Article
Astronomy & Astrophysics
Shoko Imamura, Yasuhito Sekine, Yu Maekawa, Hiroyuki Kurokawa, Takenori Sasaki
Summary: Highly concentrated liquid brine formed repeatedly through ice melting and/or deliquescence has the potential to generate characteristic geomorphic features on Mars. However, the dynamics of repeated brine flows have received little investigation. This study conducted laboratory experiments to investigate the flow behavior of brine upon repeated cycles of seepage and drying in glass beads on slopes. The results suggest that precipitated salts play a role in the formation of transient surface flows on Mars, even at low seepage rates.
Article
Astronomy & Astrophysics
Leszek Czechowski, Natalia Zalewska, Anita Zambrowska, Marta Ciazela, Piotr Witek, Jan Kotlarz
Summary: This paper investigates a small region in Chryse Planitia where several subparallel chains of cones are observed. The authors propose that most of these cones are formed by outgassing of Martian regolith due to a decrease in atmospheric pressure. Magma heating may also play a role, but its impact is limited. The subparallel chains of cones can be formed above various linear structures, such as aquifers, outcrops, fissures, and heat sources. Thermal advection could transport heat and facilitate the rapid loss of volatiles. The researchers also suggest that similar processes may have occurred in other regions of Chryse Planitia based on their observation of similar structures.
Article
Astronomy & Astrophysics
Chloe B. Beddingfield, Jeffrey E. Moersch, Harry Y. McSween
Summary: The text discusses the study of impact crater rims on Mars and finds that the thermal inertia values of crater rims are related to their degradation state, which can be used to estimate the relative age and degradation level of impact craters.
Article
Astronomy & Astrophysics
Naofumi Takaki, Yuichiro Cho, Tomokatsu Morota, Eri Tatsumi, Rie Honda, Shingo Kameda, Yasuhiro Yokota, Naoya Sakatani, Toru Kouyama, Masahiko Hayakawa, Moe Matsuoka, Manabu Yamada, Chikatoshi Honda, Hidehiko Suzuki, Kazuo Yoshioka, Kazunori Ogawa, Hirotaka Sawada, Patrick Michel, Seiji Sugita
Summary: Understanding the geological modification processes on asteroids is crucial for understanding their surface evolution. Recent experiments have shown that seismic shaking may not play a significant role in modifying the geology of asteroids. Further analysis indicates that seismic shaking models cannot explain the distribution of craters on small asteroids.
Article
Astronomy & Astrophysics
Yann Leseigneur, Mathieu Vincendon
Summary: While dust is an important parameter of Mars climate, its behavior can be erratic and is notably related to Global Dust Storms. Long-term monitoring of dust dynamics is required to better understand surface-atmosphere dust exchanges on Mars. A new method based on OMEGA NIR dataset is presented to detect atmospheric dust as a function of space and time.
Article
Astronomy & Astrophysics
Kierra A. Wilk, Janice L. Bishop, Catherine M. Weitz, Mario Parente, Arun M. Saranathan, Yuki Itoh, Christoph Gross, Jessica Flahaut, Frank Seelos
Summary: This study investigates the unique spectral features of materials in the Ius Chasma region on Mars, focusing on the Geryon Montes area. The presence of a distinct doublet feature at the border of phyllosilicate-bearing and sulfate-bearing regions is identified and analyzed using hyperspectral images. The findings suggest that these unique alteration phases may have formed through acid alteration of ancient smectites.
Article
Astronomy & Astrophysics
Mikhail A. Kreslavsky, Anastasia Yu Zharkova, James W. Head, Maria Gritsevich
Summary: Boulders on Mercury are primarily associated with fresh impact craters hundreds of meters in diameter or larger, and are about 30 times less abundant compared to boulders on the lunar highlands. Possible factors contributing to the relative rarity of boulders on Mercury include higher thermal stresses, rapid material fatigue, and a thicker regolith.
Article
Astronomy & Astrophysics
M. Angrisani, E. Palomba, A. Longobardo, A. Raponi, F. Dirri, C. Gisellu
Summary: In this study, the composition and particle size of V-type asteroids were investigated through spectroscopic analysis. The researchers found possible chronological links between impact events on Vesta and the formation of V-type families. The results also suggest the presence of other basaltic parent bodies apart from Vesta.
Article
Astronomy & Astrophysics
Peixin Du, Shun Wang, Peng Yuan, Jiacheng Liu, Dong Liu, Haozhe Guo, Xinyi Xiang, Xiaolong Guo
Summary: Allophane is a widely present soil mineral on Earth and potentially on Mars, with adsorption and environmental indication functions. The structure and formation processes of allophane have been studied through hydrothermal synthesis and characterization using advanced techniques. Variations in the initial Si/Al molar ratio lead to different structures of allophane. FTIR and MAS NMR techniques have been proven useful in detecting and studying the properties and composition of allophane. However, visible and near-infrared techniques may not be sufficient for studying poorly ordered aluminosilicate components on Mars' surface.
Article
Astronomy & Astrophysics
Rupali Mohanty, P. Senthil Kumar, K. Jaya Prasanna Lakshmi, Vivek Krishnan, Abhisek Mishra, G. Sree Sai Karthik
Summary: This study presents new evidence for ejecta boulder falls around 135 fresh simple impact craters in the Orientale multi-ring basin on the Moon. These boulder falls exhibit characteristics different from moonquake-triggered boulder falls, such as radial boulder trails, shorter trail lengths, narrower trail widths, and shallower trail depths. The boulder falls are believed to be produced by ejecta boulders during the ejecta blanket formation stage of the impact craters.
Article
Astronomy & Astrophysics
M. S. Fernanders, R. Gough, V. F. Chevrier, Z. R. Schiffman, S. B. Ushijima, G. M. Martinez, E. G. Rivera-Valentin, P. D. Archer, J. Clark, B. Sutter, M. A. Tolbert
Summary: Chlorine in various forms is widespread on Mars, with perchlorates and chlorides being commonly found. While perchlorates have been extensively studied, chlorate salts have received less attention. Laboratory studies revealed differences in water uptake behavior between sodium chlorate and magnesium chlorate salts at different temperatures, suggesting temperature-dependent deliquescence properties. Observations also showed the potential interaction of magnesium chlorate with water vapor under specific environmental conditions.
Article
Multidisciplinary Sciences
S. Maurice, B. Chide, N. Murdoch, R. D. Lorenz, D. Mimoun, R. C. Wiens, A. Stott, X. Jacob, T. Bertrand, F. Montmessin, N. L. Lanza, C. Alvarez-Llamas, S. M. Angel, M. Aung, J. Balaram, O. Beyssac, A. Cousin, G. Delory, O. Forni, T. Fouchet, O. Gasnault, H. Grip, M. Hecht, J. Hoffman, J. Laserna, J. Lasue, J. Maki, J. McClean, P. -y. Meslin, S. Le Mouelic, A. Munguira, C. E. Newman, J. A. Rodriguez Manfredi, J. Moros, A. Ollila, P. Pilleri, S. Schroder, M. de la Torre Juarez, T. Tzanetos, K. M. Stack, K. Farley, K. Williford
Summary: The acoustic environment on Mars was unknown before the Perseverance rover landing. This study presents the first characterization of the acoustic environment on Mars using Perseverance microphone recordings, providing important data for atmospheric studies.
Article
Astronomy & Astrophysics
David Trang, Tyra Tonkham, Justin Filiberto, Shuai Li, Myriam Lemelin, Catherine M. Elder
Summary: Using remote data analysis, we have found strong relationships between localized pyroclastic deposits on the lunar surface and water abundance, composition, and physical properties. These relationships can be used to infer the gas content, cooling rate, optical density, fragmentation degree, and water distribution within the lunar interior during volcanic eruptions. This research is of great importance for understanding eruption dynamics and behavior.
Article
Astronomy & Astrophysics
Tiantian Liu, Greg Michael, Wilhelm Zuschneid, Kai Wuennemann, Juergen Oberst
Summary: Through numerical modeling and geochemical analysis, it is found that almost all lunar mare surfaces in the soil samples contain non-mare material, mainly derived from different geologic processes such as lateral transport, downslope slumping, and high-velocity ejecta.
Article
Astronomy & Astrophysics
Qinghai Sun, Wenzhe Fa, Meng-Hua Zhu, Jun Du
Summary: In this study, the morphology of impact craters on the Moon was analyzed, showing differences in slope, height, and rock abundance between craters in maria and non-maria regions. The findings also revealed differences in degradation rates and depth-dependent features among different terrains. The revised onset of transitional crater diameters was also determined.
Article
Geochemistry & Geophysics
L. P. Ogorodova, Yu D. Gritsenko, M. F. Vigasina, V. S. Rusakov, L. Melchakova, A. Yu Bychkov, D. A. Ksenofontov
Summary: In this study, four samples of natural Ti-bearing garnets from Russia were analyzed using various techniques. The formation enthalpies and standard Gibbs free energies of these garnets were determined and used for quantitative modeling of the stability fields.
GEOCHEMISTRY INTERNATIONAL
(2022)
Article
Chemistry, Physical
Evgeny V. Zharikov, Valentina B. Dudnikova, Nina G. Zinovieva, Kirill A. Subbotin, Denis A. Lis, Anatoly I. Titov
Summary: The study reveals that grown NGM crystals are non-stoichiometric with molybdenum deficiency, and the content of cationic vacancies increases up to 10% with Gd excess. Oxygen vacancies in the crystals vary from 0.5% to 5% of anion sites, indicating possible mechanisms for the formation of cationic and anionic vacancies in NGM crystals.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Geochemistry & Geophysics
Svetlana N. Teplyakova, Cyril A. Lorenz, Marina A. Ivanova, Munir Humayun, Nataliya N. Kononkova, Sergey E. Borisovsky, Alexander Korochantsev, Ian A. Franchi, Nina G. Zinovieva
Summary: Karavannoe, a pallasite found in Russia in 2010, is a member of the ESP group with olivine and metal as its main components. The metal formation is oxidized and corresponds to the fractional crystallization of metallic liquids derived from CV- or CO-chondrites.
METEORITICS & PLANETARY SCIENCE
(2022)
Article
Materials Science, Ceramics
Diana I. Pchelina, Vera D. Sedykh, Nataliya I. Chistyakova, Vyacheslav S. Rusakov, Yulia A. Alekhina, Alexey N. Tselebrovskiy, Bernard Fraisse, Lorenzo Stievano, Moulay Tahar Sougrati
Summary: Sr-doped (00.2) ceramic samples of lanthanum manganite oxides were synthesized and their structural, magnetic, and electronic responses were investigated. The doping induced the formation of a mixture of orthorhombic phases in the annealed samples. The study revealed the presence of nanosized magnetic clusters with fluctuating magnetic moments and the influence of matrix-clusters interactions on the relaxation behavior. Additionally, the annealing time affected the production of materials with specific properties, making it useful in technological processes.
CERAMICS INTERNATIONAL
(2023)
Article
Astronomy & Astrophysics
Jan Hendrik Pasckert, Nico Schmedemann, Andreas Nathues, Harald Hiesinger, Carolyn H. van der Bogert
Summary: This study investigated the young resurfacing absolute model ages at the floor of Occator crater on dwarf planet Ceres and explored the potential causes for these resurfacing events. The results suggest that seismic shaking may not be responsible for the observed young resurfacing, while the deposition of young cryovolcanic material seems to be the most plausible explanation.
Article
Astronomy & Astrophysics
Teng Hu, Ze Yang, Mo Li, Carolyn H. van der Bogert, Zhizhong Kang, Xiaojian Xu, Harald Hiesinger
Summary: In the future, China plans to establish an international lunar research station (ILRS) in the lunar south polar region, with a focus on long-term scientific exploration, resource identification and utilization, and lunar surface infrastructure construction. The suitability of the landing site, especially the detection and exploration of volatiles, is critical for the scientific research station. By evaluating two potential landing areas with accessible permanently shadowed regions (PSRs), we identified the high value exploration areas and potential science missions for each area, taking into account terrain, temperature, and illumination conditions. This ILRS siting strategy, emphasizing scientific constraints, provides guidance for future ILRS siting areas.
PLANETARY AND SPACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Vyacheslav S. Rusakov, Artem L. Kozlovskiy, Maxim S. Fadeev, Kamila B. Egizbek, Assel Nazarova, Kayrat K. Kadyrzhanov, Dmitriy I. Shlimas, Maxim V. Zdorovets
Summary: This paper presents the results of a study on the phase transformation and structural characteristics of iron oxide nanoparticles synthesized by chemical coprecipitation under thermal annealing. The study found that thermal annealing leads to the transformation of nanoparticles from nonstoichiometric magnetite to hematite, and the structure of nanoparticles becomes ordered and coarsened.
Article
Crystallography
Assel Nazarova, Artem L. Kozlovskiy, Vyacheslav S. Rusakov, Kamila B. Egizbek, Maxim S. Fadeev, Bekzat A. Prmantayeva, Dorota Chudoba, Maxim V. Zdorovets, Kayrat K. Kadyrzhanov
Summary: The article evaluates the applicability of different types of iron-containing nanoparticles in magnetic hyperthermia and determines their degradation resistance. The results show that Fe3O4@GdFeO3 nanoparticles have the highest efficiency, while Fe2O3@NdFeO3 and Fe3O4@GdFeO3 nanoparticles have the highest degradation resistance. It is found that interfacial boundaries can slow down the corrosion processes.
Article
Geochemistry & Geophysics
T. Frueh, H. Hiesinger, C. H. van der Bogert, J. D. Clark, T. R. Watters, N. Schmedemann
Summary: The Moon's lithosphere has undergone deformation due to tectonic processes for over 4 billion years, resulting in various surface features. Large lunar graben were formed during an early thermal expansion phase before 3.6 billion years ago. Subsequent faulting and folding of mare basalts led to the formation of wrinkle ridges, which are exclusive to lunar Maria and caused by loading from dense mare basalts. Since 3.6 billion years ago, the Moon has been in a thermal state of net contraction, resulting in the global formation of lobate scarps. Lunar tectonism is an important record of the Moon's thermal evolution.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Astronomy & Astrophysics
E. Tatsumi, F. Vilas, J. de Leon, M. Popescu, S. Hasegawa, T. Hiroi, F. Tinaut-Ruano, J. Licandro
Summary: By studying the near-ultraviolet (NUV) absorption of primitive asteroids, strong correlations were found between NUV and OH-band (2.7 μm) absorptions, indicating that NUV absorption can be indicative of hydrated silicates. In addition, there is a significant difference in NUV absorption between large and small asteroids, with large asteroids mainly classified as C types and small asteroids mainly classified as F types. The taxonomic distribution of asteroids also differs between the inner main belt and the middle-outer main belt, with F types dominating the inner main belt.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Crystallography
T. Yu. Kiseleva, V. S. Rusakov, R. Abbas, E. V. Lazareva, P. Yu. Tyapkin, K. D. Martinson, A. S. Komlev, N. S. Perov, V. I. Popkov
Summary: Iron-containing oxides are important functional materials with various applications in biomedical technologies. This study experimentally investigated the crystal and magnetic structure evolution of Y3Fe5O12 nanoparticles, revealing the relationship between size, structural quality, and magnetic characteristics.
CRYSTALLOGRAPHY REPORTS
(2023)
Article
Crystallography
N. I. Chistyakova, A. V. Antonova, V. S. Rusakov, D. Kubaniova, J. Kohout, T. Yu. Kiseleva, M. S. Chernov, E. N. Lukyanova, V. D. Sedykh, D. G. Zavarzina
Summary: This study compared siderites of chemical and bacterial origin using Mossbauer spectroscopy, X-ray diffraction, and scanning electron microscopy. It found significant differences in crystal morphology and the physicochemical conditions of their formation, suggesting a potential diagnostic indication of biogenic siderites.
CRYSTALLOGRAPHY REPORTS
(2023)
Article
Crystallography
A. L. Kozlovskiy, V. S. Rusakov, M. S. Fadeev
Summary: This study investigates the influence of electron irradiation modification on the stability of α-Fe2O3 nanoparticles during long-term storage. The results show that electron irradiation provides stability to hydration processes and phase transformations, and higher irradiation dose increases the resistance to structural disordering, thus retaining the nanoparticle properties for a longer time.
CRYSTALLOGRAPHY REPORTS
(2023)
Article
Astronomy & Astrophysics
T. Heyer, W. Iqbal, A. Oetting, H. Hiesinger, C. H. van der Bogert, N. Schmedemann
Summary: We developed an open source QGIS extension called OpenCraterTool to independently measure and compare craters regardless of map projection. By comparing five global lunar crater datasets, we found significant differences in the number and diameter of craters, which have noticeable effects on age determination of the surfaces.
PLANETARY AND SPACE SCIENCE
(2023)
Meeting Abstract
Geochemistry & Geophysics
C. D. Schultz, B. A. Anzures, R. E. Milliken, T. Hiroi, K. Robertson
METEORITICS & PLANETARY SCIENCE
(2022)
Article
Astronomy & Astrophysics
Maria Angeles Lopez-Cayuela, Maria-Paz Zorzano, Juan Luis Guerrero-Rascado, Carmen Cordoba-Jabonero
Summary: The atmospheric dust cycle on Mars plays a dominant role in the planetary radiative balance, atmospheric photochemistry escape, and redistribution of materials on the surface. A methodology is presented to accurately describe the annual dust redistribution cycle on Mars using orbital global and seasonal measurements of atmospheric dust opacity. The analysis shows that approximately 4 trillion kilograms of dust is transported globally in the atmosphere during a typical Mars year.
Article
Astronomy & Astrophysics
Audrey Vorburger, Shahab Fatemi, Shane R. Carberry Mogan, Andre Galli, Lucas Liuzzo, Andrew R. Poppe, Lorenz Roth, Peter Wurz
Summary: The study presents new model results for the composition of Ganymede's atmosphere, finding that sublimation remains the major source process for H2O, while radiolysis induced by auroral electrons dominates the source fluxes for O2 and H2.
Article
Astronomy & Astrophysics
Qi He, Zhi Cao, Yuqi Qian, Hejiu Hui, Ioannis Baziotis, Long Xiao, Zaicong Wang, Biji Luo, Yiheng Li, Zongjun Ying, Yang Li
Summary: The Chang'e-5 mission collected lunar soil containing magnesian troctolitic granulites, which provide valuable information on the composition of the lunar crust. Through analysis and modeling, it is suggested that these granulites may have originated from the Pythagoras crater and were transported to the landing site.
Article
Astronomy & Astrophysics
Jordan M. Bretzfelder, Kathryn M. Stack, Abigail A. Fraeman, Mackenzie Day, William E. Dietrich, Alexander B. Bryk
Summary: This study investigates the development of bedrock ridges on Mars and their implications for wind history, deposition, and erosion in Gale crater.
Article
Astronomy & Astrophysics
Lot Ram, Diptiranjan Rout, Rahul Rathi, Paul Withers, Sumanta Sarkhel
Summary: This study investigates the impacts of interplanetary coronal mass ejections (ICMEs) on the Martian ionosphere, specifically the behavior of the ionospheric peak density and height during ICME passages. The study used observations from the Radio Occultation Science Experiment (ROSE) aboard the MAVEN spacecraft and selected 8 ICMEs from existing catalogs. The results show that ICMEs lead to an elevation of the ionospheric peak height and a decrease in peak density, and propose that vertical pressure gradient and electron temperature enhancement are plausible causes for ionospheric variability.
Article
Astronomy & Astrophysics
Benoit Jabaud, Riccardo Artoni, Gabriel Tobie, Erwan Le Menn, Patrick Richard
Summary: The Cassini spacecraft discovered active jets of water vapour and ice grains at the South Pole of Enceladus, resulting in the deposit of freshly erupted materials on the moon's icy surface. Similar processes may be happening on Europa as well. Determining the mechanical properties of fresh icy powder-like materials is essential for future landing and sampling missions. The flowability and surface energy of ice powders decrease with increasing temperatures, which may have implications for stable landing and the flow of ice materials on Enceladus and Europa.
Article
Astronomy & Astrophysics
Lydie Bonal, Eric Quirico, Gilles Montagnac, Mutsumi Komatsu, Yoko Kebukawa, Hikaru Yabuta, Kana Amano, Jens Barosch, Laure Bejach, George D. Cody, Emmanuel Dartois, Alexandre Dazzi, Bradley De Gregorio, Ariane Deniset-Besseau, Jean Duprat, Cecile Engrand, Minako Hashiguchi, Kanami Kamide, David Kilcoyne, Zita Martins, Jeremie Mathurin, Smail Mostefaoui, Larry Nittler, Takuji Ohigashi, Taiga Okumura, Laurent Remusat, Scott Sandford, Miho Shigenaka, Rhonda Stroud, Hiroki Suga, Yoshio Takahashi, Yasuo Takeichi, Yusuke Tamenori, Maximilien Verdier-Paoletti, Shohei Yamashita, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Hisayoshi Yurimoto, Shogo Tachibana, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Satoru Nakazawa, Masahiro Nishimura, Tatsuaki Okada, Takanao Saiki, Kanako Sakamoto, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Tomohiro Usui, Sei-ichiro Watanabe, Toru Yada, Kasumi Yogata, Makota Yoshikawa
Summary: This paper focuses on characterizing the thermal history of asteroid Ryugu by studying the structure of polyaromatic carbonaceous matter in the returned samples. The study finds that there is no structural difference in the polyaromatic component between the two sampling sites on Ryugu, indicating that the thermal metamorphism related to radioactive decay was not significant. However, some structural variability is observed within the particle set.
Article
Astronomy & Astrophysics
M. Luginin, A. Fedorova, D. Belyaev, F. Montmessin, O. Korablev, J. -l. Bertaux
Summary: Spectroscopic solar occultation measurements by the SPICAV/SOIR instrument onboard the Venus Express orbiter provided new data on the upper haze aerosol properties, its distribution, and variations. A joint analysis of data from two spectrometers revealed a bimodal distribution in about 50% of observations previously believed to be unimodal, and characterized the size distribution 10 km higher in the atmosphere compared to previous analysis.
Article
Astronomy & Astrophysics
A. Mahieux, S. Viscardy, K. L. Jessup, F. P. Mills, L. Trompet, S. Robert, S. Aoki, A. Piccialli, A. C. Vandaele
Summary: We report on the mean upper limit number densities and volume concentrations of H2CO, O-3, NH3, HCN, N2O, NO2, NO, and HO2 at the Venus terminator above the cloud layer. Attempts to detect these species using a statistical algorithm and the method presented by Trompet et al. (2021) were unsuccessful, and upper limits of detection are provided.
Article
Astronomy & Astrophysics
P. M. Streeter, S. R. Lewis, M. R. Patel, J. A. Holmes, K. Rajendran
Summary: The northern polar vortex on Mars shows a high degree of interannual repeatability in its structure and evolution, except during large dust storms. The seasonal timing of these storms seems to be the key factor determining their impacts on the polar vortex.
Article
Astronomy & Astrophysics
Michael T. Mellon, Hanna G. Sizemore, Jennifer L. Heldmann, Christopher P. McKay, Carol R. Stoker
Summary: The search for life is a major focus of Mars exploration, with temperature and water activity being key factors for habitability. The most recent habitable conditions occurred about 510 kyrs ago and lasted for about 10s of kyrs each occurrence. All latitudes offer potential for life exploration, but middle-latitude sites have access to 100-kyr-old ice that experienced past habitable conditions, while high-latitude sites offer access to ancient ice over 1 Myrs old.
Article
Astronomy & Astrophysics
Anthony Ozerov, Jeffrey C. Smith, Jessie L. Dotson, Randolph S. Longenbaugh, Robert L. Morris
Summary: The Geostationary Lightning Mapper (GLM) instruments, with their large combined field of view, are useful for studying the population of atmospheric phenomena like bolides. However, there are biases when using GLM for non-lightning purposes, which need to be studied and accounted for before precise measurements of bolide flux can be obtained. A Bayesian Poisson regression model was developed to estimate instrumental biases and the latitudinal variation of bolide flux concurrently. The estimated bias corresponds to the known sensitivity of the GLM instruments, and the latitudinal flux variation estimates are consistent with a strong bias towards high-velocity bolides, as compared to existing theoretical models.
Article
Astronomy & Astrophysics
P. Beck, P. Y. Meslin, A. Fau, O. Forni, O. Gasnault, J. Lasue, A. Cousin, S. Schroeder, S. Maurice, W. Rapin, R. C. Wiens, A. M. Ollila, E. Dehouck, N. Mangold, B. Garcia, S. Schwartz, W. Goetz, N. Lanza
Summary: Analysis of data obtained by ChemCam on Mars reveals that the carbon signal is mainly related to ionization of the atmosphere, with variability potentially linked to the physical state of the atmosphere. Up to sol 3355, no carbonate was detected in the ChemCam dataset, suggesting that it is not a major constituent (>50%) in the analyzed targets and that carbon in soils is not enriched beyond the limit of detection. The dominant salts found in Gale are sulfate and chlorides, while the absence of carbonates, seen in Jezero, may be due to differences in protolith.
Article
Astronomy & Astrophysics
Eloy Pena-Asensio, Jaakko Visuri, Josep M. Trigo-Rodriguez, Hector Socas-Navarro, Maria Gritsevich, Markku Siljama, Albert Rimola
Summary: The observation of interstellar objects 1I/'Oumuamua and 2I/Borisov suggests the existence of a larger population of smaller projectiles that impact our planet with unbound orbits. A statistical evaluation of uncertainties in the CNEOS database and study of its hyperbolic fireballs reveals an anisotropic geocentric radiant distribution and low orbital inclinations, challenging the assumption of a randomly incoming interstellar population. These findings suggest that apparent interstellar meteors may, in fact, be the result of accelerated meteoroid impacts caused by close encounters with massive objects within or passing through our solar system.
Article
Astronomy & Astrophysics
Cecilia W. S. Leung, Leslie K. Tamppari, David M. Kass, German Martinez, Erik Fischer, Michael D. Smith
Summary: Using a combination of orbital and surface observations, this study investigates the vertical distribution of water vapor in the lower atmospheres of Mars. The findings suggest that the assumption of uniformly mixed water vapor in the boundary layer is not always consistent with observational constraints. The results provide important insights into the seasonal transport of water and the role of regolith-atmospheric exchange.