21-EPN-FT1-033: Spectral Signatures of Amino Acid and Polypeptide Embedded in Water Ices – Implications for Biosignature Identification on Icy Moons

21-EPN-FT1-033: Spectral Signatures of Amino Acid and Polypeptide Embedded in Water Ices – Implications for Biosignature Identification on Icy Moons

Visit by Surendra Vikram Singh of the Physical Research Laboratory (India), to TA2.8 CSS (Cold Surfaces Spectroscopy) at IPAG (France).
Dates of visit: 23 May – 06 June 2022

Report Summary: The objective of the experiments was to obtain a spectral library of biomolecules such as amino acids in water ice in context of icy bodies of Solar System.

We performed a series of measurements obtaining reflectance spectra of glycine –water ice mixtures in the VIS-NIR range (0.4-4.2 μm) at the temperature range of 110-250 K and at three different concentrations, using Cold Surface Spectroscopy Facility (CSS) setup at IPAG. Glycine –
water ice mixtures were studied in two different mixing modes (inter and intra mixing) to get the spectral variations due to dissolving amino acids into water. R

eflectance spectra of pure glycine and pure water ice were also obtained for reference. Reflectance spectra for a shocked glycine sample (obtained from HISTA facility at PRL) was also studied to understand the effect of shock induced chemistry. These measurements will support to find the spectral signature of amino acids on icy bodies of Solar System.


21-EPN-FT1-030: Laboratory simulation of the Martian surface brightness temperature response to Phobos eclipses

21-EPN-FT1-030: Laboratory simulation of the Martian surface brightness temperature response to Phobos eclipses

Visit by Nils Mueller of Freie Universität Berlin (Germany) and Joerg Knollenberg of DLR (Germany) to TA2 Facility 25 – Swedish Planetary Ices Laboratory.
Dates of visit: 10-19 April 2024

Report Summary: The objective of this series of experiments was to support the data interpretation of short changes in insolation of planetary bodies as they happen during solar eclipses or transits. The temperature response of Martian regolith to the transit of Phobos has been observed by NASA’s InSight mission and interpreted in terms of layering in the near-surface. The Planetary Ices Laboratory is capable of simulating such events on Earth using a thermal vacuum chamber that is tolerant to dust and a solar simulator. The chamber was evacuted, either refilled with 5.5 mbar CO2 or left at <1e-4 mbar (simulating Mars and space, respectively), cooled below -60 °C, then the contained regolith analogue material was illuminated until the temperature approached an equilibrium.

During our time in the planetary ices lab we conducted tests with different materials configurations. The first consists of 2-4 mm Mojave Mars Simulant (MMS) filling the tray to a depth of 2 cm. The second adds 2 or 3 monolayers of <100 μm MMS. The third extends the dust layer to approximately 3 mm. The fourth adds cm sized clasts to recreate a typical planetary scene. The eclipses consisted of closing the shutter of the solar simulator for various durations. The corresponding temperature response of the material extends to different depths an therefore may sense different layers. The surface temperature was measured using a radiometer comparable to those on past Mars and future Phobos missions.


21-EPN-FT1-024: Untangling Rock-Inhabiting Microorganisms and their Biosignatures from the Mars-like Area of Puna Plateau

21-EPN-FT1-024: Untangling Rock-Inhabiting Microorganisms and their Biosignatures from the Mars-like Area of Puna Plateau, Argentinian Andes

Visit by Lorenzo Aureli and Gerardo Antonio Stoppiello of the University of Tuscia to TA1.6 Argentinian Andes (Argentina).
Dates of visit: 17-23 April 2022

Report Summary: The hostile current conditions on the surface of Mars entail that, if any form of life exists or ever existed on the planet, it may have adopted survival strategies like those evolved by terrestrial microorganisms inhabiting extremely harsh regions. Here, one of the most common strategies observed is endolithic growth, defined as the colonisation of the small interstices and cracks inside rocks where microorganisms can be protected from external hostile conditions. On the other hand, environments exhibiting a strong negative hydrological balance can be characterised by the sporadic presence of pools saturated in minerals. Here, microorganisms can induce carbonate precipitation along with the physicochemical factors occurring in these environments, causing the formation of sedimentary structures in which they can be trapped.

From an astrobiological perspective, several studies showed how the early Mars environment may have exhibited an overall desertic environment hosting localised water basins. Therefore, the possibility that microbial forms of life may have existed on Mars makes hypothetical endolithic habitats and evaporite deposits on the planet interesting targets for the search for tracks of past life. From this perspective, the southern end of the Puna Plateau in the Argentinian Andes (Catamarca province, Argentina) may represent an excellent model to understand how putative microorganisms may be adapted to the early Martian environments and how to detect their signatures. For this reason, a sampling campaign was performed at the Laguna Negra Lake (Puna Plateau region) in April 2022, with the purpose to characterise different microbial habitats hosted in the site.


21-EPN-FT1-020: Preservational Potential of Microbialite Biosignatures in Basalt-Hosted Lacustrine Environments

21-EPN-FT1-020: Preservational Potential of Microbialite Biosignatures in Basalt-Hosted Lacustrine Environments – Perspectives for Martian Biogeochemistry and Mars Sample Return

Visit by Keyron Hickman-Lewis of the Natural History Museum, London (UK) to TA1.6 Argentinian Andes (Argentina).
Dates of visit: 04-10 April 2023

Report Summary: With Europlanet support, we visited two field sites in Argentinian Patagonia in which well-preserved palaeolacustrine stromatolitic carbonates occur. The stromatolites examined range from several tens of thousands to several million years in age and occur in palaeolake settings that bear resemblance to similar environments identified on the Noachian–Hesperian Mars. We performed field investigations of the occurrence and macrostructure of these stromatolites and collected samples to enable a multidisciplinary study of the microbial biosignatures preserved within.

We identified morphologically diverse stromatolites including domical, columnar and crust-precipitating forms, from which we will seek evidence for diversity in microstructural complexity, organic compositions, and inorganic geochemistry. The regional and local setting of these stromatolites, coupled with their microbially dominated compositions, means that these materials provide exceptional field analogues and potential ecosystem analogues for similar sequences on the ancient Mars, and may provide guidance for biosignature exploration strategies and life detection in geological materials at the Martian surface during ongoing and future rover missions. Upon return to our home institutions, these materials were studied using a range of bulk and in situ microscopy and spectroscopy techniques to evaluate the nature and distribution of microbial biosignatures preserved within.


21-EPN-FT1-008: Detection of Isotopic Biosignatures in Antarctica Subfossils

21-EPN-FT1-008: Detection of Isotopic Biosignatures in Antarctica Subfossils – Implication for the Search of Life on Mars

Visit by Alessia Cassaro of the University of Tuscia (Italy) to TA2 Facility 16 – Carbon-14 Dating AMS Laboratory.
Dates of visit: 12-16 December 2023.

Report Summary: Victoria Land, Timber Peak (Northern Victoria Land) and Mt. Fleming (Southern Victoria Land) localities are considered as a good terrestrial analogue of the Martian surface. These localities are characterized by harsher climatic conditions and endolithic microbial communities represent a borderline lifestyle. The survival of these communities depends on a delicate balance of biological, geological and climatic factors. Any unfavourable change of this equilibrium may result in the death of the community and the alteration of the rock, potentially followed by the formation of trace fossils. This process could be similar to that experienced by hypothetical life-forms on early Mars, or reflect a decay mechanism in Mars history.

Detecting traces of extant or recently extinct life is one main goals of the upcoming NASA Mars 2020 and the near future ESA ExoMars missions. In this context, the characterisation of Antarctica subfossil rocks, may be used in support of space missions. To date, only morphological descriptions (culture-dependent method) and microanalytical techniques (SEM-EDX, confocal Raman and Infrared and EPR spectroscopies) have already been performed on these samples. In this context, the main aim of this Europlanet project will be the characterisation of carbon isotopes (13C/12C) composition on samples from Timber Peak and Mt. Fleming localities. Control samples will be compared with irradiated samples (117 kGy of gamma rays) in order to i) determine the sources of organic matter and ii) understand if cosmic-ray exposure, similar to those reported on the surface of Mars for 1.5 millions of years and 13 millions of years at 2 meters beneath the surface, may altered carbon isotopic composition.


21-EPN-FT1-016: Metabolic responses of Antarctic melanised microorganism to simulated Martian conditions

21-EPN-FT1-016: Metabolic responses of Antarctic melanised microorganism to simulated Martian conditions

Visit by Ilaria Catanzaro, University of Tuscia (Italy) to TA2.19 Center for Microbial Life Detection, Medical University Graz (Austria).
Dates of visit: 30 May – 03 June 2022

Report Summary: Current hostile conditions on the surface of Mars entail that, if any life form has ever existed on the planet, it may have adopted survival strategies like those evolved by terrestrial microorganisms inhabiting extreme environments e.g. Antarctica. There, one of the most common strategies observed is the cryptoendolithic microbial growth where free-living black fungi living along with algae and lichens within rocky interstices serve as a shield from excessive harmful solar radiation, and their extremotolerance can be mainly due to the presence of thick, highly melanised cell walls.

The ability of these cryptoendolytic microorganisms to thrive under extreme conditions raises the question of whether they cope with them by also regulating their metabolic expression in addition to melanin production, and whether a hypothetical microbial life on Mars could ever have arisen with similar adaptive strategies. In this optic, this study aimed to examin the metabolic regulation of melanised, cryptoendolithic microorganisms in martian scenario. To achieve this goal, colonies of the cryptoendolithic black fungus Cryomyces antarcticus previously exposed to simulated martian conditions such as perchlorates, sulfatic regolith soil and γ radiation, were then analysed with NMR spectrometry at the Center for Microbial Life Detection of the Medical University of Graz. Sample preparation and analysis were carried out in the Facility using standard protocols. Although only preliminary data are available at the time of report writing, significant differences in fungal metabolic expression were observed between the different simulated martian conditions tested.


21-EPN-FT1-012: Zebra dolomites revised – clumped isotope analysis as a tool to assess recrystallisation and dolomite cementation in overpressured settings

21-EPN-FT1-012: Zebra dolomites revised – clumped isotope analysis as a tool to assess recrystallisation and dolomite cementation in overpressured settings

Visit by Rudy Swennan, KU Leuven (Belgium), to TA2 Facility 17 – Isotoptech Stable/Clumped Isotopes Laboratory (Hungary).
Dates of visit: 22 – 31 August 2022.

Report Summary: Zebra dolomites are marked by an alternation of millimeter thick dark colored, as recrystallised interpreted bands and white cement bands. Disruption of the banding is manifested by displacements that gradually increases and subsequently deceases before disappearing. This disruption also occurs at intracrystalline scale with crystal rehealing features as observable under cathodoluminescence. This disruption of the zebra dolomites is explained by dolomitization in relation to overpressured fluid flow.  

In the framework of the Europlanet project zebra dolomite samples from 3 deep Belgian boreholes (Soumagne, Soiron and Bolland) were selected for clumped isotope analysis.  The aim was to sample and analyse the dark fine crystalline and white coarse dolomite cements separately to infer the original (re)crystallization temperature.  The following research questions were raised: i) is there a systematic difference in deduced temperature between the dark and white dolomite bands.  If so then this could help to better constrain the recrystallisation and cementation.  This would allow to assess the potential resetting of the original clumped isotope signature of the dark bands due to recrystallisation; ii) if the cement phases display uniform temperatures then this temperature can be compared with the minimum crystallization temperature deduced from primary fluid inclusion microthermometry [1]. The discrepancy between both temperatures, which links to the pressure correction, normally allows to quantify the overpressure of the system; iii) based on deduced crystallization temperature and δ18OPDB, the δ18OSMOW of the fluid can be assessed, allowing to constrain the origin of the dolomitizing fluids, certainly when combined with Sr isotope analysis.


21-EPN-FT1-010: Tracking the Thermal Evolution of the Miocene Ries Crater Lake as a Potential Analogue for Microbial Habitats on Early Mars

21-EPN-FT1-010: Tracking the Thermal Evolution of the Miocene Ries Crater Lake as a Potential Analogue for Microbial Habitats on Early Mars

Visit by Duncan Mifsud, University of Kent (UK), to TA2 Facility 17 – Isotoptech Stable/Clumped Isotopes Laboratory (Hungary).
Dates of visit: 21 March – 01 April 2022.

Report Summary: We have measured the clumped carbonate (13C18O16O) isotope ratios, as well as the stable isotope ratios δ18O and δ13C, of a number of bioherm, travertine, and crater fill marl samples from a drill core taken from the Nördlinger Ries Crater (NRC) in Bavaria, Germany. The aim of the project was to make use of the clumped carbonate isotope ratios so as to re-construct a palaeotemperature record of the lake environment, which could be used to assess its habitability in the time since its formation. Such information would be useful for assessing the past habitability of similar crater lake environments on Mars, which are presently of great interest.

At first glance, our results demonstrate that the analysed carbonate samples were formed at temperatures well below what would be expected in the NRC lake environment. On closer inspection, however, it was hypothesised that our carbonate samples were either collected from too high up in the stratigraphy, or they were formed under non-equilibrium conditions and thus suffered from kinetic fractionation effects. The result of the latter is a depression of the precipitation temperature as calculated by palaeothermometric scales.

Future studies are planned to investigate samples from suevite (i.e. the oldest crater infill) and to quantify the extent and causes of these kinetic fractionation effects. Future studies on other crater fill marls may thus also be worthwhile.


21-EPN-FT1-028 – Integrated aDNA, Sr-O-C isotope data and 14C dates to link human individuals to Roman military units

21-EPN-FT1-028 – Integrated aDNA, Sr-O-C isotope data and 14C dates to link human individuals to Roman military units

Visit by Lisette Kootker, Vrie University Amsterdam (Netherlands), to TA2 Facility 16 – Carbon-14 Dating AMS Laboratory (Hungary).
Dates of visit: 28 November – 02 December 2022.

Report Summary: The lower German limes, the most northern frontier of the Roman Empire on mainland Europe, was the earliest linear frontier of the Roman Empire. Where the Lower German limes ends in the North Sea, the unique Roman cemetery of Valkenburg Marktveld was excavated that plays a key role in understanding the population dynamics in a Roman borderland and coastal landscape. In addition to our current biomolecular research, AMS radiocarbon dates were proposed of 29 adult individuals who were subjected to isotope and aDNA studies with the aim to establish an essential and reliable dating framework that will contribute to the human story and understanding the human history at the Marktveld site.

Prior to the Europlanet TA visit at the Isotoptech Zrt. AMS laboratory, collagen was successfully extracted from 27 individuals. During the visit, our team had the opportunity to learn how the MICADAS system applied to analyse the collagen samples was operated. The calibrated 14C dates range between 343 BCE to 244 CE. Additional δ13C and δ15N will be used to evaluate the collagen quality and possible impact of reservoir effects. Preliminary analysis shows the presence of four groups: 1) pre-Roman; 2) 100 BCE – 60 CE; 3) up to 125 CE, and finally; 4) and younger than 125 BCE. The associated 87Sr/86Sr show slightly higher mean and more variation in the last two groups than the first two (0.7102 ± 0.0010 vs. 0.7096 ± 0.0009). The 14C data will be reposited in IsoArc


21-EPN-FT1-023: Diagnostics of electron collisions with small organic molecules present in the atmospheres of small bodies and planets

21-EPN-FT1-023: Diagnostics of electron collisions with small organic molecules present in the atmospheres of small bodies and planets

Visit by Bartosz Michalczuk, Siedlce University (Poland), to TA2 Facility 13 – Electron Induced Fluorescence Laboratory (Slovakia).
Dates of visit: 21 – 30 November 2022

Report Summary:

The main objective of the project was to study electron impact processes of small organic compounds, using acetone as the first target.

  • Record and analyse emission spectra of acetone induced by electron impact at several different energies in the range 10 – 100 eV.
  • Determine emission cross sections corresponding to selected most intensive transitions in range of impact energies (from the thresholds of selected process to 100 eV).
  • Identify neutral products of electron impact fragmentation of acetone.
  • Determine reaction kinetics parameters such as threshold energies for selected electron impact excitation reactions of acetone.

During the first half of the visit, we measured electron-impact spectra of acetone at multiple electron energies and generated partial spectral electron energy map which provides the spectral information at various electron energies and thus the efficiency curves (relative emission cross-section curves).
During the second half of the visit, the measured data was partially analysed. The emission band in the range of 415 – 445 nm corresponds to the radiation of CH (A2Δ–X2Π) (ν,ν) fragment. Less intensive radiation of CH (B2Σ−–X2Π) (0,0) fragment was identified within 386 – 402 nm. Several emission lines of hydrogen’s Balmer series Hγ – Hη were detected throughout the spectrum as well. Individual rotational transitions from P, Q, R branches of both CH fragments were identified according to LIFBASE 2.1.1 spectroscopy tool, which is software to chart the spectroscopy of diatomic molecules. The rotational temperature of the LIFBASE spectrum was set to ~ 5000 K.

Read the full scientific report, with kind permission by Steve Bromley.


21-EPN-FT1-019: Isotopic composition of single detrital carbonate grains in the source-to-sink study of the Bengal Fan record

21-EPN-FT1-019: Isotopic composition of single detrital carbonate grains in the source-to-sink study of the Bengal Fan record

Visit by Mara Limonta, University of Milano-Bicocca (Italy), to TA2.10 Stable, Rare Gas and Radiogenic Isotope Facility at CRPG (France).
Dates of visit: 25 July – 05 August 2022

Report Summary: The Bengal Fan forms the largest deep-sea turbidite system on Earth and hosts a unique sedimentary record of the evolution of the Himalayan orogenic belt.

This study aims to develop a new protocol to analyse single-grain isotopic signatures of detrital carbonates with primary application in source-to-sink studies and to foster the application of oxygen and carbon isotopes on single detrital grains of carbonates as a provenance tracer. δ18O and δ13C fingerprint of single detrital carbonate grains in Bengal Fan turbidites (IODP Expedition 354) will allow to detect and quantify the signature of different carbonate rocks from the Tethys Himalaya and High Himalaya and to better reconstruct the evolution of erosion processes in the Himalayan belt. This work will allow also testing the feasibility of the new single-grain approach. δ18O and δ13C fingerprint of detrital carbonate grains of selected Bengal Fan turbidites could not be measured due to their fine sand to silt grain-size.

We establish the grain-size feasibility limit at 200 microns in grain diameter. Otherwise, oxygen and carbon isotopic signature of single carbonate grains from Marsyandi and Kali Gandaki modern sand-sized river sediments were analysed to characterize isotopic fingerprint of carbonatic source rocks of Tethys Himalaya unit exposed along their drainage basin. Detrital carbonates of Marsyandi and Kali Gandaki rivers show similar low δ18O values, indicating depletion by metamorphic reactions. δ13C values range from +2‰ and -2‰ and mostly positive δ13C values characterise Kali Gandaki, whereas mostly negative δ13C values characterise Marsyandi carbonate grains.


21-EPN-FT1-006: Melting phase relations of subduction zone minerals and their nitrogen budget

21-EPN-FT1-006: Melting phase relations of subduction zone minerals and their nitrogen budget

Visit by Caterina Melai, University of Bayreuth (Germany) to TA2.9 Ion Probe Facility (IPF), CRPG (France).
Dates of visit: 29 August – 02 September 2022

Report Summary: In this study the phase relations of hydrous aluminosilicate minerals (e.g. montmorillonite, phlogopite, phengite and serpentinite) that are present in sedimentary layers or form during early prograde metamorphism of the oceanic lithosphere are investigated at sub-arc conditions. The investigated minerals are potential hosts for nitrogen at different P-T conditions along the subducting slab, depending on their phase stabilities and the N partitioning upon partial melting of these phases. In the present analytical session, several minerals in equilibrium with melt (quenched glass) have been analysed by means of SIMS.

The measurements in this report were performed using the CAMECA 1280 HR2 Ion Probe at CRPG, France. All the experimental capsules planned for the session were analysed and additional secondary standards were investigated.

The experimental samples showed consistent and reproducible N content on the different measured spots both on the mineral and the melt phase. More challenging was the measurements of the standards that confirmed the existing concern on the possible matrix effect during SIMS measurements of mineral phases. The different behaviour of the light elements analysed in a glass or crystalline matrix appears to have a strong effect on the measured nitrogen ion yield.

The work performed during this analytical session at the SIMS, allowed the acquisition of the N data for the calculation of the partition coefficients between mineral and melt while providing additional evidence for the need of further investigation of the matrix effect for this technique.

Read the full scientific report, with kind permision from Caterina Melai.


21-EPN-FT1-005: Reading the sedimentary archive of discontinuity surfaces

21-EPN-FT1-005: Reading the sedimentary archive of discontinuity surfaces

Visit by Simon Andrieu, Aarhus University (Denmark) to TA2.9 Ion Probe Facility (IPF), CRPG (France).
Dates of visit: 18-22 October 2021

Report Summary: Discontinuity surfaces, associated with seafloor cementation, are hence of primordial importance for fully apprehending the geological record, yet they have received far less attention than the sedimentary rocks surrounding them. Fundamental problems that are still not sufficiently understood concern the lateral change of discontinuities. In this project, we tackle this issue by studying the lateral variation of five distinct discontinuity horizons present in the Middle Jurassic of the High Atlas (Morocco), where outstanding exposures permit to track these surfaces over tens of kilometres. Hence, the purpose of this work is to characterise at a high-resolution the large-scale variation of petrographic and geochemical (C, O and Sr-isotopes) properties of discontinuities (matrix and cement phases) along dip and strike of a Jurassic moderately deepening ramp. δ18O (176 values) and δ13C (105 values) signatures were obtained on twenty-one cements and grain types, including 14 different early calcite cements and fabrics corresponding to dogtooth cements (7), turbid synaxial cements (1) and micritic/microsparitic fabrics (6).

Data confirm that dogtooth cements can precipitate in marine phreatic, meteoric phreatic and shallow burial environments. The highly negative δ18O values of micritic fabrics and turbid synaxial cements, which form in seawater, indicate that they transformed during subsequent diagenesis (i.e during meteoric water circulation or shallow burial). It indicates that they precipitate initially with an unstable mineralogy (aragonite or high-magnesium calcite). δ18O and δ13C data on early cements suggest that a same discontinuity can change laterally from a subaerial exposure surface to a marine surface.

Read the full scientific report, with kind permision from Simon Andrieu.


21-EPN-FT1-025: Ammonium salts reflectance spectra changing viewing geometry for distinguish them on the surface of icy planetary bodies

21-EPN-FT1-025: Ammonium salts reflectance spectra changing viewing geometry for distinguish them on the surface of icy planetary bodies

Visit by Maximiliano Fastelli and Matteo Bisolfati, University of Perugia (Italy), to TA2.8 CSS (Cold Surfaces Spectroscopy) at IPAG (France).
Dates of visit: 13-25 June 2022

Report Summary: During the Europlanet 2024 RI TA Fast Track call, reflectance VIS-NIR spectra were collected at the CSS facility (IPAG) in Grenoble, France. Different viewing geometries were chosen to collect BRDF spectral data of a selected group of ammonium minerals. BRDF were collected in the 1 – 4.8 μm range considering a set of 3 incidence angles (i) (i = 0°; 30°; 60°) and 8 emergence angles (e) between -70° and 70° at room temperature. The NH4+overtone and combination bands located at ~ 1.09, 1.32, 1.62, 2.04, 2.2 and 3.05 μm are experimentally investigated.

The bands position remains unchanged varying geometrical configuration. On the other hand bands area and depth shows the highest values for i = 0° and 30° and e below 40°. These band parameters at ± 70° emergence angles evidence a decrease in their values. A general trend of spectral red shift with phase angle is observed. The bidirectional reflectance spectroscopy of selected samples shows important variations with the observation geometry of the measurements. Furthermore, from these preliminary data analyses, can be observed how reflectance values and spectral slope are affected by geometry of measurements. The surfaces of the planetary bodies are irregular and rough, which is why the effect of the observation geometry must also be considered. The collected data set can be helpful in the context of future missions aimed to understand the nature of minerals on icy and small bodies. NH4+–bearing minerals identification has a strong impact on understand their thermal evolution and the construction of geophysical internal models.


21-EPN-FT1-003: Biogeochemical tools to search for biosignatures in microbial carbonates from extreme environments

21-EPN-FT1-003: Biogeochemical tools to search for biosignatures in microbial carbonates from extreme environments

Visit by Sylvie Bruggmann, University of Lausanne (Switzerland) and Camila Areias, Vrije Universiteit Amsterdam (Netherlands), to TA1.6 Argentinian Andes (Argentina).
Dates of visit: 10-16 December 2022

Report Summary: Microorganisms evolved under extreme conditions as the first forms of life on Earth. In the geological record, signatures of these microbial communities can be preserved in the chemistry of sedimentary rocks as microbialites. The identification of their biogenicity, however, is often ambiguous, as biosignatures can be overprinted, and abiotic processes may form similar signatures. Microbialites forming under extreme conditions on the modern Earth can be used as analogues to better understand the formation of biosignatures, and to improve their identification in sedimentary rocks from Earth and Mars.

The TA1 Facility 6 in the Argentinian Andes provides an ideal environment where carbonaceous microbialites form under extreme conditions, such as cold temperatures, low precipitation and high UV radiation. To better resolve the ambiguity of biosignatures, we use a combined approach of organic and inorganic biogeochemical tools to examine sediment and water samples. The organic tool focuses on lipid biomarkers that can be attributed to specific biogenic sources, such as cyanobacteria. In addition, the inorganic tool utilises elemental concentration and isotope compositions of biologically relevant metals, such as Fe or Sr, which can record information of a biogenic or abiotic origin. The combination of these organic and inorganic tools can improve the identification of biosignatures and their credibility can be enhanced.


21-EPN-FT1-018: Assessing analogues to early Earth environmental conditions in high-altitude hypersaline Andean lakes

21-EPN-FT1-018: Biogeochemistry in extreme environments: assessing analogues to early Earth environmental conditions in high-altitude hypersaline Andean lakes

Visit by Alexandra Rodler, Austrian Academy of Sciences (Austria) to TA1.6 Argentinia Andes (Argentina).
Dates of visit: 11-16 December 2022

Microbial activity leaves fingerprints in the sedimentary record, for example, by changes in trace element and isotope ratios. If distinguishable from purely abiotic processes, these traces can potentially be used as biosignatures for geobiological and astrobiological research. Modern analogue environments are useful for better understanding traces of microbial life in the geologic record. This can help to define search criteria for potentially habitable environments on other terrestrial planets. The test site for this project is the Precambrian-analogue TA1 Facility 6 in the Argentinian Andes. This is a shallow lake system with extensive microbial mats, hypersaline conditions at slight acidity, with extreme temperature fluctuations and high-UV ray influx.

Using samples from this site, this project compares between chemically- and microbially influenced carbonate precipitation to further explore if trace element behaviour is related to biological processes, and if specific elements can be used as potential biosignatures. Furthermore, this project investigates trace element behaviour along redox gradients between hydrogenetic and diagenetic microbialite growth. To address if certain elements can serve as biosignatures, we pair petrographic/mineralogical approaches with high-resolution sampling for analysing trace elements as well as redox-sensitive elements and their stable isotopes. The results of this work are integrated in ongoing work focused on the geochemistry of carbonate phases of modern and ancient microbialites as well as the ongoing microbiological work including microbial diversity and metagenomics at this site. This ensures that the results are integrated in and compatible with these diverse fields of research.


21-EPN-FT1-029: Petrographical, mineralogical and geochemical study of the meteorite Gueltat Zemmour Morocco

21-EPN-FT1-029: Petrographical, mineralogical and geochemical study of the meteorite Gueltat Zemmour Morocco, observed fall in August 2018.

Visit by El Mehdi El Hachimi, Hassan II University of Casablanca (Morocco) to TA2 Facility 3 – NHM Petrology, Mineralogy and Chemistry Facility (UK).
Dates of visit: 28 November -16 December 2022

Report Summary: The Gueltat Zemmour meteorite project was undertaken to conduct laboratory analyses using various techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The XRD results were divided into two aspects: mineral identification and mineral quantification. The SEM technique was performed on two sections and provided EDS analyses of interesting mineral phases on the meteorite, as well as compositional and single element maps. The EPMA technique was used to analyze the major and minor element compositions of sulfide, silicate, and metal. The LA-ICP-MS technique was used to determine trace element compositions in areas of interest determined by SEM and EPMA, and no halite minerals were found. The analyses yielded numerous encouraging results, including 500 SEM spectra, 177 analyses for silicates, 69 for metal and sulfides from EPMA, and 48 analyses from LA-ICP-MS. Therefore, the results from SEM, XRD, EPMA, and particularly LA-ICP-MS appear to represent the completeness of the scientific data required to create a brilliant research article.


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21-EPN-FT1-021: Diffuse chemotrophic microbialites as analogues for martian life

21-EPN-FT1-021: Diffuse chemotrophic microbialites as analogues for martian life

Visit by Laura Clodoré, Centre de Biophysique Moléculaire-CNRS, Orléans (France) to TA2 Facility 3 – NHM Petrology, Mineralogy and Chemistry Facility (UK).
Dates of visit: 27 June – 05 July 2022

Report Summary:

Understanding the characteristics and microbial-scale habitats of the oldest traces of life on Earth requires the use of multiple complementary methods that will be relevant both for in situ analysis of Martian rocks, as well as for identifying signatures of biological processes (biosignatures) in returned samples. 

In this respect, fossilised chemolithotrophic microorganisms found in ancient volcanoclastic sediments from the East Pilbara craton, Western Australia, an environment having similar conditions to early Mars, can be used as analogues for the kinds of primitive microorganisms that could be found on Mars. We performed combined analyses using FTIR spectroscopy, SEM observations, EDX mapping and LA-ICP-MS in order to investigate the distribution and the molecular and elemental composition of the carbonaceous matter. These results will complete a detailed morphological, mineralogical and geochemical dataset and that will enable the assessment of the astrobiological potential of these Mars analogue sediments.


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21-EPN-FT1-026: Biogeochemical cycling in the lake systems of the Argentinian Puna

21-EPN-FT1-026: Biogeochemical cycling in the lake systems of the Argentinian Puna: An investigation into the microbial communities of an exceptional Hesperian martian analogue

Visit by Ben Tatton, The Open University (UK) to TA1.6 Argentinian Andes (Argentina).
Dates of visit: 17-26 April 2022

Report Summary: Fieldwork undertaken as part of the Europlanet fast track funding call took place between 16/04/22 and 26/04/22 as part of an international team of scientists from The Open University, The Università degli Studi della Tuscia, and The Universidad Nacional de Córdoba.

Fieldwork was conducted at two high-altitude Andean Lake (HAAL) sites, Laguna Negra, and Laguna de Antofagasta. The focus of the research was to collect sediment cores and water samples from Laguna de Antofagasta to assess how microbial communities change as a factor of depth within the sediment. During the trip, a total of 5 x 30 cm cores, 5 x 250 ml of lake water for culturing, and 15 x lake water samples for geochemical analysis were collected. Furthermore, environmental variables were taken with pH, temperature, conductivity, redox potential, and UV monitored. The trip was a resounding success with enough samples taken to permit the progression of my PhD. The data gained from the trip will contribute to two or three data chapters. These chapters will focus on the geochemical characterisation of the site, the microbiology of the site, and potentially simulation experiments which will focus on Noachian/Hesperian Mars relevant metabolisms. We expect to find that LDA is a suitable geochemical analogue for Gale Crater during the Noachian Hesperian transition. We also expect that the types of metabolisms found within the sediments are similar to those predicted to have been present on Noachian/Hesperian Mars.


21-EPN-FT1-015: Characterising electron impact induced UV-Optical emission of simple molecules relevant to atmospheres of small Solar System bodies

21-EPN-FT1-015: Characterising electron impact induced UV-Optical emission of simple molecules relevant to atmospheres of small Solar System bodies

Visit by Steven Bromley, Auburn University (USA), to TA2 Facility 13 – Electron Induced Fluorescence Laboratory (Slovakia).
Dates of visit: 25 July – 08 August 2022

Report Summary: The goal of the 2022 visit was to study and measure the electron-impact induced emission from dissociation and/or ionisation of CO and CO2 between 0 – 100 eV electron energy. These experiments are part of a longer-term plan to characterize the electron-impact-induced emission features of oxygen-containing molecules found in cometary environments. These data are expected to be used in future modelling and analyses of data acquired in situ during the Rosetta mission to comet 67P/Churyumov-Gerasimenko. We aim to understand the conditions in the inner coma and how electron-impact-induced emission features can probe the physical and chemical processes occurring in the near-nucleus coma environment.  

During the first half of the visit, we measured electron-impact spectra of CO2 gas at multiple electron energies. Electron impact of CO2 can give rise to emission from CO, CO+, CO2+, and excited states of C and O atoms. Since the probabilities of the different reaction channels depend strongly on the collision energy, these spectral features offer a way to diagnose the conditions of plasmas containing CO2. The collected spectra and threshold measurements are in reasonable agreement with the limited data in the literature. During the second half of the visit, we measured electron-impact spectra of CO gas at numerous electron energies. Many of the spectral features for neutral CO, CO+, and atomic C and O were characterised, as a function of electron energy, for the first time. Given the time-consuming nature of the measurements, data analysis and additional measurements will continue remotely. 

 Visiting postdoc Steve Bromley and PhD student Barbora Stachova discussing the electron impact spectrum of CO gas at 100 eV electron beam energy.
Visiting postdoc Steve Bromley and PhD student Barbora Stachova discussing the electron impact spectrum of CO gas at 100 eV electron beam energy. Credit: S Bromley

Read the full scientific report, with kind permission by Steve Bromley.