralogical composition, average grain size and optical maturity) over large areas of the lunar surface. A new set of basic mineral spectra of the lunar soil for using with spectral mixing models is proposed. Used together with the nonlinear mixing model (Shkuratov et al., 1999), the set is able to describes Chandrayaan-1 M³ instrument spectra collected from test areas which includes the Shapley crater with its surroundings containing mare and highland terrains well. The new set includes a virtual “gray component” with a “flat” (constant) spectrum, accounting for the factors that change general surface albedo, such as spectrally neutral components (e.g., agglutinate glasses), errors in the photometric reduction, uncertainties in estimations of lunar regolith porosity <em>q</em> and the mean grain size <em>S</em> of the basic minerals. The proposed new method takes into account the influence of space weathering and nonlinear correlation between the compositional and spectral parameters of the lunar soils delivering values for the optical properties and mineralogical abundance determination of the lunar regolith which are compatible with the results found from lunar samples measurements in the laboratory. The proposed approach can be used for analyzing spectral observations not only of the lunar surface but also for other surfaces with are covered by regolith.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"244 ","pages":"Article 105870"},"PeriodicalIF":2.4,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140127085","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}

{"title":"Possible influence of Martian surface mineralogy on the detectability of atmospheric trace gases - mid-infrared simulation results","authors":"","doi":"10.1016/j.pss.2024.105877","DOIUrl":"10.1016/j.pss.2024.105877","url":null,"abstract":"<div><p>The paper focuses on the influence of the optical properties of Martian surface minerals on remotely detected gaseous components of the Martian atmosphere, when the spectrometer receives a combined signal from the Martian soil and atmosphere. Our considerations are primarily concerned with the detectability of methane, but the problem may also apply to other trace gases. Detections of methane in the Martian atmosphere have been reported from Mars Express (orbiting Mars), the Curiosity rover on the Martian surface, and from Earth. Its presence in the Martian atmosphere is being questioned today. The reason for these doubts is that both spectrometers onboard ExoMars Trace Gas Orbiter have not yet detected any methane in the Martian atmosphere using the very sensitive solar occultation method. The solar occultation method is unable to probe the lowest layers of the atmosphere at mid-latitudes, and so, its presence in this part of the atmosphere is assumed to be due to its possible source in the ground, as suggested by some works.</p><p>This paper considers whether the spectral characteristics of the soil may hinder the remote detection of methane. One of the examples discussed in the article relates to the possible observation of methane over mineralogical surfaces that may be the source of this gas. The examples of other surface mineralogical compositions are also discussed. The series of numerical simulations carried out in the region of the strong methane absorption band and the examples where the optical properties of the surface change the shape and contrast of this absorption band are shown. The codes used provide estimates of the spectral reflectance/emittance and total radiance of the Martian surface and atmosphere in the mid-infrared spectral region. The surface covered by dust was described by the reflectance and emittance calculated from n,k using Mie and Hapke theories or known from laboratory measurements. The different concentrations of atmospheric trace gases were taken into account.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"249 ","pages":"Article 105877"},"PeriodicalIF":1.8,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140127046","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}

{"title":"The equilibrium vapor pressures of ammonia and oxygen ices at outer solar system temperatures","authors":"B.P. Blakley ,&nbsp;Will M. Grundy ,&nbsp;Jordan K. Steckloff ,&nbsp;Sugata P. Tan ,&nbsp;Jennifer Hanley ,&nbsp;Anna E. Engle ,&nbsp;Stephen C. Tegler ,&nbsp;Gerrick E. Lindberg ,&nbsp;Shae M. Raposa ,&nbsp;Kendall J. Koga ,&nbsp;Cecilia L. Thieberger","doi":"10.1016/j.pss.2024.105863","DOIUrl":"https://doi.org/10.1016/j.pss.2024.105863","url":null,"abstract":"<div><p>Few laboratory studies have investigated the vapor pressures of the volatiles that may be present as ices in the outer solar system; even fewer studies have investigated these species at the temperatures and pressures suitable to the surfaces of icy bodies in the Saturnian and Uranian systems (&lt;100 K, &lt;10⁻⁹ bar). This study adds to the work of Grundy et al. (2024) in extending the known equilibrium vapor pressures of outer solar system ices through laboratory investigations at very low temperatures. Our experiments with ammonia and oxygen ices provide new thermodynamic models for these species’ respective enthalpies of sublimation. We find that ammonia ice, and to a lesser degree oxygen ice, are stable at higher temperatures than extrapolations in previous literature have predicted. Our results show that these ices should be retained over longer periods of time than previous extrapolations would predict, and a greater amount of these solids is required to support observation in exospheres of airless bodies in the outer solar system.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"244 ","pages":"Article 105863"},"PeriodicalIF":2.4,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140163255","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}

{"title":"Europa’s structural conditions for the existence of subsurface ocean and the absence of metallic core-driven magnetic field","authors":"Jun Kimura","doi":"10.1016/j.pss.2024.105868","DOIUrl":"10.1016/j.pss.2024.105868","url":null,"abstract":"&lt;div&gt;&lt;p&gt;During the Galileo spacecraft’s flyby of Europa, magnetic field measurements detected an inductive signal due to the response of Europa’s interior conductors to temporal fluctuations in the Jovian magnetic field. In contrast, no signatures of intrinsic magnetic field originating from the dynamo motion in the metallic core were acquired. These measurements suggest that a global sub-surface ocean containing electrolytes exists beneath the solid ice shell and that the metallic core lacks convection. Europa’s interior is expected to be divided into the metallic core, rocky mantle and hydrosphere based on the moment of inertia factor estimated from gravity field measurements. Specifically, the thickness of the outermost water layer is 120&lt;!--&gt; &lt;!--&gt;–&lt;!--&gt; &lt;!--&gt;170 km, and the radius of the metallic core is 0.12&lt;!--&gt; &lt;!--&gt;–&lt;!--&gt; &lt;!--&gt;0.43 times the surface radius. No systematic investigation of Europa’s internal evolution has been conducted to estimate the current state of the subsurface ocean and to explain the absence of a core dynamo field within such uncertainty for internal structure and material properties (especially ice properties). Herein, I performed a numerical simulation of the long-term thermal evolution of Europa’s interior and investigated the temporal changes in the ocean thickness as well as the temperature and heat flow of the metallic core. If the ice reference viscosity is greater than 5 × 10&lt;sup&gt;14&lt;/sup&gt; Pa&lt;!--&gt; &lt;!--&gt;s, the sub-surface ocean can persist even in the absence of tidal heating. In the case of a tidal heating of 10 mW/m&lt;sup&gt;2&lt;/sup&gt; and 20 mW/m&lt;sup&gt;2&lt;/sup&gt;, the ice shell thickness is &lt;span&gt;&lt;math&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; &lt;!--&gt; &lt;!--&gt;90 km if the ice reference viscosity is &lt;span&gt;&lt;math&gt;&lt;mo&gt;≥&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; &lt;!--&gt; &lt;!--&gt;1 × 10&lt;sup&gt;15&lt;/sup&gt; and 1 × 10&lt;sup&gt;14&lt;/sup&gt; Pa&lt;!--&gt; &lt;!--&gt;s, respectively. Regardless of the ice reference viscosity, if the tidal heating is &lt;span&gt;&lt;math&gt;&lt;mo&gt;≥&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; &lt;!--&gt; &lt;!--&gt;50 mW/m&lt;sup&gt;2&lt;/sup&gt;, the shell thickness will be &lt;span&gt;&lt;math&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; &lt;!--&gt; &lt;!--&gt;40 km. The thermal history of the metallic core is determined by the hydrosphere thickness and the metallic core density, and is unaffected by variations in the ice shell (ocean) thickness. Preferred conditions for the absence of the core dynamo include CI chondritic abundance for the long-lived radioactive isotopes, lower initial core–mantle boundary (CMB) temperature and thicker hydrosphere. The core may be molten without convection if the composition is near the eutectic in a Fe–FeS alloy, or not molten (without convection) if the composition is near the Fe or FeS endmember. Specifically, if the rocky mantle has a CI chondritic radioisotope abundance, any core composition and hydrosphere thickness allow the absence of the core dynamo if the initial temperature at the CMB is lower than 1,250 K. If the rocky mantle has the ordinary chondritic radioisotope abundance, or a higher initial temperature (&lt;span&gt;&lt;math&gt;&lt;mo&gt;∼&lt;/m","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"243 ","pages":"Article 105868"},"PeriodicalIF":2.4,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140044010","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}

{"title":"Near-Earth asteroids of cometary origin associated with the Virginid complex","authors":"G.I. Kokhirova ,&nbsp;A.I. Zhonmuhammadi ,&nbsp;U.H. Khamroev ,&nbsp;M.N. Latipov ,&nbsp;T.J. Jopek","doi":"10.1016/j.pss.2024.105869","DOIUrl":"https://doi.org/10.1016/j.pss.2024.105869","url":null,"abstract":"<div><p>The Virginid meteoroid streams produce a series of meteor showers active annually during February–May. A certain parent comet is not found but a related association of some showers with near-Earth asteroids was previously established and a cometary origin of these asteroids was suggested. We performed a new search for NEAs belonging to the Virginid asteroid–meteoroid complex. On the base of calculation of orbital evolution of a sample of NEAs and determination of theoretical features of related showers a search for observable active showers close to theoretically predicted ones was carried out. As a result, the predicted showers of 27 NEAs were identified with the showers of the Virginid complex. Revealed association points to a cometary nature of NEAs that are moving within the stream and may be considered as extinct fragments of a larger comet-progenitor of the Virginid asteroid–meteoroid complex.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"243 ","pages":"Article 105869"},"PeriodicalIF":2.4,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140052662","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}

{"title":"Seasonal variation in atmospheric optical depth (AOD) and thermal inertia (TI) inter-relationship over Martian Gale crater","authors":"Farzana Shaheen,&nbsp;Mili Ghosh Nee Lala,&nbsp;A.P. Krishna,&nbsp;Swagata Payra","doi":"10.1016/j.pss.2024.105865","DOIUrl":"10.1016/j.pss.2024.105865","url":null,"abstract":"<div><p>Investigating the relationship between thermal inertia (TI) and aerosol optical depth (AOD) is significant in giving insights into the seasonality of dust deposition and lifting phenomenon. The present study focuses on establishing a relationship of AOD with TI and different particle sizes over different Martian seasons. Two different Martian landforms (exposed rock and sand dunes) have been used to establish these relationships. TI layer was generated using THEMIS nighttime images for different seasons, whereas Curiosity Rover measured AOD values and Mars Climate database (MCD) visible column dust optical depth were used to derive rover equivalent AOD. An inverse relation was observed between AOD and TI for exposed rock and sand dune regions for all the seasons with low to moderate coefficient of determination (R²⁾. A similar inverse trend was observed between rover equivalent AOD and particle size with R² values ranging from 0.8 in the case of sand dunes (winter) to 0.93 in exposed rock (autumn). The results were further compared within the AOD obtained from orbiter image (HRSC) derived using Shadow method for spring season (Shaheen et al., 2022). The same inverse relation was found within TI having good R² values of 0.61 for exposed rock and 0.76 for the sand dunes. Error estimation using Mean Absolute Error (MAE), Root Mean Square Error (RMSE), Normalized Mean Square Error (NMSE), Fractional Bias (FB), Index of agreement errors was carried out for TI vs. AOD and particle size vs. AOD. Excellent statistical significance was obtained for AOD and particle size, in the case of sand dunes it was 0.96 for autumn and 0.99 in case of exposed rock for spring season, respectively.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"242 ","pages":"Article 105865"},"PeriodicalIF":2.4,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140010778","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}

{"title":"Galactic cosmic rays at 0.7 A.U. with Venus Express housekeeping data","authors":"Thomas Rimbot ,&nbsp;Olivier Witasse ,&nbsp;Marco Pinto ,&nbsp;Elise Wright Knutsen ,&nbsp;Beatriz Sánchez-Cano ,&nbsp;Simon Wood ,&nbsp;Elena Tremolizzo ,&nbsp;Willi Exner","doi":"10.1016/j.pss.2024.105867","DOIUrl":"https://doi.org/10.1016/j.pss.2024.105867","url":null,"abstract":"<div><p>We apply a previously developed procedure to characterize galactic cosmic rays (GCRs) at 0.7 A.U. with engineering data coming from the Venus Express mission. The engineering parameters are the Error Detection and Correction EDAC cumulative counters, used for detection and correction of memory errors induced by highly energetic particles. It has already been demonstrated that the slope of this counter measures GCR fluxes using data from Mars Express (1.5 A.U.) and Rosetta (up to 4 A.U.) data. Here, we reproduce these methods using Venus Express EDAC data in order to understand the behavior of GCRs closer to the Sun. We again witness the anti-correlation of EDAC slope with the solar activity and further investigate this procedure. The resulting time-lag between maximum sunspot number and minimum GCRs intensity at Venus is close to one day instead of the expected several months. This work represents one of the first characterization of galactic cosmic rays at small distances to the Sun over a long period of time and further cements the value of using EDAC counters as scientific information.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"242 ","pages":"Article 105867"},"PeriodicalIF":2.4,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139992756","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}

{"title":"Lunar simulant behaviour in molten fluoride salt for ISRU applications","authors":"M. Maes ,&nbsp;M. Gibilaro ,&nbsp;P. Chamelot ,&nbsp;C. Chiron ,&nbsp;S. Chevrel ,&nbsp;P. Pinet ,&nbsp;L. Massot ,&nbsp;J.J. Favier","doi":"10.1016/j.pss.2024.105854","DOIUrl":"https://doi.org/10.1016/j.pss.2024.105854","url":null,"abstract":"<div><p>This study investigated the behaviour of a lunar mare crystalline analog dissolved in molten LiF–NaF at 800 °C for the <em>in situ</em> production of metals as a part of In Situ Resource Utilization (ISRU) research. Molten fluorides have the capability to dissolve metallic oxides, and the Hall-Héroult process uses this kind of media to produce Al from Al₂O₃.The first step was to compare the individual solubility of the main oxides composing the mare lunar soil (SiO₂, Al₂O₃, Fe₂O₃, and MgO) with the solubility of the crystalline analog using Inductively Coupled Plasma – Atomic Emission Spectroscopy (ICP-AES). The species concentration added jointly are lower than the concentration of the same species added separately. Nonetheless, this study showed that LiF–NaF can be used to dissolve the analog with a maximum solubility of 3.9 wt% at 800 °C. Cyclic voltammograms were also used to verify the electroactivity of all oxide species in LiF–NaF, wherein all the main oxides are electroactive except SiO₂ and TiO₂. Then electrolyses on different cathodic substrates were performed at different conditions and the obtained cathodic products were analysed with a scanning electron microscope (SEM) coupled with an energy dispersive spectroscopy (EDS). Despite the non-electroactivity of SiO₂ and TiO₂, they were extracted in an alloyed form through Under Potential Deposition (UPD). Metallic deposition of other metals such as aluminium and titanium was achieved on carbon electrode. Finally, a synthetic mixture made of the different oxide species with the same chemical composition as the simulant, was investigated as a viable substitute for lunar mare soil. Its electrochemical behaviour was identical to the crystalline lunar simulant showing that our original process based on oxides dissolution is not influenced by the amorphous/crystalline state of the raw material.</p><p>the outputs of LiF–NaF molten process are not critically influenced by the physical state of the lunar regolith.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"242 ","pages":"Article 105854"},"PeriodicalIF":2.4,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0032063324000187/pdfft?md5=ef167a51d1a5b6f322e65e2913b65c38&pid=1-s2.0-S0032063324000187-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140024096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}