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Journal articleJenniskens P, Zolensky ME, Gordon A, et al., 2026,
Meteor over New York City: brines in a primitive CM asteroid
, Science Advances, Vol: 12, ISSN: 2375-2548The CI (Ivuna-type) carbonaceous material returned from asteroids Ryugu and Bennu contain mobilized sodium from the evaporation or freezing of liquid water into brines, shedding light on the internal structure of ice-rich CI-type worlds and the formation of prebiotic organic compounds. The formation of brines has not been demonstrated in CM (Mighei-type) carbonaceous chondrites, which also supplied organic matter to the early Earth. Here, we announce the fall of a primitive meteorite from a daytime fireball over the New York metropolitan area in July 2024. It is a CM2 breccia that contains unique CM1 clasts rich in water and sodium. The meteorite contains abundant amino acids and other products of organic chemistry in brines that reveal subsurface processes on CM-type asteroid parent bodies.
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Journal articleGumbley JJ, Lau N, Watson JS, et al., 2026,
Oxidative polymerization of organic compounds in the presence of iron-bearing minerals: implications for organic preservation on Mars
, ACS Earth and Space Chemistry, Vol: 10, Pages: 1493-1506, ISSN: 2472-3452Exploring for evidence of life on Mars involves detecting organic signals that may reflect the prebiotic processes which led to the emergence of life or the molecular remnants of biology. For detection at the present day, organic signals, whether abiotic or biological in origin, must have survived over periods that extend to billions of years. The terrestrial fossil organic record indicates that polymerization enhances preservation over time. One polymer-forming process that is observed on Earth, but may be especially relevant to Mars, is oxidative polymerization, where organic compounds are assembled into polymers or macromolecules by reaction with oxidants. On Earth, oxidative polymerization commonly uses atmospheric oxygen, but mineral oxidants can also promote the reaction. Oxidized iron can act as a polymerizing agent for organic compounds and is widespread on the surface of Mars. For instance, the iron oxyhydroxide goethite (α-FeO(OH)) has been detected on Mars by spectrometers carried by orbiters and rovers. This study examines whether Fe(III)-bearing minerals under Mars-relevant conditions can promote oxidative coupling of simple aromatic compounds. Our results show that in environments representative of the Martian near surface, the ferric/iron(III) content of goethite causes oxidative coupling of 2-naphthol (C10H8O) to its dimer, 1,1′-bi-2-naphthol (BINOL) and, under certain conditions, to larger fused-ring aromatic products. Recognition of the effective polymerization of organic compounds in the presence of a mineral that is common on Mars provides direction for the ongoing search for preserved Martian organic matter when selection of landing sites or sampling locations is taking place.
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Journal articleGumbley JJ, Watson JS, Sephton M, 2026,
Serpentinization-driven redox disequilibria in the Jezero paleolake as a potential energy source for primitive life on early Mars
, npj Space Exploration, Vol: 2, ISSN: 3059-3700We propose fracture-localized serpentinization of the olivine-rich Seitah formation in Jezero crater on Mars could have delivered hydrogen to sustain a redox potential. Using Perseverance data, we calculate the formation could have generated 0.7–1.3 mol H₂ per kg of serpentinized rock. H₂-rich and CO₂-poor fluids introduced to Jezero's circumneutral paleolake bottom waters would have created a redox disequilibrium with dissolved inorganic carbon (DIC). At this pH, carbonate equilibria maintain DIC predominantly as bicarbonate (HCO₃⁻, 80–95% of DIC) with dissolved CO₂(aq) suppressed (5–20%). Under low-temperature paleolake conditions (0–10 °C) the reaction is kinetically inhibited allowing H₂–CO₂ redox disequilibria to persist. We use a sensitivity-based kinetic framework to show H2-CO2 disequilibria lifetimes within Jezero extend from centuries to millions of years under representative activation energy bounds. Chemoautotrophs can exploit H₂–CO₂/HCO₃⁻ redox gradients. We apply an energy-flux framework, calculate chemical affinities of 10–30 kJ mol⁻¹ H₂ and estimate that individual serpentinization vent fields could support microbial populations of 10¹⁴–10¹⁶ cells. Our results demonstrate the paleolake possessed the conditions necessary to produce a redox battery that could power primitive life. Similar environments on early Mars could have had the same potential.
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Journal articleMcCall MA, Watson JS, Tan JSW, et al., 2025,
Biochar stability revealed by FTIR and machine learning
, ACS Sustainable Resource Management, Vol: 2, Pages: 842-852, ISSN: 2837-1445Biochar is a carbon-rich and environmentally recalcitrant material, with strong potential for climate change mitigation. There is a need for rapid and accessible estimations of biochar stability, the resistance to biotic and abiotic degradation in soil. This study builds on previous work by integrating Fourier-transform infrared spectroscopy (FTIR) data with predictive modeling to estimate standard stability indicators: H:C and O:C molar ratios. Lignocellulosic feedstocks were pyrolyzed at highest treatment temperatures (HTT) ranging from 150–700 °C, and all samples achieved H:C < 0.7 and O:C < 0.4 at HTT of 400 °C and above. Several statistical and machine learning models were developed using FTIR spectra. The random forest (RF) models, which incorporated full data preprocessing, yielded the highest accuracy (R2 = 0.96 for both ratios) when tested on an unseen feedstock. Variable importance analysis identified spectral regions linked to aromaticity and inversely correlated to C–O stretches in cellulose and lignin as key predictors. The findings of this study verify that FTIR data can serve as a rapid and accurate tool for estimating biochar stability.
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Journal articleMcCall MA, Watson JS, Sephton MA, 2024,
Predicting stability of barley straw-derived biochars using Fourier transform infrared spectroscopy
, ACS Sustainable Resource Management, Vol: 1, Pages: 1975-1983, ISSN: 2837-1445In order to estimate the ability of biochar to sequester carbon as part of greenhouse gas removal technology, there is a need for rapid and accessible estimations of biochar stability. This study employs a novel method using Fourier transform infrared spectroscopy (FTIR) to predict common stability indicators, namely H:C and O:C molar ratios. Biochars derived from barley straw were produced at temperatures from 150 to 700 °C. The greatest compositional changes of the biochars occurred between 200 and 400 °C. All biochars produced at ≥400 °C achieved H:C < 0.7 and O:C < 0.4, indicative of biochars suitable for soil application. Regression models were built using FTIR data to predict H:C and O:C molar ratios. The H:C model produced a coefficient of determination (R2) of 0.99, mean absolute percentage error (MAPE) 6.86%, and root-mean-square error (RMSE) of 0.07. The O:C model achieved the same R2 (0.99), MAPE of 9.02%, and RMSE of 0.03. Our results demonstrate that combining FTIR data with modeling is a promising rapid and accessible method for attaining biochar stability data.
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Journal articleSalter TL, Watson JS, Sephton MA, 2024,
The effects of some common inorganic soil components on the pyrolytic analysis of plastics
, Journal of Analytical and Applied Pyrolysis, Vol: 182, ISSN: 0165-2370Plastics and microplastics are major hazards for the environment and human health. Plastic materials in the sedimentary record are a marker for modern anthropogenic activity. One environmental reservoir of plastics and microplastics is soil. One method to detect the presence of plastics in soil, and to thereby recognise the presence of its hazards, is pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). Yet soils are multicomponent mixtures and any analytical artefacts generated will reduce our ability to monitor the presence of plastics. We have studied the Py-GC-MS responses for the polymers polyethylene (PE), polypropylene (PP), polystyrene (PS) and poly(vinyl chloride) (PVC), in the presence of individual phyllosilicate (kaolinite, illite and montmorillonite) and iron oxyhydroxide/oxide (goethite and magnetite) minerals that may be present in soil. Our data show the distinctive polymer fingerprint becomes obscured when analysed with minerals. We have isolated the effects of some potential inorganic soil components so that responses from complex matrices can be deconvolved. The mineral-assisted aromatisation of compounds affects the diagnostic signals of the original polymer, particularly for those polymers (PE and PP) which have a large aliphatic hydrocarbon signature when analysed alone. Iron oxyhydroxide/oxide are shown to have a greater effect on the data than phyllosilicates. Our results will help guide future interpretations of Py-GC-MS data obtained when monitoring soils for plastic contamination. Py-GC-MS is most commonly applied as a qualitative method, yet detailed quantitation of the organic-inorganic reactions we have described, albeit analytically complex, would represent a useful future study.
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Journal articleSims MJE, Sephton MA, Watson JS, et al., 2024,
Biomarker evidence for the depositional environment of basinal UK Mississippian mudstones
, Geological Society Special Publication, Vol: 534, Pages: 1-24, ISSN: 0305-8719The regional character of organic matter type and depositional conditions of Pendleian, Brigantian and Arnsbergian mudstones between the Craven Basin and the Widmerpool Gulf was compared through interpretation of biomarker and pyrolysis data from 201 samples recovered from 9 boreholes. The Carboniferous seaways have been determined to commonly host dysoxic conditions, enabling preservation of a mixture of marine and terrestrial organic matter types. Photic zone anoxia evidenced by aryl-isoprenoids was determined to be persistent during ‘marine’ conditions represented by marine band, high sea level and carbonate facies. Observation and correlation of diasteranes and Ts/Tm ratios within the samples and to other maturity parameters highlighted a significant clay mineral catalytic and/or hydrocarbon retention effect in the samples. This influenced both biomarkers as well as Tmax thermal maturity data reducing the reliability of such results in interpreting burial and ultimately reserve potential.
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Journal articleSephton MA, Chan QHS, Watson JS, et al., 2024,
Insoluble macromolecular organic matter in the Winchcombe meteorite
, Meteoritics and Planetary Science, Vol: 59, Pages: 1131-1144, ISSN: 1086-9379The Winchcombe meteorite fell on February 28, 2021 in Gloucestershire, United Kingdom. As the most accurately recorded carbonaceous chondrite fall, the Winchcombe meteorite represents an opportunity to link a tangible sample of known chemical constitution to a specific region of the solar system whose chemistry can only be otherwise predicted or observed remotely. Winchcombe is a CM carbonaceous chondrite, a group known for their rich and varied abiotic organic chemistry. The rapid collection of Winchcombe provides an opportunity to study a relatively terrestrial contaminant-limited meteoritic organic assemblage. The majority of the organic matter in CM chondrites is macromolecular in nature and we have performed nondestructive and destructive analyses of Winchcombe by Raman spectroscopy, online pyrolysis–gas chromatography–mass spectrometry (pyrolysis–GC–MS), and stepped combustion. The Winchcombe pyrolysis products were consistent with a CM chondrite, namely aromatic and polycyclic aromatic hydrocarbons, sulfur-containing units including thiophenes, oxygen-containing units such as phenols and furans, and nitrogen-containing units such as pyridine; many substituted/alkylated forms of these units were also present. The presence of phenols in the online pyrolysis products indicated only limited influence from aqueous alteration, which can deplete the phenol precursors in the macromolecule when aqueous alteration is extensive. Raman spectroscopy and stepped combustion also generated responses consistent with a CM chondrite. The pyrolysis–GC–MS data are likely to reflect the more labile and thermally sensitive portions of the macromolecular materials while the Raman and stepped combustion data will also reflect the more refractory and nonpyrolyzable component; hence, we accessed the complete macromolecular fraction of the recently fallen Winchcombe meteorite and revealed a chemical constitution that is similar to other meteorites of
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Journal articleChan QHS, Watson JS, Sephton MA, et al., 2024,
The amino acid and polycyclic aromatic hydrocarbon compositions of the promptly recovered CM2 Winchcombe carbonaceous chondrite
, Meteoritics and Planetary Science, Vol: 59, Pages: 1101-1130, ISSN: 1086-9379The rapid recovery of the Winchcombe meteorite offers a valuable opportunity to study the soluble organic matter (SOM) profile in pristine carbonaceous astromaterials. Our interests in the biologically relevant molecules, amino acids—monomers of protein, and the most prevalent meteoritic organics—polycyclic aromatic hydrocarbons (PAHs) are addressed by analyzing the solvent extracts of a Winchcombe meteorite stone using gas chromatography mass spectrometry. The Winchcombe sample contains an amino acid abundance of ~1132 parts-per-billion that is about 10 times lower than other CM2 meteorites. The detection of terrestrially rare amino acids, including α-aminoisobutyric acid (AIB); isovaline; β-alanine; α-, β-, and γ-amino-n-butyric acids; and 5-aminopentanoic acid, and the racemic enantiomeric ratios (D/L = 1) observed for alanine and isovaline indicate that these amino acids are indigenous to the meteorite and not terrestrial contaminants. The presence of predominantly α-AIB and isovaline is consistent with their formation via the Strecker-cyanohydrin synthetic pathway. The L-enantiomeric excesses in isovaline previously observed for aqueously altered meteorites were viewed as an indicator of parent body aqueous processing; thus, the racemic ratio of isovaline observed for Winchcombe, alongside the overall high free:total amino acid ratio, and the low amino acid concentration suggest that the analyzed stone is derived from a lithology that has experienced brief episode(s) of aqueous alteration. Winchcombe also contains 2- to 6-ring alkylated and nonalkylated PAHs. The low total PAHs abundance (6177 ppb) and high nonalkylated:alkylated ratio are distinct from that observed for heavily aqueously altered CMs. The weak petrographic properties of Winchcombe, as well as the discrepancies observed for the Winchcombe SOM content—a low total amino acid abundance comparable to heavily altered CMs, and ye
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Journal articleKomies S, Sun J, Hodges C, et al., 2024,
Low-cost thermal-infrared ‘THz-Torch’ spectroscopy
, IEEE Access, Vol: 12, Pages: 21868-21885, ISSN: 2169-3536The low-cost thermal infrared ‘THz-Torch’ concept (referred to here as ‘THz-T’) was firstintroduced over a decade ago, and since then the associated ‘over the THz horizon’ thermal infrared(10-100 THz) implementation technologies have continued to advance. While short range secure wirelesscommunications links have received a great deal of attention, material spectroscopy has only briefly beenintroduced in a short conference abstract. Here, for the first time, we explore in depth the basic conceptsbehind THz-T spectroscopy. Moreover, when compared to the unvalidated results within our previous work,we demonstrate an enhanced experimental THz-T spectrometer. A detailed thermal noise power link budgetmodel for both the transmission and reflection modes of operation has been undertaken and independentlyvalidated. As a proof of principle, a diverse array of different material types has been characterized. Thisincludes glass sheets, semiconductor wafers, ceramic plate, plastic tape, plastic sheets, as well as polymerand cotton paper banknotes. THz-T technology has the advantages of hardware simplicity and low costnon-destructive testing for ubiquitous applications.
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Journal articleTan J, Salter T, Watson J, et al., 2023,
Organic biosignature degradation in hydrothermal and serpentinizing environments: Implications for life detection on Icy Moons and Mars
, Astrobiology, Vol: 10, Pages: 1045-1055, ISSN: 1531-1074Evidence of liquid water is a primary indicator of habitability on the icy moons in our outer solar system as well as on terrestrial planets such as Mars. If liquid water-containing environments host life, some of its organic remains can be fossilized and preserved as organic biosignatures. However, inorganic materials may also be present and water-assisted organic-inorganic reactions can transform the organic architecture of biological remains. Our understanding of the fate of these organic remains can be assisted by experimental simulations that monitor the chemical changes that occur in microbial organic matter due to the presence of water and minerals. We performed hydrothermal experiments between 100–300°C involving lipid-rich microbes and natural serpentinite mineral mixtures generated by the subaqueous hydrothermal alteration of ultramafic rock. The products reveal what the signals of life may look like when subjected to water-organic-inorganic reactions. Straight and branched chain lipids in unaltered samples are joined by cyclization and aromatization products in hydrothermally altered samples. Hydrothermal reactions produce distinct products that are not present in the starting materials including small, single-ring, heteroatomic and aromatic compounds such as indoles and phenols. Hydrothermal reactions in the presence of serpentinite minerals lead to the significant reduction of these organic structures and their replacement by diketopiperazines (DKPs) and dihydropyrazines (DHPs), which may be compounds that are distinct to organic-inorganic reactions. Given that the precursors of DKPs and DHPs are normally lost during early diagenesis, the presence of these compounds can be an indicator of co-existing recent life and hydrothermal processing. However, the thermal stability of these compounds reveals that the formation and preservation of these compounds only occurs within a distinct temperature window. Serpentinite is also found to have a preser
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Journal articleSephton MA, Tan JSW, Watson JS, et al., 2023,
Organic geochemistry of in situ thermal-based analyses on Mars: the importance and influence of minerals
, Journal of the Geological Society, Vol: 180, Pages: 1-10, ISSN: 0016-7649A high priority goal for past, present and future missions to Mars is the search for evidence of past or present life. Some of the most information-rich signals are those represented by organic biomarkers. Thermal extraction has historically been the most popular in situ analysis technique employed on Mars owing to its elegance and ability to liberate both small compounds and large macromolecular networks. The geological record of Mars contains a variety of minerals, some of which can interact with organic matter when subjected to thermal extraction. Here we discuss the organic records that may be associated with these mineral hosts and the problems encountered when mineral-organic mixtures are analysed by thermal-based methods. We also suggest potential mitigations for future experiments of a similar nature and note that these mitigating steps can be applied not only in situ on Mars but also after samples are returned to Earth as part of Mars Sample Return where more resources and time for sample preparation are available.
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Journal articleSalter TL, Watson JS, Sephton MA, 2023,
Effects of minerals (phyllosilicates and iron oxides) on the responses of aliphatic hydrocarbon containing kerogens (Type I and Type II) to analytical pyrolysis
, Journal of Analytical and Applied Pyrolysis, Vol: 170, Pages: 1-8, ISSN: 0165-2370Organic matter in sediments is dominated by kerogen, a high molecular weight geomacromolecule. Kerogen can be subdivided into Types I to IV that provide paleoenvironmental and petroleum potential information. Kerogen typing can be performed by several chemical methods including elemental analysis (H/C and O/C), FTIR and pyrolysis-gas chromatography techniques. However, kerogens occur naturally within mineral matrices and these can influence the chemical responses. We have examined the effects of a range of minerals (namely kaolinite, lizardite, ripidolite, illite, montmorillonite, haematite, goethite, limonite and magnetite) on the responses of kerogen to pyrolysis-gas chromatography-mass spectrometry. We used aliphatic hydrocarbon containing kerogen Types I and II from Carboniferous Midland Valley shales of Scotland and the Jurassic Oxford Clay of southern England, respectively, as well as a pure synthetic aliphatic polymer, polyethylene. We find that the aliphatic organic matter in Type I kerogens is transformed by interaction with minerals during pyrolysis to give a signal incorrectly suggesting more contributions from land plant-containing kerogens, such as a large number of aromatic molecules. Pyrolysis with goethite, limonite and magnetite leads to almost complete destruction of the organic matter. Hence, the mineral composition of sedimentary rocks during pyrolysis should be considered when assigning kerogen types. Failure to consider the effects of minerals can lead to incorrect assignment of kerogen type and, therefore, erroneous interpretations of paleoenvironments and petroleum potential.
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Journal articleRoyle SHH, Cropper L, Watson JSS, et al., 2023,
Solid-Phase Microextraction for Organic Contamination Control Throughout Assembly and Operational Phases of Space Missions
, ASTROBIOLOGY, Vol: 23, Pages: 127-143, ISSN: 1531-1074 -
Journal articleKumar P, Zavala-Reyes JC, Kalaiarasan G, et al., 2023,
Characteristics of fine and ultrafine aerosols in the London underground.
, Science of the Total Environment, Vol: 858, ISSN: 0048-9697Underground railway systems are recognised spaces of increased personal pollution exposure. We studied the number-size distribution and physico-chemical characteristics of ultrafine (PM0.1), fine (PM0.1-2.5) and coarse (PM2.5-10) particles collected on a London underground platform. Particle number concentrations gradually increased throughout the day, with a maximum concentration between 18:00 h and 21:00 h (local time). There was a maximum decrease in mass for the PM2.5, PM2.5-10 and black carbon of 3.9, 4.5 and ~ 21-times, respectively, between operable (OpHrs) and non-operable (N-OpHrs) hours. Average PM10 (52 μg m-3) and PM2.5 (34 μg m-3) concentrations over the full data showed levels above the World Health Organization Air Quality Guidelines. Respiratory deposition doses of particle number and mass concentrations were calculated and found to be two- and four-times higher during OpHrs compared with N-OpHrs, reflecting events such as train arrival/departure during OpHrs. Organic compounds were composed of aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) which are known to be harmful to health. Specific ratios of PAHs were identified for underground transport that may reflect an interaction between PAHs and fine particles. Scanning transmission electron microscopy (STEM) chemical maps of fine and ultrafine fractions show they are composed of Fe and O in the form of magnetite and nanosized mixtures of metals including Cr, Al, Ni and Mn. These findings, and the low air change rate (0.17 to 0.46 h-1), highlight the need to improve the ventilation conditions.
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Journal articleKing AJ, Daly L, Rowe J, et al., 2022,
The Winchcombe meteorite, a unique and pristine witness from the outer solar system.
, Science advances, Vol: 8, ISSN: 2375-2548Direct links between carbonaceous chondrites and their parent bodies in the solar system are rare. The Winchcombe meteorite is the most accurately recorded carbonaceous chondrite fall. Its pre-atmospheric orbit and cosmic-ray exposure age confirm that it arrived on Earth shortly after ejection from a primitive asteroid. Recovered only hours after falling, the composition of the Winchcombe meteorite is largely unmodified by the terrestrial environment. It contains abundant hydrated silicates formed during fluid-rock reactions, and carbon- and nitrogen-bearing organic matter including soluble protein amino acids. The near-pristine hydrogen isotopic composition of the Winchcombe meteorite is comparable to the terrestrial hydrosphere, providing further evidence that volatile-rich carbonaceous asteroids played an important role in the origin of Earth's water.
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Journal articleSalter TL, Watson J, Waite JH, et al., 2022,
Hydrothermal processing of microorganisms: Mass spectral signals of degraded biosignatures for life detection on icy moons
, ACS Earth and Space Chemistry, Vol: 6, Pages: 2508-2518, ISSN: 2472-3452Life detection missions to the outer solar system are concentrating on the icy moons of Jupiter and Saturn and their inferred sub-surface oceans. Access to evidence of habitability, and possibly even life, is facilitated by the ejection of subsurface material in plumes and outgassing fissures. Orbiting spacecraft can intersect the plume material or detect past sputtered remnants of outgassed products and analyse the contents using instruments such as mass spectrometers. Hydrothermalism has been proposed for the subsurface environments of icy moons and the organic remains of any associated life would be expected to suffer some degradation through hydrothermalism, radiolysis, or spacecraft flyby impact fragmentation. Hydrothermalism is treated here for the first time in the context of the Europa Clipper mission.To assess the influence of hydrothermalism on the ability of orbiting mass spectrometers to detect degrading signals of life, we have subjected Earth microorganisms to laboratory hydrothermal processing. The processed microorganism samples were then analysed using gas chromatography-mass spectrometry (GC-MS) and mass spectra were generated. Certain compound classes, such as carbohydrates and proteins are significantly altered by hydrothermal processing, resulting in small one-ring and two-ring aromatic compounds such as indoles and phenols. However, lipid fragments, such as fatty acids, retain their fidelity and their provenance is easily recognised as biological in origin. Our data indicate that mass spectrometry measurements in the plumes of icy moons, using instruments such as the MAss Spectrometer for Planetary Exploration (MASPEX) onboard the upcoming Europa Clipper mission, can reveal the presence of life even after significant degradation by hydrothermal processing has taken place.
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Journal articlePeers De Nieuwburgh C, Watson J, Weiss D, et al., 2022,
Environmental screening of water associated with shale gas extraction by fluorescence excitation emission matrix
, Environmental Science: Water Research & Technology, Vol: 8, Pages: 2196-2206, ISSN: 2053-1400The shale revolution has involved the production of oil and gas from shale reservoirs enabled by modern techniques such as horizontal drilling and hydraulic fracturing. Large volumes of water-based fluids are required for hydraulic fracturing, some of which return to the surface as produced water. The recycling and effective disposal of produced water reduces water demand and avoids environmental impacts, respectively. Yet risks of water quality degradation surrounding shale oil and gas extraction operations remain highest during produced water treatment and disposal. Risk assessments related to produced water use are difficult to generate due to a lack of standard monitoring methods to characterise produced water and a lack of baseline monitoring data of surrounding water resources. We have performed a study on laboratory shale leachates using fluorescence Excitation Emission Matrix (EEM) spectra and have demonstrated the utility of this spectroscopic technique as a standard method for environmental screening in which the chemical constitution of produced water is monitored. EEM spectra recorded in this work show that dissolved organic matter (DOM) in laboratory shale leachates contains chromophores such as humic acid-like and soluble microbial-like material. Short emission wavelengths (<380 nm) EEM spectra may indicate anthropogenic contamination incidents in future operations, especially as they correspond to fluorescence signatures of some injection fluid additives. Our simple fluorescence method requires little sample preparation and could be coupled with remote sensors for real time, in-situ monitoring of contamination incidents.
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Journal articleFarley KA, Stack KM, Shuster DL, et al., 2022,
Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars
, Science, Vol: 377, ISSN: 0036-8075<jats:p>The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater’s sedimentary delta, finding that the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Magnesium-iron carbonates along grain boundaries indicate reactions with carbon dioxide–rich water under water-poor conditions. Overlying Séítah is a unit informally named Máaz, which we interpret as lava flows or the chemical complement to Séítah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks have been stored aboard Perseverance for potential return to Earth.</jats:p>
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Journal articleKminek G, Benardini JN, Brenker FE, et al., 2022,
COSPAR Sample Safety Assessment Framework (SSAF).
, Astrobiology, Vol: 22, Pages: S186-S216, ISSN: 1531-1074The Committee on Space Research (COSPAR) Sample Safety Assessment Framework (SSAF) has been developed by a COSPAR appointed Working Group. The objective of the sample safety assessment would be to evaluate whether samples returned from Mars could be harmful for Earth's systems (e.g., environment, biosphere, geochemical cycles). During the Working Group's deliberations, it became clear that a comprehensive assessment to predict the effects of introducing life in new environments or ecologies is difficult and practically impossible, even for terrestrial life and certainly more so for unknown extraterrestrial life. To manage expectations, the scope of the SSAF was adjusted to evaluate only whether the presence of martian life can be excluded in samples returned from Mars. If the presence of martian life cannot be excluded, a Hold & Critical Review must be established to evaluate the risk management measures and decide on the next steps. The SSAF starts from a positive hypothesis (there is martian life in the samples), which is complementary to the null-hypothesis (there is no martian life in the samples) typically used for science. Testing the positive hypothesis includes four elements: (1) Bayesian statistics, (2) subsampling strategy, (3) test sequence, and (4) decision criteria. The test sequence capability covers self-replicating and non-self-replicating biology and biologically active molecules. Most of the investigations associated with the SSAF would need to be carried out within biological containment. The SSAF is described in sufficient detail to support planning activities for a Sample Receiving Facility (SRF) and for preparing science announcements, while at the same time acknowledging that further work is required before a detailed Sample Safety Assessment Protocol (SSAP) can be developed. The three major open issues to be addressed to optimize and implement the SSAF are (1) setting a value for the level of assurance to effectively exclude the presence
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