¹Tatsumi, Eri,²Vilas, Faith,^3,4De León, Julia,⁵Popescu, Marcel,¹Hasegawa, Sunao,⁶De Prá, Mario,^3,4Tinaut-Ruano, Fernando,^3,4Licandro, Javier
Astronomy and Astrophysics 693, A140 Open Access Link to Article [DOI 10.1051/0004-6361/202450662]
¹Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Kanagawa, Sagamihara, Japan
²Planetary Science Institute (PSI), Tucson, AZ, United States
³Instituto de Astrofísica de Canarias (IAC), University of La Laguna, Tenerife, La Laguna, Spain
⁴Department of Astrophysics, University of La Laguna, Tenerife, La Laguna, Spain
⁵Astronomical Institute of the Romanian Academy, 5 Cuţitul de Argint, Bucharest, 040557, Romania
⁶Florida Space Institute, University of Central Florida, Orland, CA, United States

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¹Matthew J. O. Svensson,¹Gordon R. Osinski,¹Fred J. Longstaffe,²Timothy A. Goudge,³Haley M. Sapers
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14330]
¹Department of Earth Sciences, The University of Western Ontario, London, Ontario, Canada
²Department of Earth and Planetary Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas, USA
³Department Astronomy & Planetary Science, Northern Arizona University, Flagstaff, Arizona, USA
Published by arrangement with John Wiley & Sons

Impact-generated hydrothermal systems and postimpact crater lake systems are well-documented geological phenomena; however, evidence of hydrothermal venting into impact crater lake systems has rarely been reported. We investigated the well-preserved contact between hydrothermally altered impact melt-bearing breccia (outer/surficial suevite) and postimpact crater lake deposits sampled by the Wörnitzostheim drill core at the Ries impact structure, Germany. We logged the upper 32 m of core, describing sedimentary structures and general lithological and mineralogical variations. Mineralogy was studied in detail using X-ray diffraction, optical microscopy, backscattered electron imagery, secondary electron imagery, and wavelength-dispersive spectroscopy analyses. Twelve different units were identified in the logged section of drill core, which we broadly separated into four distinct groups: (1) marlstones and limestones, (2) sand/siltstones, (3) conglomerates, and (4) impact melt-bearing breccias. The sedimentary deposits (groups 1–3) likely represent a transition from a back-stepping alluvial fan to a transgressing, shallow lake shoreline. Secondary dolomite, smectitic clay minerals and clinoptilolite occur as void-filling phases in the conglomerates—the earliest sedimentary deposits of the Wörnitzostheim drill core. A potential temperature range of 50–130°C was estimated for these void-filling minerals based on previous mineral synthesis experiments, and the typical mineral assemblages reported for the principal sequence of hydrothermal mineralization in impact craters and argillic alteration. Early postimpact sedimentary deposits likely host limited hydrothermal mineralization, potentially indicating ideal conditions for some microbial life forms during initial crater lake formation.

¹Oliver Christ,²Anna Barbaro,^3,4Ludovic Ferrière,³Lidia Pittarello,¹M. Chiara Domeneghetti,²Frank E. Brenker,^1,5Fabrizio Nestola,¹Matteo Alvaro
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14326]
¹Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
²Schwiete Cosmochemistry Laboratory, Department of Geoscience, Goethe-University Frankfurt, Frankfurt, Germany
³Natural History Museum Vienna, Vienna, Austria
⁴Natural History Museum Abu Dabi, Abu Dhabi, United Arab Emirates
⁵Section Alessandro Guastoni, Museum of Nature and Humankind, University of Padova, Padova, Italy
Published by arrangement with John Wiley & Sons

Iron meteorites, originating from the deepest parts of their parent bodies and separated during major break-up events, surprisingly rarely contain diamonds despite experiencing similar pressure–temperature conditions as diamond-bearing ureilites. In this study, graphite from three non-magmatic IAB iron meteorites Canyon Diablo, Campo del Cielo, and Yardymly was analyzed using micro-Raman spectroscopy, revealing the presence of the graphite G-band, the disorder-induced D-band, and occasionally the D′-band. Temperature estimates based on the G-band full width at half maximum (ranging from 1155 to 1339°C) are consistent with those found in ureilites. However, unlike in ureilites, no diamond bands were detected, as confirmed by μ-X-ray diffraction. The absence of diamonds is interpreted to be related to the thermal and mechanical properties of the iron meteorite matrix. Its high thermal diffusivity results in similar temperatures to ureilites, but its ductility dissipates shock-wave energy through plastic deformation, unlike the brittle ureilite matrix, which more effectively transmits the energy. Consequently, graphite in iron meteorites was heated but did not experience the high-pressure conditions required for diamond formation. Thus, we propose that impacts must either involve substantial energy or that graphite must be located close to the impact site, where it can experience high energies before these dissipate.

¹Jambon, Albert,²Bielińska, Gerta,²Kosiński, Maciej,²Wieczorek-Szmal, Magdalena,^3,5Miśta-Jakubowska, Ewelina,⁴Tarasiuk, Jacek,⁵Dzięgielewski, Karol
Journal of Archaelogical Science: Reports 62, 104982 Link to Article [DOI 10.1016/j.jasrep.2025.104982]
¹Université de la Côte d’Azur, Sorbonne Université, CNRS, OCA, IRD, Géoazur, Sophia-Antipolis, Valbonne, 06560, France
²Częstochowa Museum, Najświętszej Marii Panny 47, Częstochowa, 42-217, Poland
³National Centre for Nuclear Research, Sołtana 7, Otwock, 05-400, Poland
⁴Faculty of Physics and Applied Computer Science, AGH University of Krakow, Mickiewicza 30, Kraków, 30-059, Poland
⁵Institute of Archaeology, Jagiellonian University, ul. Gołębia 11, Kraków, 31-007, Poland

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¹Huang, Yongsong,¹Santos, Ewerton,¹Alexandre, Marcelo R.,²Heck, Philipp R.,¹Milliken, Ralph,³Glavin, Daniel P.,³Dworkin, Jason P.
Rapid Communications in Mass Spectrometry 39, e9979 Link to Article [DOI 10.1002/rcm.9979]
¹Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, United States
²Robert A. Pritzker Center for Meteoritics and Polar Studies, Negaunee Integrative Research Center, Field Museum of Natural History, Chicago, IL, United States ³Solar System Exploration Division, NASA Goddard Space Center, Greenbelt, MD, United States

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¹Takaaki Noguchi,¹Akira Miyake,²Hikaru Yabuta,³Yoko Kebukawa,⁴Hiroki Suga,⁵Makoto Tabata,⁶Kyoko Okudaira,⁷Akihiko Yamagishi,^8,9H. Yano
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14327]
¹Division of Earth and Planetary Sciences, Kyoto University, Kyoto, Japan
²Department of Earth and Planetary Systems Science, Hiroshima University, Hiroshima, Japan
³Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo, Japan
⁴NanoTerasu Promotion Division, Japan Synchrotron Radiation Research Institute, Sendai, Miyagi, Japan
⁵Faculty of Science, Chiba University, Chiba, Japan
⁶Division of Information Systems and Aizu Research Center for Space Informatics (ARC-Space), Department of Computer Science and Engineering, University of Aizu, Fukushima, Japan
⁷Department of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
⁸Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa, Japan
⁹Space and Astronautical Science, Graduate Institute for Advanced Studies, SOKENDAI, Sagamihara, Kanagawa, Japan
Published by arrangement with John Wiley & Sons

The Tanpopo experiment is Japan’s first astrobiology mission aboard the Japanese Experiment Module Exposed Facility on the International Space Station. The Tanpopo-1 mission exposed silica aerogel panels to low Earth orbit from 2015 to 2016 to capture micrometeoroids. We identified an impact track measuring approximately 8 mm long, which contained terminal grains in the silica aerogel panel oriented toward space. The impact track exhibited a bulbous cavity with two thin, straight tracks branching from it, each preserving a terminal grain at their ends. The terminal grains were extracted from the silica aerogel and analyzed using scanning transmission electron microscopy and scanning transmission X-ray microscopy to investigate their X-ray absorption near-edge structure (STXM-XANES). Both grains are Fe-bearing and relatively homogeneous orthopyroxene crystals (En88.4±0.4 and En88.2±1.8). The recovery of Fe-bearing low-Ca pyroxene aligns with previous studies of micrometeoroids captured in LEO. Micrometeoroids containing Fe-bearing olivine and low-Ca pyroxene are likely abundant in LEO.

¹Vladimir Svetsov,¹Valery Shuvalov,¹Dmitry Glazachev,¹Olga Popova,¹Natalia Artemieva,¹Elena Podobnaya,¹Valery Khazins
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14329]
¹Sadovsky Institute of Geosphere Dynamics, Russian Academy of Sciences, Moscow, Russia
Published by arrangement with John Wiley & Sons

We completed numerical simulations of a number of asteroid and comet impacts on Earth to predict related shock wave and thermal radiation effects and to estimate seismic effects, as well as ionospheric disturbances. Using interpolation of the results, we were able to estimate these effects for arbitrary impact parameters. In addition, we used previously developed models to estimate the size of the impact crater and ejecta thickness. Finally, we developed a user-friendly web-based calculator (https://asteroidhazard.pro/) that quickly estimates shock wave pressure and radiation exposure at a given location, as well as crater size and average ejecta layer thickness, if any, seismic magnitude, change in ionospheric density, and some other values. The input parameters of the calculator are the impactor diameter and density, its speed and inclination angle of the trajectory above the atmosphere, and the coordinates of the observer (the point on the ground where it is necessary to determine the impact consequences). This paper describes the methods of numerical simulations and techniques for approximating the results. We present a few examples of how to assess the impact hazard, in particular, overpressure and wind speed on the surface, thermal radiation, and seismic shaking after a crater-forming impact or an airburst in the atmosphere.

^1,7,8Wen Yu et al. (>10)
Earth and Planetary Science Letters 655, 119263 Link to Article [https://doi.org/10.1016/j.epsl.2025.119263]
¹Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
⁷CAS center for Excellence in Comparative Planetology, Hefei 230026, China
⁸Key Laboratory of Space Manufacturing Technology, Chinese Academy of Sciences, Beijing, 100094, China
Copyright Elsevier

The image of a bone-dry surface in the Moon’s non-polar regions impinged by the Apollo missions was changed by the detection of widespread absorption near 3 µm in 2009, interpreted as a signature of hydration. However, debates persist on the relative contribution of molecular water (H2O) and other hydroxyl (OH) compounds to this hydration feature, as well as the cause of the potential temperature-dependence of the OH/H2O abundance. Resolving these debates will help to estimate the inventory of water on the Moon, a crucial resource for future space explorations. In this study, we measured the abundance and isotope composition of hydrogen within the outermost micron of Chang’e-5 soil grains, collected from the lunar surface and from a depth of 1 m. These measurements, combined with our laboratory simulation experiments, demonstrate that solar-wind-induced OH can be thermally retained in lunar regolith, with an abundance of approximately 48–95 ppm H2O equivalent. This abundance exhibits small latitude dependence and no diurnal variation. By integrating our results with published remote sensing data, we propose that a high amount of molecular water (∼360 ± 200 ppm H2O) exists in the subsurface layer of the Moon’s non-polar regions. The migration of this H2O accounts for the observed latitude and diurnal variations in 3 µm band intensity. The inventory of OH and H2O proposed in this study reconciles the seemingly conflicting observations from various instruments, including infrared/ultraviolet spectroscopies and the Neutral Mass Spectrometer (NMS). Our interpretation of the distribution and dynamics of lunar hydration offers new insights for future lunar research and space

¹ Tiwari,¹Gaurav Joshi,¹Pradyut Phukon,¹Amar Agarwal,²Mamilla Venkateshwarlu
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14323]
¹Applied Structural Geology Lab, Department of Earth Sciences, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India
²CSIR-National Geophysical Research Institute, Hyderabad, Telangana, India
Published by arrangement with John Wiley & Sons

At the Dhala impact structure, the monomict breccia and the impact melt rock outcrops are present in proximity. Generally, these impactite lithologies are formed by different mechanisms and in different parts of the crater. The emplacement setting of impact melt rocks at Dhala has been well studied. Therefore, we studied the emplacement of monomict breccia using field, microscopic, and magnetic fabric investigations. Our results show that the intensities of the rock magnetic parameters in monomict breccia are comparable with the unshocked target granitoid at Dhala. Thus, the magnetic fabrics developed during pre-impact processes and were not altered due to impact. The absence of the reorientation of magnetic fabrics indicates that the peak shock pressures were below 0.5 GPa. Such shock pressures typically exist near the crater wall/floor or outside the crater. Moreover, there is no local variation in the orientations of magnetic fabrics at different locations in the same outcrop. Thus, the monomict breccia was not displaced from their pre-impact position. Based on the shock barometry and absence of displacement, we propose that the present-day annular outcrops of monomict breccia are located just outside the final crater. Furthermore, the monomict breccia annular outcrop ring has an internal diameter of ~4.5 km and is juxtaposed with impact melt rocks, which formed within the crater (previous studies). We, thus, suggest that the present-day crater diameter is ~4.5 km.

¹Taddei, Alice,²Holtstam, Dan,^1,3Bindi, Luca
Mineralogical Magazine (in Press) Link to Article [DOI 10.1180/mgm.2024.78]
¹Dipartimento di Scienze della Terra, Università degli Studi di Firenze, via La Pira 4, Firenze, I-50121, Italy
²Department of Geosciences, Swedish Museum of Natural History, Box 50007, Stockholm, SE-10405, Sweden
³CNR, Istituto di Geoscienze e Georisorse, sezione di Firenze, via La Pira 4, Firenze, I-50121, Italy

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