Pub Date : 2025-02-20DOI: 10.1016/j.pss.2025.106075
Iman Shafieenejad
This study aims to optimize the velocity change of the Didymos asteroid using the Whale Optimization Algorithm (WOA). The deflection of asteroids that pose significant threats to Earth is a crucial aspect of upcoming space missions. In this research, a spacecraft is attached to the Didymos asteroid, utilizing its gravitational force as a perturbation to modify the asteroid's trajectory. The transfer of kinetic energy from the spacecraft to the asteroid induces a change in velocity (ΔV). The findings indicate that the most substantial impact on velocity occurs in the radial direction, showing divergent oscillatory behavior. The results suggest that the optimal point for significant velocity change is located shortly after the perihelion. At this point, WOA achieves the maximum velocity change. Additionally, the stability of the asteroid's deflection is investigated due to the nonlinear characteristics of the orbital motion equations. The optimal velocity change is identified as at , occurring after the perihelion at . This study introduces a novel optimization approach for asteroid deflection, emphasizing the nonlinear dynamics of orbital motion.
{"title":"Maximizing the velocity deflection of asteroid Didymos using the Whale Optimization Algorithm","authors":"Iman Shafieenejad","doi":"10.1016/j.pss.2025.106075","DOIUrl":"10.1016/j.pss.2025.106075","url":null,"abstract":"<div><div>This study aims to optimize the velocity change of the Didymos asteroid using the Whale Optimization Algorithm (WOA). The deflection of asteroids that pose significant threats to Earth is a crucial aspect of upcoming space missions. In this research, a spacecraft is attached to the Didymos asteroid, utilizing its gravitational force as a perturbation to modify the asteroid's trajectory. The transfer of kinetic energy from the spacecraft to the asteroid induces a change in velocity (ΔV). The findings indicate that the most substantial impact on velocity occurs in the radial direction, showing divergent oscillatory behavior. The results suggest that the optimal point for significant velocity change is located shortly after the perihelion. At this point, WOA achieves the maximum velocity change. Additionally, the stability of the asteroid's deflection is investigated due to the nonlinear characteristics of the orbital motion equations. The optimal velocity change is identified as <span><math><mrow><mo>Δ</mo><msub><mi>V</mi><mrow><mi>t</mi><mi>o</mi><mi>t</mi><mi>a</mi><mi>l</mi></mrow></msub><mo>=</mo><mn>2.5139</mn><mo>×</mo><mn>1</mn><msup><mn>0</mn><mrow><mo>−</mo><mn>7</mn></mrow></msup><mrow><mo>(</mo><mfrac><mrow><mi>k</mi><mi>m</mi></mrow><mi>s</mi></mfrac><mo>)</mo></mrow></mrow></math></span> at <span><math><mrow><mo>Δ</mo><mi>t</mi><mo>=</mo><mn>27.657</mn><mrow><mo>(</mo><mi>h</mi><mo>)</mo></mrow></mrow></math></span>, occurring after the perihelion at <span><math><mrow><msub><mrow><mi>t</mi><mrow><mo>(</mo><mi>h</mi><mo>)</mo></mrow></mrow><mrow><mo>Δ</mo><msub><mi>V</mi><mi>max</mi></msub></mrow></msub></mrow></math></span>. This study introduces a novel optimization approach for asteroid deflection, emphasizing the nonlinear dynamics of orbital motion.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"258 ","pages":"Article 106075"},"PeriodicalIF":1.8,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-20DOI: 10.1016/j.pss.2025.106076
John R. Marshall , Lori K. Fenton
On Saturn's moon Titan the unique combination of low gravity, low-density surface materials (ices), and high atmospheric density may enable the wind to roll pebble, cobble, and perhaps even small boulder-size stones. If so, Titan's aeolian environment would be unlike that of Earth or Mars where wind is generally limited to transporting sand and dust much less than a couple of millimeters in size. To investigate the rolling-stone possibility we conducted a mathematical analysis constrained by conventional engineering and aerodynamic theory. We show that the minimum wind strength to cause saltation of sand on Titan is sufficient, under certain geological conditions, to also roll stones as large as ∼0.5 m diameter. Various features previously mapped on Titan have characteristics consistent with fields of wind-rolled stones, with the most compelling candidate being radar-bright ‘streak-like plains’ that are elongated parallel to nearby linear dunes. Possible implications for Titan science and the Dragonfly mission are considered.
{"title":"Rolling stones on Titan","authors":"John R. Marshall , Lori K. Fenton","doi":"10.1016/j.pss.2025.106076","DOIUrl":"10.1016/j.pss.2025.106076","url":null,"abstract":"<div><div>On Saturn's moon Titan the unique combination of low gravity, low-density surface materials (ices), and high atmospheric density may enable the wind to roll pebble, cobble, and perhaps even small boulder-size stones. If so, Titan's aeolian environment would be unlike that of Earth or Mars where wind is generally limited to transporting sand and dust much less than a couple of millimeters in size. To investigate the rolling-stone possibility we conducted a mathematical analysis constrained by conventional engineering and aerodynamic theory. We show that the minimum wind strength to cause saltation of sand on Titan is sufficient, under certain geological conditions, to also roll stones as large as ∼0.5 m diameter. Various features previously mapped on Titan have characteristics consistent with fields of wind-rolled stones, with the most compelling candidate being radar-bright ‘streak-like plains’ that are elongated parallel to nearby linear dunes. Possible implications for Titan science and the Dragonfly mission are considered.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"258 ","pages":"Article 106076"},"PeriodicalIF":1.8,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488290","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}
Comets, asteroids, and other small bodies are thought to be remnants of the original planetesimal population of the Solar System. As such, their physical, chemical, and isotopic properties hold crucial details on how and where they formed and how they evolved. Yet, placing precise constraints on the formation region of these bodies has been challenging. Data from spacecraft missions have a particularly high potential of addressing the question of the origin of the visited bodies. ESA’s Rosetta mission to comet 67P/Churyumov-Gerasimenko returned data from the comet for two years on its journey around the Sun. This extensive data set has revolutionized our view on comets and still holds unsolved problems.
Here, we aim to determine comet 67P’s bulk elemental composition from Rosetta data, including its refractory-to-ice ratio. We use these results to constrain the temperature in the protoplanetary disk where comets formed and, using a disk model, the formation location.
We use the Rosetta/ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) measurement of the volatile/ice composition and the Rosetta/COSIMA (COmetary Secondary Ion Mass Analyzer) measurements of the refractory composition of comet 67P. These measurements are combined using a Monte Carlo method. The refractory-to-ice ratio is a free parameter that is constrained a posteriori.
Using only the composition, we constrain the refractory-to-ice ratio to , and derive the bulk elemental abundances for 67P of H, C, N, O, Na, Mg, Al, S, K, Ar, Ca, Cr, Mn, Fe, Kr, and Xe. We find the noble gas xenon in near solar elemental abundance in comet 67P. Krypton is slightly depleted, while argon is heavily depleted. Comet 67P is enriched in all three noble gases by up to 2.5 orders of magnitude compared to CI chondrites. We show this is consistent with a formation region between 25 and 35 au in a protoplanetary disk region with temperatures between 30 and 40 K and with the trapping of dust for a long time in rings of the protoplanetary disk.
{"title":"The refractory-to-ice ratio in comet 67P: Implications on the composition of the comet-forming region of the protoplanetary disk","authors":"Raphael Marschall , Alessandro Morbidelli , Yves Marrocchi","doi":"10.1016/j.pss.2025.106061","DOIUrl":"10.1016/j.pss.2025.106061","url":null,"abstract":"<div><div>Comets, asteroids, and other small bodies are thought to be remnants of the original planetesimal population of the Solar System. As such, their physical, chemical, and isotopic properties hold crucial details on how and where they formed and how they evolved. Yet, placing precise constraints on the formation region of these bodies has been challenging. Data from spacecraft missions have a particularly high potential of addressing the question of the origin of the visited bodies. ESA’s Rosetta mission to comet 67P/Churyumov-Gerasimenko returned data from the comet for two years on its journey around the Sun. This extensive data set has revolutionized our view on comets and still holds unsolved problems.</div><div>Here, we aim to determine comet 67P’s bulk elemental composition from Rosetta data, including its refractory-to-ice ratio. We use these results to constrain the temperature in the protoplanetary disk where comets formed and, using a disk model, the formation location.</div><div>We use the Rosetta/ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) measurement of the volatile/ice composition and the Rosetta/COSIMA (COmetary Secondary Ion Mass Analyzer) measurements of the refractory composition of comet 67P. These measurements are combined using a Monte Carlo method. The refractory-to-ice ratio is a free parameter that is constrained a posteriori.</div><div>Using only the composition, we constrain the refractory-to-ice ratio to <span><math><mrow><mn>0</mn><mo>.</mo><mn>5</mn><mo><</mo><mi>χ</mi><mo><</mo><mn>1</mn><mo>.</mo><mn>7</mn></mrow></math></span>, and derive the bulk elemental abundances for 67P of H, C, N, O, Na, Mg, Al, S, K, Ar, Ca, Cr, Mn, Fe, Kr, and Xe. We find the noble gas xenon in near solar elemental abundance in comet 67P. Krypton is slightly depleted, while argon is heavily depleted. Comet 67P is enriched in all three noble gases by up to 2.5 orders of magnitude compared to CI chondrites. We show this is consistent with a formation region between 25 and 35 au in a protoplanetary disk region with temperatures between 30 and 40 K and with the trapping of dust for a long time in rings of the protoplanetary disk.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"259 ","pages":"Article 106061"},"PeriodicalIF":1.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143473935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-16DOI: 10.1016/j.pss.2025.106072
Susan J. Conway , Valentin T. Bickel , Lori K. Fenton , Manish R. Patel , Helen C. Carson , Antoine Blouin , Justin Crevier , Evan Blanc , Bao Nhi Nguyen , James A. Holmes , Brian Jackson , Lonneke Roelofs
Dust devils are atmospheric vortices that loft dust from the ground, typically at the hottest times of the day and year on Mars. They contribute dust to the atmosphere and so indirectly affect the global atmospheric circulation. Their size, shape and velocity can provide indications of the weather on Mars. Hence, tracking their occurrence in time and space provides useful data for understanding Mars’ current climate. They are also of relevance to landed missions as they can clean solar panel surfaces, extending mission lifetimes. Despite the numerous observations and surveys of dust devils to date, the global extent, distribution and occurrence of dust devils is not yet consistently constrained, mainly due to the relatively limited spatial and temporal scope of manual analyses. To provide the most comprehensive global catalogue of active martian dust devils to date, we applied a RetinaNet convolutional neural network to existing remote sensing images of Mars to identify the distinctive signature of the light-toned lofted dust cloud and dark shadow formed by active dust devils on Mars. The algorithm used ∼6 m/pixel Context Camera (CTX) images from Mars Years 28–36, scanning through a total of 132 359 images. False positives were manually removed with the help of the Zooniverse platform, resulting in 13 409 detections. This survey presents the most spatially and temporally exhaustive global catalogue of dust devils to date. We confirm many trends revealed in disparate previous studies. For example, approximately half of the detections are concentrated in the Amazonis Planitia monitoring site – a hotspot identified from previous imaging campaigns. In addition, we confirm that orbital observations are not well-suited for detecting dust devils at landing sites, despite the ubiquitous detection of vortices with in-situ data. Our study reveals previously understudied hotspots where dust devil lofted clouds can be seen from orbit, most notably southern Hellas Planitia where only dust devil tracks had been previously extensively reported. Importantly, our results reveal latitudinal clusters of dust devils, and in particular large dust devils, at around 60°N and 60°S during local summer solstice, which had only been hinted at by previous work. This concentration is at a much higher latitude than previous modelling suggests, indicating that dust devil generation on Mars is controlled by more factors than are currently accounted for.
{"title":"A global survey for dust devil vortices on mars using MRO context camera images enabled by neural networks","authors":"Susan J. Conway , Valentin T. Bickel , Lori K. Fenton , Manish R. Patel , Helen C. Carson , Antoine Blouin , Justin Crevier , Evan Blanc , Bao Nhi Nguyen , James A. Holmes , Brian Jackson , Lonneke Roelofs","doi":"10.1016/j.pss.2025.106072","DOIUrl":"10.1016/j.pss.2025.106072","url":null,"abstract":"<div><div>Dust devils are atmospheric vortices that loft dust from the ground, typically at the hottest times of the day and year on Mars. They contribute dust to the atmosphere and so indirectly affect the global atmospheric circulation. Their size, shape and velocity can provide indications of the weather on Mars. Hence, tracking their occurrence in time and space provides useful data for understanding Mars’ current climate. They are also of relevance to landed missions as they can clean solar panel surfaces, extending mission lifetimes. Despite the numerous observations and surveys of dust devils to date, the global extent, distribution and occurrence of dust devils is not yet consistently constrained, mainly due to the relatively limited spatial and temporal scope of manual analyses. To provide the most comprehensive global catalogue of active martian dust devils to date, we applied a RetinaNet convolutional neural network to existing remote sensing images of Mars to identify the distinctive signature of the light-toned lofted dust cloud and dark shadow formed by active dust devils on Mars. The algorithm used ∼6 m/pixel Context Camera (CTX) images from Mars Years 28–36, scanning through a total of 132 359 images. False positives were manually removed with the help of the Zooniverse platform, resulting in 13 409 detections. This survey presents the most spatially and temporally exhaustive global catalogue of dust devils to date. We confirm many trends revealed in disparate previous studies. For example, approximately half of the detections are concentrated in the Amazonis Planitia monitoring site – a hotspot identified from previous imaging campaigns. In addition, we confirm that orbital observations are not well-suited for detecting dust devils at landing sites, despite the ubiquitous detection of vortices with in-situ data. Our study reveals previously understudied hotspots where dust devil lofted clouds can be seen from orbit, most notably southern Hellas Planitia where only dust devil tracks had been previously extensively reported. Importantly, our results reveal latitudinal clusters of dust devils, and in particular large dust devils, at around 60°N and 60°S during local summer solstice, which had only been hinted at by previous work. This concentration is at a much higher latitude than previous modelling suggests, indicating that dust devil generation on Mars is controlled by more factors than are currently accounted for.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"259 ","pages":"Article 106072"},"PeriodicalIF":1.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511080","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}
Pub Date : 2025-02-16DOI: 10.1016/j.pss.2025.106073
Mark T. Lemmon , Ingrid J. Daubar , Maria E. Banks , Jeremie Vaubaillon , Eleanor K. Sansom , Justin N. Maki
Meteor surveys on other planets, such as Mars, can be used to constrain the variation in the meteoroid flux away from Earth. Images from the Spirit rover have previously been used for one such survey. We report on the sampling and results of a new survey conducted with InSight lander images. The InSight survey used cameras with wider fields of view and faster optics than the Spirit survey and comprised 9.7 h of cumulative exposure time, compared to 2.7 h for Spirit. No meteors were identified. We determined that while the InSight survey was more sensitive to bright meteors, it was less sensitive to faint meteors due to compression-related issues. Further, we determined that the Spirit survey was substantially less sensitive than previously reported, and neither survey had sufficient sensitivity to test theoretical expectations given expected detections ≪1. We conclude with recommendations for the design of any future surveys.
{"title":"The InSight Mars lander's meteor search","authors":"Mark T. Lemmon , Ingrid J. Daubar , Maria E. Banks , Jeremie Vaubaillon , Eleanor K. Sansom , Justin N. Maki","doi":"10.1016/j.pss.2025.106073","DOIUrl":"10.1016/j.pss.2025.106073","url":null,"abstract":"<div><div>Meteor surveys on other planets, such as Mars, can be used to constrain the variation in the meteoroid flux away from Earth. Images from the Spirit rover have previously been used for one such survey. We report on the sampling and results of a new survey conducted with InSight lander images. The InSight survey used cameras with wider fields of view and faster optics than the Spirit survey and comprised 9.7 h of cumulative exposure time, compared to 2.7 h for Spirit. No meteors were identified. We determined that while the InSight survey was more sensitive to bright meteors, it was less sensitive to faint meteors due to compression-related issues. Further, we determined that the Spirit survey was substantially less sensitive than previously reported, and neither survey had sufficient sensitivity to test theoretical expectations given expected detections ≪1. We conclude with recommendations for the design of any future surveys.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"258 ","pages":"Article 106073"},"PeriodicalIF":1.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-15DOI: 10.1016/j.pss.2025.106064
Jan Deca , Andrey Divin , Peter Stephenson , Pierre Henri , Marina Galand , Austin Smith
The European Space Agency’s Rosetta mission measured the complex plasma environment surrounding comet 67P/Churyumov-Gerasimenko for more than two years. In this work, the collisionless dynamics of the plasma interaction during the comet’s weakly outgassing phases is investigated through a fully kinetic semi-implicit particle-in-cell approach. The effects of an asymmetric outgassing profile with respect to the upstream plasma conditions are compared with a spherically symmetric Haser model. The three-dimensional shape of the plasma density and the parallel acceleration potential are used as primary measures. It is found that the four-fluid coupled system is not majorly distorted. The different components of the potential structure can be associated with the large-scale behavior and density profiles of the four simulated plasma species. The implications for the acceleration and cooling of electrons within the cometary plasma environment are identified by contrasting the differences in the shape of the acceleration potential between the distinct asymmetric outgassing models. The analysis provides a detailed overview that can help interpret past Rosetta plasma measurements and could be key to help disentangle the physical drivers active in the plasma environment of comets visited by future exploration missions.
{"title":"A fully kinetic perspective on weakly active comets: Asymmetric outgassing","authors":"Jan Deca , Andrey Divin , Peter Stephenson , Pierre Henri , Marina Galand , Austin Smith","doi":"10.1016/j.pss.2025.106064","DOIUrl":"10.1016/j.pss.2025.106064","url":null,"abstract":"<div><div>The European Space Agency’s Rosetta mission measured the complex plasma environment surrounding comet 67P/Churyumov-Gerasimenko for more than two years. In this work, the collisionless dynamics of the plasma interaction during the comet’s weakly outgassing phases is investigated through a fully kinetic semi-implicit particle-in-cell approach. The effects of an asymmetric outgassing profile with respect to the upstream plasma conditions are compared with a spherically symmetric Haser model. The three-dimensional shape of the plasma density and the parallel acceleration potential are used as primary measures. It is found that the four-fluid coupled system is not majorly distorted. The different components of the potential structure can be associated with the large-scale behavior and density profiles of the four simulated plasma species. The implications for the acceleration and cooling of electrons within the cometary plasma environment are identified by contrasting the differences in the shape of the acceleration potential between the distinct asymmetric outgassing models. The analysis provides a detailed overview that can help interpret past Rosetta plasma measurements and could be key to help disentangle the physical drivers active in the plasma environment of comets visited by future exploration missions.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"258 ","pages":"Article 106064"},"PeriodicalIF":1.8,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453877","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}
Pub Date : 2025-02-13DOI: 10.1016/j.pss.2025.106065
R.H. Quan, Z.G. Liu, Z.Y. Song
Charged dust on the surface of airless celestial bodies, such as the Moon and asteroids, poses a threat to space missions. Further research into charged dust is essential for the success of future space missions. In this study, we investigated the charging and dynamics of dust particles by examining different work functions. By integrating the photoelectron energy distribution function over four different work functions, we evaluated the variations in photoelectron density within the dust charge environment caused by changes in the work function. Using the photoelectron density corresponding to each work function, we solved the dust charging and dynamic equations for each type of dust under two different gravitational acceleration values. The results revealed that dust with a lower work function reaches higher equilibrium states, though it takes longer to achieve these states. These equilibrium states include charging currents, charge numbers, and levitation heights. The results also showed that equilibrium states have an inverse relationship with the work functions of dust particles as the solar zenith angle (SZA) varies from 0°to 90°, displaying consistent trends under different gravitational accelerations. Additionally, we found that dust particles could not levitate stably at a critical SZA, with this critical SZA following the same pattern as that of the work function. These findings could inform the design of dust mitigation strategies for future space missions, enhancing the safety and longevity of spacecraft operating on airless celestial bodies.
{"title":"Effect of work function on dust charging and dynamics on airless celestial body","authors":"R.H. Quan, Z.G. Liu, Z.Y. Song","doi":"10.1016/j.pss.2025.106065","DOIUrl":"10.1016/j.pss.2025.106065","url":null,"abstract":"<div><div>Charged dust on the surface of airless celestial bodies, such as the Moon and asteroids, poses a threat to space missions. Further research into charged dust is essential for the success of future space missions. In this study, we investigated the charging and dynamics of dust particles by examining different work functions. By integrating the photoelectron energy distribution function over four different work functions, we evaluated the variations in photoelectron density within the dust charge environment caused by changes in the work function. Using the photoelectron density corresponding to each work function, we solved the dust charging and dynamic equations for each type of dust under two different gravitational acceleration values. The results revealed that dust with a lower work function reaches higher equilibrium states, though it takes longer to achieve these states. These equilibrium states include charging currents, charge numbers, and levitation heights. The results also showed that equilibrium states have an inverse relationship with the work functions of dust particles as the solar zenith angle (SZA) varies from 0°to 90°, displaying consistent trends under different gravitational accelerations. Additionally, we found that dust particles could not levitate stably at a critical SZA, with this critical SZA following the same pattern as that of the work function. These findings could inform the design of dust mitigation strategies for future space missions, enhancing the safety and longevity of spacecraft operating on airless celestial bodies.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"258 ","pages":"Article 106065"},"PeriodicalIF":1.8,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-07DOI: 10.1016/j.pss.2025.106052
P.M. Thesniya , Jappji Mehar , V.J. Rajesh
This study investigates the morphology and ejecta emplacement dynamics of the Copernican-aged Das crater on the lunar farside. High-resolution panchromatic images, and spectral, and topographic data from lunar orbiter missions were utilized for the study. The identified morphological features in the crater such as central peaks, wall terraces, and impact melt deposits reflect how impact event interacted with the lunar surface. Based on our findings and existing knowledge of cratering processes, we discuss the stages in the evolution of the Das crater, involving excavation, rebound effects, wall collapse, and cavity modification. The impact melting that occurred during cavity modification significantly influences crater morphology and structural features such as central peaks and hummocky floor deposits. The effects of voluminous melting are also seen in the late-stage flow emplacement and rim veneers. Floor subsidence and structural adjustments, driven by extensive slumping and terrace formation, further shape the morphology of the crater. We propose a multi-stage process for ejecta emplacement during crater formation. The contiguous ejecta blanket forms via ballistic sedimentation in the excavation stage, followed by melt-ejecta emplacement in subsequent stages. The asymmetric distribution of ballistic ejecta around Das crater, notably the lack of secondary crater chains in the NNE direction, implied an oblique impact. This asymmetry, along with the circularity of the crater, indicated an impact direction from NNE to SSW, with an angle of 15°–25° relative to the horizontal. The crater elongation in the east-west direction results from post-impact modifications rather than the impact trajectory. The distribution of melt deposits is mainly concentrated in the eastern part of the crater, contrary to an expected downrange emplacement. This phenomenon is attributed to asymmetric cavity modification processes facilitated by pre-impact topographic asymmetry. Overall, these findings highlight the complex interplay between impact dynamics, topographic features, and post-impact modification processes in shaping the morphology of lunar craters, providing valuable insights into lunar surface evolution and impact cratering processes.
{"title":"Investigation of morphology and impact ejecta emplacement of the Copernican Das crater on the lunar farside","authors":"P.M. Thesniya , Jappji Mehar , V.J. Rajesh","doi":"10.1016/j.pss.2025.106052","DOIUrl":"10.1016/j.pss.2025.106052","url":null,"abstract":"<div><div>This study investigates the morphology and ejecta emplacement dynamics of the Copernican-aged Das crater on the lunar farside. High-resolution panchromatic images, and spectral, and topographic data from lunar orbiter missions were utilized for the study. The identified morphological features in the crater such as central peaks, wall terraces, and impact melt deposits reflect how impact event interacted with the lunar surface. Based on our findings and existing knowledge of cratering processes, we discuss the stages in the evolution of the Das crater, involving excavation, rebound effects, wall collapse, and cavity modification. The impact melting that occurred during cavity modification significantly influences crater morphology and structural features such as central peaks and hummocky floor deposits. The effects of voluminous melting are also seen in the late-stage flow emplacement and rim veneers. Floor subsidence and structural adjustments, driven by extensive slumping and terrace formation, further shape the morphology of the crater. We propose a multi-stage process for ejecta emplacement during crater formation. The contiguous ejecta blanket forms via ballistic sedimentation in the excavation stage, followed by melt-ejecta emplacement in subsequent stages. The asymmetric distribution of ballistic ejecta around Das crater, notably the lack of secondary crater chains in the NNE direction, implied an oblique impact. This asymmetry, along with the circularity of the crater, indicated an impact direction from NNE to SSW, with an angle of 15°–25° relative to the horizontal. The crater elongation in the east-west direction results from post-impact modifications rather than the impact trajectory. The distribution of melt deposits is mainly concentrated in the eastern part of the crater, contrary to an expected downrange emplacement. This phenomenon is attributed to asymmetric cavity modification processes facilitated by pre-impact topographic asymmetry. Overall, these findings highlight the complex interplay between impact dynamics, topographic features, and post-impact modification processes in shaping the morphology of lunar craters, providing valuable insights into lunar surface evolution and impact cratering processes.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"258 ","pages":"Article 106052"},"PeriodicalIF":1.8,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-07DOI: 10.1016/j.pss.2025.106062
A.A. Alves , V. Carruba , E.M.D.S. Delfino , V.R. Silva , L. Blasco
Secular resonances occur when there is a commensurability between the fundamental frequencies of asteroids and planets. These interactions can affect orbital elements like eccentricity and inclination. In this work, our focus is to study the resonance, which affects highly inclined asteroids in the inner main belt around the Phocaea family. Traditionally, the identification of these asteroids was done manually, which demanded a significant amount of time and became unfeasible due to the large volume of data. Our goal is to develop deep learning models for the automatic identification of asteroids affected by this resonance. In this work, Convolutional Neural Network (CNN) models, such as VGG, Inception, and ResNet, as well as the Vision Transformer (ViT) architecture, are used. To evaluate the performance of the models, we used metrics such as accuracy, precision, recall, and F1-score, applied to both filtered and unfiltered elements. We applied deep learning methods and evaluated which one presented the best effectiveness in the classification of asteroids affected by the secular resonance. To improve the performance of the models, we employed regularization techniques, such as data augmentation and dropout. CNN models demonstrated excellent performance with both filtered and unfiltered elements, but the Vision architecture stood out, providing exceptional performance across all used metrics and low processing times.
{"title":"Deep learning identification of asteroids interacting with g-s secular resonances","authors":"A.A. Alves , V. Carruba , E.M.D.S. Delfino , V.R. Silva , L. Blasco","doi":"10.1016/j.pss.2025.106062","DOIUrl":"10.1016/j.pss.2025.106062","url":null,"abstract":"<div><div>Secular resonances occur when there is a commensurability between the fundamental frequencies of asteroids and planets. These interactions can affect orbital elements like eccentricity and inclination. In this work, our focus is to study the <span><math><mrow><mi>g</mi><mo>−</mo><msub><mrow><mi>g</mi></mrow><mrow><mn>6</mn></mrow></msub><mo>−</mo><mi>s</mi><mo>+</mo><msub><mrow><mi>s</mi></mrow><mrow><mn>6</mn></mrow></msub></mrow></math></span> resonance, which affects highly inclined asteroids in the inner main belt around the Phocaea family. Traditionally, the identification of these asteroids was done manually, which demanded a significant amount of time and became unfeasible due to the large volume of data. Our goal is to develop deep learning models for the automatic identification of asteroids affected by this resonance. In this work, Convolutional Neural Network (CNN) models, such as VGG, Inception, and ResNet, as well as the Vision Transformer (ViT) architecture, are used. To evaluate the performance of the models, we used metrics such as accuracy, precision, recall, and F1-score, applied to both filtered and unfiltered elements. We applied deep learning methods and evaluated which one presented the best effectiveness in the classification of asteroids affected by the secular resonance. To improve the performance of the models, we employed regularization techniques, such as data augmentation and dropout. CNN models demonstrated excellent performance with both filtered and unfiltered elements, but the Vision architecture stood out, providing exceptional performance across all used metrics and low processing times.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"258 ","pages":"Article 106062"},"PeriodicalIF":1.8,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.pss.2025.106037
Jaroslav Klokočník , Jan Kostelecký , Aleš Bezděk
Gravity strike angles are one of the gravity aspects. They are computed from global static gravity field models. They react to changes in density variation and porosity. Internal rock anisotropy and stresses can be detected by strike angles. They run parallel with the direction of weakness in the strength of the rock, e.g., the direction schistosity and/or the presence of faults or micro-fault zones. Thus, they can help to describe the underground causative body in another way than traditional gravity anomalies. We used the GRGM1200A gravity field model for the Moon to the degree and order of 600 in spherical harmonic expansion and LOLA topography. The results show that the strike angles are more frequently and more intensively aligned (combed) near the poles than in other places. The strike angles are highly combed for the Malapert A crater (the landing site of IM-1/Odyssey) as well as for the localities selected by NASA for the forthcoming Artemis missions. Our method, which has already been applied many times on diverse geological features on the Earth, provides quick and cheap remote sensing procedure, a preliminary diagnostic tool, independent of all others, in search of lunar water.
{"title":"Groundwater at the southern pole of the Moon via the gravity strike angles: IM-1 and Artemis","authors":"Jaroslav Klokočník , Jan Kostelecký , Aleš Bezděk","doi":"10.1016/j.pss.2025.106037","DOIUrl":"10.1016/j.pss.2025.106037","url":null,"abstract":"<div><div>Gravity strike angles are one of the gravity aspects. They are computed from global static gravity field models. They react to changes in density variation and porosity. Internal rock anisotropy and stresses can be detected by strike angles. They run parallel with the direction of weakness in the strength of the rock, e.g., the direction schistosity and/or the presence of faults or micro-fault zones. Thus, they can help to describe the underground causative body in another way than traditional gravity anomalies. We used the GRGM1200A gravity field model for the Moon to the degree and order of 600 in spherical harmonic expansion and LOLA topography. The results show that the strike angles are more frequently and more intensively aligned (combed) near the poles than in other places. The strike angles are highly combed for the Malapert A crater (the landing site of IM-1/Odyssey) as well as for the localities selected by NASA for the forthcoming Artemis missions. Our method, which has already been applied many times on diverse geological features on the Earth, provides quick and cheap remote sensing procedure, a preliminary diagnostic tool, independent of all others, in search of lunar water.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"256 ","pages":"Article 106037"},"PeriodicalIF":1.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143262625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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