^1,2Lei Jin,³Tsz Wai Lo,³Ian Tong Fong
Research in Astronom and Astrophysics 25, 075008 Link to Article [DOI 10.1088/1674-4527/add8fa]
¹State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China
²CNSA Macau Center for Space Exploration and Science, Macau 999078, China
³Premier School Affiliated to Hou Kong Middle School, Macau 999078, China

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¹Pengyue Wang (王鹏越),²Edward Cloutis,¹Ye Su (苏烨),¹Man-To Hui (许文韬)
The Astrophysical Journal Letters 985, L18 Open Access Link to Article [DOI 10.3847/2041-8213/adce6e]
¹State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, People’s Republic of China
²Department of Geography, University of Winnipeg, Winnipeg, Canada

Most near-Earth objects are thought to originate from the collisional fragments of the main asteroid belt. One question that remains to be resolved is the proportion of near-Earth objects sampling the core area material of the parent body to the outer layers. In this study, we developed a method to determine the petrologic type of ordinary chondrite parent bodies based on reflectance spectroscopy. We also calculated the petrologic type of asteroid (25143) Itokawa, which is consistent with the returned samples from the JAXA Hayabusa mission. Finally, we calculate the petrologic type of 28 LL near-Earth asteroids. Our results show that the surface material of most LL chondrite near-Earth asteroids is of petrologic grade higher than 4. The ratio of LL chondrite near-Earth asteroids with high petrologic type (5 and 6) to LL chondrite near-Earth asteroids with low petrologic type is 0.79. This also means that LL chondrite near-Earth asteroids may originate primarily from the core area of the main belt parent body or bodies.

^1,2,3Mariona Badenas-Agusti,⁴Siyi Xu (许偲艺),²Andrew Vanderburg,²Kishalay De,⁵Patrick Dufour,^1,4Laura K Rogers,^2,6Susana Hoyos,⁷Simon Blouin,²Javier Viaña,¹Amy Bonsor,⁶Ben Zuckerman
Monthly Notices of the Royal Astronomical Society 540, 746-773 Open Access Link to Article [https://doi.org/10.1093/mnras/staf777]
¹Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
²Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
³Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
⁴Gemini Observatory/NSF’s NOIRLab, 950 North Cherry Avenue, Tucson, AZ 85719, USA
⁵Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada
⁶Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA 90095-1567, USA
⁷Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 2Y2, Canad

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^1,2Patrick M. Shober,²Jeremie Vaubaillon,^3,4Hadrien A. R. Devillepoix,^3,4Eleanor K. Sansom,^3,4Sophie E. Deam,^2,5Simon Anghel,²Francois Colas,⁶Pierre Vernazza,⁷Brigitte Zanda
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.70041]
¹Astromaterials Research and Exploration Science Directorate (ARES), NASA Johnson Space Center, Houston, Texas, USA
²LTE, Observatoire de Paris, Université PSL, Sorbonne Université, Université de Lille, LNE, CNRS, Paris, France
³Space Science and Technology Centre, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
⁴International Centre for Radio Astronomy Research, Curtin University, Perth, WA, Australia
⁵Astronomical Institute of the Romanian Academy, Bucharest, Romania
⁶Institut de Minéralogie, Physique des Matériaux et Cosmochimie, Muséum National d’Histoire Naturelle, CNRS, Paris, France
⁷Laboratoire d’Astrophysique de Marseille, Aix Marseille Université, Aix-Marseille University, CNRS, CNES, LAM, Institut Origines, Marseille, France
Published by arrangement with John Wiley & Sons

Instrumentally determined pre-atmospheric orbits of meteorites offer crucial constraints on the provenance of extraterrestrial material and the dynamical pathways that deliver it to Earth. However, recovery efforts are focused on larger and slower impacts due to their higher survival probabilities and ease of detection. In this study, we investigate the prevalence of these biases in the population of recovered meteorites with known orbits. We compiled a data set of 75 meteorites with triangulated trajectories and compared their orbits to 538 potential 1 g meteorite-dropping fireballs detected by the Global Fireball Observatory, the European Fireball Network, and the Fireball Recovery and InterPlanetary Observation Network. Our results reveal that objects with small semi-major axis values (a1.8 au) appear 2–3 more often than expected. The current sample of meteorites with known orbits does not reflect the sources of meteorites in our collections, and it is essential to account for search and recovery biases to obtain a more representative understanding of meteorite source contributions.

Kecheng Du^a,b et al. (>5)

Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2025.116821]
^aCollege of Surveying and Geo-Informatics, Tongji University, Shanghai, China
^bShanghai Key Laboratory for Planetary Mapping and Remote Sensing for Deep Space Exploration, Tongji University, Shanghai, China
Copyright Elsevier

In January 2019, China’s Chang’e-4 (CE-4) spacecraft successfully landed in Von Kármán crater on the farside of the Moon. During nearly six years of operation until November 2024, the Visible and Near-infrared Image Spectrometer (VNIS) onboard the Yutu-2 rover acquired in-situ spectral data along an approximately 1600 m traverse path, offering critical opportunities to investigate subtle mineralogical variations within the patrol region. In this study, we analyzed these spectral data using a sparse spectral decomposition method with TiO2 constraints to quantitatively estimate the abundances of six lunar minerals, including high‑calcium pyroxene, low-calcium pyroxene, olivine, plagioclase, ilmenite and agglutinate/glass. We further examined the mineralogical properties of regolith and rocks in Yutu-2’s patrol area to identify trends and correlations in compositional variations. By comparing results with Kaguya Multiband Imager data products, we identified a gradual decreasing spatial distribution in plagioclase abundance along the traverse path, likely attributable to ejecta from the Zhinyu crater. Furthermore, analysis of Moon Mineral Mapper (M3) data revealed samples with similar spectral characteristics near Zhinyu crater, supporting this hypothesis. Additionally, the impact of secondary impact craters on local regions was qualitatively and quantitatively assessed using VNIS spectral features and agglutinate/glass abundance. These findings enhance understanding of the complex origin and evolution of materials at the CE-4 landing site region.

Fred Jourdan^a,b,c, Nicholas E. Timms^c, Tomoki Nakamura^d, William D.A. Rickard^b, Celia Mayers^b

Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2025.09.020]
^aWestern Australian Argon Isotope Facility, Curtin University, Australia
^bJohn de Laeter Centre, Curtin University, Australia
^cSpace Science and Technology Centre & School of Earth and Planetary Sciences, Curtin University, Australia
^dLaboratory for Early Solar System Evolution, Department of Earth Science Graduate School of Science, Tohoku University Aoba, Sendai, Miyagi Japan
Copyright Elsevier

Asteroid Itokawa is made of reassembled fragments from a monolithic parent asteroid which got shattered during a collision with a large object. Data are scarce regarding the metamorphic processes that occurred on the monolithic parent body and the age and nature of the catastrophic disruption event. Here, we investigate the timing of the metamorphism inside the parent body of Asteroid Itokawa and the age and nature of the catastrophic breakup event recorded in particles returned from Itokawa. We studied three regolith dust particles recovered by the Hayabusa space craft from the rubble pile asteroid 25,143 Itokawa using electron backscatter diffraction, time-of-flight secondary ion mass spectrometry, and ⁴⁰Ar/³⁹Ar dating techniques. Our results show that none of the particles show noticeable sign of shock metamorphism. Two of the particles yielded ⁴⁰Ar/³⁹Ar age of 4559 ± 61 and 4130 ± 33 million years (Ma), while a third particle returned a maximum error age of 703 ± 53 Ma. When combined with existing data, and diffusion models, these results show that ∼4.5 billion years (Ga) ago, Itokawa’s parent monolithic body cooled down from a peak metamorphism temperature ∼800 °C to ∼300 °C in less than 64 million years at a depth of >20 km. Then at ∼4.22 Ga, Itokawa’s parent body was shattered in a collisional process involving a heterogeneous temperature distribution during the impact, with some regions escaping shock metamorphism and experiencing less than a few hundred degrees Celsius. The fragments re-agglomerated in a larger rubble pile body where they subsequently cooled down over tens of millions of years. For the next 4 billion years, Asteroid Itokawa was regularly impacted and progressively shrunk by mass wasting.

Damanveer S. Grewal^a, Sujoy Mukhopadhay^b

Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2025.09.014]
^aDepartment of Earth and Planetary Sciences, Yale University, New Haven, CT 06511, USA
^bSchool of Earth and Space Exploration, Arizona State University, Tempe, AZ 85281, USA
Copyright Elsevier

The distinct accretionary histories of Earth and Mars – with Earth experiencing protracted growth and small contributions from outer solar system (carbonaceous, CC) materials, and Mars undergoing rapid growth with building materials drawn almost exclusively from the inner solar system (non-carbonaceous, NC) – highlight key differences in planetary formation. These contrasts underscore the importance of a comparative planetology framework for understanding the origin of volatiles in terrestrial planets. In this study, we examined the relationship between the carbon (C) isotopic compositions of planetary and planetesimal reservoirs to trace the origin of volatiles on Earth and Mars. The mean δ13C value of magmatic C in Martian meteorites (−20 ‰) is significantly lower than that of the bulk silicate Earth (BSE), with a canonical value of −5 ‰. While basaltic achondrites, magmatic iron meteorites, and ordinary chondrites from the NC reservoir display δ13C values similar to Martian meteorites, the BSE δ13C value is comparable to volatile-rich CC chondrites such as CI, CM, and CR, as well as with enstatite chondrites and ureilites from the NC reservoir. If Martian magmas underwent minimal C isotopic fractionation during degassing or degassed under kinetic conditions, then the δ13C value of the Martian mantle likely reflects accretion from thermally processed undifferentiated (ordinary chondrite-like) and differentiated NC materials. In contrast, if extensive degassing occurred via Rayleigh fractionation under equilibrium conditions, the δ13C value of the Martian mantle would have a higher δ13C value (−12 to −10 ‰) than that recorded in Martian meteorites – though still lighter than that of the canonical BSE δ13C. This implies a contribution from relatively 13C-rich NC materials, potentially similar to enstatite chondrites. For BSE, although the canonical δ13C value of –5 ‰ overlaps with those of enstatite chondrites and ureilites, the late-stage delivery of volatile-rich CC materials during the main phase of Earth’s growth, which was critical for establishing its water and nitrogen inventories, likely biased its C isotopic composition towards a CC-like signature. However, a lower mean δ13C value of −8.4 ‰ of the MORB mantle, as proposed by recent studies, could mean that Earth’s mantle still preserves the signature of 13C-poor, thermally processed NC materials accreted during the early stages of the planet’s growth. The observed heterogeneity in mantle C isotopic compositions, similar to that seen in H and N isotopes, could therefore reflect a mixed contribution from both NC and CC materials. These findings suggest that the δ13C value of the BSE could be lower than the canonical estimate and may align more closely with the proposed value for the MORB mantle. Taken together, these findings suggest that the contrasting accretionary histories of Earth and Mars led to fundamentally different pathways for volatile acquisition. These divergent pathways likely shaped the long-term geochemical evolution of each planet and influenced their potential for habitability.

Li Zhao^a,b,e, Liwu Li^a,c, Chunhui Cao^a,c, Qingyan Tang^d, Xianbin Wang^a

Icarus (in Press) Open Access Link to Article [https://doi.org/10.1016/j.icarus.2025.116803]
^aInstitut für Planetologie, Universität Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
^bDepartment of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, USA
^aApollo 15 Commander, USA
Copyright Elsevier

Peng Chen^a et al. (>5)

Icarus (in Press) Open Access Link to Article [https://doi.org/10.1016/j.icarus.2025.116808]
^aHigh Pressure Science Experiment Center, College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
Copyright Elsevier

Courtney Jean Rundhaug^a, Martin Schiller^a, Martin Bizzarro^a, Zhengbin Deng^a,b, Hermann Dario Bermúdez^c,d,e
Earth and Planetary Science Letters 669, 119592 Open Access Link to Article [https://doi.org/10.1016/j.epsl.2025.119599]
^aCentre for Star and Planet Formation, Globe Institute, University of Copenhagen, Øster Voldgade 5–7, 1350 Copenhagen K, Denmark
^bDeep Space Exploration Laboratory/CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
^cDepartment of Earth and Environmental Studies, Montclair State University, Montclair, NJ 07043, USA
^dGrupo de Investigación Paleoexplorer, 1400-37 Trexlertown Rd, PA 18062, USA
^eDepartamento de Geociencias, Universidad Nacional de Colombia, Bogotá 11001, Colombia

The Cretaceous-Paleogene boundary (KPB) represents a massive extinction event in Earth’s history, probably triggered by the Chicxulub asteroid impact ∼66 Ma. The event dispersed vast volumes of ejecta materials including exceptionally preserved impact spherules in the Gorgonilla Island KPB section. Previous work identified three populations of spherules at Gorgonilla: 1) ballistically transported molten spherules, 2) a mixture of molten and condensed spherules dispersed by the expansion of a high-temperature, turbulent cloud (the “pyrocloud”), and 3) tiny droplets condensed from the plume (the “fireball layer”). We determine the Mg, Fe, and Ca isotopic compositions of pristine spherules to better understand the evaporation and condensation thermodynamics within the pyrocloud. We detect enrichment in mass bias corrected µ⁴⁸Ca and µ²⁶Mg* isotope signatures from the terrestrial value corresponding to an impactor contribution of ∼17–25%, most likely from a CM or CO chondrite-like asteroid. The mass-dependent δ²⁵Mg and δ⁵⁶Fe compositions are generally light or unfractionated, suggesting incomplete recondensation as the pyrocloud cooled and expanded. Combined δ²⁵Mg and δ⁵⁶Fe signatures reveal decoupling of these isotope systems, likely due to differing condensation rates. Thus, we calculate a higher average condensation rate of Fe than Mg, reflecting the thermodynamic decoupling and more complete recondensation signatures of Fe in the pyrocloud vapor. While we uncover information about the evaporation and condensation thermodynamics in the pyrocloud, the exact formation mechanisms of the complete suite of spherules remain complex with some spherules potentially forming from multiple mechanisms, including recondensation and splash–melting.