Meteoritics & Planetary Science最新文献

{"title":"Araguainha Dome, Brazil: A polygonal impact structure due to a complex pre-impact regional structural framework","authors":"Renato B. Bernardes,&nbsp;Wolf U. Reimold,&nbsp;Roger L. Gibson,&nbsp;Julia B. Curto Ma,&nbsp;Adolfo B. Silva,&nbsp;Natalia Hauser","doi":"10.1111/maps.70159","DOIUrl":"https://doi.org/10.1111/maps.70159","url":null,"abstract":"<p>We investigated the structural framework of the north–northwestern Paraná Basin in Brazil to test whether the pre-impact structures in this region may have had any influence on the first-order formation and morphostructure of the Araguainha impact structure (AIS). The AIS—an ~40-km-diameter, erosional remnant of the largest confirmed, complex impact structure in South America—was formed approximately 259–252 Ma in a mixed sedimentary-crystalline target. We employed a multi-method approach, including airborne geophysics, remote sensing, lineament analysis, fieldwork, and modeling of the shape of the (apparent) outer rim trace. This approach reveals that prominent NE–SW- and NW–SE-trending lineaments characterize the AIS region. Much of this fabric can be linked to regional structures associated with the Paraguay Belt and, to a lesser extent, the Transbrasiliano Lineament—both of which influenced the NNW Paraná Basin during its pre-impact evolution. We present evidence that this preexisting regional structural framework partially controlled the formation and shape of the AIS. The AIS and its central uplift are asymmetric features, with the asymmetry of the central uplift evident from the time of its formation. Our results suggest that the shape of the AIS rim trace is consistent with a polygonal structure. At the analyzed scale, the AIS rim trace is best described as an irregular nine-sided polygon. This polygonal shape was likely formed during the modification stage, when crater collapse was influenced by the regional pre-impact structural fabric. Our findings improve understanding of the cratering process in structurally heterogeneous targets and provide valuable insights into the target region's subsurface structural framework.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 7","pages":"1355-1385"},"PeriodicalIF":3.2,"publicationDate":"2026-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70159","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148533055","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":"In search of the historical roots of the extraterrestrial impact theory, III: Earth's revolutions versus mega-impact periodicity after the mid-19th-century French geologist Félix de Boucheporn","authors":"Grzegorz Racki,&nbsp;Vincent Thiéry","doi":"10.1111/maps.70153","DOIUrl":"https://doi.org/10.1111/maps.70153","url":null,"abstract":"<p>Despite the inspiring discoveries in Laplace's <i>System of the World</i> (1796), the relatively little-known contributions of the French to the theory of celestial collisions in the 19th century deserve greater recognition. In fact, only a few French impactists emerged during this time, such as Nérée Boubée (1806–1862) and Frédéric Chapel (1849–1932). In particular, Chapel, a military officer, was a farseeing pioneer of the Spaceguard and planetary defense programs proposed in 1883. However, a unique case is René-Charles-Félix Bertrand de Boucheporn (1811–1857), a superb field geologist, mining engineer, and natural philosopher. In 1844, he published the voluminous treatise <i>Studies on the History of the Earth and the Reasons of the Revolutions of its Surface</i>. Drawing on the work of two of the most eminent figures in French science, Laplace and Cuvier, Boucheporn shed new light on the fossil record, periodically disturbed by bolide mega-impacts. His novel “system of geology” was based on the premise that repeated cometary impacts formed the equatorial mountains and marked the boundaries of geological periods by altering the biosphere as a result of climate change. Unlike Laplace, Boucheporn supposed that, despite their low density, the huge and fast cometary projectiles could alter the Earth's axis of rotation. He highlighted that, on a geological time scale, bolide impacts occurred with “a probability equivalent to certainty.” Boucheporn also conducted a refined analysis of comet impact probability, arguing that a mega-collision would occur within 3 million years, which would coincide with the typical duration of geological periods. As recently evaluated by Şengör, Boucheporn's treatment of bolide bombardment was much more sophisticated than that of his predecessors. From a modern perspective, the extreme catastrophism proposed by Boucheporn was flawed, especially due to the substantial overestimation of comet size and speed. He advocated a model of impact-forced punctuated evolution of the biosphere. Indicating the inevitability of an extraterrestrial impact in the geological past, he developed Laplace's laconic consideration of rare events into a meaningful hypothesis with a mathematical basis (rediscovered as a basic neocatastrophic theory by Gretener as late as 1967).</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 7","pages":"1146-1162"},"PeriodicalIF":3.2,"publicationDate":"2026-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148533005","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":"Geophysical investigation of the Santa Marta impact structure—Piauí State, Brazil","authors":"Elienara Vasconcelos,&nbsp;João De Oliveira,&nbsp;Marcos Vasconcelos,&nbsp;Martyn Unsworth,&nbsp;Andrea Santos-Matos,&nbsp;Florivaldo Sena","doi":"10.1111/maps.70152","DOIUrl":"https://doi.org/10.1111/maps.70152","url":null,"abstract":"<p>The Santa Marta impact structure in northeastern Brazil, recognized as a partially preserved complex crater, was investigated through an integrated geophysical study employing magnetotelluric (MT) and gravity methods. Our research provides constraints on the crater's subsurface architecture. The study utilized broadband MT data from 17 stations and gravity measurements from 226 stations distributed across the structure. The MT data revealed a distinct three-layered resistivity profile: (i) a shallow resistive layer (100–1000 Ω·m) interpreted as impact breccias and Cretaceous sandstones, (ii) an intermediate conductive zone (1–50 Ω·m) correlated with Paleozoic shales of the Parnaíba Basin, and (3) most significantly, a deep-seated conductive anomaly (1–20 Ω·m) beneath the central uplift. This deep conductivity anomaly likely results from impact-induced fracturing coupled with subsequent fluid infiltration pathways. Gravity data exhibited asymmetric Bouguer anomalies (−41 to −27 mGal) that deviate from the typical circular pattern observed in impact structures. Density contrasts (0.3–1.8 g/cm³) suggest substantial basement uplift and preferential erosional patterns. Dimensionality analysis of the MT data confirmed predominant 3-D effects, necessitating 3-D inversion techniques to accurately resolve the structure's complex geometry. The integrated resistivity and density contrast models reveal a subdivision of both the central uplift and the annular basin, and the asymmetric gravity signature may indicate postimpact deformation effects. Our results advance the understanding of the Santa Marta structure, establishing a robust geophysical framework for future investigations of similar structures in Brazil and globally. The study conclusively demonstrates that Santa Marta represents a highly complex impact structure in terms of both electrical resistivity and density distributions, directly reflecting its fundamental geological asymmetry.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 7","pages":"1399-1416"},"PeriodicalIF":3.2,"publicationDate":"2026-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70152","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148533462","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":"Geology of the central uplift of the Kamestastin Lake impact structure, Labrador, Canada","authors":"A. C. Singleton,&nbsp;G. R. Osinski","doi":"10.1111/maps.70184","DOIUrl":"https://doi.org/10.1111/maps.70184","url":null,"abstract":"<p>The ~28 km Kamestastin (Mistastin) Lake impact structure is a relatively well-preserved and well-exposed complex impact structure. The central uplift of this structure is accessible as two islands in the middle of Kamestastin Lake. We present an updated, detailed geological map and description of Horseshoe and Bullseye islands that provides increased accuracy and detail of the target rock outcrop and contact locations. In addition, we document six occurrences of impact melt-poor breccia dikes and one occurrence of impact melt rock on Horseshoe Island for the first time. The impact melt rock outcrop is proposed to be a remnant of a veneer of impact melt on the original central peak, and the impact melt-bearing breccia dikes to have had a dynamic emplacement mechanism. We also carried out the first detailed, systematic shock study of the central uplift. Planar deformation features in quartz and diaplectic feldspar glass suggest local peak shock pressure of up to 45 GPa. These shock pressures are higher than the peak pressures recorded in the central uplifts of similarly sized impact structures. We suggest that this difference is due to the minimal erosion of the central uplift at the Kamestastin Lake impact structure.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 7","pages":"1417-1433"},"PeriodicalIF":3.2,"publicationDate":"2026-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70184","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148533511","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":"Polymict melt-bearing breccia dikes in the Morokweng impact structure formed by slip-induced mechanical mixing of pseudotachylite and cataclasite along large-displacement impact faults","authors":"Roger L. Gibson,&nbsp;S'lindile S. Wela,&nbsp;Leonidas C. Vonopartis,&nbsp;Marco A. G. Andreoli","doi":"10.1111/maps.70136","DOIUrl":"https://doi.org/10.1111/maps.70136","url":null,"abstract":"<p>A core drilled through shocked and faulted Archean granitoid gneisses and dolerites in the eroded peak ring of the 70–80 km diameter Morokweng impact structure intersects multiple centimeter- to meter-wide clastic-matrix breccias containing a polymict clast population of lithic and mineral clasts and altered, millimeter- to centimeter -size, melt clasts. These polymict melt-bearing (PMB) breccias occur both as discrete dikes and in meter- to decameter-wide composite breccia intersections where they are intimately associated with cataclasite and pseudotachylite. Petrographic and bulk-rock geochemical analysis confirms that the PMB breccias comprise fragmental and melt material derived exclusively from the granitoid and doleritic wallrocks, with local geochemical deviations attributable to metasomatic hydrothermal alteration. Notwithstanding their almost complete replacement by smectite and zeolite assemblages, the melt clasts display textural and compositional characteristics identical to the pseudotachylite dikes. Composite lithic-melt clasts indicate an intimate association of melting with cataclasis and comminution prior to their incorporation into the PMB breccias. While most melt clasts display sharp, angular shapes, indicating brittle fracturing, local preservation of delicate filaments intruding the adjacent clastic matrix and bulbous to cuspate-lobate melt clast margins against the matrix indicate incorporation into the breccias while still molten and/or plastic. We propose that the PMB breccias formed by a combination of dynamic injection of friction melt into the cataclasite portions of large fault zones and the development of shear-induced Kelvin–Helmholz instabilities along the melt-cataclasite interface during ongoing fault slip. Melt injection into brecciated wallrock and smaller fractures hosting incoherent cataclasite may have been assisted by a pumping-suction mechanism driven by complex, rapidly changing, block movements during crater wall collapse and peak ring formation. Cooling of the pseudotachylite melts during continued shear or compression of the breccia zones led to their embrittlement and mechanical entrainment as fragments into the incohesive cataclastic fault material, producing the hybrid PMB breccia type. Although the complex strain patterns during peak ring formation could have played a role in extending the duration of shear movements affecting the breccias, we propose that the sequence of cataclasis, frictional melting, melt injection, quenching, brecciation of quenched melt, and melt clast entrainment necessary to produce the PMB breccias can be reconciled with a single, continuous, long-duration, large-magnitude, slip event during collapse of the transient crater wall.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 7","pages":"1288-1308"},"PeriodicalIF":3.2,"publicationDate":"2026-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70136","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148522793","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":"Introduction to the special issue of Meteoritics & Planetary Science in honor of Christian Koeberl on his retirement as Professor of the University of Vienna, Austria—A dedication","authors":"Wolf Uwe Reimold,&nbsp;Toni Schulz,&nbsp;Ludovic Ferrière","doi":"10.1111/maps.70186","DOIUrl":"https://doi.org/10.1111/maps.70186","url":null,"abstract":"&lt;p&gt;In this special issue, some of Christian's former students, colleagues, friends, and other members of the larger impact, meteorite, and planetary science community make contributions related to some of the main research topics that Christian has worked about over the past nearly 40 years. This includes the combination of geology and astronomy—both of which have been Christian's scientific hobby horses, history of science, and quality/quality control of scientific publications. Then follow sections on tektites, impact structures and impactites, impact ejecta deposits, and meteorites and asteroids—all major topics of Christian's passion.&lt;/p&gt;&lt;p&gt;However, let us begin with a few words about him—the person, the scholar, and the scientist. Christian Koeberl was born in Vienna (Austria) in 1959 and enjoyed the first 5 years of his life right in the center of this great city, close to the famous St. Stephan Cathedral. Let us assume that he did well enough in primary school, as he was allowed to enter high school. Allegedly he was doing just fine there, in most topics, except in Latin, and was really achieving well in chemistry and physics. This led to a recommendation to continue his high school experience at the “Höhere Bundeslehr- und Versuchsanstalt für Chemische Industrie” (“Higher Federal Institution for Teaching and Experimentation of the Chemical Industry”). It is said that he did reasonably well there, too, until his graduation in 1978. During that time, he was already spending many weekends at the Vienna Planetarium following his interest in astronomy. He ended up helping with running planetarium shows, and, on occasion, also with stargazing events at the public “Urania” observatory. However, and despite his keen interest, after his graduation from the chemistry-focused high school, his father wanted him to study something that would lead to a “decent” profession, not something as esoteric as astronomy.&lt;/p&gt;&lt;p&gt;Christian had already worked in a summer job during school vacations at the laboratory of a large refinery just outside Vienna. He started to study chemistry at the Technical University in Vienna in 1978 and 2 years later also registered for astronomy studies (with chemistry as a second topic) at the university. Logically, he became interested in combining his interests in astronomy (especially of the planets) and chemistry by considering some graduate work in cosmochemistry, which was made possible in the Institute of Analytical Chemistry at the University of Vienna. In addition, he became involved with a search for exoplanets (which had not yet been discovered back then but were suspected to exist). Historical research on the astronomical basis for the specific spatial orientation of medieval churches started a lifelong fascination for science historical issues.&lt;/p&gt;&lt;p&gt;The involvement with cosmochemistry caused a lasting and formidable interest in researching the origin of tektites. In the early 1980s, this was a strongly and at times co","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 7","pages":"1101-1107"},"PeriodicalIF":3.2,"publicationDate":"2026-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70186","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148533062","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":"Revisiting the Hummeln structure, Sweden—A shallow marine Cambrian impact structure","authors":"S. Alwmark,&nbsp;J. Granbom,&nbsp;P. Ahlberg,&nbsp;M. Calner,&nbsp;S. Richoz,&nbsp;K. J. Gajewska,&nbsp;W. R. Hyde,&nbsp;K. Ljung,&nbsp;C. Alwmark","doi":"10.1111/maps.70160","DOIUrl":"https://doi.org/10.1111/maps.70160","url":null,"abstract":"&lt;p&gt;Hummeln is a simple impact structure located in south-eastern Sweden. It is approximately 1.2 km in diameter and almost completely covered by a lake. Here, we present the first detailed investigation of impactites and mapping of the 164.25 m deep drill core Hummeln-1 with a focus on impact metamorphism and the impact process. We find that the drilling has penetrated a complex sedimentary succession representing syn- to postimpact crater fill. It consists of (from base to top) lithic impact breccia (Unit 1), overlain by diamictite and graywacke with an overall fining upward trend grading from sandy into silty to clayey turbidites (Units 2, 3), and, lastly, suspension dominated marine clays and limestone (Units 4, 5). The crater fill was deposited mostly as gravity slides and sediment gravity flows (debris flows, (hyper)concentrated density flows and turbidity flows), which transported sediment into the crater as a series of fan lobes prograding toward the crater center. We have identified shocked quartz in 12 samples covering the interval of 160.69–56.60 m in the drill core and in samples of polymict and suevitic breccia obtained during fieldwork. Shocked quartz grains dominantly record planar fractures (PFs), with an average of 1.5–3.5 sets per grain. We measured a total of 122 PF sets in 54 grains, with orientations parallel to the &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;10&lt;/mn&gt;\u0000 &lt;mover&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;¯&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt;, (0001), and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;11&lt;/mn&gt;\u0000 &lt;mover&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mo&gt;¯&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt; orientations being most common (30%, 26%, 21%, respectively). In the same samples, we also measured and indexed 14 sets of planar deformation features (PDFs) in eight grains, oriented parallel to the basal plane (50%), as well as rhombohedral planes &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;10&lt;/mn&gt;\u0000 &lt;mover&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;¯&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mn&gt;4&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;10&lt;/mn&gt;\u0000 &lt;mover&gt;\u0000 ","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 7","pages":"1213-1242"},"PeriodicalIF":3.2,"publicationDate":"2026-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70160","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148533823","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.70207","DOIUrl":"https://doi.org/10.1111/maps.70207","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 7","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70207","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148533067","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":"Preventing and correcting spread of misinformation about near-Earth objects, impacts, airbursts, and planetary defense: Case studies","authors":"Mark Boslough,&nbsp;Peter Brown,&nbsp;Andy Bruno,&nbsp;Paul Chodas,&nbsp;Gareth Collins,&nbsp;Tyrone L. Daulton,&nbsp;Alan Harris,&nbsp;Christian Koeberl,&nbsp;Ania Losiak,&nbsp;David Morrison,&nbsp;Olga Popova,&nbsp;Darrel Robertson,&nbsp;Elizabeth A. Silber,&nbsp;Matthias van Ginneken","doi":"10.1111/maps.70140","DOIUrl":"https://doi.org/10.1111/maps.70140","url":null,"abstract":"<p>The landscape of scientific publishing and communication is changing rapidly with the accelerating growth of open-access outlets that lack rigorous peer review, revenue-driven online media, inadequately trained journalists, social media, online influencers, podcasts, celebrity endorsements of pseudoscience, anti-science political movements, and the emergence of artificial intelligence. Near-Earth objects, impacts, and airbursts—particularly when related to global catastrophes or planetary defense—often attract intense public interest and the kind of media coverage that is prone to the spread of misinformation. The field of planetary defense has profound consequences, so maintaining public trust is essential to its success. Scientists cannot afford to ignore these challenges merely because they fall outside the scope of conventional scientific discourse. This paper classifies several types of misinformation, presents representative case studies in planetary defense and planetary science, and offers practical approaches for mitigation. We consider (1) rapidly evolving news events requiring timely expert response; (2) intermediate-term cases involving inadequately reviewed publications, overpromotion, and uncritical reporting; and (3) long-term, persistent, and self-perpetuating myths that can grow organically and insidiously, even within the scientific community. We also discuss how misinformation can originate and proliferate through inadequate peer review, news releases and press conferences, exploitation of limited scientific literacy, unsubstantiated claims, and amplification of false narratives by artificial intelligence. Finally, we suggest proactive strategies for preventing and correcting misinformation, with particular attention to its implications for planetary defense.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 7","pages":"1122-1145"},"PeriodicalIF":3.2,"publicationDate":"2026-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148533570","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":"Analysis of hydrogen, carbon, oxygen, sulfur, chlorine, and mercury in samples returned from asteroid (101955) Bennu","authors":"Hisayoshi Yurimoto,&nbsp;Shogo Tachibana,&nbsp;Hisashi Homma,&nbsp;Shintaro Komatani,&nbsp;Tomoaki Watanabe,&nbsp;Kazuko Motomura,&nbsp;Yoshinobu Hosoi,&nbsp;Satoru Tanaka,&nbsp;Mai Sakaguchi,&nbsp;Noriyuki Kawasaki,&nbsp;Jessica J. Barnes,&nbsp;Ann N. Nguyen,&nbsp;Harold. C. Connolly Jr.,&nbsp;Dante S. Lauretta","doi":"10.1111/maps.70158","DOIUrl":"https://doi.org/10.1111/maps.70158","url":null,"abstract":"<p>NASA's OSIRIS-REx mission delivered pristine regolith samples from the near-Earth carbonaceous asteroid (101955) Bennu, enabling direct assessment of primitive asteroid material free from terrestrial alteration. We report comprehensive analyses of H, C, O, S, Cl, and Hg in Bennu samples using X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectrometry (TG-MS), combination analyses of pyrolysis and combustion (EMIA-Step), and direct Hg measurements. Quantification of O, Si, S, Cl, and Ge by XRF is reported for Bennu samples for the first time. TG-MS reveals ~15 mass% total mass loss, with H₂O and CO₂ release patterns attributed to phyllosilicates, carbonates, and organic matter. Bennu samples contain substantially higher interlayer H₂O than those from asteroid Ryugu, consistent with subsurface deeper sampling by OSIRIS-REx. Total carbon abundance is ~4.1 mass%, dominated by organic carbon (~2.9 mass%), comparable to Ryugu samples. Mercury abundances (82–141 ng g⁻¹) are far lower than those reported for CI chondrites, indicating pervasive terrestrial contamination in meteorite samples. We recommend a Hg abundance of 98 ± 2 ng g⁻¹ for Bennu samples and pristine CI-like material, demonstrating that returned asteroid samples provide the most reliable record of primitive carbonaceous matter.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 6","pages":"1012-1025"},"PeriodicalIF":2.4,"publicationDate":"2026-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148221769","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}