Pub Date : 2025-09-09DOI: 10.1016/j.pss.2025.106199
Alexander E. Dubinov, Ilya N. Kitayev
A non-ideal dusty planetary plasma was considered, consisting of a mixture of three gases – gases of inertialess electrons and ions, and a gas of negatively charged dust particles. Electrons and ions in the plasma were thought to be Boltzmann-distributed, and the dust gas obeyed the equation of state of the non-ideal gas previously deduced by Avinash. Stationary dust-acoustic waves DAWs in such plasma were studied for the first time. The study was carried out in the gas dynamic approach.
The linear theory of DAWs has been developed, within the framework of which a dispersion equation was derived and an exact expression for the linear velocity of a dust sound was obtained.
The non-linear theory of large amplitude DAWs in a non-ideal dust plasma based on the Bernoulli pseudopotential method was first developed. Pseudopotential analysis showed that stationary DAWs in the considered plasma can have the form of either a nonlinear periodic wave or the form of solitons. The wave velocity ranges in these two forms are defined.
The dependence of the maximum velocity of DA-solitons and the maximum Mach number on the value of the parameter of non-ideality is calculated. It was also found that with an increase of the parameter of non-ideality, the amplitude of the extreme soliton decreases, and its width at half-maximum practically does not depend on this parameter.
The developed theory can be used to describe DAWs appearing in dense non-ideal plasmas near planets, their satellites and comets.
{"title":"Nonlinear theory of dust-acoustic waves in planetary plasmas with non-ideal dust fraction","authors":"Alexander E. Dubinov, Ilya N. Kitayev","doi":"10.1016/j.pss.2025.106199","DOIUrl":"10.1016/j.pss.2025.106199","url":null,"abstract":"<div><div>A non-ideal dusty planetary plasma was considered, consisting of a mixture of three gases – gases of inertialess electrons and ions, and a gas of negatively charged dust particles. Electrons and ions in the plasma were thought to be Boltzmann-distributed, and the dust gas obeyed the equation of state of the non-ideal gas previously deduced by Avinash. Stationary dust-acoustic waves DAWs in such plasma were studied for the first time. The study was carried out in the gas dynamic approach.</div><div>The linear theory of DAWs has been developed, within the framework of which a dispersion equation was derived and an exact expression for the linear velocity of a dust sound was obtained.</div><div>The non-linear theory of large amplitude DAWs in a non-ideal dust plasma based on the Bernoulli pseudopotential method was first developed. Pseudopotential analysis showed that stationary DAWs in the considered plasma can have the form of either a nonlinear periodic wave or the form of solitons. The wave velocity ranges in these two forms are defined.</div><div>The dependence of the maximum velocity of DA-solitons and the maximum Mach number on the value of the parameter of non-ideality is calculated. It was also found that with an increase of the parameter of non-ideality, the amplitude of the extreme soliton decreases, and its width at half-maximum practically does not depend on this parameter.</div><div>The developed theory can be used to describe DAWs appearing in dense non-ideal plasmas near planets, their satellites and comets.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106199"},"PeriodicalIF":1.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-08DOI: 10.1016/j.pss.2025.106189
Joel Patzwald , Rafael Kleba-Ehrhardt , Tjorben Griemsmann , Norbert Nowaczyk , Stefan Linke , Ludger Overmeyer , Enrico Stoll , David Karl
Sustainable and fast exploration and colonisation of our solar system are only possible if humans learn to use the resources of other celestial bodies, such as our Moon, to build settlements and infrastructure, extract valuable materials for the production of secondary goods and obtain consumables such as water and oxygen for life support and as fuel. The most abundant resource on the Moon is the lunar regolith, a layer of loose pulverised rock material covering the Moons surface many meters thick. So-called ISRU (in-situ resource utilisation) technologies are being developed to make use of this material. To develop and test such technologies on Earth, analogue materials (simulants) are essential. In a previous study, the LX lunar regolith simulant system was developed for this purpose, and the base simulants LX-T100 and LX-M100 were characterised regarding their mineralogy and chemistry, particle size distribution, particle morphology, density, void ratio and porosity. This study presents the second part of a comprehensive characterisation of the base simulants, aimed at providing detailed insights into their adsorption behaviour and specific surface area, compressibility, flow properties, magnetic properties and optical properties. Using the Brunauer–Emmett–Teller (BET) method, the specific surface area was precisely quantified, being, for example, relevant to the adhesion and reactivity of lunar dust. Compressibility was measured using an oedometer test, providing insight into the settlement behaviour of the simulants under load. Flow properties were assessed through a series of dynamic and static tests, including angle of repose, Hausner ratio, rheometry and direct shear measurements, to determine the simulant’s handling and transportation behaviour. The magnetic properties were characterised to understand the magnetic susceptibility and remanence, which are crucial for dust mitigation strategies and electromagnetic interference assessments. Spectral reflectance was evaluated using spectrophotometry across relevant wavelengths, providing useful data for remote sensing calibration and surface composition analysis. It was shown that the simulants are good analogues for simulating adsorption, compression, and flow behaviour. However, their ability to represent magnetic and optical properties remains limited. The results from these investigations contribute to a more thorough understanding of the LX base simulants, enhancing their fidelity for scientific research.
{"title":"Properties of novel LX lunar regolith simulant system — the base simulants: Part 2","authors":"Joel Patzwald , Rafael Kleba-Ehrhardt , Tjorben Griemsmann , Norbert Nowaczyk , Stefan Linke , Ludger Overmeyer , Enrico Stoll , David Karl","doi":"10.1016/j.pss.2025.106189","DOIUrl":"10.1016/j.pss.2025.106189","url":null,"abstract":"<div><div>Sustainable and fast exploration and colonisation of our solar system are only possible if humans learn to use the resources of other celestial bodies, such as our Moon, to build settlements and infrastructure, extract valuable materials for the production of secondary goods and obtain consumables such as water and oxygen for life support and as fuel. The most abundant resource on the Moon is the lunar regolith, a layer of loose pulverised rock material covering the Moons surface many meters thick. So-called ISRU (in-situ resource utilisation) technologies are being developed to make use of this material. To develop and test such technologies on Earth, analogue materials (simulants) are essential. In a previous study, the LX lunar regolith simulant system was developed for this purpose, and the base simulants LX-T100 and LX-M100 were characterised regarding their mineralogy and chemistry, particle size distribution, particle morphology, density, void ratio and porosity. This study presents the second part of a comprehensive characterisation of the base simulants, aimed at providing detailed insights into their adsorption behaviour and specific surface area, compressibility, flow properties, magnetic properties and optical properties. Using the Brunauer–Emmett–Teller (BET) method, the specific surface area was precisely quantified, being, for example, relevant to the adhesion and reactivity of lunar dust. Compressibility was measured using an oedometer test, providing insight into the settlement behaviour of the simulants under load. Flow properties were assessed through a series of dynamic and static tests, including angle of repose, Hausner ratio, rheometry and direct shear measurements, to determine the simulant’s handling and transportation behaviour. The magnetic properties were characterised to understand the magnetic susceptibility and remanence, which are crucial for dust mitigation strategies and electromagnetic interference assessments. Spectral reflectance was evaluated using spectrophotometry across relevant wavelengths, providing useful data for remote sensing calibration and surface composition analysis. It was shown that the simulants are good analogues for simulating adsorption, compression, and flow behaviour. However, their ability to represent magnetic and optical properties remains limited. The results from these investigations contribute to a more thorough understanding of the LX base simulants, enhancing their fidelity for scientific research.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106189"},"PeriodicalIF":1.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020372","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 : 2025-08-23DOI: 10.1016/j.pss.2025.106169
Andrea Apuzzo , Alessandro Frigeri , Francesco Salvini , Jeremy Brossier , Maria Cristina De Sanctis , Francesca Altieri , Gene Walter Schmidt , Ma_MISS team
The Rosalind Franklin rover of the European Space Agency’s ExoMars program is going to land at Oxia Planum, Mars after its launch scheduled in 2030. The mission aims to look for evidence of past and present life on Mars. The presence of fractured rocks at the landing site is of interest to the astrobiological goal of the mission because fractures represent conduits that could facility circulation of fluids. Our study is devoted to observing the orientations of the fractures and to investigate their possible origin by single or multiple processes. We first selected 50 regions of interest (ROIs) in areas of pronounced fracturing, using images from the High-Resolution Imaging Science Experiment (HiRISE) as a basemap. We then analysed the orientation of the fractures and how it varied with length. Statistical analysis shows that fractures predominantly have an E-W orientation, especially in longer fractures, while shorter fractures have a more random pattern. These orientation trends suggest a geological history influenced primarily by both hydrofracturing and tectonic processes. The preferred orientation, which is consistent with north-south tectonic shortening structures documented in the vicinity of the region, is likely to reflect a regional tectonic event between 3.7 and 4.0 billion years ago. The origin of the fractures may have promoted the migration of subsurface fluids through the fractured bedrock, potentially creating habitable conditions for microbial life. Our first study on fractures supports other studies on the geology of the ancient terrains at Oxia Planum, which hides a complex geologic history needing to be unravelled from different perspectives.
{"title":"Directional Analysis of Fractures at ESA’s Rosalind Franklin landing site, Oxia Planum, Mars","authors":"Andrea Apuzzo , Alessandro Frigeri , Francesco Salvini , Jeremy Brossier , Maria Cristina De Sanctis , Francesca Altieri , Gene Walter Schmidt , Ma_MISS team","doi":"10.1016/j.pss.2025.106169","DOIUrl":"10.1016/j.pss.2025.106169","url":null,"abstract":"<div><div>The Rosalind Franklin rover of the European Space Agency’s ExoMars program is going to land at Oxia Planum, Mars after its launch scheduled in 2030. The mission aims to look for evidence of past and present life on Mars. The presence of fractured rocks at the landing site is of interest to the astrobiological goal of the mission because fractures represent conduits that could facility circulation of fluids. Our study is devoted to observing the orientations of the fractures and to investigate their possible origin by single or multiple processes. We first selected 50 regions of interest (ROIs) in areas of pronounced fracturing, using images from the High-Resolution Imaging Science Experiment (HiRISE) as a basemap. We then analysed the orientation of the fractures and how it varied with length. Statistical analysis shows that fractures predominantly have an E-W orientation, especially in longer fractures, while shorter fractures have a more random pattern. These orientation trends suggest a geological history influenced primarily by both hydrofracturing and tectonic processes. The preferred orientation, which is consistent with north-south tectonic shortening structures documented in the vicinity of the region, is likely to reflect a regional tectonic event between 3.7 and 4.0 billion years ago. The origin of the fractures may have promoted the migration of subsurface fluids through the fractured bedrock, potentially creating habitable conditions for microbial life. Our first study on fractures supports other studies on the geology of the ancient terrains at Oxia Planum, which hides a complex geologic history needing to be unravelled from different perspectives.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"267 ","pages":"Article 106169"},"PeriodicalIF":1.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907006","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 : 2025-08-16DOI: 10.1016/j.pss.2025.106178
Brian P. Murphy , Cyrielle Opitom , Colin Snodgrass , Sophie E. Deam , Léa Ferellec , Matthew Knight , Vincent Okoth , Bin Yang
We present VLT/MUSE observations of comet 67P/Churyumov-Gerasimenko during its 2021 perihelion passage, from which we generated simultaneous maps of dust, [OI], C, NH, and CN comae across 12 pre- and post-perihelion epochs. These maps reveal the evolutionary and compositional trends of 67P’s coma and further enrich the context and findings of ESA’s Rosetta mission. Dust and gas species displayed distinct structures, where NH and CN signals were uniquely associated with known dust fans, raising the question of possible correlation to the dust and contributions of extended sources. Localised fitted NH scale lengths were 1.5-1.9 larger than those fitted for the rest of the coma, which is consistent with an extended source component for northern pre-perihelion emissions. In the southern hemisphere, CN was correlated with a prominent and sharp dust structure, potentially revealing an extended source origin via larger dust particles that preserve the CN parent species, as evidenced by higher spectral slopes in the region. Gas maps depicted two distinct evolutionary regimes: (1) evolving HO ([OI]1D) and C emissions driven by nucleus sublimation and subsolar insolation, and (2) stable NH and CN emissions associated with seasonal dynamics and possible distributed sources. Dust spectral slope maps revealed spectral slope trends consistent with Rosetta findings, while green/red [OI] ratios generally indicate a coma dominated by HO.
{"title":"Recent Chemo-morphological coma evolution of comet 67P/Churyumov–Gerasimenko","authors":"Brian P. Murphy , Cyrielle Opitom , Colin Snodgrass , Sophie E. Deam , Léa Ferellec , Matthew Knight , Vincent Okoth , Bin Yang","doi":"10.1016/j.pss.2025.106178","DOIUrl":"10.1016/j.pss.2025.106178","url":null,"abstract":"<div><div>We present VLT/MUSE observations of comet 67P/Churyumov-Gerasimenko during its 2021 perihelion passage, from which we generated simultaneous maps of dust, [OI], C<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, NH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, and CN comae across 12 pre- and post-perihelion epochs. These maps reveal the evolutionary and compositional trends of 67P’s coma and further enrich the context and findings of ESA’s Rosetta mission. Dust and gas species displayed distinct structures, where NH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and CN signals were uniquely associated with known dust fans, raising the question of possible correlation to the dust and contributions of extended sources. Localised fitted NH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> scale lengths were 1.5-1.9<span><math><mo>×</mo></math></span> larger than those fitted for the rest of the coma, which is consistent with an extended source component for northern pre-perihelion emissions. In the southern hemisphere, CN was correlated with a prominent and sharp dust structure, potentially revealing an extended source origin via larger dust particles that preserve the CN parent species, as evidenced by higher spectral slopes in the region. Gas maps depicted two distinct evolutionary regimes: (1) evolving H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O ([OI]<sup>1</sup>D) and C<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> emissions driven by nucleus sublimation and subsolar insolation, and (2) stable NH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and CN emissions associated with seasonal dynamics and possible distributed sources. Dust spectral slope maps revealed spectral slope trends consistent with Rosetta findings, while green/red [OI] ratios generally indicate a coma dominated by H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"268 ","pages":"Article 106178"},"PeriodicalIF":1.7,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989518","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 : 2025-08-12DOI: 10.1016/j.pss.2025.106182
Niklas Grimmich , Adriana Settino , Heidi Katariina Nykyri , Martin Owain Archer , Kevin-Alexander Blasl , Adrian Pöppelwerth , Rumi Nakamura , Ferdinand Plaschke
Across the Earth’s magnetopause, unless the magnetic fields stabilise the boundary, the velocity shear between the magnetospheric plasma and the shocked plasma of the solar wind can lead to the Kelvin–Helmholtz instability. This instability can develop into large-scale surface waves and vortices at the magnetopause, causing the different plasma regions to mix, which plays an important role in the transfer of energy across the magnetopause. We know from spacecraft observations and simulations that the way Kelvin–Helmholtz waves grow and evolve can be different at dawn and dusk. However, very few studies have directly observed this phenomenon on both flanks of the magnetopause simultaneously, nor have they provided a consistent explanation for the question of symmetrical or asymmetrical dawn–dusk growth of the waves. By combining measurements from the THEMIS and Cluster missions, we can report here on an event where such a simultaneous observation of the Kelvin–Helmholtz waves is possible.
For this event, we investigate and compare the typical wave parameters and the plasma mixing on the two flanks. Our results suggest an asymmetric evolution of the Kelvin–Helmholtz waves at dawn and dusk. Comparing these results with previous studies of simultaneously observed events and linking them to solar wind conditions further shows that this asymmetric growth seems to occur during the Parker spiral IMF, but probably only if the magnetic fields are strong enough to effectively stabilise the boundary at the dusk flank due to field line draping.
{"title":"Comparison of Kelvin–Helmholtz waves observed simultaneously at the dawn and dusk flanks of the Earth’s magnetopause","authors":"Niklas Grimmich , Adriana Settino , Heidi Katariina Nykyri , Martin Owain Archer , Kevin-Alexander Blasl , Adrian Pöppelwerth , Rumi Nakamura , Ferdinand Plaschke","doi":"10.1016/j.pss.2025.106182","DOIUrl":"10.1016/j.pss.2025.106182","url":null,"abstract":"<div><div>Across the Earth’s magnetopause, unless the magnetic fields stabilise the boundary, the velocity shear between the magnetospheric plasma and the shocked plasma of the solar wind can lead to the Kelvin–Helmholtz instability. This instability can develop into large-scale surface waves and vortices at the magnetopause, causing the different plasma regions to mix, which plays an important role in the transfer of energy across the magnetopause. We know from spacecraft observations and simulations that the way Kelvin–Helmholtz waves grow and evolve can be different at dawn and dusk. However, very few studies have directly observed this phenomenon on both flanks of the magnetopause simultaneously, nor have they provided a consistent explanation for the question of symmetrical or asymmetrical dawn–dusk growth of the waves. By combining measurements from the THEMIS and Cluster missions, we can report here on an event where such a simultaneous observation of the Kelvin–Helmholtz waves is possible.</div><div>For this event, we investigate and compare the typical wave parameters and the plasma mixing on the two flanks. Our results suggest an asymmetric evolution of the Kelvin–Helmholtz waves at dawn and dusk. Comparing these results with previous studies of simultaneously observed events and linking them to solar wind conditions further shows that this asymmetric growth seems to occur during the Parker spiral IMF, but probably only if the magnetic fields are strong enough to effectively stabilise the boundary at the dusk flank due to field line draping.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"267 ","pages":"Article 106182"},"PeriodicalIF":1.7,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867090","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 : 2025-08-05DOI: 10.1016/j.pss.2025.106139
Da Li , Yonghua Jiang , Jingyin Wang , Shaodong Wei , Guo Zhang , Huilong Wang
In Earth observation and planetary exploration missions, high-precision geolocation through remote sensing is crucial. However, dynamic systematic errors in satellite imagery and ancillary flight data, arising from sensor limitation and measurement technology, challenge traditional correction methods such as orientation image model and bias compensation model. This study proposes a piecewise bias matrix compensation method to improve the geolocation accuracy of linear pushbroom cameras by effectively eliminating dynamic systematic errors. The method focuses on detect orientation point exposure time utilizing the distribution characteristics of the reprojection residuals caused by dynamic system errors. This is accomplished through a stepwise strategy involving residual point cloud thinning and iterative end-point fitting algorithms, which automatically divide the sub-compensation model. Furthermore, considering the stability of the satellite’s flight attitude, a Lagrange interpolation method is introduced in the piecewise bias matrix compensation model, enhancing the internal consistency and absolute accuracy in the geometric positioning process of the optical linear pushbroom satellite. A comparison of the initial camera positioning results in the experimental dataset revealed that the reprojected errors of conjugate points in the MEX-HRSC can now achieve sub-pixel accuracy, with a maximum root mean square error of 0.54 pixels; the reprojected errors of GCPs in the XX-18 can now achieve sub-pixel accuracy, with a maximum root mean square error of 0.80 pixels. Additionally, building upon the elimination of dynamic systematic errors, this study constructs high spatial resolution DTMs of the Martian surface using high-resolution stereo imagery from the MEX-HRSC. These techniques and methods result in the intersection of corresponding rays in stereo pairs, which is crucial for subsequent 3D reconstruction.
{"title":"A generic compensation method for dynamic systematic errors in the geolocation of linear pushbroom satellite imagery","authors":"Da Li , Yonghua Jiang , Jingyin Wang , Shaodong Wei , Guo Zhang , Huilong Wang","doi":"10.1016/j.pss.2025.106139","DOIUrl":"10.1016/j.pss.2025.106139","url":null,"abstract":"<div><div>In Earth observation and planetary exploration missions, high-precision geolocation through remote sensing is crucial. However, dynamic systematic errors in satellite imagery and ancillary flight data, arising from sensor limitation and measurement technology, challenge traditional correction methods such as orientation image model and bias compensation model. This study proposes a piecewise bias matrix compensation method to improve the geolocation accuracy of linear pushbroom cameras by effectively eliminating dynamic systematic errors. The method focuses on detect orientation point exposure time utilizing the distribution characteristics of the reprojection residuals caused by dynamic system errors. This is accomplished through a stepwise strategy involving residual point cloud thinning and iterative end-point fitting algorithms, which automatically divide the sub-compensation model. Furthermore, considering the stability of the satellite’s flight attitude, a Lagrange interpolation method is introduced in the piecewise bias matrix compensation model, enhancing the internal consistency and absolute accuracy in the geometric positioning process of the optical linear pushbroom satellite. A comparison of the initial camera positioning results in the experimental dataset revealed that the reprojected errors of conjugate points in the MEX-HRSC can now achieve sub-pixel accuracy, with a maximum root mean square error of 0.54 pixels; the reprojected errors of GCPs in the XX-18 can now achieve sub-pixel accuracy, with a maximum root mean square error of 0.80 pixels. Additionally, building upon the elimination of dynamic systematic errors, this study constructs high spatial resolution DTMs of the Martian surface using high-resolution stereo imagery from the MEX-HRSC. These techniques and methods result in the intersection of corresponding rays in stereo pairs, which is crucial for subsequent 3D reconstruction.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"267 ","pages":"Article 106139"},"PeriodicalIF":1.7,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144842496","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 : 2025-08-05DOI: 10.1016/j.pss.2025.106181
R.S. Garcia , E. Fernández-Lajús , R.P. Di Sisto , R.A. Gil-Hutton
Comet 12P/Pons-Brooks, a Halley-type comet with a 71-year orbital period, was first discovered in 1812. It follows a highly inclined trajectory, originating from just beyond Neptune’s orbit. Ground-based observations have shown that the comet exhibited activity at a heliocentric distance of 11 au during its approach to the Sun. Numerous studies have since focused on its behavior, particularly its pre-perihelion outbursts, which have provided valuable insights into its dynamic and volatile nature.
This study examines the dust behavior of 12P following its perihelion passage. Using the 0.6 m Helen Sawyer Hogg telescope at the Complejo Astronómico El Leoncito (CASLEO), a series of images were captured between May and June 2024 using broadband I, R, and V filters. Morphological, photometric, and numerical analyses were performed to investigate the comet’s dust characteristics. Enhanced imaging revealed two active regions within an isotropic coma, which contributed to its distinctive “devil comet” appearance. Photometric analysis, based on the magnitudes and dust production rate from the parameter, indicated ordinary dust behavior, with no characteristic outbursts observed.
To gain further insights into 12P’s dust behavior, the data were fitted to a new theoretical model for studying dust in comets. This model suggests that the dust coma primarily consisted of large particles emitted from two high-latitude active areas at a velocity of approximately , assuming a rotation period of 57 h.
12P/庞斯-布鲁克斯彗星是一颗轨道周期为71年的哈雷彗星，于1812年首次被发现。它遵循一个高度倾斜的轨道，起源于海王星的轨道之外。地面观测表明，这颗彗星在接近太阳的过程中，在距太阳11天文单位的日心距离处表现出活动。从那以后，许多研究都集中在它的行为上，特别是它在近日点前的爆发，这为它的动态和不稳定的本质提供了有价值的见解。这项研究考察了12P经过近日点后的尘埃行为。利用位于Astronómico El Leoncito （CASLEO）的0.6米Helen Sawyer Hogg望远镜，在2024年5月至6月期间使用宽带I， R和V滤波器捕获了一系列图像。形态学、光度学和数值分析研究了这颗彗星的尘埃特征。增强成像显示，在一个各向同性的彗发中有两个活跃区域，这导致了它独特的“魔鬼彗星”外观。光度分析，根据A（0°）fρ参数的星等和尘埃产生率，表明普通的尘埃行为，没有观察到特征爆发。为了进一步了解12P的尘埃行为，这些数据被用于研究彗星尘埃的新理论模型。该模型表明，尘埃昏迷主要由两个高纬度活动区域以大约409ms−1的速度发射的大颗粒组成，假设旋转周期为57 h。
{"title":"Comet 12P/Pons-Brooks: Dust properties","authors":"R.S. Garcia , E. Fernández-Lajús , R.P. Di Sisto , R.A. Gil-Hutton","doi":"10.1016/j.pss.2025.106181","DOIUrl":"10.1016/j.pss.2025.106181","url":null,"abstract":"<div><div>Comet 12P/Pons-Brooks, a Halley-type comet with a 71-year orbital period, was first discovered in 1812. It follows a highly inclined trajectory, originating from just beyond Neptune’s orbit. Ground-based observations have shown that the comet exhibited activity at a heliocentric distance of 11 au during its approach to the Sun. Numerous studies have since focused on its behavior, particularly its pre-perihelion outbursts, which have provided valuable insights into its dynamic and volatile nature.</div><div>This study examines the dust behavior of 12P following its perihelion passage. Using the 0.6 m Helen Sawyer Hogg telescope at the Complejo Astronómico El Leoncito (CASLEO), a series of images were captured between May and June 2024 using broadband I, R, and V filters. Morphological, photometric, and numerical analyses were performed to investigate the comet’s dust characteristics. Enhanced imaging revealed two active regions within an isotropic coma, which contributed to its distinctive “devil comet” appearance. Photometric analysis, based on the magnitudes and dust production rate from the <span><math><mrow><mi>A</mi><mrow><mo>(</mo><mn>0</mn><mo>°</mo><mo>)</mo></mrow><mi>f</mi><mi>ρ</mi></mrow></math></span> parameter, indicated ordinary dust behavior, with no characteristic outbursts observed.</div><div>To gain further insights into 12P’s dust behavior, the data were fitted to a new theoretical model for studying dust in comets. This model suggests that the dust coma primarily consisted of large particles emitted from two high-latitude active areas at a velocity of approximately <span><math><mrow><mn>409</mn><mspace></mspace><msup><mrow><mtext>ms</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>, assuming a rotation period of 57 h.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"267 ","pages":"Article 106181"},"PeriodicalIF":1.7,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867091","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 : 2025-07-23DOI: 10.1016/j.pss.2025.106167
Debashis Chatterjee , Prithwish Ghosh
This study demonstrates the critical need for circular data analysis in interpreting meteor impact locations on Venus. Traditional linear methods need to be improved to capture the cyclic nature of these data. We can better identify patterns and trends using specialized circular data techniques, enhancing our understanding of the mechanisms behind meteor impacts. By employing specialized statistical techniques that capture the cyclic nature of angular data, our analysis included Watson’s test at a 0.05 significance level, showing that the Venus surface crater dataset’s location parameters and solar elevations conform to a Von Mises distribution, while daytime and nighttime solar elevations do not. Using Bayesian Information Criterion (BIC) scores, we also determine that a two-component mixture of Fisher–von Mises distributions best models the spatial distribution of impact craters. These findings enhance our understanding of meteor impact processes on Venus and highlight the advantages of applying maximum-entropy directional models to planetary science.
{"title":"On the directional nature of the fall of celestial objects on the surface of Venus","authors":"Debashis Chatterjee , Prithwish Ghosh","doi":"10.1016/j.pss.2025.106167","DOIUrl":"10.1016/j.pss.2025.106167","url":null,"abstract":"<div><div>This study demonstrates the critical need for circular data analysis in interpreting meteor impact locations on Venus. Traditional linear methods need to be improved to capture the cyclic nature of these data. We can better identify patterns and trends using specialized circular data techniques, enhancing our understanding of the mechanisms behind meteor impacts. By employing specialized statistical techniques that capture the cyclic nature of angular data, our analysis included Watson’s test at a 0.05 significance level, showing that the Venus surface crater dataset’s location parameters and solar elevations conform to a Von Mises distribution, while daytime and nighttime solar elevations do not. Using Bayesian Information Criterion (BIC) scores, we also determine that a two-component mixture of Fisher–von Mises distributions best models the spatial distribution of impact craters. These findings enhance our understanding of meteor impact processes on Venus and highlight the advantages of applying maximum-entropy directional models to planetary science.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"266 ","pages":"Article 106167"},"PeriodicalIF":1.7,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767142","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 : 2025-07-22DOI: 10.1016/j.pss.2025.106180
Jayanta Kumar Pati , Anuj Kumar Singh , Shivanshu Dwivedi
Bolide impacts are associated with enormous amount of kinetic energy which transforms into humongous shock pressures (∼100 GPa) and temperatures (up to 20,000 °C) on the planetary surfaces. These extreme conditions result in unique shock features that are routinely used as diagnostic evidence to confirm the meteorite impact origin of a structure. Occurrence of diaplectic glass pseudomorphing various minerals is one of the unequivocal evidences of shock metamorphism. Similarly, complete rock melting requires pressure in the excess of 60 GPa; however, the melting processes are not well constrained and remain ambiguous. The present study focuses on shock-induced melting of a quartzo-feldspathic lithic clast within an impact melt breccia sample from the Dhala structure, India. Multiple felsic melt stringers and a silicic melt (similar to lechatelierite) lense were observed across the clast, displaying a linear mixing trend between K-feldspar and silica. The occurrences of planar deformation features in quartz, melt clasts, spherules, and traces of coesite indicate characteristics of shock metamorphism. The presence of coesite (a high-pressure silica polymorph), formed during shock pressure release from the silica melt, was verified through Raman spectroscopy. Compositions of felsic melt stringers seem to mimic eutectic melting similar to a synthetic K2O-Al2O3-SiO2 system suggesting the dominant role of eutectic type punctuated melting rather than instantaneous melt behaviour. This pattern contrasts with an immediate, widespread melting often reported in impactites worldwide.
{"title":"A shocked lithic clast with compositionally contrasting melt domains in the impact melt breccia-a first report from the Dhala impact structure, India","authors":"Jayanta Kumar Pati , Anuj Kumar Singh , Shivanshu Dwivedi","doi":"10.1016/j.pss.2025.106180","DOIUrl":"10.1016/j.pss.2025.106180","url":null,"abstract":"<div><div>Bolide impacts are associated with enormous amount of kinetic energy which transforms into humongous shock pressures (∼100 GPa) and temperatures (up to 20,000 °C) on the planetary surfaces. These extreme conditions result in unique shock features that are routinely used as diagnostic evidence to confirm the meteorite impact origin of a structure. Occurrence of diaplectic glass pseudomorphing various minerals is one of the unequivocal evidences of shock metamorphism. Similarly, complete rock melting requires pressure in the excess of 60 GPa; however, the melting processes are not well constrained and remain ambiguous. The present study focuses on shock-induced melting of a quartzo-feldspathic lithic clast within an impact melt breccia sample from the Dhala structure, India. Multiple felsic melt stringers and a silicic melt (similar to lechatelierite) lense were observed across the clast, displaying a linear mixing trend between K-feldspar and silica. The occurrences of planar deformation features in quartz, melt clasts, spherules, and traces of coesite indicate characteristics of shock metamorphism. The presence of coesite (a high-pressure silica polymorph), formed during shock pressure release from the silica melt, was verified through Raman spectroscopy. Compositions of felsic melt stringers seem to mimic eutectic melting similar to a synthetic K<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub> system suggesting the dominant role of eutectic type punctuated melting rather than instantaneous melt behaviour. This pattern contrasts with an immediate, widespread melting often reported in impactites worldwide.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"266 ","pages":"Article 106180"},"PeriodicalIF":1.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771267","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 : 2025-07-19DOI: 10.1016/j.pss.2025.106179
Grace Richards , Richárd Rácz , Sándor T.S. Kovács , Victoria Pearson , Geraint Morgan , Manish R. Patel , Simon Sheridan , Duncan V. Mifsud , Béla Sulik , Sándor Biri , Nigel J. Mason , Robert W. McCullough , Zoltán Juhász
Saturn's magnetosphere contains trapped plasma and energetic charged particles which constantly irradiate the surface of Enceladus. In this study, we exposed Enceladean surface ice analogues containing H2O, CO2, CH4, and NH3 to water-group ions (e.g., O+, O3+, OH+, and H2O+) having energies between 10 and 45 keV with the aim of exploring the chemical evolution of these ices and characterising the extent to which the surface material on Enceladus is weathered by Saturn's radiation environment. Each irradiation process was monitored in situ using Fourier-transform mid-infrared transmission absorption spectroscopy, and post-irradiative warming of the ices was performed to better characterise complex organic molecules formed as a result of the mobilisation of radiolytically generated radicals. Irradiation resulted in the formation of CO, OCN−, and NH4+ in all experiments, and the radiolytic formation of formamide, acetylene, acetaldehyde, and hydroxymethyl radicals was also tentatively suggested in most experiments. Post-irradiative warming of the ices resulted in the formation of carbamic acid, ammonium carbamate, and an alcohol species. Although many of these products have not been previously observed on Enceladus' surface, some have been detected in Enceladus' plumes. Since our results demonstrate that the radiolytic formation of these molecules can occur over timescales similar to the exposure times of plume and surface material to magnetospheric radiation, questions must be raised as to whether such material originates directly from the subsurface ocean or is instead formed within the radiation-rich space environment.
{"title":"Water-group ion irradiation studies of Enceladus ice analogues: Can radiolysis account for material in and around the south polar plume?","authors":"Grace Richards , Richárd Rácz , Sándor T.S. Kovács , Victoria Pearson , Geraint Morgan , Manish R. Patel , Simon Sheridan , Duncan V. Mifsud , Béla Sulik , Sándor Biri , Nigel J. Mason , Robert W. McCullough , Zoltán Juhász","doi":"10.1016/j.pss.2025.106179","DOIUrl":"10.1016/j.pss.2025.106179","url":null,"abstract":"<div><div>Saturn's magnetosphere contains trapped plasma and energetic charged particles which constantly irradiate the surface of Enceladus. In this study, we exposed Enceladean surface ice analogues containing H<sub>2</sub>O, CO<sub>2</sub>, CH<sub>4</sub>, and NH<sub>3</sub> to water-group ions (e.g., O<sup>+</sup>, O<sup>3+</sup>, OH<sup>+</sup>, and H<sub>2</sub>O<sup>+</sup>) having energies between 10 and 45 keV with the aim of exploring the chemical evolution of these ices and characterising the extent to which the surface material on Enceladus is weathered by Saturn's radiation environment. Each irradiation process was monitored <em>in situ</em> using Fourier-transform mid-infrared transmission absorption spectroscopy, and post-irradiative warming of the ices was performed to better characterise complex organic molecules formed as a result of the mobilisation of radiolytically generated radicals. Irradiation resulted in the formation of CO, OCN<sup>−</sup>, and NH<sub>4</sub><sup>+</sup> in all experiments, and the radiolytic formation of formamide, acetylene, acetaldehyde, and hydroxymethyl radicals was also tentatively suggested in most experiments. Post-irradiative warming of the ices resulted in the formation of carbamic acid, ammonium carbamate, and an alcohol species. Although many of these products have not been previously observed on Enceladus' surface, some have been detected in Enceladus' plumes. Since our results demonstrate that the radiolytic formation of these molecules can occur over timescales similar to the exposure times of plume and surface material to magnetospheric radiation, questions must be raised as to whether such material originates directly from the subsurface ocean or is instead formed within the radiation-rich space environment.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"266 ","pages":"Article 106179"},"PeriodicalIF":1.7,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722323","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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