¹Karl Wimmer,²Edwin Gnos,³Beda Hofmann,⁴Sandro Boschetti,⁴Jan Walbrecker,⁴Hansruedi Maurer
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.70079]
¹Independent Researcher, Nördlingen, Germany
²Natural History Museum of Geneva and Earth and Environmental Sciences, University of Geneva, Geneva, Switzerland
³Natural History Museum Bern, Bern, Switzerland
⁴Institute of Geophysics, ETH Zürich, Zürich, Switzerland
Published by arrangement with John Wiley & Sons

With a size of 51.2 × 7.2 km, the 10.9 ± 1.7 ka old Jiddat al Harasis 091 L5 chondrite strewn field is the largest known in Oman. It consists of more than 700 meteorites with a total mass of >4.5 tons from which the largest six stones of >100 kg to 1.5 tons make up two thirds of the total mass. Small stones are underrepresented, consistent with a fracturing behavior of a meteor with low shock level. Modeling yields that a bolide with 28 ± 12 tons (115 ± 15 cm radius) entered the atmosphere at a shallow angle of 22° ± 2° with a velocity of about 16 kms−1. For ~16 s, it produced a spectacular meteor along a luminous path of ~200 km length. Mass mixing within the rather straight and narrow strewn field indicates a sequence of multiple fragmentations from below 50 km down to 7 km altitude. This can be resolved adopting a wind profile from nowadays winter season, as the weather patterns with alternating Monsoon and Passat winds in the region are rather well known and repeatable since the last ice age. The largest masses with 1447 and 842 kg, respectively, produced impact breccia consisting of limestone and meteorite fragments. According to the model, the biggest mass hit the ground at a velocity of 175 ms−1 and released an impact energy of 22 MJ, corresponding to 5.3 kg TNT. This may have produced an impact crater of ~1 m diameter which, however, is not preserved. Breccia found below a much smaller mass of 68 kg deserves an explanation beyond impact energy.

^1,2Tian Zhang, ^1,2,3Hong Tang, ^1,2,3Xiongyao Li, ^1,3Bing Mo, ¹Yuanyun Wen, ⁴Sheng Zhang, ^1,3Wen Yu, ^1,2Chuanjiao Zhou, ^1,2Haiyan Long, ^1,2,3Jianzhong Liu
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2025.11.047]
¹Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
²College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
³CAS Center for Excellence in Comparative Planetology, Hefei 230026, China
⁴College of Resources and Environment Engineering, Guizhou University, Guiyang 550025, China
Copyright Elsevier

The degassing of solar wind-related volatiles is thought to contribute to volatile cycling on the Moon. However, it remains uncertain which lunar minerals preferentially release them. Here, we report an unusual foamy texture found only on the surface of ilmenite crystals within a Chang’e-6 (CE-6) basalt clast. The distribution and chemical composition of this texture indicates that it results from in-situ melting of the ilmenite surface rather than from an impact-induced splash melt. Considering the evidence—including the long exposure time, presence of deep-seated planar defects, open vesicles, large spherical np-Fe⁰ particles, and a rutile-like mineral—the foamy texture is interpreted to result from the intense release of abundant solar wind-related volatiles (e.g., H/H2, He, and OH/H2O) by an impact-induced conductive heating event. Restriction of the foamy texture to the surface of ilmenite within the CE-6 basalt clast indicates that solar wind composition, especially for H-related volatiles, are released more intensely from ilmenite than from silicate minerals such as pyroxene and plagioclase. Our findings suggest that solar wind-related volatiles released from high-Ti mature regolith likely made a greater contribution to the lunar exosphere and the lunar surface volatiles, including polar deposits, relative to those from low-Ti immature regions. This has important implications for understanding volatile cycles and future in-situ resource utilization on the Moon.

^1,2Michael T. Thorpe,²Elizabeth B. Rampe,^3,4Juergen Thieme,³Eric Dooryhee,^2,5Seungyeol Lee,⁶Roy Christoffersen
American Mineralogist 110,1689-1701 Open Access Link to Article [https://doi.org/10.2138/am-2023-9290]
¹University of Maryland, NASA Goddard Space Flight Center, and CRESST II, Greenbelt, Maryland 20771, U.S.A.
²NASA Johnson Space Center, Houston, Texas 77058, U.S.A.
³Brookhaven National Lab, NSLS-II, Upton, New York 11973, U.S.A.
⁴Institute for X-Ray Physics, Georg-August University Goettingen, Goettingen University, Göttingen 37073, Germany
⁵Department of Earth and Environmental Sciences, Chungbuk National University, Seowon-Gu, Cheongju, Chungbuk 28644, Korea
⁶Amentum JETS-II contract, NASA Johnson Space Center, Houston, Texas 77058, U.S.A.
Copyright: The Mineralogical Society of America

Mudrocks and mud-sized sediments (i.e., silt to clay) dominate the surface of Earth and Mars. These fine-grained sediments preserve a rich history of sedimentary processes from source to sink and shed light on ancient climates. However, both the physical and chemical nature of these materials make them difficult to fully characterize with traditional laboratory techniques. Here, we explore a cross-disciplinary and high-resolution approach using synchrotron radiation for X-ray diffraction, pair distribution function analysis, and submicrometer-scale X-ray fluorescence, combined with transmission electron microscopy, to better understand the nanostructure and composition of mud-sized sediments from a glacio-fluvial watershed in southwest Iceland. Our results demonstrate that sediments in the cold and wet climate of Iceland are more altered than previously thought, as evidenced by the identification of kaolinite and mixed-layer kaolinite-smectite. Additionally, sediments are enriched in amorphous materials and nanocrystalline phases, as determined from grain morphologies and compositions consistent with allophane, hisingerite, ferrihydrite, and halloysite. These alteration products are present as intimate mixtures that vary across depositional sites, demonstrating the dynamic nature of the secondary assemblage from source to sink. This work has implications for Mars, where, for example, basalt-sourced sedimentary rocks from Gale crater are abundant in clay minerals and amorphous materials. Finally, this work underpins the importance of using high-resolution techniques, a coordinated methodology, and developing innovative approaches for future planetary sample return missions (e.g., Mars sample return).