Meteoritics & Planetary Science最新文献

{"title":"Thermal histories of El Médano 300 (EM 300) and Northwest Africa 8155 (NWA 8155): Implications for the diversity of IAB-ungrouped iron meteorites and their parent bodies","authors":"L. Perez,&nbsp;M. Roskosz,&nbsp;F. Danoix,&nbsp;L. Kern,&nbsp;V. Megevand,&nbsp;C. Brillatz,&nbsp;B. Devouard,&nbsp;J. Gattacceca,&nbsp;M. Gounelle","doi":"10.1111/maps.70172","DOIUrl":"https://doi.org/10.1111/maps.70172","url":null,"abstract":"<p>This study provides the first petrographic, crystallographic, and chemical comparison between El Médano 300 (EM 300) and Northwest Africa 8155 (NWA 8155), two particular IAB-ungrouped iron meteorites. Both contain exceptionally large graphite nodules and “flowers”, providing unique insights into carbon behavior in metallic melts and cooling conditions. Despite these similarities, they differ in their petrography, crystallography, and chemical composition. Whereas EM 300 exhibits a homogeneous metallic phase with rounded kamacite grains, originating from at least two taenite crystals, NWA 8155 displays a heterogeneous composition with elongated kamacite crystals, from a unique taenite crystal, along with martensite and residual taenite. Variations in nickel and highly siderophile elements contents point to different degrees of partial melting, indicating in turn formations within two different metallic pools, most probably on separate parent bodies. Troilite textures in EM 300 (spidery), compared to NWA 8155 (bulky), suggest an impact-related origin. Abundant small schreibersite grains in EM 300 indicate faster post-impact cooling. Finally, the absence of silicates in both meteorites suggests efficient metal-silicate segregation or formation within metallic parent bodies. These results provide new insights into the diversity of thermal and collisional histories among IAB-ungrouped iron meteorites, supporting the idea that each one may represent a single parent body and therefore reflecting the diversity of early planetesimal natures and evolutions.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":"1763-1787"},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70172","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Raman analysis of organic refractory materials after energetic processing: Evidence for amorphous carbon on TNOs and comets","authors":"M. Germanà,&nbsp;A. Vyjidak,&nbsp;G. A. Baratta,&nbsp;B. M. Giuliano,&nbsp;R. G. Urso,&nbsp;C. Scirè,&nbsp;D. Fulvio,&nbsp;T. Grassi,&nbsp;P. Jusko,&nbsp;P. Caselli,&nbsp;M. E. Palumbo","doi":"10.1111/maps.70190","DOIUrl":"https://doi.org/10.1111/maps.70190","url":null,"abstract":"<p>Amorphous carbon (αC) is found in various extraterrestrial particles, including those thought to originate from the outer Solar System. αC can form through two main processes involving C-rich materials: exposure to energetic charged particles and thermal processing. Laboratory analyses can constrain the origin of αC in space, as it is not easily detectable through remote sensing. We here investigate the formation of αC on the icy surface of Trans-neptunian objects and Oort cloud comets throughout their exposure to energetic ions. We use organic refractory residues (ORRs), which are laboratory simulants of refractory organics in space, obtained from the irradiation (200 keV ions) of various icy mixtures (N₂, CO, CH₄, CH₃OH). <i>As formed</i> ORRs were further irradiated at room temperature (αC-ORRs) and analyzed by Raman spectroscopy. Our <i>as formed</i> ORRs do not exhibit αC that is in turn detected in αC-ORRs. The carbonaceous structure of αC-ORRs shows high disorder and dependence on the initial icy composition. Nitrogen-bearing αC-ORRs exhibit structural properties similar to some extraterrestrial particles likely originating from icy outer bodies, whereas annealed αC-ORRs mimic materials that underwent different degrees of metamorphism. Our findings highlight how Raman characterization of αC in extraterrestrial samples serves as a strong analysis tool in providing insights into the evolution of different Solar System objects.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":"1994-2015"},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70190","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visible, near-, and thermal infrared spectra of asteroid Bennu samples: Relationship to and implications for remote sensing of carbonaceous asteroids","authors":"V. E. Hamilton,&nbsp;E. A. Cloutis,&nbsp;R. E. Milliken,&nbsp;P. Haenecour,&nbsp;D. R. Golish,&nbsp;K. J. Domanik,&nbsp;T. J. McCoy,&nbsp;L. P. Keller,&nbsp;A. A. Simon,&nbsp;H. H. Kaplan,&nbsp;C. A. Goodrich,&nbsp;S. A. Sandford,&nbsp;D. Applin,&nbsp;T. Hiroi,&nbsp;D. H. Hill,&nbsp;N. G. Lunning,&nbsp;F. M. McCubbin,&nbsp;S. A. Eckley,&nbsp;C. J. Snead,&nbsp;E. H. Blumenfeld,&nbsp;J. E. Aebersold,&nbsp;C. Schultz,&nbsp;N. Bowles,&nbsp;K. A. Shirley,&nbsp;S. S. Russell,&nbsp;J. J. Barnes,&nbsp;T. J. Zega,&nbsp;D. N. DellaGiustina,&nbsp;A. J. Ryan,&nbsp;D. P. Glavin,&nbsp;J. P. Dworkin,&nbsp;H. C. Connolly Jr.,&nbsp;D. S. Lauretta","doi":"10.1111/maps.70176","DOIUrl":"https://doi.org/10.1111/maps.70176","url":null,"abstract":"<p>Remote spectroscopy is used to characterize the mineralogy and infer the history of planetary bodies. Carbonaceous asteroids, such as B-type (101955) Bennu, represent the earliest stages of planet formation. B types have a blue (negative) spectral slope and comprise &lt;5% of asteroids. Samples from Bennu returned by the OSIRIS-REx spacecraft complement remote observations of this rare population. We show here, using laboratory spectra that are directly comparable to spacecraft data, that OSIRIS-REx accurately determined Bennu's dust content and most of its surface composition. However, spectra of the asteroid exhibit stronger water absorptions than those of bulk samples, possibly due to hydrous, Mg-rich phosphate or solar wind implantation at Bennu's uppermost surface. Bennu samples spectrally resemble the most aqueously altered carbonaceous meteorites and samples of (162173) Ryugu, indicating similarly pervasive aqueous alteration. However, one carbon-enriched Bennu stone does not appear to have a spectral analog among Ryugu samples or meteorites. Our findings demonstrate the leverage obtained using a wide range of wavelengths and that sample analysis anchors the interpretations of remote sensing, leading to more robust characterization of planetary surface composition and evolution.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":"1788-1805"},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70176","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morpho-structural analysis of impact craters on Pluto: Implications for the study of complex craters","authors":"N. de Campos,&nbsp;A. P. Crósta","doi":"10.1111/maps.70193","DOIUrl":"https://doi.org/10.1111/maps.70193","url":null,"abstract":"<p>We used Pluto's global digital elevation model to automatically perform a morphometric analysis of impact craters. Triangular irregular networks (TINs) were generated for each crater, providing a detailed representation of crater topography and enabling more accurate morpho-structural analysis. A dedicated toolkit generated radial profiles for each crater providing diameter, depth, and, when present, central peak height measurements. Pluto's craters were classified into simple, transitional complex, and complex categories. For all complex craters, central peak heights were measured, representing the first comprehensive compilation of these data. A subset of well-preserved complex craters was further subdivided based on morpho-structural characteristics into three distinct classes: Complex I, II, and III, resulting in a new catalog of craters. The simple-to-complex transition in Pluto occurs at diameters of 10–14 km. Transitional craters are generally deeper than complex craters of similar diameter, while Complex I-type craters exhibit relatively high central peaks at smaller diameters, and Complex II and III show progressively lower relative peaks at larger diameters.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":"1950-1964"},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70193","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Presolar stardust in the ungrouped chondrite Chwichiya 002","authors":"Lucas R. Smith,&nbsp;Pierre Haenecour,&nbsp;Jessica J. Barnes,&nbsp;Kenneth Domanik,&nbsp;Mason Neuman,&nbsp;Kun Wang,&nbsp;Piers Koefoed,&nbsp;Elias Bloch,&nbsp;Ryan Ogliore","doi":"10.1111/maps.70166","DOIUrl":"https://doi.org/10.1111/maps.70166","url":null,"abstract":"<p>We performed an in-depth study of the mineralogy, petrology, chemical composition, and presolar grain abundance of the C3.00-ungrouped chondrite Chwichiya 002 using a combination of in situ and bulk analytical methods. Chwichiya 002's bulk composition is significantly enriched compared to CI chondrites (over 20 × CI for Sr, Ba, U) in rare earth and trace elements like Li, Sr, Ba, U, and Pb, indicating effects of terrestrial weathering. Concentrations of Ti and Al are similar to CI chondrites, but notably depleted relative to other carbonaceous chondrite groupings, suggesting that the parent body of Chwichiya 002 accreted from a source with a near CI composition of refractory elements, and with a low quantity of calcium–aluminum-rich inclusions. A slight reduction in Fe is linked to the predominance of FeO-poor chondrules and olivine, likely a remnant of Chwichiya 002's formation history. Our findings uncovered phyllosilicates in the matrix and combinations of tochilinite–cronstedtite, confirming that Chwichiya 002 underwent more extensive alteration on its parent body than previously believed. We identified 12 O-anomalous presolar grains (8 Group 1, 4 Group 4) and nine presolar SiC grains, with abundances of 12.1 + 4.6/−3.5 ppm for O-rich grains and 7.8 + 3.6/−2.6 ppm for SiC grains. The relatively low occurrence of O-rich presolar grains is similar to what is seen in CM2 chondrites and samples from asteroid 162173 Ryugu, despite Chwichiya 002 being classified as type 3.00 petrologically. We conclude that Chwichiya 002 formed from a refractory-poor source similar to CM and CO chondrites, primarily consisting of FeO-poor chondrules and olivine, and underwent a moderate level of aqueous alteration on its parent body. Furthermore, the mineralogy, petrology, and compositional data reported in this study, combined with previous data on the O-isotopes of Chwichiya 002, suggest that the sample may better be classified as a CM2.8 or CM 2.9 chondrite.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":"1742-1762"},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced aqueous alteration in primitive meteorites: Micro- to nanoscale studies of CR1 iron sulfides","authors":"S. A. Singerling","doi":"10.1111/maps.70177","DOIUrl":"https://doi.org/10.1111/maps.70177","url":null,"abstract":"<p>This study documents micro- to nanoscale observations of primary nebular and secondary parent body iron sulfides in the CR1 GRO 95577. Despite the extensive alteration of the bulk sample, some primary sulfides managed to avoid alteration, having originally formed in the solar nebula during chondrule formation by either fission-sulfidization or crystallization. Secondary sulfides formed by precipitation from a fluid during aqueous alteration on the parent body and show features such as lath-like or euhedral morphologies, fine-scale intergrowths with serpentine, and porosity in pyrrhotite. Microstructures in pentlandite are most consistent with formation via impact-induced shock. Experiments have the potential to better constrain the effects of shock on pentlandite. Given pentlandite's ubiquity in both minimally and heavily altered meteorites, it has the potential to be used as a shock indicator for samples otherwise ill-suited to shock determination (i.e., heavily aqueously altered materials).</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":"1806-1825"},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70177","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover","authors":"","doi":"10.1111/maps.70222","DOIUrl":"https://doi.org/10.1111/maps.70222","url":null,"abstract":"<p>\u0000 \u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70222","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LifeMet: Report on the 2024–2025 meteorite recovery expedition in Dronning Maud Land, Antarctica for the study of microbe–meteorite interactions","authors":"Rachael Lappan,&nbsp;Rachel S. Kirby,&nbsp;Andrew G. Tomkins","doi":"10.1111/maps.70178","DOIUrl":"https://doi.org/10.1111/maps.70178","url":null,"abstract":"<p>Since the discovery of nine meteorites near the Yamato mountains in 1969, Antarctica has been recognized as a superb location for meteorite recovery. While Antarctic recovery expeditions prioritize meteorite preservation for mineralogical and planetary studies, meteorites are not typically collected for biological applications. The LifeMet expedition was the first Australian Antarctic meteorite recovery expedition, conducted in the 2024–2025 austral summer in the Wohlthat and Orvin Mountains in Dronning Maud Land, Antarctica. The expedition had two primary objectives: (1) to examine whether Antarctic microorganisms colonize and consume nutrients from meteorites, providing insights into microbial ecosystem formation, interactions with uncommon minerals and extremophile survival strategies in Antarctica; and (2) to evaluate the practical and logistical factors influencing meteorite recovery in these regions, and the suitability of recovery approaches for biological sampling. A total of 13 stones, including one confirmed meteorite, were recovered. Adjacent environments (air, sediment, snow, ice, and terrestrial rocks) were sampled to characterize microbial sources. We found that low-altitude blue ice zones were poorly suited to meteorite recovery; however, microbe–meteorite interactions may be enhanced in these areas due to warmer temperatures and periodic ice melting. Our observations suggest that the low albedo of meteorites may promote the formation of periodically water-filled potholes and cryoconite, which may support microbial proliferation. In contrast, meteorites stranded on nunataks are minimally oxidized. Based on our observations at ~71°S, blue ice fields at altitudes above ~2000 m are better suited to meteorite recovery at current climatic conditions.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":"1847-1860"},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70178","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges of measuring volatiles in enstatite chondrites and evaluating their contribution to earth's volatile inventory","authors":"M. L. Gray,&nbsp;M. K. Weisberg,&nbsp;C. M. O'D. Alexander,&nbsp;J. Wang,&nbsp;D. I. Foustoukos,&nbsp;D. S. Ebel","doi":"10.1111/maps.70192","DOIUrl":"https://doi.org/10.1111/maps.70192","url":null,"abstract":"<p>Measurements of bulk H, N, and C abundances and isotopic compositions were conducted on (metal-free) aliquots of 12 powdered enstatite chondrite (EC) samples, from both EH and EL chemical groups, and four aubrites. The ECs covered a range of petrologic types, including both falls and finds. To understand the internal H distributions, the H concentrations of individual silicate minerals were analyzed in situ by NanoSIMS in polished thick sections of six of the ECs. Using these data, combined with published data on H carriers and their modal abundances in ECs, we estimate here that the major silicate minerals, matrix, and mesostasis in unequilibrated ECs account for less than 20% of the total H budget. For the metamorphosed E4–6 chondrites, which exhibit a recrystallized matrix and mesostasis, over 99% of the bulk H contents remain unexplained. We attribute the discrepancies between our analyzed bulk H elemental compositions and the bulk H values reconstituted from in situ measurements are attributed to terrestrial contamination, as water adheres to grain boundaries, surfaces, and fractures. Water also reacts with reduced phases, regardless of whether the meteorite is a fall or find. Similar H isotopic compositions for falls and heavily weathered finds are consistent with, but do not require, that the majority of EC H is terrestrial. Attempts to remove organic terrestrial contamination by solvent extractions only served to moderately shift the H, N, and C isotopic compositions. The δD, δ¹⁵N, and δ¹³C values of EC powders are lighter than BSE, although δD and δ¹³C values partially overlap with atmospheric values. Reconstruction of the H budget of an EL-like parent body with an onion-shell structure suggests that such bodies could account for at most a fourth of the bulk silicate Earth's (BSE's) water budget.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":"1928-1949"},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of a local BCC-type coordination of cobalt in FCC taenite of iron meteorites","authors":"Kanako Yoshihara,&nbsp;Akira Yoshiasa,&nbsp;Huimin Shao,&nbsp;Makoto Tokuda,&nbsp;Ginga Kitahara,&nbsp;Hiroshi Isobe","doi":"10.1111/maps.70180","DOIUrl":"https://doi.org/10.1111/maps.70180","url":null,"abstract":"<p>Ni, Co, and Fe K-edge X-ray absorption fine structure (XAFS) measurements were performed, revealing an unexpected local structure around Co in well-known iron and stony-iron meteorites. Cobalt is enriched in kamacite but remains in taenite at concentrations of at least 0.3 atom%. The Co K-edge X-ray absorption near-edge structure (XANES) spectra of taenite with a face-centered cubic (FCC) structure in all examined iron meteorites exhibited an unexpected body-centered cubic (BCC)-type local coordination, with Co showing a coordination number of 8 + 6. The local FCC and BCC structures can be clearly distinguished based on their XANES patterns. In taenite, up to 20% of the local structure is inferred to be BCC in regions where three-dimensional periodicity is maintained. Moreover, local BCC structures are likely to predominate in subregions that do not contribute to three-dimensional periodicity. Co transforms into a locally ordered BCC structure within the high-temperature parent FCC phase of iron meteorites. In this phase, Co appears to have a stronger affinity for Fe than for Ni, leading to the formation of Co-Fe clusters with a regular BCC arrangement.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 8","pages":"1861-1874"},"PeriodicalIF":3.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70180","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}