Extraterrestrial Materials Research Articles

A naturally occurring Al-Cu-Fe-Si quasicrystal in a micrometeorite from southern Italy

Quasicrystals, solids with rotational symmetries forbidden for crystals, are usually synthesized in the laboratory by mixing specific ratios of selected elemental components in the liquid and quenching under strictly controlled protocols. Nevertheless, the discovery of Al-Cu-Fe natural quasicrystals in the Khatyrka meteorite showed that these exotic phases could also form in high-velocity impact-induced shock events introducing an endeavour to search them in cosmic material. Here we report the discovery of an extraterrestrial icosahedral quasicrystal with an unusual composition Al51.7(6)Cu30.8(9)Fe10.3(4)Si7.2(9), ideally Al52Cu31Fe10Si7, found in a scoriaceous micrometeorite, named FB-A1, recovered at the top of Mt. Gariglione (Italy). The chemistry of the icosahedral phase was characterized by electron microprobe, and the rotational symmetry was confirmed by means of electron backscatter diffraction. The FB-A1 micrometeorite represents the third independent discovery of naturally occurring intermetallic Al-Cu-Fe-(Si) alloys in extraterrestrial bodies and the second case of extraterrestrial material containing a natural quasicrystal, after Khatyrka meteorite.

Analytical Techniques for Identification and Characterization of Extraterrestrial Organic Matter

Advances in analytical techniques are essential for understanding the nature, formation, and evolutionary history of extraterrestrial organic matter. In this chapter, we briefly review analytical techniques used to detect and characterize organic matter in extraterrestrial materials. Mass spectrometry is often coupled with gas chromatography or liquid chromatography for elemental and isotopic analysis, and for identifying specific organic compounds. Spectroscopy involves interaction of molecules with electromagnetic radiation at various wavelengths. Almost every wavelength—from X-rays to radio waves—can be used for spectroscopic measurements. The most major microscopic and nanoscopic techniques are scanning and/or transmission electron microscopy. Spectroscopy and mass spectrometry can also be coupled with microscopic analysis for detailed compositional investigations.

Extraterrestrial Organic Matter: An Introduction

Extraterrestrial organic matter forms in a variety of locations in space through different mechanisms. Its nature, distribution, formation mechanisms and locations are of particular interest. Some organic molecules can even be considered as key players for the emergence of life. Although new organic species are continuously detected in the interstellar media, Solar System bodies, and extraterrestrial materials, their formation and evolution are still not fully understood. Ground-based and space observations can detect organic matter in different objects with a range of complexity and diversity, while laboratory investigations of astromaterials allow detailed characterization of extraterrestrial organic matter with high precision. This issue reviews different aspects of extraterrestrial organic matter, including its origin, evolution, diversity, and delivery.

Diversity of Complex Organic Matter in Carbonaceous Chondrites, IDPs, and UCAMMs

Complex organic matter is present in many extraterrestrial materials such as chondrite meteorites, micrometeorites, and interplanetary dust. The observed complexity of this organic matter is due to the combination of diversity of primitive organic materials that accreted onto asteroids and the subsequent effect of hydrothermal and/or metamorphic alteration that took place after accretion. These processes resulted in a variety of carbonaceous grain morphologies, elemental abundances, and organic functional group compositions. Some carbonaceous dust grains and micrometeorites have cometary origins and provide insights into the unique processing histories on those outer Solar System bodies. Isotopic analyses can help distinguish carbonaceous grains that retain their pre-accretion heritage, while advanced microscopy techniques reveal the interplay of complex organic matter with surrounding mineral.

Chemical analysis of Chang’e-5 lunar soil using LA–ICP–MS in highly diluted fused glass discs

The bulk chemical compositions of extraterrestrial material can provide critical information on the evolution and magmatism of planetary bodies. However, accurate measurements are challenging, because these samples, particularly returned samples,...

Fine-grained interplanetary dust input during the Turonian (Late Cretaceous): evidence from osmium isotope and platinum group elements

The Turonian age (~ 90–94 Ma) was the hottest geological interval in the Cretaceous and also marked by the K3 event, a pronounced enrichment of 3He in pelagic sediments (i.e., massive input of extraterrestrial materials). Here, we present Os isotopic (187Os/188Os) and platinum group element (PGE) data from Turonian sedimentary records. After a sharp unradiogenic shift during the end-Cenomanian oceanic anoxic event 2, the 187Os/188Os ratios declined continuously throughout the Turonian, which could be ascribed to the formations of several large igneous provinces (LIPs). Because the interval with the most unradiogenic 187Os/188Os ratios (i.e., enhanced LIP volcanism) does not correspond to the warmest interval during the mid-Cretaceous, additional sources of CO2, such as subduction zone volcanism or the kimberlite formation, may explain the Cretaceous Thermal Maximum. As Os isotope ratios do not show any sharp unradiogenic shifts and PGE concentrations do not exhibit a pronounced enrichment, an influx of fine-grained cosmic dust to the Earth’s surface, possibly from the long-period comet showers, can be inferred at the time of the 3He enrichment during the mid-Turonian K3 event. Our findings highlight the different behaviors of 3He and PGE information in the sedimentary rocks during the input of fined-grained extraterrestrial materials.

The UCLA Cosmochemistry Database

The UCLA Cosmochemistry Database was initiated as part of a data-rescue and -storage project aimed at archiving a variety of cosmochemical data acquired at University of California, Los Angeles (UCLA). The data collection includes elemental compositions of extraterrestrial materials analyzed by UCLA cosmochemists over the last five decades. The analytical techniques include atomic absorption spectrometry (AAS) and neutron activation analysis (NAA) at UCLA. The data collection is stored on the Astromaterials Data System (Astromat). We provide both interactive tables and downloadable datasheets for users to access all data. The UCLA Cosmochemistry Database archives cosmochemical data that are essential tools for increasing our understanding of the nature and origin of extraterrestrial materials. Future studies can reference the data collection in the examination, analysis, and classification of newly acquired extraterrestrial samples.

The oxidation state of titanium in silicate melts

Titanium occurs as Ti3+, in addition to the more usual Ti4+, in extraterrestrial materials such as Lunar basalts and chondritic meteorites. The proportion of Ti as Ti3+ was investigated by Ti K-edge X-ray absorption near edge structure (XANES) spectroscopy for five silicate glass compositions quenched from melts equilibrated at 1400 °C, atmospheric pressure, and oxygen fugacities (fO2) in log units relative to the fayalite-magnetite-quartz (FMQ) buffer from FMQ+3.3 to FMQ-10.2 (+6.6 to −6.9 log units relative to the iron-wüstite, IW, buffer). All spectra could be well fit using a linear combination of the spectra recorded from the most oxidised and reduced samples of the same composition, indicating that the samples only contain two Ti species. Ti3+/ΣTi (where ΣTi = Ti3+ + Ti4+) = 0 for the most oxidised samples but is unknown for the most reduced. Thus, the linear combination fit results were used in a regression model in which Ti3+/ΣTi of the reduced end-member was varied to give Ti3+/ΣTi values of the other samples that best fit the thermodynamically expected dependence of Ti3+/ΣTi on fO2. The most reduced samples were found to have Ti3+/ΣTi ∼ 0.6. The resulting modified equilibrium constants of the Ti oxidation reaction, logK', are linearly correlated with the optical basicity (Λ) parameterisation of melt composition, such that as Λ increases, Ti3+/ΣTi decreases, at constant fO2. This correlation allows Ti3+/ΣTi to be predicted for other compositions and, assuming that the temperature dependence of Ti3+/Ti4+ is parallel to FMQ, a general equation relating Ti3+/Ti4+ to fO2 was obtained: log(Ti3+/Ti4+) = −0.25ΔFMQ − 0.32(19) − 3.44(32)Λ. This equation was used to predict Ti3+/ΣTi as a function of fO2 for high-Ti Mare basalt, chondrule (CV and CM), and calcium aluminium inclusion (CAI; Type A and B) compositions. For melts of these compositions Ti3+ = Ti4+ at ∼ FMQ-10.8, −9.5, −9.3, −10.6, and −10.2 (∼IW-7.5, −6.2, −6.0, −7.3, and −6.9), respectively, independent of temperature.

The iron oxidation state of Ryugu samples

AbstractThe Hayabusa2 mission sampled Ryugu, an asteroid that did not suffer extensive thermal metamorphism, and returned rocks to the Earth with no significant air exposure. It therefore offers a unique opportunity to study the redox state of carbonaceous Cb‐type asteroids and evaluate the overall redox state of the most primitive rocks of the solar system. An analytical framework was developed to investigate the iron mineralogy and valence state in extraterrestrial material at the micron scale by combining x‐ray diffraction, conventional Mössbauer (MS), and nuclear forward scattering (NFS) spectroscopies. An array of standard minerals was analyzed and cross‐calibrated between MS and NFS. Then, MS and NFS spectra on three Ryugu grains were collected at the bulk and the micron scales. In Ryugu samples, iron is essentially accommodated in magnetite, clay minerals (serpentine–smectite), and sulfides. Only a single set of Mössbauer parameters was necessary to account for the entire variability observed in MS and NFS spectra, at all spatial scales investigated. These parameters therefore make up a fully consistent iron mineralogical model for the Ryugu samples. As far as MS and NFS spectroscopies are concerned, Ryugu grains are overall similar to each other and share most of their mineralogical features with CI‐type chondrites. In detail however, no ferrihydrite is found in Ryugu particles even at the very sensitive scale of Mössbauer spectroscopy. The typical Fe3+/Fetot of clay minerals is much lower than typical redox ratios measured in CI chondrites (Fe3+/Fetot = 85%–90%). Furthermore, magnetite from Ryugu is stoichiometric with no significant maghemite component, whereas up to 12% of maghemite was previously identified in the Orgueil's so‐called magnetite. These differences suggest that most CI meteorites suffered terrestrial alteration and that the preterrestrial composition of these carbon‐rich samples was less oxidized than previously measured. However, it is not clear yet whether or not the parent bodies of CI chondrites were as reduced as Ryugu. Finally, the high spatial resolution of NFS allows to disentangle the redox state and the crystal chemistry of iron accommodated in serpentine and smectite. The most likely polytype of serpentine is lizardite, containing <35% of Fe3+, a fraction of which being tetrahedrally coordinated. Smectite is more oxidized (Fe3+/Fetot > 65%) and mainly contains octahedral ferric iron. This finding implies that these clays formed from highly alkaline fluids and the spatial variability highlighted here may suggest a temporal evolution or a spatial variability of the nature of this fluid.

Analyze mass spectrometry data with artificial intelligence to assist the understanding of past habitability of Mars and provide insights for future missions

This paper presents an application of artificial intelligence on mass spectrometry data for detecting habitability potential of ancient Mars. Although data was collected for planet Mars the same approach can be replicated for any terrestrial object of our solar system. Furthermore, proposed methodology can be adapted to any domain that uses mass spectrometry. This research is focused in data analysis of two mass spectrometry techniques, evolved gas analysis (EGA-MS) and gas chromatography (GC-MS), which are used to identify specific chemical compounds in geological material samples. The study demonstrates the applicability of EGA-MS and GC-MS data to extra-terrestrial material analysis. Most important features of proposed methodology includes square root transformation of mass spectrometry values, conversion of raw data to 2D sprectrograms and utilization of specific machine learning models and techniques to avoid overfitting on relative small datasets. Both EGA-MS and GC-MS datasets come from NASA and two machine learning competitions that the author participated and exploited. Complete running code for the GC-MS dataset/competition is available at GitHub.11https://github.com/IoannisNasios/MarsSpectrometry2_GasChromatography. Raw training mass spectrometry data include [0, 1] labels of specific chemical compounds, selected to provide valuable insights and contribute to our understanding of the potential past habitability of Mars.

Production rates of cosmogenic nuclides in extraterrestrial material using GEANT4 software

AbstractWe present a model for the calculation of the production rates of cosmogenic nuclides in extraterrestrial material. The model is based on the Monte Carlo simulation software Geant4. Using this software an application simulating the irradiation of the spherical body with predefined chemical composition by galactic cosmic-ray protons was developed. The fluxes of secondary neutrons and protons generated within the body of the sample are calculated. These are further used for the calculation of the production rates for cosmogenic nuclides. The plausibility of the presented model was tested in case of the well-studied meteoritic sample Knyahinya for which the production rates of cosmogenic nuclides were previously measured and also calculated using MCNP simulation software. The production rates for 3He, 10Be, 21Ne, 22Ne, 26Al, 36Cl, 38Ar, 39Ar, 41Ca and 53Mn have been calculated in Knyahinya meteorite and for 10Be, 26Al and 36Cl in Apollo 17 sample 73,002.

Geochemical evaluation of cosmic spherules collected from the Central Indian Ocean Basin

Micrometeorites (MMs) significantly contribute to the extraterrestrial material the Earth receives and represent a broader range of precursors than known meteorites. Low sedimentation rates prevalent in the deep-sea regions far away from land provide a unique opportunity for collecting MMs from these least disturbed regions. In the present study, we have studied 305 cosmic spherules recovered from the Central Indian Ocean Basin (CIOB); that have undergone melting during hypervelocity entry into the Earth's atmosphere. During the atmospheric entry, primary signatures of MMs are lost depending upon the extent of heating, complicating the identification of the parent body. Nevertheless, we have tried to relate these cosmic spherules to their respective parent bodies based on elemental ratios present in them, considering atmospheric ablative losses of various elements. The chemical analyses indicate that many deep-sea cosmic spherules are linked to carbonaceous chondrites. Around 239 porphyritic olivines (PO), 42 relict olivines are studied for their textural development and composition during recrystallisation during atmospheric entry. Thirty-zoned olivines are analysed from rim to core to understand various elements behaviour during atmospheric entry. Seawater plays a vital role in eroding these cosmic spherules material, and its effect is also discussed. As most of the recent micrometeorite collections focus on the polar region, these deep-sea spherules will significantly add to the information about the extraterrestrial matter reaching the Earth.

Multiscale evidence for weathering and the preservation of carbonaceous material in an Antarctic micrometeorite

Micrometeorites (MMs) recovered from the Earth’s surface may have undergone significant changes prior to their collection, including weathering while residing in the terrestrial environment. These alteration processes, such as the precipitation of hydrous phases, may overprint both primary and atmospheric entry features, obscuring pre-existing material properties. In addition, weathering exerts a prominent control on the geochemical interactions, such as species mobility, between extraterrestrial material and the terrestrial environment, particularly in Antarctica. In this study, we have characterised the textural and compositional consequences of weathering on an unmelted, fine-grained, Antarctic MM, which includes the mapping of nanometre-scale features using atom probe tomography. In particular, we investigate geochemical behaviour across textural boundaries in the MM and observe nanoscale elemental heterogeneity within complex alteration assemblages. In one sample region, a compositional boundary is highlighted by distinct elemental differences, consistent with a weathering encrustation of mixed mineralogies, while analyses in other targeted regions show evidence for nanoscale elemental networks, as well as a grain boundary adjacent to a carbon-rich region. We discuss our findings in the context of terrestrial weathering as a dominant cause for the nanoscale features observed. Weathering processes responsible for these features include the leaching of extraterrestrial material, precipitation of secondary alteration products with associated layering, and the influence of mechanical stress on pre-existing weaknesses. From these results, we derive a weathering sequence to explain the formation of the alteration product assemblage and highlight the controls on MM geochemistry in the terrestrial environment. Our observations show that nanoscale carbonaceous material may be preserved in oxy-hydroxides under icy conditions, which can also act as tracers for local environmental changes.

Cosmogenic 3He anomaly K1 vs. the early Campanian isotopic event (ECE) as recorded in pelagic limestones of the Umbria-Marche succession (Italy)

In this paper, we report on a biostratigraphic, magnetostratigraphic, and stable isotope (δ13C and 3He) analysis across three pelagic limestone sections of the Campanian Scaglia Rossa Formation exposed in the classic Bottaccione Gorge at Gubbio (Umbria region), near the village of Furlo, and near the town of Apiro (both in the Marche region), all located in the Umbria-Marche basin of the northeastern Apennines of central Italy. These sections record the coincidental occurrence of an extraterrestrial 3He (3HeET) anomaly known as K1 and a negative shift in the δ13C record known as the early Campanian event. Cyclostratigraphic spectral analysis of the Furlo section based on a high-resolution magnetic susceptibility record in these pelagic limestones revealed that the regular orbitally forced Milankovitch cycles are somewhat disturbed or blurred through the interval of the coincident 3HeET K1 anomaly and the early Campanian event isotopic anomaly, suggesting a causal effect resulting from the enhanced influx of extraterrestrial material (i.e., interplanetary dust particles and a myriad of small meteorite impacts). This would have altered the transparency of the atmosphere, causing a short-lived climate change event.

Magnetofossils: Relicts and Records of Deep Time and Space

Magnetofossils are magnetic nanoparticles that represent the fossil remains of microorganisms that biomineralize magnetic minerals in a genetically controlled manner. Most magnetofossils found in the geologic record are produced by magnetotactic bacteria, which use them for navigating within their living environment. Magnetofossils can be identified using a combination of magnetic and imaging techniques. A common attribute of magnetofossils, although not pervasive, is that they are arranged in chains, which determines their specific magnetic properties. Magnetofossil signatures have been reported from ancient rocks to modern sediments and even in extraterrestrial materials. They provide a window into biomineralization, past environments, and ancient magnetic fields, as well as supplying fuel for questions on the origin of life in the Solar System.

Organic Catalytic Activity as a Method for Agnostic Life Detection.

An ideal life detection instrument would have high sensitivity but be insensitive to abiotic processes and would be capable of detecting life with alternate molecular structures. In this study, we propose that catalytic activity can be the basis of a nearly ideal life detection instrument. There are several advantages to catalysis as an agnostic life detection method. Demonstrating catalysis does not necessarily require culturing/growing the alien life and in fact may persist even in dead biomass for some time, and the amplification by catalysis is large even by minute amounts of catalysts and, hence, can be readily detected against abiotic background rates. In specific, we propose a hydrolytic catalysis detection instrument that could detect activity in samples of extraterrestrial organic material from unknown life. The instrument uses chromogenic assay-based detection of various hydrolytic catalytic activities, which are matched to corresponding artificial substrates having the same, chromogenic (preferably fluorescent) upon release, group; D- and L-enantiomers of these substrates can be used to also answer the question whether unknown life is chiral. Since catalysis is a time-proportional product-concentration amplification process, hydrolytic catalytic activity can be measured on a sample of even a minute size, and with instruments based on, for example, optofluidic chip technology.

Present status and recent progress of research, using photoemission-electron microscopy at SPring-8

Photoemission electron microscopy (PEEM), particularly when combined with synchrotron radiation, exerts a powerful functionality in spectroscopy applications. The use of PEEM has steadily expanded the availed analysis objects at the SPring-8 synchrotron facility, such as magnetic materials, thin-film devices, semiconductors, monolayers, extraterrestrial matter, and multiferroics. Some special experimental settings such as time-resolved or operando measurements have also been developed according to user requests. In this paper, we present an overview on the achievements of PEEM studies so far and introduce some recent technical and scientific progress at SPring-8.

Critical Aspects of Material Selection in the Packaging and Transporting of Returned Extraterrestrial Samples.

In the framework of the EU-funded EURO-CARES project, aimed at determining the actions to develop a European facility for curation of extraterrestrial samples returned by space missions, we identified the requirements (mainly in terms of materials selection) of the transportation containment facility which should contain the Sample Return Capsule (SRC), which in turn contains the extraterrestrial material returned to Earth. Transportation box design for restricted (i.e., possibly related to biological life) and unrestricted samples is different. Packaging and transport of restricted samples must guarantee the samples' preservation from the terrestrial environment and the safety of people performing these operations and, hence, must be done according to World Health Organization (WHO) rules. In the case of unrestricted samples, the only requirement is sample preservation. We propose a triple packaging as follows: (1) primary receptacle; (2) secondary package (plastic material), optional for unrestricted samples; (3) rigid, cushioned outer layer. Only for restricted samples, an additional layer is proposed, that is, the overpack. The primary receptacle coincides with the SRC. The plastic material of the secondary package must have a low outgassing rate (i.e., <10-7 torr/s) and preferably low permeability and cost. Teflon and Neoflon would be the best choices. The outer package must be rigid and resistant to breakage, and our trade-off analysis identified stainless steel and aluminum alloys as best options. The outer should be filled with an inert atmosphere to inhibit oxidation within the sample in case of leak: argon is more inert than nitrogen, but the latter is easily available. The overpack allows the box environment control (e.g., real-time contamination monitoring); ISO containers could be used to this end. Contamination of the environment inside the box can be monitored by different instruments, which should be selected on the basis of mission requirements. There are no mass limitations for box transport by ground or ship, but these solutions imply a long journey duration. Any aircraft might be used for transporting unrestricted samples. Only cargo aircraft may be used for transporting restricted samples, unless the total sample mass is lower than 50 g (WHO guidelines).

Gas chromatography coupled-to Fourier transform orbitrap mass spectrometer for enantioselective amino acid analyses: Application to pre-cometary organic analog

Gas chromatography (GC) is a separation technique commonly developed for targeted in situ analyses in planetary space missions. It is coupled with low-resolution mass spectrometry to obtain additional structural information and allow compound identification. However, ground-based analyses of extraterrestrial samples have shown the presence of large molecular diversities. For future targeted in situ analyses, it is therefore essential to develop new technologies. High resolution mass spectrometry (HRMS) is currently being spatialized using FT-orbitrap-MS technology. In this contribution, the coupling of gas chromatography with FT-orbitrap-MS is studied for targeted amino acid analyses. The method for enantioselective separation of amino acids was optimized on a standard mixture comprising 47 amino acid enantiomers. Different ionization modes were optimized, chemical ionization with three different reactive gasses (NH3, CH4 and NH3/CH4) and electron impact ionization at different electron energies. Single ion and full scan monitoring modes were compared, and detection and quantification limits were estimated by internal calibration under the optimized conditions. The GC-FT-orbitrap-MS demonstrated its ability to separate 47 amino acid enantiomers with minimal co-elution. Furthermore, due to the high mass resolution and accuracy of FT-orbitrap-MS, with mass extraction, the S/N is close to zero, allowing average LOD values of 10⁻7 M, orders of magnitude lower than conventional GC–MS techniques. Finally, these conditions were tested for enantioselective analysis of amino acids on an analog of a pre-cometary organic material showing similarities to that of extraterrestrial materials.

Influence of pH and salts on DMF-DMA derivatization for future Space Applications

For gas chromatography - mass spectrometry (GC-MS) analyses performed in situ, pH and salts (e.g., chlorides, sulfates) may enhance or inhibit the detection of targeted molecules of interest for astrobiology (e.g. amino acids, fatty acids, nucleobases). Obviously, salts influence the ionic strength of the solutions, the pH value, and the salting effect. But the presence of salts may also produce complexes or mask ions in the sample (masking effect on hydroxide ion, ammonia, etc.). For future space missions, wet chemistry will be conducted before GC-MS analyses to detect the full organic content of a sample. The defined organic targets for space GC-MS instrument requirements are generally strongly polar or refractory organic compounds, such as amino acids playing a role in the protein production and metabolism regulations for life on Earth, nucleobases essential for DNA and RNA formation and mutation, and fatty acids that composed most of the eukaryote and prokaryote membranes on Earth and resist to environmental stress long enough to still be observed on Mars or ocean worlds in geological well-preserved records. The wet-chemistry chemical treatment consists of reacting an organic reagent with the sample to extract and volatilize polar or refractory organic molecules (i.e. dimethylformamide dimethyl acetal (DMF-DMA) in this study). DMF-DMA derivatizes functional groups with labile H in organics, without modifying their chiral conformation. The influence of pH and salt concentration of extraterrestrial materials on the DMF-DMA derivatization remains understudied. In this research, we studied the influence of different salts and pHs on the derivatization of organic molecules of astrobiological interest with DMF-DMA, such as amino acids, carboxylic acids, and nucleobases. Results show that salts and pH influence the derivatization yield, and that their effect depend on the nature of the organics and the salts studied. Second, monovalent salts lead to a higher or similar organic recovery compared to divalent salts regardless of pH below 8. However, a pH above 8 inhibits the DMF-DMA derivatization influencing the carboxylic acid function to become an anionic group without labile H. Overall, considering the negative effect of the salts on the detection of organic molecules, future space missions may have to consider a desalting step prior to derivatization and GC-MS analyses.