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The Perseverance rover landed in Jezero crater, Mars, in February 2021. We used the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument to perform deep-ultraviolet Raman and fluorescence spectroscopy of three rocks within the crater. We identify evidence for two distinct ancient aqueous environments at different times. Reactions with liquid water formed carbonates in an olivine-rich igneous rock. A sulfate-perchlorate mixture is present in the rocks, which probably formed by later modifications of the rocks by brine. Fluorescence signatures consistent with aromatic organic compounds occur throughout these rocks and are preserved in minerals related to both aqueous environments.

Our appreciation of the potential distribution of life in the Solar System has been impacted by the discovery that organisms are able to occupy the most extreme environments on Earth. The persistence of life in the deepest parts of oceans, the deep sedimentary and crustal biosphere accessed by deep drill holes, hot springs, deserts, and polar regions has led to diverse hypotheses regarding the potential for extraterrestrial life on other planets. This chapter provides an overview on how scientists explore the habitability of other planets and moons of our Solar System and far away in outer space and how future space missions aim to find evidence for extraterrestrial life.

The icy moons of the outer Solar System display evidence of subsurface liquid water and, therefore, potential habitability for life. Flybys of Saturn's moon Enceladus by the Cassini spacecraft have provided measurements of material from plumes that suggest hydrothermal activity and the presence of organic matter. Jupiter's moon Europa may have similar plumes and is the target for the forthcoming Europa Clipper mission that carries a high mass resolution and high sensitivity mass spectrometer, called the MAss Spectrometer for Planetary EXploration (MASPEX), with the capability for providing detailed characterization of any organic materials encountered. We have performed a series of experiments using pyrolysis-gas chromatography-mass spectrometry to characterize the mass spectrometric fingerprints of microbial life. A range of extremophile Archaea and Bacteria have been analyzed and the laboratory data converted to MASPEX-type signals. Molecular characteristics of protein, carbohydrate, and lipid structures were detected, and the characteristic fragmentation patterns corresponding to these different biological structures were identified. Protein pyrolysis fragments included phenols, nitrogen heterocycles, and cyclic dipeptides. Oxygen heterocycles, such as furans, were detected from carbohydrates. Our data reveal how mass spectrometry on Europa Clipper can aid in the identification of the presence of life, by looking for characteristic bacterial fingerprints that are similar to those from simple Earthly organisms.

The Winchcombe meteorite fell on 28th February 2021 in Gloucestershire, UK. As the most accurately recorded carbonaceous chondrite fall, the Winchcombe meteorite is 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 non-destructive and destructive analyses of Winchcombe by Raman spectroscopy, online pyrolysis-gas chromatography (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 is 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 non-pyrolyzable 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 the CM group.

Organic 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.

The 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 yet the high free:total amino acid and nonalkylated:alkylated PAH ratios are on par with the less altered CMs—suggest that Winchcombe could represent a class of weak, poorly lithified meteorite not been previously studied.

Space missions concerned with life detection contain highly sensitive instruments for the detection of organics. Terrestrial contamination can interfere with signals of indigenous organics in samples and has the potential to cause false positive biosignature detections, which may lead to incorrect suggestions of the presence of life elsewhere in the Solar System. This study assessed the capability of solid phase micro extraction (SPME) as a method for monitoring organic contamination encountered by spacecraft hardware during assembly and operation. SPME-gas chromatography-mass spectrometry (SPME-GC-MS) analysis was performed on potential contaminant source materials, which are commonly used in spacecraft construction. The sensitivity of SPME-GC-MS to organics was assessed in the context of contaminants identified in molecular wipes taken from hardware surfaces on the ExoMars Rosalind Franklin rover. SPME was found to be effective at detecting a wide range of common organic contaminants that include aromatic hydrocarbons, non-aromatic hydrocarbons, nitrogen-containing compounds, alcohols and carbonyls. A notable example of correlation of contaminant with source material was the detection of benzenamine compounds in an epoxy adhesive analyzed by SPME-GC-MS and in the ExoMars rover surface wipe samples. The current form of SPME-GC-MS does not enable quantitative evaluation of contaminants, nor is it suitable for the detection of every group of organic molecules relevant to astrobiological contamination concerns, namely, large and/or polar molecules such as amino acids. However, it nonetheless represents an effective new monitoring method for rapid, easy identification of organic contaminants commonly present on spacecraft hardware and could thus be utilized in future space missions as part of their contamination control and mitigation protocols.

Life detection missions to the outer solar system are concentrating on the icy moons of Jupiter and Saturn and their inferred subsurface 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 analyze 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 analyzed 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 recognized 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.

We compared various pollutant concentrations (PM1, PM2.5, PM10, PNC, BC) at four different urban microenvironments (MEs) in London (Indoor, IN; Traffic Intersection, TI; Park, PK; and Street Canyon, SC). The physico-chemical characteristics of particles were analysed, and the respiratory deposition doses (RDD) were estimated. Field measurements were conducted over a period of 121 days. The mean PM2.5 (PNC) concentrations were found to be 9.47 ± 7.05 (16366 ± 11815), 8.09 ± 4.57 (10951 ± 6445), 5.11 ± 2.96 (7717 ± 4576), 3.88 ± 3.06 (5672 ± 2934) μg m−3 (# cm−3) at TI, SC, PK and IN, respectively. PM2.5, PM10 and PNC exhibited a trend of TI > SC > PK > IN; higher concentrations for PM1 and BC were observed at IN than PK due to the emissions from printers, producing a trend of TI > SC > IN > PK. We observed 12%–30% higher fine PM concentrations at TI and SC sites during morning peak (07:00–09:30) than the evening peak hours (16:00–19:00); while IN showed a smaller variation in fine PM concentrations compared with outdoor TI, PK and SC sites owing to their prevalence in the IN for a longer time. Fine and ultrafine PM containing potentially toxic trace transition metals including Fe, Ti, Cr, Mn, Al and Mg were detected by high resolution electron microscopy at all sites. There was a similar relative abundance of different elements at the TI, IN and PK sites, which suggests a transport of PM between MEs. RDD for PM1 was highest (2.45 ± 2.27 μg h−1) at TI for females during running; PM2.5 and PM10 were highest at SC (11.23 ± 6.34 and 37.17 ± 20.82 μg h−1, respectively). The results show that the RDD variation between MEs does not follow the PM concentration trend. RDD at PK was found to be 39%–53% lower than TI and SC during running for all the PM fractions. Overall, the study findings show the air quality variation at different MEs and reveals the exposure inequalities around the city, which enable the management of personal exposure by selecting appropriate MEs for different activities.

The 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 (

Underground 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.

The 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 of martian life in the samples, (2) carrying out an analogue test program, and (3) acquiring relevant contamination knowledge from all Mars Sample Return (MSR) flight and ground elements. Although the SSAF was developed specifically for assessing samples from Mars in the context of the currently planned NASA-ESA MSR Campaign, this framework and the basic safety approach are applicable to any other Mars sample return mission concept, with minor adjustments in the execution part related to the specific nature of the samples to be returned. The SSAF is also considered a sound basis for other COSPAR Planetary Protection Category V, restricted Earth return missions beyond Mars. It is anticipated that the SSAF will be subject to future review by the various MSR stakeholders.

Ancient martian organic matter is likely to take the form of kerogen-like recalcitrant macromolecular organic matter (MOM), existing in close association with reactive mineral surfaces, especially iron oxides. Detecting and identifying a biological origin for martian MOM will therefore be of utmost importance for life detection efforts at Mars. We show that Type I and Type IV kerogens provide effective analogues for putative martian MOM of biological and abiological (meteoric) provenances respectively. We analyse the pyrolytic breakdown products when these kerogens are mixed with mineral matrices highly relevant for the search for life on Mars. We demonstrate that, using traditional thermal techniques as generally used by the Sample Analysis at Mars and Mars Organic Molecule Analyser instruments, even the breakdown products of highly recalcitrant MOM are transformed during analysis in the presence of reactive mineral surfaces, particularly iron. Analytical transformation reduces the diagnostic ability of this technique, as detected transformation products of both biological and abiological MOM may be identical (low molecular weight gas phases and benzene) and indistinguishable. The severity of transformational effects increased through: calcite < kaolinite < haematite < nontronite < magnetite < goethite. Due to their representation of various habitable aqueous environments and the preservation potential of organic matter by iron, it is not advisable to completely avoid iron-rich strata. We conclude that haematite-rich localities, with evidence of extensive aqueous alteration of originally reducing phases, such as the Vera Rubin Ridge, may be relatively promising targets for identifying martian biologically-sourced MOM.

Answering the question of whether life ever existed on Mars is a key goal of both NASA's and ESA's imminent Mars rover missions. The obfuscatory effects of oxidizing salts, such as perchlorates and sulfates, on organic matter during thermal decomposition analysis techniques are well established. Less well studied are the transformative effects of iron oxides and (oxy)hydroxides, which are present in great abundances in the martian regolith. We examined the products of flash pyrolysis-gas chromatography-mass spectrometry (a technique analogous to the thermal techniques employed by past, current, and future landed Mars missions) which form when the cyanobacteria Arthrospira platensis are heated in the presence of a variety of Mars-relevant iron-bearing minerals. We found that iron oxides/(oxy)hydroxides have transformative effects on the pyrolytic products of cyanobacterial biomolecules. Both the abundance and variety of molecular species detected were decreased as iron substrates transformed biomolecules, by both oxidative and reductive processes, into lower fidelity alkanes, aromatic and aryl-bonded hydrocarbons. Despite the loss of fidelity, a suite that contains mid-length alkanes and polyaromatic hydrocarbons and/or aryl-bonded molecules in iron-rich samples subjected to pyrolysis may allude to the transformation of cyanobacterially derived mid-long chain length fatty acids (particularly unsaturated fatty acids) originally present in the sample. Hematite was found to be the iron oxide with the lowest transformation potential, and because this iron oxide has a high affinity for codeposition of organic matter and preservation over geological timescales, sampling at Mars should target sediments/strata that have undergone a diagenetic history encouraging the dehydration, dihydroxylation, and oxidation of more reactive iron-bearing phases to hematite by looking for (mineralogical) evidence of the activity of oxidizing, acidic/neutral, and either hot or long-lived fluids.

CM2 chondrites experienced widespread aqueous and short term thermal alteration on their parent bodies. Whilst previous Raman spectroscopic investigations have investigated insoluble organic matter (IOM), they have not taken into account the binary nature of IOM. Studies employing mass spectrometry have indicated that IOM also known as macromolecular organic matter (MOM) is in fact composed of two distinct fractions: labile organic matter (LOM) and refractory organic matter (ROM). The ROM component represents the aromatic rich and heteroatom poor component of IOM/MOM, whilst the LOM fraction represents a more heteroatom and aliphatic rich component. Here we report Raman 2D maps and spectroscopic data for Murchison and Mighei, both before and after chemical degradation, which attacks and liberates LOM. The removal of LOM simulates the effects of aqueous alteration, where ester and ether bonds are broken and is thought to release some components to the soluble organic matter (SOM) fraction, also known as the free organic matter fraction (FOM). Raman spectroscopy can be used to reveal the nature of bonding (sp2 and sp3) within carbonaceous materials such as meteoritic organic matter, through evaluation of the D and G band peak centres and FWHM values from the recorded data. The presence of sp3 orbitals indicates that the organic materials contain aliphatic linkages and/or heteroatoms. Statistical analysis of the Raman parameters obtained here indicates that the organic matter originating the Raman response is indistinguishable between the bulk (chemically untreated) and chemically degraded (treated with KOH and HI) samples. Such an observation indicates that the ROM fraction is the major contributor to the Raman response of meteoritic organic matter and thus Raman spectroscopy is unlikely to record any aqueous alteration processes that have affected meteoritic organic matter. Therefore, studies which use Raman to probe the IOM are investigating just one of the components of IOM and not the entire fraction. Studies that aim to investigate the effects of aqueous alteration on meteoritic organic matter should use alternate techniques to Raman spectroscopy. Furthermore, the indistinguishable nature of the Raman response of ROM from Murchison and Mighei suggests these meteorites inherited a ROM component that is chemically similar, reflecting either a common process for the formation of CM2 meteoritic ROM and/or that these meteorites probed the same ROM reservoir.

This study compares the chemical integrity of English Oak (Quercus robur) samples with an age range of four centuries by analysing the lignin degradation. The samples were collected from four historic British vessels and thus represent samples of diverse ages which have nonetheless experienced similar non-arboreal environments. We conclude that the Mary Rose, the oldest vessel studied and the recipient of the most intensive conservation efforts, has been well-preserved through treatment with PEG, and we present a baseline for assessing whether a ship has been biologically degraded.The work combines quantitative analytic chemistry techniques (e.g., THM-GC-MS) with the conservation of large historic artifacts.

Comparisons between the preservation potential of Mars-analog environments have historically been qualitative rather than quantitative. Recently, however, laboratory-based artificial maturation combined with kinetic modeling techniques have emerged as a potential means by which the preservation potential of solvent-soluble organic matter can be quantified in various Mars-analog environments. These methods consider how elevated temperatures, pressures, and organic-inorganic interactions influence the degradation of organic biomarkers post-burial. We used these techniques to investigate the preservation potential of deposits from a circumneutral iron-rich groundwater system. These deposits are composed of ferrihydrite (Fe5HO8 · 4H2O), an amorphous iron hydroxide mineral that is a common constituent of rocks found in ancient lacustrine environments on Mars, such as those observed in Gale Crater. Both natural and synthetic ferrihydrite samples were subjected to hydrous pyrolysis to observe the effects of long-term burial on the mineralogy and organic content of the samples. Our experiments revealed that organic-inorganic interactions in the samples are dominated by the transformation of iron minerals. As amorphous ferrihydrite transforms into more crystalline species, the decrease in surface area results in the desorption of organic matter, potentially rendering them more susceptible to degradation. We also find that circumneutral iron-rich deposits provide unfavorable conditions for the preservation of solvent-soluble organic matter. Quantitative comparisons between preservation potentials as calculated when using kinetic parameters show that circumneutral iron-rich deposits are ∼25 times less likely to preserve solvent-soluble organic matter compared with acidic, iron-rich environments. Our results suggest that circumneutral iron-rich deposits should be deprioritized in favor of acidic iron- and sulfur-rich deposits when searching for evidence of life with solvent extraction techniques.

International audience; Interplanetary dust is a scientifically important constituent of the Solar System that consists of material shed by asteroids, comets, and other airless bodies. As used here, the term “dust” includes interplanetary dust particles and micrometeoroids. Dust has been studied by missions such as Mariner, Pioneer, and Voyager in both interplanetary space and in the vicinity of most of the planets.To date, however, no dedicated interplanetary dust instrument has yet been employed for detailed analysis of the dust environment of Mars. Partial data on dust flux has been provided by the 1965 Mariner IV flyby, the MAVEN orbiter, and other missions, but a complete understanding of interplanetary dust abundance, composition, debris hazard, annual flux variation, and origins is lacking. These data are critical for understanding the effects of dust upon the martian system, including the carbonaceous input into the regolith of Mars and its moons, the chemical input into the martian atmosphere, potential effects upon remote sensing data, the hypothesized existence of a Phobos dust ring, and possible annual variations from meteor shower infall. These effects have direct ramifications for interpretation of Mars/Phobos/Deimos mission science and analysis of returned samples from those worlds. To remediate this shortfall, the authors recommend that a dedicated interplanetary dust analysis instrument should be included in the instrument package for an upcoming martian orbiter in the near term. Such an interplanetary dust analysis instrument should collect data over a time period of several martian years in order to generate a statistically robust data set on interplanetary dust concentration and flux over a wide range of mass, and to discern temporal variation over multiple martian years.

Summary The Carboniferous mudstones of northern England have been considered as a potential source rock for development of shale gas resources. The viability of the source rock is in part dependent on its potential to generate hydrocarbons. New geochemical data from boreholes across northern England is presented, and the original organic parameters are predicted for mudstones of different ages. The findings concur with other assessments of the mudstones, that they contain a considerable detrital and inert component which could be detrimental to the development of the resources. New original organic content parameters for the source rock are recommended for future petroleum systems modelling and resource interpretation.

Introduction: The potential habitability of the icy moons of Jupiter and Saturn, in particular Europa and Enceladus, has been hotly debated in recent years. There is evidence of subsurface liquid water oceans [1], and complex organic molecules (>200 amu) have been detected in the plumes from Enceladus [2]. Plumes are also thought to arise from the surface of Europa [3], which will be the target of the Europa Clipper spacecraft, due to be launched in a few years. In a similar manner to the Ion and Neutral Mass Spectrometer (INMS) on Cassini [4], the Europa Clipper will also carry a mass spectrometer, MASPEX [5], enabling molecular detection of material in the plumes. Extremophile Archaea and Bacteria, besides being some of the simplest known forms of life, can withstand extreme conditions of temperature, salinity and acidity, and have been observed in hydrothermal vents on Earth. Similar organisms are the most likely candidates for life on icy moons. The purpose of our current work is to study the mass spectral fingerprint of earthly simple Archaea and Bacteria to understand the spectra that would arise from similar organisms in the vicinity of icy moons and distinguish them from abiotic compounds. Nonbiological organic materials generally have complete structural diversity and are characterized by the presence of racemic mixtures and polycyclic aromatic hydrocarbons (PAHs). These are absent in biological materials which tend to have specific structures and show chiral preference. Methods: Different strains of Archaea and Bacteria, including cyanobacteria, were obtained in freeze-dried form (DSMZ GmbH). These include extremophiles isolated from sea ice (Shewanella frigidimarina) and hot springs (Metallosphaera hakonensis). They were analyzed in pure form with flash pyrolysis-GC-MS. This enabled identification of the decomposition fragments that are representative of the different components of bacteria. Flash pyrolysis offers a good analogue of the impact fragmentation that occurs as the spacecraft flies through a plume. In our experiments pyrolysis is coupled with gas chromatography-mass spectrometry (GC-MS). This separates the pyrolysis products, enabling identification of individual molecules. This GC stage is missing on the spacecraft instruments but simulated INMS or MASPEX spectra can be reconstructed from the chromatograms. Additional experiments were carried out to understand the degradation of bacterial signals under conditions relevant to icy moons. Hydrous pyrolysis was used to simulate hydrothermal degradation, where bacteria are subjected to increased pressures and temperatures, in the presence of water [6]. Results: Our results show that pyrolysis-GC-MS analysis of intact archaea and bacteria produces distinctive fingerprints of biotic substances, shown in Figure 1. Decomposition products from protein, amino acid, carbohydrate and lipid species were detected from all the strains analyzed. The compound types detected are detailed in Table 1. Compound type Possible origin Alkylbenzenes, e.g. toluene, styrene, ethylbenzene Protein Nitrogen containing heterocycles, e.g. indole, benzyl nitrile, pyrrole Proteins, amino acids 2,5-Diketopiperazines Peptides, proteins Oxygen containing heterocycles (furans), e.g. methyl-furan, dimethyl-furan, furfural, maltol Carbohydrates Phenols, e.g. phenol, cresol Protein, carbohydrates Alkanes Lipids Fatty acid, e.g. hexadecenoic acid Lipids Table 1: Possible origin of compound types detected from bacteria and archaea analyzed with pyrolysis-GC-MS. Using GC-MS, we have been able to identify the molecules detected, shown in Figure 1A, and hence identify the ion series that represent specific compound types which are related to different components of the organisms. These ion series greatly help with the interpretation of complex mass spectra when no separation technique is present, i.e. in INMS and MASPEX. The chromatogram can be converted into a mass spectrum, Figure 1B, with lines joining the peaks in a specific series. This mass spectrum is more representative of the data acquired in space missions. Although only a relatively small number of strains have been analyzed in this study, there is diversity among the results obtained with differing ratios of carbohydrate and protein products detected. However, all the strains also share common features, such as the presence of indole and phenols. The mass spectra obtained from Archaea and Bacteria are clearly different from those of abiotic materials such as meteorites [7], which show features as discussed in the Introduction. This shows that mass spectrometry is a powerful technique for distinguishing between non-biological and biological materials. As well as understanding the mass spectra of intact bacteria, it is important to understand how these spectra will change under different sample processing methods. Thermal processing is likely to be present on icy moons, both on and under the icy crust and as material is ejected into space. Hydrous pyrolysis can also simulate conditions near hydrothermal vents. Increased amounts of sample processing degrade the biotic fingerprint of the bacteria. Understanding the degradation pattern and being able to recognize where the spectral features originate from may play an important role in future spectral interpretation. It will also be important to note at what point the compounds detected become indistinguishable from abiotic materials. Acknowledgments: We thank the MASPEX team for useful discussions. References: [1] Pappalardo R. T. et al. (1999) J. Geophys. Res., 104 (E10), 24015-24055. [2] Postberg F. et al. (2018) Nature, 558, 564-568. [3] Paganini L. et al. (2019) Nat. Astron., doi:10.1038/s41550-019-0933-6. [4] Waite J. H. et al. (2004) Space Sci. Rev., 114, 113–231. [5] Brockwell T. G. et al. (2016) IEEE Aerospace Conference 2016. [6] Sephton M. A. et al. (1999) Planet. Space Sci., 47, 181-187. [7] Sephton M. A. et al. (2018) Astrobiology, 18, 7, 843-855.

The icy moons of the outer Solar System present the possibility of subsurface water, habitable conditions, and potential abodes for life. Access to evidence that reveals the presence of life on the icy moons can be facilitated by plumes that eject material from the subsurface out into space. One instrument capable of performing life-search investigations at the icy moons is the MAss SPectrometer for Planetary EXploration/Europa (MASPEX), which constitutes a high-resolution, high-sensitivity multibounce time-of-flight mass spectrometer capable of measuring trace amounts (ppb) of organic compounds. MASPEX has been selected for the NASA Europa Clipper mission and will sample any plumes and the surface-sputtered atmosphere to assess any evidence for habitability and life. MASPEX is capable of similar investigations targeted at other icy moons. Data may be forthcoming from direct sampling but also impact dissociation because of the high speed of some analytes. Impact dissociation is analogous to the dissociation provided by modern analytical pyrolysis methods. Radiolytic dissociation on the europan surface before or during the sputtering process can also induce fragmentation similar to pyrolysis. In this study, we have compiled pyrolysis mass spectrometry data from a variety of biological and nonbiological materials to demonstrate the ability of MASPEX to recognize habitability and detect life in any plumes and atmospheres of icy moons. Key Words: Europa-Icy moons-Life detection-Mass spectrometry-Organic matter. Astrobiology 18, 843-855.

Past life on Mars will have generated organic remains that may be preserved in present day Mars rocks. The most recent period in the history of Mars that retained widespread surface waters was the late Noachian and early Hesperian and thus possessed the potential to sustain the most evolved and widely distributed martian life. Guidance for investigating late Noachian and early Hesperian rocks is provided by studies of analogous acidic and sulfur-rich environments on Earth. Here we report organic responses for an acid stream containing acidophilic organisms whose post-mortem remains are entombed in iron sulphates and iron oxides. We find that, if life was present in the Hesperian, martian organic records will comprise microbial lipids. Lipids are a potential sizeable reservoir of fossil carbon on Mars, and can be used to distinguish between different domains of life. Concentrations of lipids, and particularly alkanoic or “fatty” acids, are highest in goethite layers that reflect high water-to-rock ratios and thus a greater potential for habitability. Goethite can dehydrate to hematite, which is widespread on Mars. Mars missions should seek to detect fatty acids or their diagenetic products in the oxides and hydroxides of iron associated with sulphur-rich environments.

Jarosite on Mars is of significant geological and astrobiological interest, as it forms in acidic aqueous conditions that are potentially habitable for acidophilic organisms. Jarosite can provide environmental context and may host organic matter. The most common extraction technique used to search for organic compounds on the surface of Mars is pyrolysis. However, thermal decomposition of jarosite releases oxygen into pyrolysis ovens, which degrades organic signals. Jarosite has a close association with the iron oxyhydroxide goethite in many depositional/diagenetic environments. Hematite can form by dehydration of goethite or directly from jarosite under certain aqueous conditions. Goethite and hematite are significantly more amenable than jarosite for pyrolysis experiments employed to search for organic matter. Analysis of the mineralogy and organic chemistry of samples from a natural acidic stream revealed a diverse response for organic compounds during pyrolysis of goethite-rich layers but a poor response for jarosite-rich or mixed jarosite-goethite samples. Goethite units that are associated with jarosite, but do not contain jarosite themselves, should be targeted for organic detection pyrolysis experiments on Mars. These findings are extremely timely, as exploration targets for Mars Science Laboratory include Vera Rubin Ridge (formerly known as “Hematite Ridge”), which may have formed from goethite precursors. Key Words: Mars—Pyrolysis—Jarosite—Goethite—Hematite—Biosignatures. Astrobiology 18, 454–464.

Heavy oil is recovered from reservoirs using steam-assisted technology, which can lead to H2S generation if the oil is relatively sulfur-rich. We have used laboratory aquathermolysis to simulate the steam-assisted gravity drainage process and have compared free heavy oil to that contained within the mineral matrix. The presence of a mineral matrix was found to affect the amount of H2S produced and the chemical properties of the oil generated. Our findings show that H2S production is initiated by the presence of naturally occurring minerals at specific temperatures and pressures and production techniques that avoid these conditions will minimize H2S production.

Extraterrestrial organic matter has been widely studied; however, its response to pressure has not. Primitive organic matter bearing meteorites, such as CI and CM carbonaceous chondrites, have experienced variable pressures, up to 10 GPa. To appreciate the effects of these pressures on the organic content of these bodies, the model compounds isophthalic acid, vanillin and vanillic acid were subjected to pressures of up to 11.5 GPa and subsequently decompressed. High resolution synchrotron source Fourier Transform Infrared (FTIR) was used to determine the effects of different benzene substituents at high pressure on both the vibrational assignments of the benzene core of the molecules and the ability of the aromatic compounds to form intermolecular hydrogen bonds. The presence of additional peaks at high pressure was found to coincide with molecules that contain carboxyl groups, these features are interpreted as C-H---O intermolecular hydrogen bonds. The formation of these hydrogen bonds has implications for the origination of macromolecular organic matter (MOM), owing to the importance of such attractive forces during episodes of cross linking, such as esterification. Pressure-induced hydrogen bond formation is a process by which aromatic MOM precursors could have cross linked to generate the organic polymers found within extraterrestrial bodies today.

Seeking evidence of life in the solar system will be partly the search for organic signatures in rock matrices. The search for organic matter is common to petroleum exploration on Earth and life search missions to Mars. Despite some commonality between investigations into life records on Earth and Mars, there are also significant differences. Favourable organic concentrations in petroleum source rocks are much higher than those needed for life-search targets on Mars. Choosing samples for collection on Mars for return to Earth requires more care at earlier stages than needed for collection of samples on Earth. During and after collection, samples of Mars must be protected from organic contamination that could confuse their potentially weak and poorly understood signals. While operations on Mars provide effectively unlimited samples but with limited instrumentation, analysis on Earth involve constrained amounts of returned samples but access to the world’s best analytical capabilities. Returning samples from Mars also presents the potential for historical firsts including new technologies and important preparations for the eventual human exploration of the Red Planet.

This study reports a multidisciplinary approach to determining hydrocarbon charge-points and migration in the Wessex Basin, southern England. Geochemical analysis of reservoir core material (Bridport Sandstone and Inferior Oolite) using gas chromatography-mass spectrometry (GC-MS), suggests that the oil in the Wessex Basin is from a single source, and that small variations in environmentally sensitive biomarkers are likely due to small differences in maturity or depositional conditions during the formation of the oil over millions of years. Using seismic data, basin modelling revealed two potential hydrocarbon migration pathways from the hanging wall of the Purbeck fault into the Sherwood Sandstone reservoir at Wytch Farm. One of these potential pathways is represented by cores termed Creech and the other Bushey Farm. To try to distinguish between the two potential pathways, cores were studied using mineral magnetic techniques. The magnetic signature was characterised using low-temperature (

The Planetary Protection of Outer Solar System (PPOSS) project tackled the science, technology and policy-making components related to biological and organic contamination of outer solar system bodies, in particular icy moons. This intensive three-year program has provided an international platform and forum where science, industry and policy actors met to nurture and catalyze discussions, exchange of knowledge and produce policy recommendations on the matter of planetary protection. The main objectives of the PPOSS project are to: Describe the state-of-the-art and good practice for implementing planetary protection requirements, and identify good practices and lessons to be learnt. Identify scientific challenges, requirements and knowledge gaps related to planetary protection of outer solar system bodies, including small solar system bodies. Develop a European engineering roadmap for the industry sector. Review the international outer solar system planetary protection regulation structure and categorization and suggest improvements, and, Facilitate the dissemination of knowledge related to planetary protection. The PPOSS project gathers seven European partner organizations, one international partner and one international observer.

Conclusively detecting, or ruling out the possibility of, life on the icy moons of the outer solar system will require spacecraft missions to undergo rigorous planetary protection and contamination control procedures to achieve extremely low levels of organic terrestrial contamination. Contamination control is necessary to avoid forward contamination of the body of interest and to avoid the detection of false positive signals which could either mask indigenous organic chemistry of interest or cause an astrobiological false alarm. Here we test a new method for rapidly and inexpensively assessing the organic cleanliness of spaceflight hardware surfaces using solid phase micro extraction (SPME) fibres to directly swab surfaces. The results suggest that the method is both time and cost efficient. The SPME-gas chromatography mass spectrometry (GC-MS) method is sensitive to common mid-weight, non-polar contaminant compounds, e.g. aliphatic and aromatic hydrocarbons, which are common contaminants in laboratory settings. While we demonstrate the potential of SPME for surface sampling, the GC-MS instrumentation restricts the SPME-GC-MS technique’s sensitivity to larger polar and non-volatile compounds. Although not used in this study, to increase the potential range of detectable compounds, SPME can also be used in conjunction with high performance liquid chromatography/liquid chromatography-mass spectrometry systems suitable for polar analytes [Kataoka et al., 2000]. Thus, our SPME method presents an opportunity to monitor organic contamination in a relatively rapid and routine way that produces information-rich data sets.

Part of this work was supported by UK Space Agency Grant ST/N000560/1 and by internal funding by Tufts University and the School of Earth and Environmental Sciences at the University of St Andrews. The observed fall and rapid recovery of the Tissint Mars meteorite has provided minimally contaminated samples of the Martian surface. We report analyses of Tissint for organic compounds by pyrolysis-gas chromatography-mass spectrometry and for soluble salts by ion chromatography. Pyrolysis-gas chromatography-mass spectrometry analysis shows the presence of organic compounds similar to those in the Mars EETA79001 and Nakhla meteorites. The organic profile is dominated by aromatic hydrocarbons, including oxygen and nitrogen-containing aromatics, and sulfur-containing species including thiophenes. The soluble salts in Tissint are dominated by sulfate and various oxidation states of chlorine, including perchlorate. The organic compounds and salts in the soils from the Tissint recovery strewn field differ significantly from those found in Tissint suggesting minimal terrestrial contamination. Our results support the hypothesis that the soluble inorganic components of Tissint are most likely a result of indigenous fluid inclusion, thus providing a glimpse into the composition of early Martian fluids. Publisher PDF

The detection of chlorinated hydrocarbons by Curiosity on Mars has been attributed to the presence of unidentified indigenous organic matter. Similarly, oxychlorines on Earth have been proposed to be responsible for the apparent lack of organics in the Atacama Desert. The presence of perchlorate (ClO4-) poses a unique challenge to the measurement of organic matter due to the oxidizing power of oxychlorines during commonly used pyrolysis-gas chromatography-mass spectrometry (py-GC-MS) methods. Here, we show that perchlorates and other oxyanion salts inhibit the detection of organic compounds but that removing these problematic species prior to pyrolysis by using an optimal sample extraction duration and suitable ratios of water to sample mass enables analysis. We have characterized leached and unleached samples containing perchlorates from the Atacama Desert and have found that after leaching, the py-GC-MS chromatograms of the dried mineral residues show identifiable biomarkers associated with indigenous cyanobacteria. Samples which were pyrolyzed without leaching showed no detectable organic matter other than background siloxane and very weak or no trace of detectable polychlorinated benzenes. Dried sample residues remaining after leaching, the mineral matrix and water-insoluble organic matter, showed a strong organic response in all cases when analyzed by py-GC-MS. These residues are most likely the product of the pyrolysis of water-insoluble organics originally present in the samples. In addition, our results imply that previous soil analyses which contained high levels of oxyanions and concluded that organics were either not present or were present at extremely low levels should be reexamined.

Returning samples from Mars will require an effective method to assess and select the highest-priority geological materials. The ideal instrument for sample triage would be simple in operation, limited in its demand for resources, and rich in produced diagnostic information. Pyrolysis–Fourier infrared spectroscopy (pyrolysis-FTIR) is a potentially attractive triage instrument that considers both the past habitability of the sample depositional environment and the presence of organic matter that may reflect actual habitation. An important consideration for triage protocols is the sensitivity of the instrumental method. Experimental data indicate pyrolysis-FTIR sensitivities for organic matter at the tens of parts per million level. The mineral matrix in which the organic matter is hosted also has an influence on organic detection. To provide an insight into matrix effects, we mixed well-characterized organic matter with a variety of dry minerals, to represent the various inorganic matrices of Mars samples, prior to analysis. During pyrolysis-FTIR, serpentinites analogous to those on Mars indicative of the Phyllocian Era led to no negative effects on organic matter detection; sulfates analogous to those of the Theiikian Era led, in some instances, to the combustion of organic matter; and palagonites, which may represent samples from the Siderikian Era, led, in some instances, to the chlorination of organic matter. Any negative consequences brought about by these mineral effects can be mitigated by the correct choice of thermal extraction temperature. Our results offer an improved understanding of how pyrolysis-FTIR can perform during sample triage on Mars. Key Words: Mars—Life-detection instruments—Search for Mars’ organics—Biosignatures. Astrobiology 16, 831–845.

Na–H3O jarosite was synthesized hydrothermally at 413 K for 8 days and investigated using single-crystal X-ray diffraction (XRD) and electron microprobe analysis (EMPA). The chemical composition of the studied crystal is [Na0.57(3) (H3O)0.36 (H2O)0.07]A Fe2.93(3) (SO4)2 (OH)5.70 (H2O)0.30, and Fe deficiency was confirmed by both EMPA and XRD analysis. The single-crystal XRD data were collected at 298 and 102 K, and crystal structures were refined in space group $$ R\overline{3}m$$ . The room-temperature data match structural trends of the jarosite group, which vary linearly with the c axis. The low-temperature structure at 102 K shows an anisotropic decrease in the unit cell parameters, with c and a decreasing by 0.45 and 0.03 %, respectively. Structural changes are mainly confined to the A site environment. Only minor changes occur in FeO6 and SO4 polyhedra. The structure responds upon cooling by increasing bond length distortion and by decreasing quadratic elongation of the large AO12 polyhedra. The structural parameters at low temperature follow very similar patterns to structural changes that correspond to compositional variation in the jarosite group, which is characterised by the flexibility of AO12 polyhedra and rigidity of Fe(OH)4O2–SO4 layers. The most flexible areas in the jarosite structure are localized at AO12 edges that are not shared with neighbouring FeO6 octahedra. Importantly, for the application of XRD in planetary settings, the temperature-related changes in jarosite can mimic compositional change.

Significance It has remained an unresolved question whether microorganisms recovered from the most arid environments on Earth are thriving under such extreme conditions or are just dead or dying vestiges of viable cells fortuitously deposited by atmospheric processes. Based on multiple lines of evidence, we show that indigenous microbial communities are present and temporally active even in the hyperarid soils of the Atacama Desert (Chile). Following extremely rare precipitation events in the driest parts of this desert, where rainfall often occurs only once per decade, we were able to detect episodic incidences of biological activity. Our findings expand the range of hyperarid environments temporarily habitable for terrestrial life, which by extension also applies to other planetary bodies like Mars., Traces of life are nearly ubiquitous on Earth. However, a central unresolved question is whether these traces always indicate an active microbial community or whether, in extreme environments, such as hyperarid deserts, they instead reflect just dormant or dead cells. Although microbial biomass and diversity decrease with increasing aridity in the Atacama Desert, we provide multiple lines of evidence for the presence of an at times metabolically active, microbial community in one of the driest places on Earth. We base this observation on four major lines of evidence: (i) a physico-chemical characterization of the soil habitability after an exceptional rain event, (ii) identified biomolecules indicative of potentially active cells [e.g., presence of ATP, phospholipid fatty acids (PLFAs), metabolites, and enzymatic activity], (iii) measurements of in situ replication rates of genomes of uncultivated bacteria reconstructed from selected samples, and (iv) microbial community patterns specific to soil parameters and depths. We infer that the microbial populations have undergone selection and adaptation in response to their specific soil microenvironment and in particular to the degree of aridity. Collectively, our results highlight that even the hyperarid Atacama Desert can provide a habitable environment for microorganisms that allows them to become metabolically active following an episodic increase in moisture and that once it decreases, so does the activity of the microbiota. These results have implications for the prospect of life on other planets such as Mars, which has transitioned from an earlier wetter environment to today’s extreme hyperaridity.

On Earth, geophysical and geochemical data are used in the exploration and production of petroleum. Geophysical data are used to reveal what is below the Earth’s surface and where petroleum deposits may be located. Geochemical data are used to identify the chemistries and therefore potential petroleum products of organic-rich source rocks and to assess whether those source rocks are mature enough to have generated petroleum. Geochemical data are also used to correlate organic-rich source rocks with identified petroleum reservoirs to reveal possible migration routes and to reveal whether reservoirs are subdivided into compartments. In space, similar approaches are followed to search for past or present life on other planets and moons with geophysical methods revealing the environment and geochemical methods identifying the source of any organic matter.

In this paper, we report the pyrolysis and formation of magnetic minerals in three source rock samples from the Wessex Basin in Dorset, southern England. The experimental conditions in the laboratory recreated the catagenesis environment of oil source rocks. Magnetic analysis of both the heated and the unheated samples at room temperature and at very low-temperatures (5 K), coupled with transmission electron-microscopy imaging and X-ray analysis, revealed the formation of nanometre-sized (

The major organic component in carbonaceous chondrites is a highly aromatic macromolecular material. Aromatic organic matter and phyllosilicates are colocated in these meteorites, and it is possible that the physical association represents a synthetic chemical relationship. To explore the potential reactions that could take place to produce the aromatic macromolecular material, we heated various simple aromatic units in the presence of montmorillonite with different exchanged cations. The majority of cation-exchanged montmorillonites tested, sodium-, aluminum-, iron-, nickel-, and cobalt-rich montmorillonites, do not produce polymerization products. By contrast, Fe(3+) cation-exchanged montmorillonite readily facilitates addition reactions between aromatic hydrocarbons. A feasible mechanism for the process is oxidative coupling, which involves a corresponding reduction of the Fe(3+) cation to its Fe(2+) counterpart. A similar reduction process for the other metal cations does not take place, highlighting the importance of iron. This simple process is one feasible mechanism for the construction of aromatic macromolecules such as those found in carbonaceous chondrites. The search for a relationship between Fe(3+)-rich phyllosilicates and aromatic organic structures (particularly dimers, trimers, and more polymerized forms) in carbonaceous chondrites would represent an effective test for constraining the role of clay catalysis in the early Solar System.

Black shales in the Holy Cross Mountains area of Poland provide a record of environmental change across the Ordovician–Silurian boundary. The changing depositional conditions have generated a variation in organic matter contents above and below the boundary. Investigating the organic constitution of these black shales has the potential to reveal how their organic matter contents were generated and how suitable these rocks and their lateral equivalents may be for exploitation as shale gas reservoirs. One outcrop at the Holy Cross Mountains with a continuous section across the Ordovician–Silurian boundary occurs near the village of Bardo Stawy in the Kielce region, and contains sandy-silty mudstones, as well as grey and black shales. Organic geochemical analyses of samples at Bardo Stawy reveals low Total Organic Carbon (TOC) contents for Ordovician samples and higher TOC values for Silurian samples. Organic biomarkers indicate that the Ordovician rocks were deposited in a shallow-marine shelf setting, while the Silurian rocks were deposited in a deeper marine environment. The progressive increase in TOC from the uppermost Ordovician to the lowermost Silurian rocks reflects increasingly oxygen-poor depositional conditions during the post-glacial transgression. Following the deposition and preservation of organic matter in the Ordovician and Silurian rocks, these rocks were buried and subjected to thermal maturation. Rock Eval and biomarker thermal maturity parameters all indicate that the organic matter is mature and lies within the oil window. The Ordovician and Silurian shales have direct relevance to recent attempts to discover and exploit shale gas reservoirs in Poland. Our data and interpretations suggest that the relatively low TOC values (

Assessing oil in place and the proportion of oil that is producible are two critical measurements in evaluating liquid rich unconventional well and play economics. Current methodologies to evaluate Oil-In-Place (OIP) include log calculated estimates, petroleum systems charge modeling, and direct geochemical measurements. The standard open system programmed pyrolysis method has been modified to remove a broader range of thermally extracted free and adsorbed hydrocarbons and non-hydrocarbons in liquid rich unconventional plays. The added isotherms with a relatively low temperature start results in additional free hydrocarbon S1 peaks. The extra S1 peaks are used to assist in evaluating in-situ hydrocarbon quality. Examination of as received and post solvent extracted programmed pyrolysis data from replicate samples indicates a significant amount of solvent extractable free hydrocarbon is not captured in the S1 and rolls over into the S2 peak. This observation suggests the S1 peak may not represent total oil in place less evaporative losses. This paper examines a new multi-step high resolution on-column thermal extraction system to provide an inexpensive screening tool to map zones of higher in place oil and evaluate chemical characteristics which can be used to assist in estimating productivity. The thermal extraction unit is coupled to a flame ionization detector (FID) by a short uncoated capillary column to generate a high resolution thermal extraction profile (thermogram) with four temperature fractions. The area under each thermal peak provides direct measurements of volatized hydrocarbon and non-hydrocarbon compounds. Examination of individual compounds within each thermal fraction demonstrates multi-step thermal extraction is not a simple fractional distillation but also is impacted by inorganic and organic interactions. If we assume each thermal fraction represents oil compounds with increased complexity, then one can use peak area ratios to estimate in-situ fluid make-up and the proportion of in-situ oil that can be considered producible with completions enhancement.

The role of heat in the generation of petroleum has led to the study of organic matter-containing rocks by laboratory heating techniques. In particular, heat is used for the thermal extraction of organic matter in preparation for characterization by a range of detectors. Recently, thermal extraction has been used to answer certain planetary science questions such as the history of habitability for planets in the solar system and the search for evidence of life outside the Earth. The development of new thermal extraction protocols for challenging planetary science objectives provides methods that are readily translatable back to petroleum activities and include new shale screening and assessment techniques.

The first step in many life detection protocols on Mars involves attempts to extract or isolate organic matter from its mineral matrix. A number of extraction options are available and include heat and solvent assisted methods. Recent operations on Mars indicate that heating samples can cause the loss or obfuscation of organic signals from target materials, raising the importance of solvent-based systems for future missions. Several solvent types are available (e.g. organic solvents, surfactant based solvents and subcritical water extraction) but a comparison of their efficiencies in Mars relevant materials is missing. We have spiked the well characterised Mars analogue material JSC Mars-1 with a number of representative organic standards. Extraction of the spiked JSC Mars-1 with the three solvent methods provides insights into the relative efficiency of these methods and indicates how they may be used on future Mars missions.

Article history:Received 24 December 2012Received in revised form 21 August 2013Accepted 9 November 2013Available online 19 November 2013Keywords:sporopolleninthermal maturationpalynologypalynomorphsporeheating Sporopolleninistheprimarybiopolymerfoundinthewallsofpollenandspores;duringmaturationsporopollen-in undergoes a number of discrete chemical changes, despite maintaining identifiable morphological featureswhich can be exploited for palynological study. Here we report the results of heating experiments performedusing Lycopodium clavatum spores designed to investigate the changes that occur within sporopollenin acrossa wide range of temperatures (0–350 °C) to simulate different degrees of maturation. Changes in sporopolleninfunctionality were assessed using Fourier transform infrared (FTIR) microspectroscopy. Our analyses show thatthechemicalstructureofsporopolleninremainsrelativelystableoverawiderangeofsimulatedmaturationcon-ditions, untila threshold of250–300 °C is reached,at which point a reorganisation of chemical structure begins.ComparisonoftheseartificiallymaturedsporeswithfossilmaterialobtainedfromaCarboniferous-agesectioninthe United Kingdom shows a strong chemical resemblance, suggesting that our experimental procedure accu-rately reflects the process of maturation and provides an insight into the chemical stability of sporopollenin inthe geosphere.© 2013 Published by Elsevier B.V.

Meteorites can have played a role in the delivery of the building blocks of life to Earth only if organic compounds are able to survive the high pressures and temperatures of an impact event. Although experimental impact studies have reported the survival of organic compounds, there are uncertainties in scaling experimental conditions to those of a meteorite impact on Earth and organic matter has not been found in highly shocked impact materials in a natural setting. Impact glass linked to the 1.2-km-diameter Darwin crater in western Tasmania is strewn over an area exceeding 400 km 2 and is thought to have been ejected by a meteorite impact about 800 kyr ago into terrain consisting of rainforest and swamp. Here we use pyrolysis-gas chromatography-mass spectrometry to show that biomarkers representative of plant species in the local ecosystem - including cellulose, lignin, aliphatic biopolymer and protein remnants - survived the Darwin impact. We find that inside the impact glass the organic components are trapped in porous carbon spheres. We propose that the organic material was captured within impact melt and preserved when the melt quenched to glass, preventing organic decomposition since the impact. We suggest that organic material can survive capture and transport in products of extreme impact processing, at least for a Darwin-sized impact event. © 2013 Macmillan Publishers Limited.