Article
Astronomy & Astrophysics
Ted L. Roush
Summary: In this study, the imaginary indices of refraction for carbonates were estimated from reflectance spectra, and a Kramers-Konig analysis was used to determine the real indices of refraction as a function of wavelength. The resulting complex refractive indices cover a wide wavelength range and improve the spectral resolution for carbonates, consistent with previous studies.
Article
Astronomy & Astrophysics
E. Bruschini, C. Carli, A-C Buellet, M. Vincendon, F. Capaccioni, M. Ferrari, F. Vetere, A. Secchiari, D. Perugini, A. Montanini
Summary: In this study, we reported the reflectance spectra of silicic samples mixed with graphite and discussed the effects of graphite on the reflectance spectra. Our results showed that graphite mixed with silicate materials reduces albedo and decreases spectral slopes of the mixtures.
Article
Astronomy & Astrophysics
Bruce Hapke
Summary: The opposition effect refers to a sharp surge in reflectance near zero phase angle in scattering media, primarily caused by coherent backscattering. The angular width and shape of the coherent backscatter peak in particulate media depend on wavelength, porosity, and particle size, according to theoretical models.
Article
Astronomy & Astrophysics
Dylan J. Shiltz, Charles M. Bachmann
Summary: In this paper, an alternative to Hapke's correction for the photometric effect of macroscopic roughness of planetary surfaces is presented. The model includes both single-facet scattering and multi-facet scattering effects. Monte Carlo simulations and laboratory experiments are used to validate the model and study the macroscopic roughness backscattering bias effect. The proposed model is found to be more accurate than Hapke's model for phase angles less than 90 degrees.
Article
Astronomy & Astrophysics
Andreas Morlok, Christian Renggli, Bernard Charlier, Olivier Namur, Stephan Klemme, Maximilian P. Reitze, Iris Weber, Aleksandra N. Stojic, Karin E. Bauch, Harald Hiesinger, Joern Helbert
Summary: The MERTIS instrument on the BepiColombo mission will map the surface of Mercury and requires a database of analog materials for spectral interpretation. We analyzed analog materials relevant to Mercury's distinct terrains using mid-infrared reflectance spectroscopy. Different mineral mixtures showed distinct spectral features dominated by glass, forsterite, or pyroxene bands. The easily obtainable spectral parameter CF can be used to classify the analog mixtures. The spectra analyzed in this study showed some similarity to certain terrains on Mercury, but could not fully reproduce the remote sensing data.
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
Laura E. Fackrell, Paul A. Schroeder, Aaron Thompson, Karen Stockstill-Cahill, Charles A. Hibbitts
Summary: Exploration of the Martian surface over the past decade has provided insights into the composition and variability of minerals in regolith and bedrock. Developing simulants can help understand the potential and limitations of using Martian soil for plant growth, by reflecting relevant data from Mars missions and serving as a test bed for further research.
Article
Astronomy & Astrophysics
Anna Barbaro, Federico Zorzi, Alessandra Lorenzetti, Sabrina Ferrari, Cristina Tubaro, Fabrizio Nestola
Summary: This study investigates the thermal stability of oldhamite (CaS) on the surface of Mercury using X-Ray Powder Diffraction (XRPD) and Thermogravimetric Analyses (TGA). The results confirm the stability of CaS within the daily temperature excursion on Mercury's surface and provide insights for interpreting data from the BepiColombo space mission.
Article
Geochemistry & Geophysics
Lingzhi Sun, Paul G. Lucey
Summary: Mineral abundance and Mg# are significant for understanding the crustal composition and thermal history of the Moon. A new set of optical constants and a mineral unmixing model were developed, which showed accurate estimation of mineral abundance and chemistry. The model was validated and used to create a global Mg# map based on Moon Mineralogy Mapper images.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2021)
Article
Optics
Yuexin Zou, Hong Pan, Shenyang Huang, Pingping Chen, Hugen Yan, Zhenghua An
Summary: Researchers have observed that the infrared emission spectrum from electrically biased GaAs devices deviates significantly from the Planck distribution due to the additional contribution of non-equilibrium hot electrons. The hot electrons emit evanescent infrared radiation, which is out-coupled by a near-field metamaterial grating, impacting the total far-field emission spectrum. Additionally, resonance emission peaks were observed when the electron hotspots spatially overlapped with the optical hotspots at the grating resonance.
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
J. O. Edgar, J. A. Gould, K. Badreshany, J. Telling
Summary: Perchlorate is widely present in the solar system and can expand the potential for habitable conditions by lowering the freezing point of liquid water. However, it poses a hazard to human health in future manned space exploration, while also serving as a potential source of oxygen and fuel.
Article
Astronomy & Astrophysics
Zixu Zhao, Jian Chen, Zongcheng Ling, Xuejin Lu, Zexi Li
Summary: The timeline of volcanic activity on the Moon is crucial for understanding its thermal evolution. This study focuses on the basaltic volcanism in the Procellarum region and analyzes its chronology, composition, and mineralogy. The results reveal three major episodes of volcanic events occurring approximately 3.5 Ga, 2.5 Ga, and 1.8 Ga.
Article
Astronomy & Astrophysics
Lingzhi Sun, Paul G. Lucey
Summary: This study provides the possibility of a more accurate interpretation of lunar thermal history through spectroscopic analysis of lunar igneous boulders.
Article
Physics, Multidisciplinary
Zhuoran Geng, Ilari J. Maasilta
Summary: This work demonstrates that complete tunneling of acoustic waves can occur when leaky surface waves are excited, regardless of the orientations of anisotropic crystals. However, the conditions for achieving complete tunneling have not been explored.
COMMUNICATIONS PHYSICS
(2023)
Article
Astronomy & Astrophysics
Shota Miyazaki, Daisuke Suzuki, Andrzej Udalski, Naoki Koshimoto, David P. Bennett, Takahiro Sumi, Nicholas Rattenbury, Han Cheongho, Fumio Abe, Richard K. Barry, Aparna Bhattacharya, Ian A. Bond, Akihiko Fukui, Hirosane Fujii, Yuki Hirao, Stela Ishitani Silva, Yoshitaka Itow, Rintaro Kirikawa, Iona Kondo, Brandon Munford, Yutaka Matsubara, Sho Matsumoto, Yasushi Muraki, Arisa Okamura, Greg Olmschenk, Clement Ranc, Yuki K. Satoh, Taiga Toda, Paul J. Tristram, Hibiki Yama, Atsunori Yonehara, Radek Poleski, Przemek Mroz, Jan Skowron, Michal K. Szymanski, Igor Soszynski, Pawel Pietrukowicz, Syzmon Kozlowski, Krzysztof Ulaczyk, Lukasz Wyrzykowski
Summary: The discovery of a sub-Jovian-mass planet, OGLE-2014-BLG-0319Lb, is reported. Characteristics and composition of this planet are determined through observations and statistical analysis. The study also highlights the importance of Galactic priors in resolving model degeneracy.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
P. Vernazza, P. Beck, O. Ruesch, A. Bischoff, L. Bonal, G. Brennecka, R. Brunetto, H. Busemann, J. Carter, C. Carli, C. Cartier, M. Ciarniello, V Debaille, A. Delsanti, L. D'Hendecourt, E. Fueri, O. Groussin, A. Guilbert-Lepoutre, J. Helbert, P. Hoppe, E. Jehin, L. Jorda, A. King, T. Kleine, P. Lamy, J. Lasue, C. Le Guillou, H. Leroux, I Leya, T. Magna, Y. Marrocchi, A. Morlok, O. Mousis, E. Palomba, L. Piani, E. Quirico, L. Remusat, M. Roskosz, M. Rubin, S. Russell, M. Schoenbaechler, N. Thomas, J. Villeneuve, V. Vinogradoff, P. Wurz, B. Zanda
Summary: The last thirty years have shown that small bodies formed in the outer Solar System are a major reservoir that is vastly undersampled in current extra-terrestrial materials. Studying these objects could lead to significant breakthroughs in planetary science by providing insights into the least processed materials closest to the origin of the Solar System. Sample return missions are necessary to achieve this goal, with proposals already submitted to ESA for future missions in the 2035-2050 time frame.
EXPERIMENTAL ASTRONOMY
(2022)
Article
Geochemistry & Geophysics
F. Zambon, C. Carli, J. Wright, D. A. Rothery, F. Altieri, M. Massironi, F. Capaccioni, G. Cremonese
Summary: This study conducted a spectral analysis of the H05-Hokusai quadrangle on Mercury using data from the MESSENGER mission. The analysis identified 11 spectral units and found correlations between some units and variations in Mg and Al.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2022)
Article
Astronomy & Astrophysics
Marcin Wrona, Milena Ratajczak, Piotr A. Kolaczek-Szymanski, Szymon Kozlowski, Igor Soszynski, Patryk Iwanek, Andrzej Udalski, Michal K. Szymanski, Pawel Pietrukowicz, Dorota M. Skowron, Jan Skowron, Przemek Mroz, Radoslaw Poleski, Mariusz Gromadzki, Krzysztof Ulaczyk, Krzysztof Rybicki
Summary: This study introduces a collection of 991 heartbeat star (HBS) candidates found in the OGLE project data archive, consisting of stars located towards the Galactic bulge, Large Magellanic Cloud, and Small Magellanic Cloud. The stars are divided into two main groups based on the evolutionary status of the primary star, with one group featuring a hot main-sequence or a Hertzsprung-gap primary star and the other group including a red giant.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Astronomy & Astrophysics
Kailash C. Sahu, Jay Anderson, Stefano Casertano, Howard E. Bond, Andrzej Udalski, Martin Dominik, Annalisa Calamida, Andrea Bellini, Thomas M. Brown, Marina Rejkuba, Varun Bajaj, Noe Kains, Henry C. Ferguson, Chris L. Fryer, Philip Yock, Przemek Mroz, Szymon Kozlowski, Pawel Pietrukowicz, Radek Poleski, Jan Skowron, Igor Soszynski, Michal K. Szymanski, Krzysztof Ulaczyk, Lukasz Wyrzykowski, Richard K. Barry, David P. Bennett, Ian A. Bond, Yuki Hirao, Stela Ishitani Silva, Iona Kondo, Naoki Koshimoto, Clement Ranc, Nicholas J. Rattenbury, Takahiro Sumi, Daisuke Suzuki, Paul J. Tristram, Aikaterini Vandorou, Philippe Beaulieu, Jean-Baptiste Marquette, Andrew Cole, Pascal Fouque, Kym Hill, Stefan Dieters, Christian Coutures, Dijana Dominis-Prester, Clara Bennett, Etienne Bachelet, John Menzies, Michael Albrow, Karen Pollard, Andrew Gould, Jennifer C. Yee, William Allen, Leonardo A. Almeida, Grant Christie, John Drummond, Avishay Gal-Yam, Evgeny Gorbikov, Francisco Jablonski, Chung-Uk Lee, Dan Maoz, Ilan Manulis, Jennie McCormick, Tim Natusch, Richard W. Pogge, Yossi Shvartzvald, Uffe G. Jorgensen, Khalid A. Alsubai, Michael Andersen, Valerio Bozza, Sebastiano Calchi Novati, Martin Burgdorf, Tobias C. Hinse, Markus Hundertmark, Tim-Oliver Husser, Eamonn Kerins, Penelope Longa-Pena, Luigi Mancini, Matthew Penny, Sohrab Rahvar, Davide Ricci, Sedighe Sajadian, Jesper Skottfelt, Colin Snodgrass, John Southworth, Jeremy Tregloan-Reed, Joachim Wambsganss, Olivier Wertz, Yiannis Tsapras, Rachel A. Street, D. M. Bramich, Keith Horne, Iain A. Steele
Summary: This study reports the first unambiguous detection and mass measurement of an isolated stellar-mass black hole. The researchers used the Hubble Space Telescope to carry out precise astrometry of a microlensing event in the Galactic bulge, and obtained the lens's mass and distance. The study also provides insights into the nature and motion of the black hole.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Casey Y. Lam, Jessica R. Lu, Andrzej Udalski, Ian Bond, David P. Bennett, Jan Skowron, Przemek Mroz, Radek Poleski, Takahiro Sumi, Michal K. Szymanski, Szymon Kozlowski, Pawel Pietrukowicz, Igor Soszynski, Krzysztof Ulaczyk, Lukasz Wyrzykowski, Shota Miyazaki, Daisuke Suzuki, Naoki Koshimoto, Nicholas J. Rattenbury, Matthew W. Hosek, Fumio Abe, Richard Barry, Aparna Bhattacharya, Akihiko Fukui, Hirosane Fujii, Yuki Hirao, Yoshitaka Itow, Rintaro Kirikawa, Iona Kondo, Yutaka Matsubara, Sho Matsumoto, Yasushi Muraki, Greg Olmschenk, Clement Ranc, Arisa Okamura, Yuki Satoh, Stela Ishitani Silva, Taiga Toda, Paul J. Tristram, Aikaterini Vandorou, Hibiki Yama, Natasha S. Abrams, Shrihan Agarwal, Sam Rose, Sean K. Terry
Summary: The analysis of five black hole candidates revealed one possible neutron star or low-mass black hole, as well as two candidates that are likely white dwarfs or neutron stars. Further observations and modeling are needed to confirm the nature of the objects. The overall sample size showed reasonable agreement with theoretical expectations on the number of black holes in the Milky Way.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Patryk Iwanek, Igor Soszynski, Szymon Kozlowski, Radoslaw Poleski, Pawel Pietrukowicz, Jan Skowron, Marcin Wrona, Przemyslaw Mroz, Andrzej Udalski, Michal K. Szymanski, Dorota M. Skowron, Krzysztof Ulaczyk, Mariusz Gromadzki, Krzysztof Rybicki, Milena Ratajczak
Summary: This article presents a collection of Mira-type variable stars found in the OGLE project database, providing their observational parameters and photometric data. The article also discusses the statistical features of these stars in different regions of the Milky Way and showcases examples of stars changing their type over time.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Environmental Sciences
Jakub Ciazela, Jaroslaw Bakala, Miroslaw Kowalinski, Stefan Plocieniak, Natalia Zalewska, Bartosz Pieterek, Tomasz Mrozek, Marta Ciazela, Grzegorz Paslawski, Marek Steslicki, Zaneta Szaforz, Jaromir Barylak, Mateusz Kuzaj, Alessandro Maturilli, Joern Helbert, Andrzej Muszynski, Miroslaw Rataj, Szymon Gburek, Mateusz Jozefowicz, Dariusz Marciniak
Summary: Sulfide ores are crucial resources for future self-sustaining Mars colonies, but current instrumentation faces challenges in detecting sulfides on the Martian surface. To address this issue, a new instrument called MIRORES has been designed to accurately measure sulfide absorption peaks in the narrow far-IR wavelength range.
Article
Geography
Christopher C. Malliband, David A. Rothery, Matthew R. Balme, Susan J. Conway, David L. Pegg, Jack Wright
Summary: This article presents the geological mapping results of Mercury's Derain quadrangle using data from the MESSENGER spacecraft. The map provides valuable information for the upcoming BepiColombo mission and is compatible with previous maps.
Article
Geochemistry & Geophysics
G. Alemanno, M. D'Amore, A. Maturilli, J. Helbert, G. Arnold, O. Korablev, N. Ignatiev, A. Grigoriev, A. Shakun, A. Trokhimovskiy
Summary: The study successfully recovered the spectral shapes of atmospheric dust and water ice aerosols from the analyzed datasets and validated the methodology applied. Through comparisons with multiple datasets, the research also assessed the temporal stability and homogeneity of dust and water ice components in the Martian atmosphere.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2022)
Article
Geography
Benjamin Man, David A. Rothery, Matthew R. Balme, Susan J. Conway, Jack Wright, David L. Pegg, Annie R. Lennox, Salvatore Buoninfante
Summary: We have created the first geological map of the Neruda Quadrangle (H13) on Mercury, which covers an area of approximately 5 million square kilometers in the southern hemisphere of the planet. The map was digitized using data from NASA's MESSENGER mission and includes three main photogeologic plains units, as well as the identification of craters and their degradation state. The map serves as a valuable resource for the upcoming BepiColombo mission to Mercury by providing context and target locations.
Article
Geography
Savana Z. Woodley, Peter Fawdon, Matthew R. Balme, David A. Rothery
Summary: We present a 1:4,000,000 scale map of tectonic landforms in Chryse Planitia and Arabia Terra, revealing evidence of widespread tectonic shortening structures in the region. The map contributes to a broader understanding of the geological history of the area and Mars' tectonic history as a whole.
Article
Geosciences, Multidisciplinary
Benjamin Man, David A. Rothery, Matthew R. Balme, Susan J. Conway, Jack Wright
Summary: Research on tectonic features on Mercury using MESSENGER imagery reveals the widespread occurrence of relatively young grabens, supporting the hypothesis of continued activity of Mercury's shortening structures and thermochemical evolution models.
Review
Astronomy & Astrophysics
Martha S. Gilmore, M. Darby Dyar, Nils Mueller, Jeremy Brossier, Alison R. Santos, Mikhail Ivanov, Richard Ghail, Justin Filiberto, Jorn Helbert
Summary: Surface mineralogy provides information about the composition, climate history, and geochemical cycling on the Venus surface. Although direct measurements in situ have not yet been conducted, various investigations have yielded a basic understanding of surface composition and weathering reactions in the current era. Laboratory experiments, theoretical modeling, and future missions will further advance our knowledge of Venus mineralogy.
SPACE SCIENCE REVIEWS
(2023)
Article
Astronomy & Astrophysics
O. Mousis, A. Bouquet, Y. Langevin, N. Andre, H. Boithias, G. Durry, F. Faye, P. Hartogh, J. Helbert, L. Iess, S. Kempf, A. Masters, F. Postberg, J. -B. Renard, P. Vernazza, A. Vorburger, P. Wurz, D. H. Atkinson, S. Barabash, M. Berthomier, J. Brucato, M. Cable, J. Carter, S. Cazaux, A. Coustenis, G. Danger, V. Dehant, T. Fornaro, P. Garnier, T. Gautier, O. Groussin, L. Z. Hadid, J. -C. Ize, I. Kolmasova, J. -P. Lebreton, S. Le Maistre, E. Lellouch, J. I. Lunine, K. E. Mandt, Z. Martins, D. Mimoun, Q. Nenon, G. M. Munoz Caro, P. Rannou, H. Rauer, P. Schmitt-Kopplin, A. Schneeberger, M. Simons, K. Stephan, T. Van Hoolst, J. Vaverka, M. Wieser, L. Woerner
Summary: Enceladus, a moon of Saturn, has an internal water ocean and expels ocean material into space. The Moonraker mission aims to investigate the composition of the plume formed by the ocean jets to understand the moon's habitability and origin. This proposed mission will use advanced instruments to pave the way for future landed missions.
PLANETARY SCIENCE JOURNAL
(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.