¹Hashiguchi, Minako et al. (>10)
Earth, Planets and Space 75, 73 Open Access Link to Article [DOI 10.1186/s40623-023-01792-w]
¹Graduate School of Environmental Studies, Nagoya University, Furo-Cho, Nagoya, Chikusa-Ku, 464-8601, Japan

We performed in-situ analysis on a ~ 1 mm-sized grain A0080 returned by the Hayabusa2 spacecraft from near-Earth asteroid (162173) Ryugu to investigate the relationship of soluble organic matter (SOM) to minerals. Desorption electrospray ionization-high resolution mass spectrometry (DESI-HRMS) imaging mapped more than 200 CHN, CHO, CHO–Na (sodium adducted), and CHNO soluble organic compounds. A heterogeneous spatial distribution was observed for different compound classes of SOM as well as among alkylated homologues on the sample surface. The A0080 sample showed mineralogy more like an Ivuna-type (CI) carbonaceous chondrite than other meteorites. It contained two different lithologies, which are either rich (lithology 1) or poor (lithology 2) in magnetite, pyrrhotite, and dolomite. CHN compounds were more concentrated in lithology 1 than in lithology 2; on the other hand, CHO, CHO–Na, and CHNO compounds were distributed in both lithologies. Such different spatial distribution of SOM is likely the result of interaction of the SOM with minerals, during precipitation of the SOM via fluid activity, or could be due to difference in transportation efficiencies of SOMs in aqueous fluid. Organic-related ions measured by time-of-flight secondary ion mass spectrometry (ToF–SIMS) did not coincide with the spatial distribution revealed by DESI-HRMS imaging. This result may be because the different ionization mechanism between DESI and SIMS, or indicate that the ToF–SIMS data would be mainly derived from methanol-insoluble organic matter in A0080. In the Orgueil meteorite, such relationship between altered minerals and SOM distributions was not observed by DESI-HRMS analysis and field-emission scanning electron microscopy, which would result from differences of SOM formation processes and sequent alteration process on the parent bodies or even on the Earth. Alkylated homologues of CHN compounds were identified in A0080 by DESI-HRMS imaging as observed in the Murchison meteorite, but not from the Orgueil meteorite. These compounds with a large C number were enriched in Murchison fragments with abundant carbonate grains. In contrast, such relationship was not observed in A0080, implying different formation or growth mechanisms for the alkylated CHN compounds by interaction with fluid and minerals on the Murchison parent body and asteroid Ryugu.

^1,2Andreas Bechtold,³Gerhard Paar,⁴Filippo Garolla,⁵Rebecca Nowak,⁵Laura Fritz,⁵Christoph Traxler,⁵Oliver Sidla,^1,2Christian Koeberl
Meteoritcs & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14054]
¹Department of Lithospheric Research, University of Vienna, Vienna, Austria
²Austrian Academy of Sciences, Vienna, Austria
³Joanneum Research, Graz, Austria
⁴SLR Engineering, Graz, Austria
⁵VRVis, Vienna, Austria
Published by arrangement with John Wiley & Sons

Past, present, and forthcoming planetary rover missions to Mars and other planetary bodies are equipped with a large number of scientific cameras. The very large number of images resulting from this, combined with tight time constraints for navigation, measurements, and analyses, pose a major challenge for the mission teams in terms of scientific target evaluation. Shatter cones are the only macroscopic evidence for impact-induced shock metamorphism and therefore impact craters on Earth. The typical features of shatter cones, such as striations and horsetail structures, are particularly suitable for machine learning methods. The necessary training images do not exist for such a case; therefore, we pursued the approach of producing them artificially. Using PRo3D, a viewer developed for the interactive exploration and geologic analysis of high-resolution planetary surface reconstructions, we virtually placed shatter cones in 3-D background scenes processed from true Mars rover imagery. We use PRo3D-rendered images of such scenes as training data for machine learning architectures. Terrestrial analog studies in Ethiopia supported our lab work and were used to test the resulting neural network of this feasibility study. The result showed that our approach with shatter cones in artificial Mars rover scenes is suitable to train neural networks for automatic detection of shatter cones. In addition, we have identified several aspects that can be used to improve the training of the neural network and increase the recognition rate. For example, using background data with a higher resolution in order to have equal resolution of object (shatter cone) and Martian background and increase the number of objects that can be placed in the training data set. Also using better lighting reconstructions and a better radiometric adaption between object and Martian background would further improve the results.

^1,2Guozhu Chen,^1,2Zhipeng Xia,^1,2Bingkui Miao,^3,4Zilong Wang,³Wei Tian,^1,2Yikai Zhang,^1,2Hao Liu,^1,2Chuangtong Zhang,^1,2Lanfang Xie,^1,2Yanhua Peng,^1,2Hongyi Chen,^1,2Xi Wang
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14058]
¹Institution of Meteorites and Planetary Materials Research, Key Laboratory of Planetary Geological Evolution, Education Department of Guangxi Zhuang Autonomous Region, Guilin University of Technology, Guilin, China
²Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration, Guilin University of Technology, Guilin, China
³Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Ministry of Education, Peking University, Beijing, China
⁴Key Laboratory of Paleomagnetism and Tectonic Reconstruction of MNR, Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, China
Published by arrangement with John Wiley & Sons

The study of lunar magma evolution holds significant importance within the scientific community due to its relevance in understanding the Moon’s thermal and geological history. However, the intricate task of unraveling the history of early volcanic activity on the Moon is hindered by the high flux of impactors, which have substantially changed the morphology of pristine volcanic constructs. In this study, we focus on a unique volcanic glass found in the lunar meteorite Northwest Africa 11801. This kind of volcanic glass is bead-like in shape and compositionally similar to the Apollo-14 and Apollo-17 very low-Ti glass. Our research approach involves conducting a comprehensive analysis of the petrology and mineralogy of the volcanic glass, coupled with multiple thermodynamic modeling techniques. Through the investigation, we aim to shed light on the petrological characteristics and evolutionary history of the glass. The results indicate that the primitive magma of the glass was created at 1398–1436°C and 8.3–11.9 kbar (166–238 km) from an olivine+orthopyroxene mantle source region. Then, the magma ascended toward the surface along a non-adiabatic path with an ascent rate of ~40 m s−1 or 0.2 MPa s−1. During the magma ascent, only olivine crystallized and the onset of magma eruption occurred at ~1320–1343°C. Finally, the glass cooled rapidly on the lunar surface with a cooling rate ranging between 20 and 200 K min−1. Considerable evidence from petrology, mineralogy, cooling rate, and the eruption rate of the glass beads strongly supports the occurrence of ancient explosive volcanism on the Moon.

¹I-Huan Chiu,²Kentaro Terada,³Takahito Osawa,⁴Changkun Park,⁵Soshi Takeshita,⁵Yasuhiro Miyake,¹Kazuhiko Ninomiya
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14059]
¹Institute Radiation Sciences, Osaka University, Osaka, Japan
²Graduate School of Science, Osaka University, Osaka, Japan
³Nuclear Science Research Institute, Japan Atomic Energy Agency, Ibaraki, Japan
⁴Korea Polar Research Institute, Incheon, Republic of Korea
⁵High Energy Accelerator Research Organization (KEK), Ibaraki, Japan
Published by arrangement with John Wiley & Sons

We report the result of a non-destructive elemental analysis of lunar meteorites using a negative muon beam at J-PARC. An experimental system of six Ge semiconductor detectors and a newly designed He analysis chamber (to enable quantitative analysis of Al) was used to provide a high signal-to-noise ratio for the detection of major elements from lunar rocks (Mg, Si, Fe, O, Ca, and Al). We performed a Monte Carlo simulation to determine the chemical compositions at two sides and the center of a sample (at depths of 0.33 and 0.96 mm below the sample surface, respectively) of the lunar meteorite DEW 12007. These results indicate that the three interior regions of DEW 12007 are likely to be 55.8:44.2, 51.4:48.6, and 54.4:45.6 wt% mixtures of anorthositic and basaltic clasts, respectively. This study is the first quantitative analysis of a heterogeneous meteorite interior using a negative muon beam. As elemental analysis using a muon beam is non-destructive and highly sensitive to light elements, including C, N, and O, the protocols established in this study are applicable to initial characterization of returned samples from the South Pole of the Moon.

¹Ali-Dib, Mohamad
Monthly Notices of the Royal Astronomical Society: Letters 520, L48 – L521 Open Access Link to Article [DOI 10.1093/mnrasl/slad002]
¹Center for Astro Particle and Planetary Physics (CAP3), New York University Abu Dhabi, PO Box, Abu Dhabi, 129188, United Arab Emirates

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¹Bonatti L.,¹Brugman B.L.,¹Subramani T.,²Leinenweber K.D.,¹Navrotsky A.
Review of Scientific Instruments 94, 054905 Link to Article [DOI 10.1063/5.0131946]
¹School of Molecular Sciences, Center for Materials of the Universe, Arizona State University, Tempe, 85287, AZ, United States
²Eyring Materials Center, Arizona State University, Tempe, 85287, AZ, United States

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¹Kremer, Christopher H.,¹Mustard, John. F.,¹Pieters, Carlé M.
Earth and Space Science 10, e2023EA002828 Open Access Link to Article [DOI 10.1029/2023EA002828]
¹Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, United States

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^1,2Lina Seybold,¹Claudia A. Trepmann,^1,2Stefan Hölzl,³Kilian Pollok,³Falko Langenhorst,¹Fabian Dellefant,^1,4Melanie Kaliwoda
Meteoritics & Planetary Science(in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14056]
¹Department of Earth and Environmental Sciences, Ludwig-Maximilians-University Munich, Munich, Germany
²Bavarian Natural History Collections, RiesKraterMuseum Nördlingen, Nördlingen, Germany
³Institute of Geoscience, Friedrich Schiller University Jena, Jena, Germany
⁴Mineralogical State Collection, Bavarian Natural History Collections, Munich, Germany
Published by arrangement with John Wiley & Sons

Shock-related calcite twins are characterized in calcite-bearing metagranite cataclasites within crystalline megablocks of the Ries impact structure, Germany, as well as in cores from the FBN1973 research drilling. The calcite likely originates from pre-impact veins within the Variscan metagranites and gneisses, while the cataclasis is due to the Miocene impact. Quartz in the metagranite components does not contain planar deformation features, indicating low shock pressures (<7 GPa). Calcite, however, shows a high density (>1/μm) of twins with widths <100 nm. Different types of twins (e-, f-, and r-twins) crosscutting each other can occur in one grain. Interaction of r- and f-twins results in a-type domains characterized by a misorientation relative to the host with a misorientation angle of 35°–40° and a misorientation axis parallel to an a-axis. Such a-type domains have not been recorded from deformed rocks in nature before. The high twin density and activation of different twin systems in one grain require high differential stresses (on the order of 1 GPa). Twinning of calcite at high differential stresses is consistent with deformation during impact cratering at relatively low shock pressure conditions. The twinned calcite microstructure can serve as a valuable low shock barometer.

¹Trygve Prestgard,¹Pierre Beck,¹Lydie Bonal,¹Jolantha Eschrig,²Jérôme Gattacceca,²Corinne Sonzogni,³Lisa Krämer Ruggiu
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14048]
¹Institut de Planétologie et d’Astrophysique de Grenoble, CNRS CNES, Université Grenoble Alpes, Grenoble, France
²CNRS, IRD, Coll France, INRA, CEREGE, Aix Marseille Univ, Aix-en-Provence, France
³Analytical-, Environmental- and Geo-Chemistry, Vrije Universiteit Brussel, Brussels, Belgium
Published by arrangement with John Wiley & Sons

Renazzo-type (CR) chondrites are a relatively rare group of carbonaceous chondrites with the vast majority having escaped thermal alteration. This means that CRs are composed of relatively unprocessed material, depending on the extent of aqueous alteration they have experienced. Hydration in CRs ranges from incipient alteration of matrix glass, up to nearly complete replacement of the rock by hydration products. The extent of secondary processes is often difficult to assess in these meteorites, due to their heterogeneity and diversity of alteration products. Yet, this is crucial in order to understand the extent of geological processing that occurred on the primary parent body. Additionally, the parent asteroids of CRs remain a mystery, mainly because terrestrial oxyhydroxide signatures dominate the reflectance spectra of CRs. In this work, we have conducted optical and IR reflectance and transmission spectra of 25 CR chondrites in order to (i) better evaluate the extent of aqueous alteration that occurred on the CR parent body, and (ii) find possible parent body candidates. Terrestrial oxyhydroxides were removed from 12 samples, as these tend to interfere with the optical-IR spectra of CRs. Our results suggest, among other, that (i) aqueous alteration in most of our CRs was limited to the matrix and (ii) most CRs may stem from a continuum of X-to-C complex asteroids, depending on their extent of aqueous alteration. More specifically, the endmembers being Xk/Xn types and Cgh/Ch types. This has strong implication in regard to what we can expect from the Psyche mission.

¹Harry Y. McSween Jr.,²James W. Head III,³A. Deanne Rogers,⁴Mariek E. Schmidt
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14057]
¹Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, Tennessee, USA
²Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island, USA
³Department of Geosciences, Stony Brook University, Stony Brook, New York, USA
⁴Department of Earth Sciences, Brock University, St. Catharines, Ontario, Canada
Published by arrangement with John Wiley & Sons

Global magmatic trends inferred from gamma-ray, visible/near-infrared, and thermal infrared spectrometers on Mars-orbiting spacecraft have been used to constrain planetary petrogenetic processes and global thermal evolution models. Inferred magmatic trends include temporal variations in the relative proportions of low-Ca and high-Ca pyroxenes, and in the abundances of potassium (and total alkalis), silica, FeO* (total iron expressed as FeO), and thorium. These patterns are evaluated for consistency with the compositions of surface igneous rocks of different ages analyzed by Mars rovers and of martian meteorites. Trends of decreasing low-Ca pyroxene/total pyroxene ratios and of decreasing potassium (and total alkalis), with time are generally supported by surface rock analyses. However, significant differences in the GRS-measured silica in Amazonian volcanoes and in martian meteorites of equivalent age result from contamination by silica-rich dust and are problematic for a silica trend. Comparison of FeO* in Noachian and Amazonian surface data shows no decrease. An inferred temporal trend in thorium is in conflict with the complex enrichment and depletion patterns of incompatible trace elements in martian meteorites of various ages. A dearth of analyses of Hesperian-age surface rocks precludes a firm evaluation of inferred Noachian-Hesperian trends and Hesperian-Amazonian trends, but abundant Noachian rocks and a few Hesperian rocks at rover sites, and Amazonian martian meteorites, collectively representing at least 16 surface locations, afford useful comparisons with orbital remote-sensing data.