Pub Date : 2024-11-15DOI: 10.1016/j.pss.2024.105984
Takashi Ito , Arika Higuchi
We describe the result of our numerical orbit simulation which traces dynamical evolution of new comets coming from the Oort Cloud. We combine two dynamical models for this purpose. The first one is semi-analytic, and it models an evolving comet cloud under galactic tide and encounters with nearby stars. The second one numerically deals with planetary perturbation in the planetary region. Although our study does not include physical effects such as fading or disintegration of comets, we found that typical dynamical resident time of the comets in the planetary region is about years. We also found that the so-called planet barrier works when the initial orbital inclination of the comets is small. A numerical result concerning the temporary transition of the comets into other small body populations such as transneptunian objects or Centaurs is discussed.
{"title":"An estimate of resident time of the Oort Cloud new comets in planetary region","authors":"Takashi Ito , Arika Higuchi","doi":"10.1016/j.pss.2024.105984","DOIUrl":"10.1016/j.pss.2024.105984","url":null,"abstract":"<div><div>We describe the result of our numerical orbit simulation which traces dynamical evolution of new comets coming from the Oort Cloud. We combine two dynamical models for this purpose. The first one is semi-analytic, and it models an evolving comet cloud under galactic tide and encounters with nearby stars. The second one numerically deals with planetary perturbation in the planetary region. Although our study does not include physical effects such as fading or disintegration of comets, we found that typical dynamical resident time of the comets in the planetary region is about <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>8</mn></mrow></msup></mrow></math></span> years. We also found that the so-called planet barrier works when the initial orbital inclination of the comets is small. A numerical result concerning the temporary transition of the comets into other small body populations such as transneptunian objects or Centaurs is discussed.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"253 ","pages":"Article 105984"},"PeriodicalIF":1.8,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142650870","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 : 2024-11-15DOI: 10.1016/j.pss.2024.105995
Wolf-Stefan Benedix , Sebastian Hegler , Christoph Statz , Ronny Hahnel , Dirk Plettemeier , Valérie Ciarletti
While ground penetrating radars have been extensively researched on Earth, the high-resolution exploration and imaging of the shallow subsurface of celestial bodies in our solar system is still in its early stages, with only a handful of systems capable of the task.
Designing high-resolution radar systems can be a complex task due to the large frequency bandwidth required by the antennas to achieve high vertical resolution. The WISDOM GPR, as part of the 2028 ExoMars mission, is a highly capable and challenging instrument in this context, given its fully-polarimetric setup and mission constraints on the operating environment, robustness, as well as mass and size budget.
This paper outlines the development and characterization process of the WISDOM antenna assembly, which can serve as a model for future radar systems. Furthermore, it presents the results of the antenna characterization as the foundation for instrument calibration and optimal radar sounding outcomes.
{"title":"The ExoMars 2028 WISDOM antenna assembly: Description and characterization","authors":"Wolf-Stefan Benedix , Sebastian Hegler , Christoph Statz , Ronny Hahnel , Dirk Plettemeier , Valérie Ciarletti","doi":"10.1016/j.pss.2024.105995","DOIUrl":"10.1016/j.pss.2024.105995","url":null,"abstract":"<div><div>While ground penetrating radars have been extensively researched on Earth, the high-resolution exploration and imaging of the shallow subsurface of celestial bodies in our solar system is still in its early stages, with only a handful of systems capable of the task.</div><div>Designing high-resolution radar systems can be a complex task due to the large frequency bandwidth required by the antennas to achieve high vertical resolution. The WISDOM GPR, as part of the 2028 ExoMars mission, is a highly capable and challenging instrument in this context, given its fully-polarimetric setup and mission constraints on the operating environment, robustness, as well as mass and size budget.</div><div>This paper outlines the development and characterization process of the WISDOM antenna assembly, which can serve as a model for future radar systems. Furthermore, it presents the results of the antenna characterization as the foundation for instrument calibration and optimal radar sounding outcomes.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"253 ","pages":"Article 105995"},"PeriodicalIF":1.8,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142650871","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 : 2024-11-10DOI: 10.1016/j.pss.2024.105998
А.T. Basilevsky , S.S. Krasilnikov , Yuan Li
The photogeologic analysis of the ShadowCam images of the permanently shadowed floor and lower parts of inner slopes of the near-polar lunar crater Shoemaker confirmed the conclusion of Basilevsky and Li (2024)that the surface morphology of the Shoemaker floor is dominated by a population of small (D < 1 km) craters. Future studies hopefully will allow to describe the morphology and morphometry (especially d/D) of the decameter-scale craters seen in the ShadowCam images. The surface of the lower parts of inners slopes of crater Shoemaker, which are permanently shadowed, has the “elephant hide” texture, that is also typical for normally illuminated slopes. So, most issues of the surface morphology were found to be identical or very close to those in normally illuminated regions of the Moon. The new finding in permanently shadowed areas is the presence of lobate-rimmed craters, whose morphology is probably indicative of water ice in the target material.
{"title":"Photogeological analysis of ShadowCam images of the permanently shadowed floor of lunar crater Shoemaker","authors":"А.T. Basilevsky , S.S. Krasilnikov , Yuan Li","doi":"10.1016/j.pss.2024.105998","DOIUrl":"10.1016/j.pss.2024.105998","url":null,"abstract":"<div><div>The photogeologic analysis of the ShadowCam images of the permanently shadowed floor and lower parts of inner slopes of the near-polar lunar crater Shoemaker confirmed the conclusion of Basilevsky and Li (2024)that the surface morphology of the Shoemaker floor is dominated by a population of small (D < 1 km) craters. Future studies hopefully will allow to describe the morphology and morphometry (especially d/D) of the decameter-scale craters seen in the ShadowCam images. The surface of the lower parts of inners slopes of crater Shoemaker, which are permanently shadowed, has the “elephant hide” texture, that is also typical for normally illuminated slopes. So, most issues of the surface morphology were found to be identical or very close to those in normally illuminated regions of the Moon. The new finding in permanently shadowed areas is the presence of lobate-rimmed craters, whose morphology is probably indicative of water ice in the target material.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"254 ","pages":"Article 105998"},"PeriodicalIF":1.8,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654042","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 : 2024-11-09DOI: 10.1016/j.pss.2024.105997
A. Tullo , C. Re , G. Cremonese , E. Martellato , R. La Grassa , N. Thomas
The present study analyses the potential of pansharpening algorithms for planetary exploration studies, testing their performance with the 4-band images from the Colour and Stereo Surface Imaging System (CaSSIS) aboard the Exomars 2016 Trace Grace Orbiter (TGO) using HiRISE images from the Mars Reconnaissance Orbiter (MRO) mission as the base. Due to the lack of suitable open-source tools, a suite of scripts was developed to improve alignment between images and enable different component substitution (CS) pansharpening algorithms. The tools developed were tested on a database of images encompassing several regions of Mars to explore its vast diversity in colours, tones, and textures. Then, the resulting images were investigated using spectral and structural performance indices, comparing the results with the source images and the colour information from the HiRISE central channels.
The results show that a substantial number of the tested algorithms are more than suitable for data enhancement, showing a considerable improvement in the structural characteristics of the images without sacrificing their spectral characteristics. In detail, the Gram-Schmidt method, widely used in terrestrial pansharpening, turns out to be the best compromise among the tested algorithms. Regarding the other tested algorithms, GIHS and the MMSE Brovey, a modified version of the classic Brovey, show the most significant increase in structural properties, while GHPF and GHPM show the interesting ability to maintain virtually unchanged spectral conditions of the multispectral source data.
In addition, the analysis reveals the applicability of pansharpening at a ground resolution increment up to 18 times, from 4.5 up to 0.25 m/px, a broader range than is usually used in traditional pansharpening.
{"title":"Performance evaluation of pansharpening for planetary exploration: A case study on the implementation of TGO CaSSIS with MRO HiRISE","authors":"A. Tullo , C. Re , G. Cremonese , E. Martellato , R. La Grassa , N. Thomas","doi":"10.1016/j.pss.2024.105997","DOIUrl":"10.1016/j.pss.2024.105997","url":null,"abstract":"<div><div>The present study analyses the potential of pansharpening algorithms for planetary exploration studies, testing their performance with the 4-band images from the Colour and Stereo Surface Imaging System (CaSSIS) aboard the Exomars 2016 Trace Grace Orbiter (TGO) using HiRISE images from the Mars Reconnaissance Orbiter (MRO) mission as the base. Due to the lack of suitable open-source tools, a suite of scripts was developed to improve alignment between images and enable different component substitution (CS) pansharpening algorithms. The tools developed were tested on a database of images encompassing several regions of Mars to explore its vast diversity in colours, tones, and textures. Then, the resulting images were investigated using spectral and structural performance indices, comparing the results with the source images and the colour information from the HiRISE central channels.</div><div>The results show that a substantial number of the tested algorithms are more than suitable for data enhancement, showing a considerable improvement in the structural characteristics of the images without sacrificing their spectral characteristics. In detail, the Gram-Schmidt method, widely used in terrestrial pansharpening, turns out to be the best compromise among the tested algorithms. Regarding the other tested algorithms, GIHS and the MMSE Brovey, a modified version of the classic Brovey, show the most significant increase in structural properties, while GHPF and GHPM show the interesting ability to maintain virtually unchanged spectral conditions of the multispectral source data.</div><div>In addition, the analysis reveals the applicability of pansharpening at a ground resolution increment up to 18 times, from 4.5 up to 0.25 m/px, a broader range than is usually used in traditional pansharpening.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"254 ","pages":"Article 105997"},"PeriodicalIF":1.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654041","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}
Halotrichite [FeAl2(SO4)4·22(H2O)] is a rare secondary sulfate mineral with its occurrence confined within the sulfide weathering zones. In the South Kerala Sedimentary Basin (SKSB) of SW India, halotrichite, here reported for the first time, is associated with an organic matter (OM)-rich carbonaceous clay layer. Field investigation revealed the prevalence of acid rock drainage (ARD) conditions similar to Martian analogue sites like Rio Tinto. The OM-layer is associated with pyrite forming substratum and Al-rich leachate associated with the Youngest Toba Tuff (YTT) cryptotephra layer. Oxidation of these units results in the formation of halotrichite, which is temporally restricted only to the dry season when the water table lowers and the OM-layer is exposed to air. X-Ray Diffraction (XRD) results for halotrichite show the presence of Al and Fe(II) sulfates. Energy Dispersive X-ray Spectroscopy (EDS) ruled out the existence of pickeringite, the Mg end-member of halotrichite-pickeringite series. XRD results for the OM-layer indicate the presence of kaolinite, quartz, goethite, and lepidocrocite. Hyperspectral analysis of the clay samples confirms that halotrichite is associated with goethite, lepidocrocite, kaolinite, and smectite. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the major constituent of the clay sample as kaolinite with traces of quartz, smectite, and OM. Raman spectrum of halotrichite shows the symmetric stretching vibration of SO42− bonded to Fe2+. Association of halotrichite with Fe, Al, and S-rich minerals is also inferred by the study of Raman spectrum of the host clay. Co-existence of halotrichite, goethite, lepidocrocite, and phyllosilicates in the study area is similar to the mineral assemblage found along the Rio Tinto River. On Mars, halotrichite is associated with the layered sulfate deposits, such as those in Valles Marineris and Meridiani Planum, and is categorized as a polyhydrated sulfate. Hence, this study on the halotrichite mineralization in the SKSB can supplement the attempts on deciphering the deposition and formation environment of similar mineralization on Mars.
光卤石[FeAl2(SO4)4-22(H2O)]是一种罕见的次生硫酸盐矿物，只出现在硫化物风化带中。在印度西南部的南喀拉拉邦沉积盆地（SKSB），光卤石首次与富含有机质（OM）的碳质粘土层伴生。实地调查显示，酸性岩石排水（ARD）条件与力拓等火星类似地点相似。OM 层与黄铁矿形成的基底层以及与最年轻的多巴凝灰岩（YTT）隐晶质层相关的富铝浸出液有关。这些单元的氧化作用会形成卤黄铁矿，而卤黄铁矿在时间上仅限于旱季，因为旱季时地下水位降低，OM 层暴露在空气中。光卤石的 X 射线衍射（XRD）结果显示存在铝和硫酸铁（II）。能量色散 X 射线光谱（EDS）排除了光卤石-黝帘石系列的镁末端成员黝帘石的存在。OM 层的 XRD 结果表明存在高岭石、石英、网纹石和鳞片石。粘土样品的高光谱分析证实，光卤石与网纹石、鳞片石、高岭石和直闪石相关联。傅立叶变换红外光谱（FTIR）分析表明，粘土样品的主要成分是高岭石，还有微量的石英、直闪石和 OM。光卤石的拉曼光谱显示了与 Fe2+ 结合的 SO42- 的对称伸缩振动。通过对主粘土拉曼光谱的研究，还可以推断出光卤石与富含铁、铝和 S 的矿物的关联。在研究区域，光卤石、网纹石、鳞片石和植硅酸盐共存，这与在力拓河沿岸发现的矿物组合相似。在火星上，光卤石与层状硫酸盐矿床有关，如海洋谷（Valles Marineris）和子午线（Meridiani Planum）的硫酸盐矿床，被归类为多水合硫酸盐。因此，对 SKSB 中光卤石成矿作用的研究可以补充对火星上类似成矿作用的沉积和形成环境的解密尝试。
{"title":"Formation of halotrichite in the South Kerala Sedimentary Basin, SW India: Implications for Martian paleo-environmental studies","authors":"Kannan J. Prakash , Libiya M. Varghese , P.B. Hiral , Suresh Evna , V.R. Rani , K.S. Sajinkumar , V.J. Rajesh , G.K. Indu , Sneha Mukherjee , J.K. Tomson","doi":"10.1016/j.pss.2024.105999","DOIUrl":"10.1016/j.pss.2024.105999","url":null,"abstract":"<div><div>Halotrichite [FeAl<sub>2</sub>(SO<sub>4</sub>)<sub>4</sub>·22(H<sub>2</sub>O)] is a rare secondary sulfate mineral with its occurrence confined within the sulfide weathering zones. In the South Kerala Sedimentary Basin (SKSB) of SW India, halotrichite, here reported for the first time, is associated with an organic matter (OM)-rich carbonaceous clay layer. Field investigation revealed the prevalence of acid rock drainage (ARD) conditions similar to Martian analogue sites like Rio Tinto. The OM-layer is associated with pyrite forming substratum and Al-rich leachate associated with the Youngest Toba Tuff (YTT) cryptotephra layer. Oxidation of these units results in the formation of halotrichite, which is temporally restricted only to the dry season when the water table lowers and the OM-layer is exposed to air. X-Ray Diffraction (XRD) results for halotrichite show the presence of Al and Fe(II) sulfates. Energy Dispersive X-ray Spectroscopy (EDS) ruled out the existence of pickeringite, the Mg end-member of halotrichite-pickeringite series. XRD results for the OM-layer indicate the presence of kaolinite, quartz, goethite, and lepidocrocite. Hyperspectral analysis of the clay samples confirms that halotrichite is associated with goethite, lepidocrocite, kaolinite, and smectite. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the major constituent of the clay sample as kaolinite with traces of quartz, smectite, and OM. Raman spectrum of halotrichite shows the symmetric stretching vibration of SO<sub>4</sub><sup>2−</sup> bonded to Fe<sup>2+</sup>. Association of halotrichite with Fe, Al, and S-rich minerals is also inferred by the study of Raman spectrum of the host clay. Co-existence of halotrichite, goethite, lepidocrocite, and phyllosilicates in the study area is similar to the mineral assemblage found along the Rio Tinto River. On Mars, halotrichite is associated with the layered sulfate deposits, such as those in Valles Marineris and Meridiani Planum, and is categorized as a polyhydrated sulfate. Hence, this study on the halotrichite mineralization in the SKSB can supplement the attempts on deciphering the deposition and formation environment of similar mineralization on Mars.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"254 ","pages":"Article 105999"},"PeriodicalIF":1.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654040","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 : 2024-10-22DOI: 10.1016/j.pss.2024.105985
Thomas Pierron, François Forget, Ehouarn Millour, Antoine Bierjon
Because of the high amount of dust in the Martian atmosphere, solar panels of landers and rovers on Mars get covered by dust in the course of their mission. This accumulation significantly decreases the available power over sols. During some missions, winds were able to blow the dust away. These ”dust cleaning events”, as they are called, were followed by an increase of the electrical current produced by the solar arrays. However, the Insight Lander solar panels were never cleaned and the mission died of dust accumulation. In order to better predict the evolution of available power produced by solar panels in the Martian conditions, this paper proposes a model of dust accumulation in which the solar flux under the accumulated dust layer is computed taking into account a full radiative transfer in the atmosphere and in the dust layer accumulated on the panel. This work uses several missions observation data to validate this model.
{"title":"Power attenuation of Martian rovers and landers solar panels due to dust deposition","authors":"Thomas Pierron, François Forget, Ehouarn Millour, Antoine Bierjon","doi":"10.1016/j.pss.2024.105985","DOIUrl":"10.1016/j.pss.2024.105985","url":null,"abstract":"<div><div>Because of the high amount of dust in the Martian atmosphere, solar panels of landers and rovers on Mars get covered by dust in the course of their mission. This accumulation significantly decreases the available power over sols. During some missions, winds were able to blow the dust away. These ”dust cleaning events”, as they are called, were followed by an increase of the electrical current produced by the solar arrays. However, the Insight Lander solar panels were never cleaned and the mission died of dust accumulation. In order to better predict the evolution of available power produced by solar panels in the Martian conditions, this paper proposes a model of dust accumulation in which the solar flux under the accumulated dust layer is computed taking into account a full radiative transfer in the atmosphere and in the dust layer accumulated on the panel. This work uses several missions observation data to validate this model.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"253 ","pages":"Article 105985"},"PeriodicalIF":1.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142551898","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 : 2024-10-11DOI: 10.1016/j.pss.2024.105983
Pamela Cambianica , Emanuele Simioni , Gabriele Cremonese , Silvia Bertoli , Elena Martellato , Alice Lucchetti , Maurizio Pajola , Cristina Re , Adriano Tullo , Matteo Massironi
Thermal models are essential for studying airless planetary surfaces, as the interaction between topography and thermophysical properties plays a crucial role in determining a surface’s response to localized illumination. Accurate temperature distribution calculations require a comprehensive investigation of sunlight scattering, a process that, despite its computational challenges, cannot be overlooked, especially when high resolution is necessary. Furthermore, thermal analysis is fundamental for assessing the stability of volatiles in polar regions. In this study, we introduce a novel approach by discretizing the Sun into 100 individual elements, allowing for a highly precise simulation of solar flux—an innovation crucial for accurately capturing temperature distributions in Mercury’s polar craters, given the planet’s proximity to the Sun. This level of discretization significantly enhances the accuracy of the thermal model, ensuring a more realistic depiction of how sunlight interacts with crater topography. We developed a dual-model approach that simulates both direct solar illumination and its scattering on two craters, Laxness and Fuller, located at Mercury’s north pole. The illumination and thermal model predict temperature distribution and heat transfer based on the material’s thermal properties and topography. The study examines the interaction between direct sunlight, causing localized heating, and scattered light, which influences the thermal response of surface materials. Detailed illumination maps and temperature profiles were generated over two Hermean years, revealing the significant impact of the self-heating effect on temperature distribution. The results show that specific regions experience indirect solar flux due to the craters’ morphology, particularly in permanently shadowed regions (PSRs) that are heated exclusively by scattered radiation. Maximum temperature profiles for the Laxness and Fuller craters show a substantial temperature increase within PSRs compared to areas exposed to direct illumination. However, while self-heating does not affect the stability of water ice in the Laxness crater, in the Fuller crater, a section within the radar-bright material reaches temperatures of up to 210 K, potentially threatening the stability of water ice. Further investigation with the onboard SIMBIO-SYS instrument on the BepiColombo mission will help to better understand the current state of these craters and their volatile deposits.
{"title":"The thermal impact of the self-heating effect on airless bodies. The case of Mercury’s north polar craters","authors":"Pamela Cambianica , Emanuele Simioni , Gabriele Cremonese , Silvia Bertoli , Elena Martellato , Alice Lucchetti , Maurizio Pajola , Cristina Re , Adriano Tullo , Matteo Massironi","doi":"10.1016/j.pss.2024.105983","DOIUrl":"10.1016/j.pss.2024.105983","url":null,"abstract":"<div><div>Thermal models are essential for studying airless planetary surfaces, as the interaction between topography and thermophysical properties plays a crucial role in determining a surface’s response to localized illumination. Accurate temperature distribution calculations require a comprehensive investigation of sunlight scattering, a process that, despite its computational challenges, cannot be overlooked, especially when high resolution is necessary. Furthermore, thermal analysis is fundamental for assessing the stability of volatiles in polar regions. In this study, we introduce a novel approach by discretizing the Sun into 100 individual elements, allowing for a highly precise simulation of solar flux—an innovation crucial for accurately capturing temperature distributions in Mercury’s polar craters, given the planet’s proximity to the Sun. This level of discretization significantly enhances the accuracy of the thermal model, ensuring a more realistic depiction of how sunlight interacts with crater topography. We developed a dual-model approach that simulates both direct solar illumination and its scattering on two craters, Laxness and Fuller, located at Mercury’s north pole. The illumination and thermal model predict temperature distribution and heat transfer based on the material’s thermal properties and topography. The study examines the interaction between direct sunlight, causing localized heating, and scattered light, which influences the thermal response of surface materials. Detailed illumination maps and temperature profiles were generated over two Hermean years, revealing the significant impact of the self-heating effect on temperature distribution. The results show that specific regions experience indirect solar flux due to the craters’ morphology, particularly in permanently shadowed regions (PSRs) that are heated exclusively by scattered radiation. Maximum temperature profiles for the Laxness and Fuller craters show a substantial temperature increase within PSRs compared to areas exposed to direct illumination. However, while self-heating does not affect the stability of water ice in the Laxness crater, in the Fuller crater, a section within the radar-bright material reaches temperatures of up to 210 K, potentially threatening the stability of water ice. Further investigation with the onboard SIMBIO-SYS instrument on the BepiColombo mission will help to better understand the current state of these craters and their volatile deposits.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"253 ","pages":"Article 105983"},"PeriodicalIF":1.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529567","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 : 2024-10-05DOI: 10.1016/j.pss.2024.105982
Mihail P. Petkov , Ryan P. Wilkerson , Gerald E. Voecks , Douglas L. Rickman , Jennifer E. Edmunson , Michael R. Effinger
Volatiles evolving from JSC-1A, NU-LHT-4M and CSM-LHT-1G lunar regolith simulants during in vacuo thermal processing were analyzed using mass spectrometry as a function of temperature. Two high-fidelity simulants, JSC-1A (mare) and NU-LHT-4M (highland), were compared to a newly developed CSM-LHT-1G highland simulant, modified to closely match lunar geochemistry. Large autogenous gas loads were observed for all investigated materials. Mineralogical knowledge was used to identify and attribute individual volatile species to reacting, transforming, or decomposing constituents (hydrates, carbonates, sulfates, sulfides, clays, etc.) of the respective regolith simulant in the self-generated gas environment. Cumulative mass losses for individual simulant components as a function of temperature were quantified using mass spectrometry in conjunction with thermogravimetric analysis. Investigation of the four components of CSM-LHT-1G – anorthosite, basalt, augite, and glass – aided the attribution of volatile species to specific compounds and their respective sources. The results showed significant decomposition of non-lunar phases present in the man-made regolith simulants below the typical glass crystallization temperatures, which paves the way to devising methods for enhancing the fidelity of the simulants. High gas loads and corrosive gases (HF and HCl) were recognized as potential hazards, pertaining to the development of large testbed facilities.
{"title":"Comparison of volatiles evolving from selected highland and mare lunar regolith simulants during vacuum sintering","authors":"Mihail P. Petkov , Ryan P. Wilkerson , Gerald E. Voecks , Douglas L. Rickman , Jennifer E. Edmunson , Michael R. Effinger","doi":"10.1016/j.pss.2024.105982","DOIUrl":"10.1016/j.pss.2024.105982","url":null,"abstract":"<div><div>Volatiles evolving from JSC-1A, NU-LHT-4M and CSM-LHT-1G lunar regolith simulants during <em>in vacuo</em> thermal processing were analyzed using mass spectrometry as a function of temperature. Two high-fidelity simulants, JSC-1A (mare) and NU-LHT-4M (highland), were compared to a newly developed CSM-LHT-1G highland simulant, modified to closely match lunar geochemistry. Large autogenous gas loads were observed for all investigated materials. Mineralogical knowledge was used to identify and attribute individual volatile species to reacting, transforming, or decomposing constituents (hydrates, carbonates, sulfates, sulfides, clays, etc.) of the respective regolith simulant in the self-generated gas environment. Cumulative mass losses for individual simulant components as a function of temperature were quantified using mass spectrometry in conjunction with thermogravimetric analysis. Investigation of the four components of CSM-LHT-1G – anorthosite, basalt, augite, and glass – aided the attribution of volatile species to specific compounds and their respective sources. The results showed significant decomposition of non-lunar phases present in the man-made regolith simulants below the typical glass crystallization temperatures, which paves the way to devising methods for enhancing the fidelity of the simulants. High gas loads and corrosive gases (HF and HCl) were recognized as potential hazards, pertaining to the development of large testbed facilities.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"252 ","pages":"Article 105982"},"PeriodicalIF":1.8,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423961","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 : 2024-09-25DOI: 10.1016/j.pss.2024.105981
I.E. Nadezhdina, A.E. Zubarev, N.A. Kozlova, N.A. Slodarzh, I.P. Karachevtseva
During the Juno Perijove 34 the JunoCam acquired four RGB images of Ganymede. These images and updated SPICE kernel for spacecraft's trajectories were used to refine previous 3D-control point network (CPN). As a result, 4954 control points were measured 22,098 times with a minimum of 2 and a maximum of 16 observations per point, based on the 302 best available images from all missions (Voyagers, Galileo and Juno). After adjustment more than 86% of points have accuracy better than 3 km (>97% - better than 5 km). A new libration value for Ganymede 18ʺ is obtained. This updated CPN was used for compiling a new Ganymede global mosaic to support the planning of observations within the JUICE mission. New detailed local DEMs were obtained by stereovectorization for Enki Catena and Tros crater regions. In the Enki chain, the ratio d/D of the depth of craters to their diameter ranges from 0.049 to 0.089 and correlates with the area types (dark or light).
{"title":"JunoPerijove 34: Update Ganymede 3D-control network and new DEMs study","authors":"I.E. Nadezhdina, A.E. Zubarev, N.A. Kozlova, N.A. Slodarzh, I.P. Karachevtseva","doi":"10.1016/j.pss.2024.105981","DOIUrl":"10.1016/j.pss.2024.105981","url":null,"abstract":"<div><div>During the Juno Perijove 34 the JunoCam acquired four RGB images of Ganymede. These images and updated SPICE kernel for spacecraft's trajectories were used to refine previous 3D-control point network (CPN). As a result, 4954 control points were measured 22,098 times with a minimum of 2 and a maximum of 16 observations per point, based on the 302 best available images from all missions (Voyagers, Galileo and Juno). After adjustment more than 86% of points have accuracy better than 3 km (>97% - better than 5 km). A new libration value for Ganymede 18ʺ is obtained. This updated CPN was used for compiling a new Ganymede global mosaic to support the planning of observations within the JUICE mission. New detailed local DEMs were obtained by stereovectorization for Enki Catena and Tros crater regions. In the Enki chain, the ratio d/D of the depth of craters to their diameter ranges from 0.049 to 0.089 and correlates with the area types (dark or light).</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"252 ","pages":"Article 105981"},"PeriodicalIF":1.8,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423822","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}
In the recent decade of astrobiological exploration of the Martian surface, there has been a shift from identifying habitable environments to finding markers indicative of biological activity. It requires a prior understanding of the physical and geochemical environment of the setting to decipher whether the conditions were conducive. Generally, quiescent surroundings of lacustrine basins are considered one of the best targets for the preservation of any biological signatures. However, due to logistical limitations, the geochemical information available is mostly restricted to small areas on the surficial level (or in the subsurface in case of layered deposits or impact craters) where sufficient satellite coverage is available and, in some areas, where rovers/landers have been deployed. In this context, terrestrial lacustrine basins offer valuable insights into the environment required for the formation of the minerals observed on the Martian surface.
This study was carried out within Sambhar Lake located in the arid/semiarid climatic zone within the Thar desert. It is a hypersaline playa that has undergone several cycles of desiccation and re-filling, sharing its climate-controlled history with that of several paleolakes on Mars. We conducted physicochemical analysis of the samples collected from the lake and its surrounding area and compared our results with samples from the Curiosity rover (at Gale crater) and to those of the studies carried out in basalt-rich parent settings of Iceland. Our results suggest that Sambhar Lake is a Na-Cl type brine with climate-driven hydrology. The shallow cores and rock samples indicated that the area is rich in evaporites. We propose that even the sites with different parent material may be crucial in understanding the geological evolution of paleolakes on Mars and that Sambhar is a great example to study tectono-geomorphic evolution and the climate-induced transition of a lacustrine basin to a playa. Additionally, the lake is also desirable to study extremophiles and their adaptation to changing environmental variables for future planetary missions, including but not limited to, Mars.
{"title":"Morphological, hydrogeochemical and sedimentological analysis of hypersaline Sambhar Lake, India: An analog to understand evaporitic paleolake basins on Mars","authors":"Deepali Singh , Priyadarshini Singh , Nidhi Roy , Saumitra Mukherjee","doi":"10.1016/j.pss.2024.105974","DOIUrl":"10.1016/j.pss.2024.105974","url":null,"abstract":"<div><div>In the recent decade of astrobiological exploration of the Martian surface, there has been a shift from identifying habitable environments to finding markers indicative of biological activity. It requires a prior understanding of the physical and geochemical environment of the setting to decipher whether the conditions were conducive. Generally, quiescent surroundings of lacustrine basins are considered one of the best targets for the preservation of any biological signatures. However, due to logistical limitations, the geochemical information available is mostly restricted to small areas on the surficial level (or in the subsurface in case of layered deposits or impact craters) where sufficient satellite coverage is available and, in some areas, where rovers/landers have been deployed. In this context, terrestrial lacustrine basins offer valuable insights into the environment required for the formation of the minerals observed on the Martian surface.</div><div>This study was carried out within Sambhar Lake located in the arid/semiarid climatic zone within the Thar desert. It is a hypersaline playa that has undergone several cycles of desiccation and re-filling, sharing its climate-controlled history with that of several paleolakes on Mars. We conducted physicochemical analysis of the samples collected from the lake and its surrounding area and compared our results with samples from the Curiosity rover (at Gale crater) and to those of the studies carried out in basalt-rich parent settings of Iceland. Our results suggest that Sambhar Lake is a Na-Cl type brine with climate-driven hydrology. The shallow cores and rock samples indicated that the area is rich in evaporites. We propose that even the sites with different parent material may be crucial in understanding the geological evolution of paleolakes on Mars and that Sambhar is a great example to study tectono-geomorphic evolution and the climate-induced transition of a lacustrine basin to a playa. Additionally, the lake is also desirable to study extremophiles and their adaptation to changing environmental variables for future planetary missions, including but not limited to, Mars.</div></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"252 ","pages":"Article 105974"},"PeriodicalIF":1.8,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311089","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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