The Long Duration Exposure Facility provided the opportunity for micrometeorite researchers to develop and test microparticle collection strategies for spacecraft, and the handling and analytical capabilities required for the Stardust, Hayabusa, and subsequent astromaterial sample return missions to succeed.

We studied a unique super‐refractory inclusion with a core‐mantle structure from CO3.0 Yamato 81020 by secondary ion mass spectrometry, electron microprobe, and scanning electron microscope techniques. The core consists largely of hibonite and nonstoichiometric Al‐rich spinel indicating formation as a liquid at an exceptionally high temperature (>1900 °C). The mantle consists almost entirely of melilite

Some basaltic eucrites and basaltic lithologies in howardites derived from the asteroid 4 Vesta exhibit unusual secondary veinlet textures consisting mostly of fayalitic olivine and Fe‐enrichments within pyroxenes. Recent studies discussed the formation of these Fe‐rich phases either by interaction with a vapor and/or liquid phase (metasomatism), or by a high‐temperature melting process. We therefore

The paragenesis of carbonates in the Cold Bokkeveld CM chondrite is determined from a detailed petrographic, chemical, spectroscopic, and isotopic study of nine associations of carbonates (aragonite, calcite, and dolomite) with other secondary minerals that occur within the meteorite. Our study reveals the existence of carbonates displaying petrographic features that are distinct from those of type

This work focuses on the historical and scientific investigation of a presumed meteorite fall that occurred in the Sicilian township of Marsala in 1834. Preliminary studies have classified this phenomenon as a “doubtful meteorite.” This term describes, according to the Nomenclature Committee of the Meteoritical Society, an object for which there was significant uncertainty over whether it was a real

The large variations in hydrogen isotope ratios found in insoluble organic matter (IOM) in chondritic meteorites may be attributed to hydrogen isotopic exchange between IOM and water during aqueous alteration. We conducted D–H exchange experiments (1) during synthesis of IOM simulant (hereafter called chondritic organic analog, COA) from formaldehyde, glycolaldehyde, and ammonia with water, and (2)

The lunar meteorite Dhofar 1436 is dominated by solar wind type noble gases. Solar argon is equilibrated with “parentless” 40Ar commonly known as lunar orphan argon. Ar‐Ar isochron analyses determined the lunar trapped 40Ar/36Ar ratio to 2.51 ± 0.04, yielding a corrected plateau age of 4.1 ± 0.1 Ga, consistent with the lunar Late Heavy Bombardment period. Lunar trapped and radiogenic argon components

The angrites are a class of achondrites that encompass a wide range of igneous textures from quenched, volcanic, and subvolcanic stones to slowly cooled, plutonic rocks. The compositions of the various geochemical reservoirs generating this variety of rocks have not been investigated fully because historically the numbers and masses of angrites available for study have been quite small. However, the

Refractory calcium‐aluminum‐rich inclusions (CAIs) and amoeboid olivine aggregates (AOAs) in chondritic meteorites are the earliest solids of our solar system, bearing the information of nebular condensation as well as accretion and asteroidal shock and metasomatism processes. While the compositions of refractory inclusions have been intensely studied for ~50 years, their physical properties such as

The Martian breccias NWA 7034, NWA 7533, and paired meteorites record events ranging in age from 4.47 Ga to <200 Ma. Published ages indicate a period of major disturbance at ~1.4 Ga, examined in detail here through 40Ar/39Ar dating of handpicked grains and two small chips. Argon diffusion parameters were obtained for six samples. Also presented are He, Ne, Ar, Kr, and Xe contents of two small (<100 µg)

The target bodies of C‐complex asteroid sample return missions are carbonaceous chondrite‐like near‐Earth asteroids (NEAs), chosen for the abundance and scientific importance of their organic compounds and “hydrous” (including hydroxylated) minerals, such as serpentine‐group phyllosilicates. Science objectives include returning samples of pristine carbonaceous regolith from asteroids for study of the

The organic compositions of carbonaceous chondrite meteorites have been extensively studied; however, there have been fewer reports of other meteorite classes, and almost none from iron meteorites, which contain much less carbon than carbonaceous chondrites but make up ~4% of observed meteorite falls. Here, we report the bulk amino acid content of three iron meteorites (Campo del Cielo, IAB; Canyon

Understanding the transformations of highly reduced enstatite chondrites (EC) in terrestrial environments, even on very short timescales, is important to make the best use of the cosmochemical and mineralogical information carried by these extraterrestrial rocks. Analogs of EC meteorites were synthesized at high pressure and high temperature. Then, their aqueous alterations, either abiotic or in the

Asteroid 4 Vesta is the only largely preserved differentiated asteroid and thus is an excellent proxy to study early magmatism occurring on planets and moons. In this study, we focus on eucrite Pecora Escarpment (PCA) 82502, a medium‐ to fine‐grained eucrite which chemical analyses suggest belongs to the main howardite–eucrite–diogenite clan, albeit with some peculiarities. We carried out backscattered

We measured noble gases in “cluster chondrite clasts” from nine unequilibrated ordinary chondrites (UOCs). For five meteorites, we also present data for so‐called “clastic matrix,” the impact‐brecciated material in which the angular to subrounded cluster chondrite clasts are often embedded. Cluster chondrite clasts are characterized by close‐fit texture of deformed and indented chondrules with lower

Colomera is the Spanish meteorite (IIE) that has aroused the greatest interest among the international scientific community. Until now, the story of the find was only partially known and certain data are incorrect. The amazing journey of this meteorite has been recounted in this work. It reveals unpublished information derived from local archives, and testimonies from the descendants of the family

In the article “Caleta el Cobre 022 Martian meteorite: Increasing nakhlite diversity” which was published in Meteoritics & Planetary Science; Volume 55 Issue 7, pp. 1539–1563 with http://dx.doi.org/10.1111/maps.13534, some of the references were incomplete, and there was one mistake in the main text. Updated references are as below: Bland P. A., Zolensky M. E., Benedix G. K., and Sephton M. A. 2006

The June 2, 2018 impact of asteroid 2018 LA over Botswana is only the second asteroid detected in space prior to impacting over land. Here, we report on the successful recovery of meteorites. Additional astrometric data refine the approach orbit and define the spin period and shape of the asteroid. Video observations of the fireball constrain the asteroid's position in its orbit and were used to triangulate

High‐resolution images and elevation data sets from the Lunar Reconnaissance Orbiter along with spectral data from the Clementine mission are used to identify and map in detail the well‐preserved Late Imbrian Tsiolkovskiy crater situated on the far side of the Moon. This study identifies five distinct morphologic units associated with Tsiolkovskiy crater and the surrounding ejecta blanket. Analysis

We report on the geochemical analyses of glassy spherules from sediments at three Transantarctic Mountain locations and the discovery of Australasian microtektites at two of these sites. Australasian microtektites are present at Mt. Raymond (RY) in the Grosvenor Mountains and Meteorite Moraine (MM) at Walcott Névé, in the Beardmore Glacier region of Antarctica. The microtektites were identified based

The geochemistry and textures of phosphate minerals can provide insights into the geological histories of parental asteroids, but the processes governing their formation and deformation remain poorly constrained. We assessed phosphorus‐bearing minerals in the three lithologies (light, dark, and melt) of the Chelyabinsk (LL5) ordinary chondrite using scanning electron microscope, electron microprobe

Remnant extraterrestrial chrome spinels from terrestrial sediments provide information on how the mixture of meteoritic materials falling to Earth has changed over Earth’s history. The parent meteorite type of each grain can be identified by characteristic elemental and oxygen‐isotope abundances. Some meteorite types can be difficult to classify because their chrome‐spinel compositional ranges overlap

Olivine is a principal anhydrous silicate mineral in chondritic meteorites. The structure of this mineral is composed of independent SiO4 tetrahedra linked by divalent cations (mainly Mg). Under hydrothermal conditions, olivine is transformed into serpentine, which is a major hydrated phyllosilicate in the matrix of carbonaceous chondrites. Although carbonaceous chondrites contain various types of

We report bulk composition data for 235 stones of ~77 lunar meteorites from northern Africa and 33 lunar meteorites from elsewhere. About 27% of the African meteorites are typical feldspathic lunar rocks, all breccias of similar bulk composition, for example, 3–5% FeO and low concentrations of incompatible elements. Nevertheless, these meteorites have a large range in Mg' (whole‐rock mole% Mg/[Mg + Fe])

Murrili, the third meteorite recovered by the Desert Fireball Network, is analyzed using mineralogy, oxygen isotopes, bulk chemistry, physical properties, noble gases, and cosmogenic radionuclides. The modal mineralogy, bulk chemistry, magnetic susceptibility, physical properties, and oxygen isotopes of Murrili point to it being an H5 ordinary chondrite. It is heterogeneously shocked (S2–S5), depending

On April 23, 2019, a meteorite fall occurred in Aguas Zarcas, Costa Rica. According to the Meteoritical Bulletin, Aguas Zarcas is a brecciated CM2 chondrite dominated by two lithologies. Our X‐ray computed tomography (XCT) results show many different lithologies. In this paper, we describe the petrographic and mineralogical investigation of five different lithologies of the Aguas Zarcas meteorite.

Opaque assemblages (OAs) are small (submillimeter) objects composed primarily of metals, sulfides, and oxides that exist in nearly all chondritic meteorite groups as discrete objects in the matrix or associated with chondrules. The size, morphology, and petrology of OAs vary greatly between different chondrite groups, with petrologic grade within a single group, and by their apparent textural setting

The distribution of shock deformation effects, as well as the structural expression of an impact structure, can be asymmetric, depending on target rock lithologies (e.g., layered versus homogenous), porosity of target rock, and angle of impact. Here, we present a detailed study of shock‐deformed quartz and zircon in silicified sandstones from the asymmetric Spider impact structure in Australia. We

The advancement in the acquisition of spectral data from meteors, as well as the capability to analyze meteoritic entries in ground testing facilities, requires the assessment of the performance of software tools for the simulation of spectra for different species. The Plasma Radiation Database, PARADE, is a line‐by‐line emission calculation tool. This article presents the extensions implemented for

Recognition of impact‐induced deformation of minerals is crucial for the identification and confirmation of impact structures as well as for the understanding of shock wave behavior and crater formation. Shock deformed mineral grains from impact structures can also serve as important geochronometers, precisely dating the impact event. We investigated zircon grains from the Mien impact structure in

For ordinary‐chondrite (OC) mass distributions, Benford’s law applies to the set of individual objects that survive intact on the Earth’s surface after atmospheric disruption of meteoroids. Among OCs, Antarctic finds conform more closely to Benford’s law than observed falls, Northwest Africa (NWA) finds, or Oman finds mainly because Antarctic OCs tend to be relatively unweathered (and mostly intact)

The Allende, Eagle Station pallasites (ESP), some ungrouped achondrites (UA), and ungrouped irons (UI) represent different types of meteorites; these are traditionally distinguished as chondrule‐bearing chondrite, chondrule‐free stony irons, stones, and irons, respectively. Oxygen isotopic compositions of meteorites have long been used as a robust tool to identify the parent bodies of these extraterrestrial

The impact melt‐bearing breccias at the Ries impact structure, Germany, host degassing pipes: vertical structures that are inferred to represent conduits along which gases and fluids escaped to the surface, consistent with hydrothermal activity that occurs soon after an impact event. Although the presence of degassing pipes has been recognized within the well‐preserved and long‐studied ejecta deposits

Apatite has been widely used for assessing the volatile inventory and hydrothermal fluid compositions of asteroidal and planetary bodies. We report the OH, F, and Cl abundances, as well as the hydrogen isotope composition, of apatite in the CM1‐2 chondrite Boriskino and in the C1‐ungrouped Bench Crater meteorite. Apatite in both meteorites is halogen‐poor, close to the hydroxylapatite endmember composition

Highly siderophile element (HSE: Au, Re, Pd, Pt, Rh, Ru, Ir, Os) abundances in planetary silicate mantles provide constraints on accretion and differentiation, as well as late accretion additions after core formation. The first in situ analyses of the HSE in mare basalt sulfide and metal phases enable the determination of the distribution of these elements during fractional crystallization processes

The continuous ejecta deposit around the rim of Lonar impact crater, central India, contains angular basaltic boulders of size ≤5 m. These boulders experienced varying level of shock between 2–30 GPa due to impact, as indicated by the extreme fracturing of these basaltic boulders, fragmentation of plagioclase and titanomagnetite constituents of these ejected boulders, and the presence of maskelynite

The CM carbonaceous chondrites provide unique insights into the composition of the protoplanetary disk, and the accretion and geological history of their parent C‐complex asteroid(s). Of the hundreds of CMs that are available for study, the majority are finds and so may have been compromised by terrestrial weathering. Nineteen falls have been recovered between 1838 and 2020, and there is a hint of

We describe a fragmented cryptocrystalline chondrule consisting solely of forsterite (Fo98) in the Murchison CM2 chondrite, with a peculiar porous texture of enigmatic origin.

The size distribution, abundance, and physical and chemical characteristics of chondritic inclusions are key features that define the chondrite groups. We present statistics on the size and abundance of the macroscopic components (inclusions) in the Murchison (CM2) and Allende (CV3) chondrites and measure their general chemical trends using established X‐ray mapping techniques. This study provides

The C1‐ungrouped carbonaceous chondrite Flensburg fell in Germany on September 12, 2019, in the daytime. We determined the atmospheric trajectory, velocity, and heliocentric orbit using one dedicated AllSky6 meteor camera and three casual video records of the bolide. It was found that the meteorite originated in the vicinity of the 5:2 resonance with Jupiter at heliocentric distance of 2.82 AU. When

X‐ray absorption fine structure (XAFS) spectroscopy methods have been applied to focused ion beam (FIB) produced sections of olivine and pyroxene for determining the valence states of Ti, V, and Cr and inferring oxygen fugacities of formation for each element. High‐quality XAFS spectra were obtained for all three elements for analytical voxels of ~10 pg and usable spectra down to the pg level are achievable

The group IIF iron meteorites and Eagle Station pallasites (PES) have highly siderophile element abundances (HSE; Re, Os, Ir, Ru, Pt, and Pd) of metal that are consistent with formation in planetesimal cores by fractional crystallization with minor to major solid metal–liquid metal mixing. Modeling of HSE abundances of the IIF irons indicates a complex formation history that included the mixing of

This study aimed to determine the volatile content (Cl, F, OH) and hydrogen isotope (D/H) ratios of apatite grains within the Martian meteorite NWA 11522, a paired stone of the ungrouped polymict breccia NWA 7034. Apatite F:Cl:OH ratios were measured via SEM‐EDS analyses, and found to be strikingly similar in all grains, and dominated by Cl. Apatite D/H ratios were measured in situ via the Cameca ims

Synchrotron Fe‐K X‐ray absorption spectroscopy and transmission electron microscopy have been used to investigate the mineralogy and Fe‐redox variations in the space‐weathered (SW) rims of asteroidal samples. This study focuses on the FIB lift‐out sections from five Itokawa grains, returned by the Hayabusa spacecraft, including samples RB‐QD04‐0063, RB‐QD04‐0080, RB‐CV‐0011, RB‐CV‐0089, and RB‐CV‐0148

Shock‐induced melting textures and high‐pressure polymorphs in 178 ordinary chondrites of all chemical groups and petrologic types were investigated. The shock‐induced melting modes were classified into three types, namely pocket, line, and network. The type of shock‐induced melting depends on the petrologic type. The width of the shock‐induced melt increased with increasing the petrologic type number

In order to understand the effects of the earliest stages of hydrothermal alteration and fluid‐assisted metamorphism on the matrices of unequilibrated ordinary chondrites (UOCs), we have investigated the fine‐grained matrix of MET 00526 (L3.05) using multiple electron microscope techniques. Iron‐rich olivines (Fa50‐100) are present in all four representative fine‐grained matrix regions analyzed in

The Pesyanoe aubrite is an essentially polymict regolith breccia comprised by fragments of different highly magnesian pyroxenitic lithologies: albite; anorthoclase and labradorite‐bearing pyroxenites; diopside and magnesian augite pyroxenites; roedderite‐ and forsterite‐bearing pyroxenites; and impact glasses; porphyritic and melt matrix breccia fragments; FeO‐rich chondritic inclusions; and exotic

We report the discovery of a unique, refractory phase‐bearing micrometeorite (WF1202A‐001) from the Sør Rondane Mountains, East Antarctica. A silicate‐rich cosmic spherule (~400 µm) displays a microporphyritic texture containing Ca‐Al‐rich inclusion (CAI)‐derived material (~5–10 area%), including high‐Mg forsterite (Fo98‐99) and enstatite (En98‐99, Wo0‐1). The micrometeorite also hosts a spherical

Two forms of carbon‐rich microfossils were discovered in the breccias of the Onaping Formation, Sudbury impact structure. The first form is represented by single particles scattered in the matrix of the breccias and included in the vesicles in altered glass. These particles are leaf‐shaped, stem‐shaped, tubular, and spherical objects ranging from 5–10 μm to 200–300 µm in size. It is suggested that

Trace elements and extant and extinct isotopic attributes in Martian meteorites have been used to argue that Mars accreted quickly, differentiated into core and mantle, and established several mantle reservoirs, possibly within 10 Ma of T0. The partitioning of trace elements in the deep mantle has been relatively unstudied, despite the need for such knowledge in understanding magma ocean crystallization

The central elevated area is a postimpact morphological landmark in the otherwise flat eroded remnant of the Dhala impact structure, India. Its base is the Bundelkhand granitic complex followed by beds of Dhala and Kaimur Formations. The beds of the Dhala and Kaimur Formation present typical sedimentary textures and structures such as cross‐bedding. The grains are angular, sorting is moderate to poor

We report the results of the complex study of the bulk interior of Bursa L6 ordinary chondrite using optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, electron microprobe analysis (EMPA), X‐ray diffraction (XRD), magnetization measurements, and Mössbauer spectroscopy. The main and minor iron‐bearing phases and their chemical compositions were determined by these

We report a NanoSIMS search for presolar grains in the CM chondrites Asuka (A) 12169 and A12236. We found 90 presolar O‐rich grains and 25 SiC grains in A12169, giving matrix‐normalized abundances of 275 (+55/−50, 1σ) ppm or, excluding an unusually large grain, 236 (+37/−34) ppm for O‐rich grains and 62 (+15/−12) ppm for SiC grains. For A12236, 18 presolar silicates and 6 SiCs indicate abundances of

The Hamburg meteorite fell on January 16, 2018, near Hamburg, Michigan, after a fireball event widely observed in the U.S. Midwest and in Ontario, Canada. Several fragments fell onto frozen surfaces of lakes and, thanks to weather radar data, were recovered days after the fall. The studied rock fragments show no or little signs of terrestrial weathering. Here, we present the initial results from an

Quartz and cristobalite ballen aggregates surrounded by dendritic cristobalite in gneiss clasts of impact melt rocks from the Ries impact structure are analyzed by Raman spectroscopy, microscopy, and electron backscattered diffraction to elucidate the development of the characteristic polycrystalline ballen that are defined by curved interfaces between each other. We suggest that the investigated ballen