20-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, University of Tuscia (Italy), 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. In this optic, 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-FT1-003: 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.
20-EPN2-066: From Geitafell volcano (Iceland) to Mars: How hydrothermal alteration of basalt can guide our understanding of habitable environments on Mars
Visit by Julia Semprich and Geoff Austin, Open University (UK), to TA1 – Iceland Field Sites, MATIS Dates of visit: 21 September – 01 October 2022
Hydrothermal systems provide conditions and nutrients for microbial life and thus have the potential to create subsurface habitats on Mars. Characteristic minerals associated with these hydrothermal systems have been detected on Mars’ surface by spectral observations from orbit, but their formation conditions and spatial distribution remain unknown. The aim of this study was a detailed characterisation of the spatial distribution and mineral chemistry of the low-grade metamorphic/hydrothermal alteration mineralogy in an extinct hydrothermal system.
Field work was conducted at the Geitafell central volcano near Hoffell in the south-eastern part of Iceland, an ideal analogue for Mars. The focus of this research was to record spatial relationships between the basaltic host rocks and the hydrothermal alteration in the field and to sample characteristic low-grade metamorphic minerals, which have also been detected on Mars.
We collected 19 samples from different alteration zones within the hydrothermal system including veins and vesicular basalt showing a range of alteration minerals such as carbonates, quartz, zeolites, chlorite, prehnite, epidote, andradite, and actinolite. We will now be able to conduct a detailed study of the samples including petrography, mineral chemistry, and spectroscopy, which can then be used to further constrain our models of hydrothermal alteration on Mars.
We expect this research to be highly relevant to the study of hydrothermal systems on Mars and particularly for sample return once the Perseverance Rover reaches the rim of Jezero Crater, which likely exposed hydrothermally altered rocks.
Banner image: View towards Hoffellsjökull glacier. CC BY-SA 3.0 (Gummao)
20-EPN2-105: Uncrewed Aerial System (UAS) and LiDAR Survey of Relict and Active Periglacial Patterned Ground as Analogues for Mars
Visit by Paul Knightly, Northern Arizona University (USA), and Shannon Hibbard, JPL (USA), to TA1 – Iceland Field Sites, MATIS Dates of visit: 22-31 August 2022
Uncrewed aerial system (UAS) and LiDAR surveys were performed at periglacial patterned ground sites, including polygons terrain and stone circles, in the Westfjords and Central Highlands, Iceland during the 2022 site field season. Shallow trenches (up to 1 m depth) were excavated to gather insitu measurements and observations to determine the presence or absence of permafrost and substrate characteristics. No permafrost was observed at either site suggesting the features may be periglacially relict. The processed UAS and LiDAR data will be used to perform morphometric evaluations of patterned ground at each site and compared to previously collected and analyzed morphometric evaluations of periglacially active patterned ground in the Canadian Arctic. The objective of this work is to develop a set of morphometric criteria for distinguishing between active and relict patterned ground. The developed criteria may help inform on the current level (or absence of) periglacial activity and ice content of patterned ground on Mars.
20-EPN2-099: Bioaerosol generation at geothermal systems: Implications for the detection of biosignatures in cryovolcanic plumes at the ocean worlds
Visit by Mark Fox-Powell and Claire Batty, Open University (UK) to TA1 – Iceland Field Sites, MATIS Dates of visit: 27 July – 09 August 2022
The aim of our project was to capture and study microscopic aerosols ejected from bubbling or geysering geothermal springs in Iceland. Our primary motivation was to understand the potential for biosignatures to become entrained within cryovolcanic plumes at icy moons, such as Saturn’s moon Enceladus, where similar bubbling of hydrothermal gases is thought to drive the formation of aerosols that are then accelerated into space. Fieldwork was conducted at geothermal systems in Iceland in July and August 2022 by a team from the Open University (UK).
We focused our aerosol sampling efforts on two locations that exhibit contrasting aerosolisation regimes: Olkelduhals hot springs, Hverageroi, which exhibit constant, moderate bubbling of geothermal gases, and Strokkur, Geysir, which experiences regular energetic geyser eruptions. Our aerosol flux monitoring showed that geothermal springs are prolific local sources of aerosols, producing fluxes orders of magnitude above background levels. We also found that aerosol production is tightly controlled by bubbling and/or eruption activity.
Successful replicate sample sets were taken at upwind locations to characterise the background aerosol environment, and at multiple downwind locations to capture geothermal aerosols. We also took samples of spring fluids, as the assumed local aerosol sources, and geothermal gases, which are responsible for driving bubbling activity. Ongoing work is investigating the chemical composition, biomass content and microbial diversity of aerosols, and the volatile profiles of geothermal gases. Our data will provide the first insights from natural analogues into the formation of aerosols within cryovolcanic plumes.
20-EPN2-120: A Molecular Toolkit to Hunt and Resolve Fungal Dark Matter (FDM) in Extreme Planetary Environments
Visit by Ali Nawaz and Christian Wurzbacher, Technical University of Munich (Germany) to TA1 – Iceland Field Sites, MATIS Dates of visit: 19 – 23 July 2022
Fungi are amazing but largely enigmatic creatures with huge diversity and biological potential in any conceivable ecosystem known so far. This holds for our planet, but this also seems true for outer space and other planetary bodies. However, we do not know what kind of extremophile fungi are or have been growing on other planets.
To have a clue, we need to explore extreme analogue sites on our planet using novel and advanced methods. Therefore, we here propose to collect and study samples from various extreme habitats of Iceland using a unique combination of Laser-microdissection of single cells and long-read sequencing to fully resolve the Fungal Dark Matter of Mars-analogue extreme sites in Iceland.
We believe that the outputs of this project will bring novel fungal species into scientific arena and the findings of this proposal will help the broader general scientific community dealing with AstroMycology in specific, and Astrobiology in general, to rightly speculate on the capabilities and limitations of microbial life in extreme environments and correlate it with the conditions of other planets.
20-EPN-003: Production and Early Preservation of Biosignatures in Glaciovolcanic Lakes: A Biogeochemical Analogue for Mars
Visit by Erin Gibbons and Richard Leveille, McGill University (Canada) to TA1 – Iceland Field Sites, MATIS Dates of visit: 28 May – 08 June 2022
The search for extraterrestrial life, either extinct or extant, on Mars is a key objective for several international space exploration programmes. To maximise the likelihood of success for these programmes, we must first study ecosystems on Earth that resemble those on Mars and investigate both the kinds of organisms that can survive there and the processes that control their ultimate preservation/fossilisation in the rock record.
We proposed that the geothermally-heated lake Gengissig, located in the Highlands of Iceland, represented an ideal natural laboratory within which to conduct a Mars-centric taphonomic study. Geologically, this setting provides an excellent analogue for Mars because the basaltic bedrock has a bulk chemical composition that is similar to the rocks measured on Mars by past and current rovers, thereby allowing us to study how signs of life may be preserved by the rock types common on Mars. Furthermore, this remote location is nearly devoid of multicellular life-forms and is isolated from anthropogenic input, providing a pristine ecosystem to study the fossilisation processes expected to be encountered on Mars – those operating on microbial life.
We collected water, rock, and lake sediment samples to investigate the site. We intentwill use a combined genomic, stable isotope, and geochemical approach to investigate the indigenous microbial communities and their ultimate fossilisation in this Mars-like terrain. the results of which will be immediately relevant towards directing current and upcoming Mars rovers towards sites on Mars most likely to retain signs of ancient extraterrestrial life.
20-EPN2-122: IceSCOPE – Iceland Subsurface Classification of Organics, PAHs, and Elements
Visit by Pablo Sobron and Kirby Simon, Impossible Sensing (US) to TA1 – Iceland Field Sites, MATIS Dates of visit: 15-18 May 2022
The recent volcanic eruption at Geldingadalir in 2021 serves as an ideal analog for studying the biogeochemistry of volcanism on other planetary bodies with active (e.g. Io) and/or extinct (e.g. Mars) volcanic systems. Along with this, comparative analog studies between a recently-active volcano like Geldingadalir and old lava fields present throughout Iceland will provide meaningful context in understanding (1) the conditions necessary for microorganisms to colonise lifeless or barren environments and (2) how life transforms the environment, which has implications in the search for extant or extinct life in our solar system.
Our technology demonstration focused on the deployment of ruggedised, handheld spectroscopic tools for surveying the biology and chemistry present in the lava fields. We deployed a gamma ray spectrometer and laser induced breakdown spectroscopy (LIBS) instrument to assess the elemental composition of the natural samples, an ultraviolet (UV) fluorescence imager to investigate organic signatures on the rock surfaces, and a near-infrared (NIR) reflectance spectrometer for determining mineralogy and molecular bonding structures.
We collected co-registered spectroscopic measurements on >5 samples throughout the Geldingadalir lava field and at a control field nearby, and surveyed >10 additional surface and subsurface features throughout the lava field with one or more of the instruments. At the conclusion of the work, we had collected >1000 UV fluorescence images, 10s of NIR reflectance and LIBS spectra, and >10 gamma ray measurements.
Suite of spectroscopic instruments deployed in the Geldingadalir lava field. Instruments include a UV fluorescence imager for investigating organic compounds and biological species (a), a NIR reflectance spectrometer for investigating mineralogy and molecular bonding (b), and a LIBS probe (c) and gamma ray spectrometer (d) for analysing the elemental composition of samples. Credit: P Sobron
Highlights of the project: Demonstration of a scientific payload for astrobiological research in volcanic environments and new understanding of microbial colonisation of fresh basalt.
Read the full scientifc report, with kind permission from Pablo Sobron and Kirby Simon.
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.
20-EPN-24: Spectral investigation of the Makgadikgadi Salt Pans as planetary analog for ancient fluvio-lacustrine environments on Mars
Visit by Katrin Stephan and Ernst Hauber, DLR Institute of Planetary Research (Germany) to TA1.5 Makgadikgadi Salt Pans (Botswana). Dates of visit: 30 July – 08 August 2022
Sedimentary environments on Mars display evidence for phyllosilicates and salts. The identification and characterisation of such minerals within ancient lacustrine environments on Mars is key to resolving its past habitability. Due to their geologic importance and their potential to preserve bio signatures (e.g. organic compounds), such deposits are prime targets for lander missions (e.g. Mars2020 and Exomars). To identify promising investigation areas and landing sites spectrometers working in the visible-near Infrared (VNIR) wavelength range are extremely useful to identify and map the surface composition of Mars and other planetary surfaces (Mars Express Omega, MRO CRISM< Cassini VIMS, Dawn VIR etc).
The Makgadikgadi Salt Pans of Botswana offer access to a depocenter in a closed basin that is characterised by clastic and chemical sediments. They are therefore an ideal analogue to collect in situ spectra at a terrestrial analogue to martian sedimentary deposits and to collect samples for investigation in the laboratory by other techniques (e.g. Raman spectroscopy). Katrin Stephan and Ernst Hauber (DLR) spent 9 days at the pans and measures a divers range of surfaces at 22 locations with a portable field spectrometer. For most of the measured sites and subsides (at most of the locations, several measurements were performed), samples were collected for further investigation in the laboratory. In parallel with the field measurements, we analyse satellite data to be able to tie the field data not only to laboratory measurements, but also to remote sensing data as we would do in planetary science.
20-EPN-28: 20-EPN-28: Microbial adaptation in the hypersaline environment of Sua Pan Evaporator Ponds in Botswana and implications for search for life on Mars
Visit by Claudia Pacelli, Italian Space Agency (Italy) and Alessia Cassaro, University of Tuscia (Italy) to TA1.5 Makgadikgadi Salt Pans (Botswana). Dates of visit: 12-21 July 2022
The current conditions of the Martian surface are considered prohibitive for life as we know it, due to strong radiation, highly oxidizing conditions, concentrated evaporative salts, and relatively low water activity. The Earth hosts a multitude of extreme environments whose physico-chemical properties partly match extraterrestrial planetary bodies (e.g. Mars). Such environments are defined “analogue sites” and may offer critical test-bed for astrobiological studies in characterising the physical and chemical boundaries within which life may exist on Earth and in assessing the habitability of other planets, understanding the biological mechanisms for survival in extreme environments. For example, the Makgadikgadi desert, located in north central Botswana is considered one of the largest deserts on Earth, where the salts concentration is up to 21% of NaCl. These conditions may be compared with those detected on Mars.
Here, the main aim of this Europlanet project was to collect soil samples of Makgadikgadi salt pans in order to i) understand the adaptations of microbial systems to extreme conditions in natural terrestrial environments, ii) correlate the biodiversity with the geological context. This study is of significant interest to astrobiology investigations, allowing to assess the effects of hypersaline environment on the survival potential of microorganism and to understand if hypothetical life-forms may exist or have existed on Mars, where the concentration of chlorate salts has been detected in many different locations, from 1970s.
Report Summary:
Read the full report, published with kind permission by Dr Pacelli and Dr Cassaro.
220-EPN2-85: Preservation of Organic Matter in Paleo-Mega Lakes: Implications for Martian Biosignatures
Visit by Charlotte Spencer-Jones, Durham University, (UK) to TA1.5 Makgadikgadi Salt Pans (Botswana). Dates of visit: 20-29 April 2022
The geological history of Mars indicates that this planet has transitioned between conditions that could have supported life. Extensive fluvial features on the Martian surface provides evidence for the presence of water in Martian history and suggests that Mars may have been habitable during the Noachian period (4.1-3.7 Ga). Therefore, establishing a suite of relevant and robust biosignatures diagnostic for past life remains one of the key methods for detecting extinct Martian lifeforms. Organic compounds are the fundamental building blocks of all terrestrial life and are widespread throughout the solar system with structurally diverse organic compounds detected in a range of extra-terrestrial samples.
The main aims of this fieldwork campaign (20-EPN2-085) were to collect a range of samples, including sediments, biofilms, and salts from the Makgadikgadi basin with accompanying physical data from the basin. The second phase of this study will characterise organic compounds within the samples. The outcome of this work will be to establish the key parameters that control organic compound preservation within Martian analogue environments. These results will determine biosignatures that could be identified during future Mars missions (e.g. ExoMars 2020) and thus highlight the mineralogies present that have the highest preservation potential for biosignatures.
Report Summary:
Read the full report, published with kind permission by Dr Spencer-Jones.
20-EPN-61: Life in extreme environments: Distribution and importance of far-red light driven photosynthesis to primary production in Martian-like environments
Visit by Dennis Nürnberg, Freie Universität Berlin, (Germany) and Daniel Canniffe, Liverpool University (UK) to TA1.5 Makgadikgadi Salt Pans (Botswana). Dates of visit: 10-19 February 2022
The aim of this project was to confirm the richness and abundance of chlorophyll f-containing cyanobacteria, and their ability to use low-energy light to perform oxygenic photosynthesis in Martian-like environments. This study was a follow-up to a 2019 sampling trip to the sabkhas of the Western Sahara (Morocco), for which we could show that chlorophyll f-cyanobacteria are highly abundant. Here we expanded this research by collecting samples from the hypersaline environments of the Sua and Ntwetwe Pans in Makgadikgadi (Botswana). Microbial mat and rock samples containing endolithic and hypolithic phototrophs were collected. Light microscopy on site confirmed the abundance of cyanobacteria of various morphologies in most collected samples. The microbial mat samples were especially rich in cyanobacteria, forming a 1-2 mm thick layer at various depths depending on the absorption properties of the top layer.
Preliminary analyses with high-performance liquid chromatography (HPLC) in combination with hyperspectral confocal fluorescence microscopy confirmed the presence of red-shifted chlorophylls in some of these samples but to less extent as observed in the sabkhas. Genomic DNA has been extracted and will be used for sequencing and phylogenetic analyses based on 16S rRNA and specific far-red light genes. This will allow to fully evaluate the microbial diversity and their ability to perform chlorophyll f-driven oxygenic photosynthesis. In addition, the enrichment and isolation process of new chlorophyll f-containing cyanobacteria has been started by transferring the samples to growth media of various salinity and keeping them under selective far-red light illumination.
Report Summary:
Read full report, published with kind permission by Dr Nürnberg and Dr Canniffe.
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
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.
20-EPN2-020: Towards prospecting ore deposits on Mars: remote sensing of the planetary field analogue in the Rio Tinto mining area, Spain.
Visit by Jakub Ciazela and Dariusz Marciniak, Institute of Geological Sciences, Polish Academy of Sciences (Poland) to TA1.2 Rio Tinto (Spain). Dates of visit: 17-27 March 2022
Report Summary: The Rio Tinto area hosts the largest known volcanogenic massive sulfide deposits on Earth. We have investigated 614 sites along a river bed (Fig. 1) located 3 m from each other. At each site, we investigated 5 random samples for pyrite content. The pyrite content was always estimated by 2 to 4 researchers, and the average for each site was computed. The average pyrite content in the entire investigated area is 7.0 vol.% (12.6 wt.%). We have observed two fields, 30 x 30 m, and 30 x 60 m, with average pyrite contents >50 wt.%, which should be suitable for its detection from the orbit, both with Sentinel-2 (field resolution of 10 m) and Landsat (30 m). Principle Component Analysis of the obtained spectra from Sentinel-2 (Fig. 2) gives similar results to mineralogical data we have retrieved in the field during our geological mapping.
By establishing our test field for remote sensing of sulfide deposits in a planetary field analog on Earth, we will be able to determine abundance thresholds for the detection of major sulfide phases on Mars and identify their key spectral features. Our results will help in 1) more efficient use of the current NIR Martian spectrometers to detect ore minerals and 2) designing new space instruments optimized for ore detection to include in future missions to Mars such as one developed at the Institute of Geological Sciences and the Space Research Centre of the Polish Academy of Sciences called MIRORES (Martian far-IR ORE Spectrometer).
20-EPN2-015: In-situ measurement and sampling of biosignature-hosting products in support of organics detection in the context of ExoMars 2022
Visit by Marco Ferrari and Simone De Angelis, IAPS-INAF (Italy) to TA1.2 Rio Tinto (Spain). Dates of visit: 11-16 July 2022
Report Summary: This project aims at sampling and performing a wide set of VIS-NIR field measurements of weathering products (e.g., sulfates, clays), rocks with hydrothermal origin, and deposits showing evidence of biosignatures. To achieve this goal, during our visit we performed 195 measurement spots with the FieldSpec 4 portable spectrometer in the range of 0.35-2.5 µm and collected 47 samples in different forms. Among all the collected samples, three of them are consistent rock blocks. This is because they will be used as a test for the laboratory model of the Ma_MISS instrument that will be able to drill them and perform the spectroscopic measurements in the borehole wall.
This campaign will also allow us to confirm the capability of the Ma_MISS instrument to detect spectral signatures of organics in geological samples containing biosignatures. With the spectroscopic data obtained in the field and the laboratory on the collected samples, we will build a spectral database that will be useful to the scientific community.
These activities on terrestrial analogs have proven useful for understanding life in extreme conditions and how these can be preserved in the form of biological signatures and detected by the scientific instruments that will be on board future missions to Mars.
In addition, this work helps in acquiring crucial preparation for the exploitation and interpretation of the scientific data that the Ma_MISS instrument will provide during the active phase of the mission.
Looking for clues about water circulation on Mars in the remote Makgadikgadi salt pans of Botswana
From 18 – 28 October 2021, researchers Erica Luzzi, Jacobs University (Germany) and Gene Schmidt, Università degli Studi Roma Tre (Italy) were funded by the Europlanet 2024 Research Infrastructure (RI) Transnational Access (TA) programme to visit the Makgadikgadi Salt Pans in Botsawana. The trip was led by Fulvio Franchi (Botswana International University of Science and Technology (BIUST)) who is responsible for the Botswana Planetary Field Analogue for Europlanet 2024 RI. In this guest post, Erica Luzzi reports on the field trip.
Our trip to Botswana through the Transnational Access offered by Europlanet has given us an incredible amount of surprises.
Figure 1: View of the Makgadikgadi Salt Pans. Credit: E Luzzi
In addition to the precious data that we collected, we indeed had a life-changing experience visiting one of the most remote places on Earth. From the absolute silence in the desert, to the calm and breath-taking landscapes in the savanna, for some moments we really felt like being on another planet. Among many adventures (and misadventures), we accessed this extraordinary place on Earth, where a lot has been studied but still leaving space for many mysteries: the Makgadikgadi salt pans (Fig. 1). These dry lands occupy a broad area in the savanna of Botswana, and are characterized by a mixture of clays and sulfates with recurrent morphologies related to desiccation processes, such as mud cracks (Fig. 2).
Mud cracks in the pan, formed by dessication processes typical of playa environments. Credit: E Luzzi
This area once hosted an ancient lake which, due to paucity of water, turned into a playa, namely a dry lake bed. Such dry environments are hypothesized to have occurred also on Mars, where also the same types of minerals have been detected.
Part of a line in the pan. The deployed cable followed the truck’s footprints that were guided by the GPS. Credit: E Luzzi.
By studying an analog field site that we can touch with our hands as it is located on Earth, we can get a variety of insights that may help us to better investigate the processes that shaped Mars into the planet we observe today.
In the region of Arabia Terra, on Mars, light-toned layered deposits often associated with mounds have been widely described in literature, and among other interpretations they were also attributed to playa-like environments. The aim of our work was to analyse the subsurface of the Makgadikgadi salt pans, looking for faults where water could have circulated and then contributed to the hydro-geological cycle that led to the deposition of such deposits.
We performed an Electrical Resistivity Tomography survey in different areas of the pans (Fig. 3).
This particular type of geophysical technique consists of placing a number of electrodes in the ground, carefully spacing them at an equal distance, and then applying a known current. Each material responds to the current in a different way, and many variables can influence the resistivity (e.g. porosity, water content, mineralogy, etc.). A preliminary version of the resulting images confirmed the occurrence of faults that will be better investigated after a robust post-processing of the data.
While we are still working on it, for now we can conclude that the survey has been successful and we look forward to linking our observations with the enigmatic deposits occurring in Arabia Terra, Mars.
Read more about Erica’s experiences on this thread on Twitter:
4) The team. Our group was composed by Gene Schmidt, first author of the future paper, Fulvio Franchi, prof at BIUST, Ame Thato Selepeng, prof at BIUST, Cabelo, an MSc student at BIUST, Rachel, driver at BIUST, and me. I thank them all for this extraordinary experience. 5/ pic.twitter.com/pabwcH8eC1
20-EPN2-121: Constraining the movement of groundwater and fluid expulsion within playa environments on Mars
Visit by Gene Schmidt, Università degli Studi Roma Tre (Italy) and Erica Luzzi, Jacobs University (Germany) to TA1.5 Makgadikgadi Salt Pans (Botswana). Dates of visit: 20-27 October 2021
Across the surface of Mars there is evidence of past lacustrine and evaporitic environments found within basins and craters, where often layered sedimentary deposits and hydrated minerals are observed. However, the intensity, duration and precise phases of water cycle activity during this period remain unresolved. Although several geological processes and locations on Earth have been previously proposed as examples to describe these deposits on Mars, we lack a strong visualisation of what water activity might have looked like during evaportic stages within basins and craters. The Makgadikgadi Salt Pans of Botswana, where once the Makgadikgadi Lake existed, is a present evaporitic environment rich in hydrated minerals and water activity. It is a depression located at the southwestern end of a northeast-southwest set of graben. Faults have been previously proposed to have been pathways for groundwater to enter basins and craters on Mars, which then contributed to both the deposition and alteration of the sedimentary deposits. Thus, imaging the subsurface of a similar environment on Earth can help us to better understand how water processes on Mars might have continued as the Martian global climate became drier.
By using the already established locations of the faults to the north of the pans, we used remote sensing techniques to trace the best location of the faults underneath the pans (Figures 1 and 2). We then used electrical resistivity surveys to image 70 – 150 m of the pans’ subsurface where the faults were deemed most likely to occur. This work allows us to better understand the possibilities of what the underlying lithology of rocks within filled basins and craters might look like. Furthermore, it demonstrates the scientific importance of future missions to employ subsurface imaging techniques on Mars.
From 29 September – 6 October 2021, researchers Daniel Toledo and Victor Apestigue (Instituto Nacional de Técnica Aeroespacial (INTA), Spain) were funded by the Europlanet 2024 Research Infrastructure (RI) Transnational Access (TA) programme to visit the Makgadikgadi Salt Pans in Botsawana. The trip was led by Fulvio Franchi (Botswana International University of Science and Technology (BIUST)) who is responsible for the Botswana Planetary Field Analogue for Europlanet 2024 RI. Ignacio Arruego, Javier Martinez-Oter and Felipe Serrano (INTA) also participated in the field trip.In this guest post, Daniel Toledo reports on the field trip.
The main goal of the field campaign in the Makgadikgadi Salts Pans was to study how dust is lifted into the air. For our investigation, we used the spare units of the Radiation and Dust Sensor (RDS) from the NASA Mars 2020 mission and the Sun Irradiance Sensor (SIS) from the ExoMars 2022 mission (see Figure 1), which are designed to study dust carried in the atmosphere of Mars by measuring how sunlight is scattered by the dust particles.
In addition to giving information about the properties of airbourne dust, these instruments are also sensitive to the presence of dust devils – swirling columns of sand and dust that are a common feature of desert areas on Mars and on Earth. RDS and SIS can detect the changes over time in the sky brightness produced by a dust devil, and this offers a unique opportunity for monitoring and studying such events during the Mars 2020 and ExoMars 2022 missions. However, to be able to characterise and interpret dust devil observations on Mars, we first need to understand how dust devils affect SIS and RDS signals by thorough testing and evaluation of the instruments in Mars-like conditions on Earth.
Figure 1. (Left) RDS instrument: two sets of eight photodiodes. One set is pointed upward, with each photodiode covering a different wavelength range between 250-1000 nanometres. The other set is pointed sideways, 20° above the horizon, and they are spaced 45° degrees apart in azimuth to sample all directions at a single wavelength; a zenith-pointed camera (Skycam) with special optics is designed to measure column optical depth.(Right) SIS instrument: Five detectors pointed at zenith and with different spectral bands and Fields of View (FOVs); twelve lateral detectors (six in the ultraviolet range and six in the near infrared range) pointed sideways; a micro-spectrometer pointed directly upwards (at zenith) with a spectral resolution of 10 nanometres in the 340-780 nanometres range.
Figure 2. Dust devils observed in Makgadikgadi Salt Pans (left panel) and on Mars (right panel). A typical dust devil on Mars spans from hundreds of metres to thousands of metres in diameter, with a height one-eight times as large. Dust devils of Mars are thought to account for the ~50% of the total dust budget, and they represent continuous source of lifted dust, active even outside the dust storms season. For these reasons, they have been proposed as the main mechanism able to sustain the constantly-observed dust haze in the martian atmosphere.
To achieve this goal, we planned a field campaign from 29 September to 6 October in the southern part of Makgadikgadi Salt Pans (see Figure 3), in the Pan near Mopipi town. This location is characterised by frequent dust devil events and conditions that promote the lifting of high levels of aerosols (dust and particles) into the atmosphere.
Each day of the campaign, we set up RDS and SIS at two different locations from sunrise to sunset, separated by about 25 m, along with:
Two cameras to record panoramic videos during the campaign period.
A Vaisala weather station to perform measurements of pressure, wind direction and intensity, temperature and relative humidity.
A ZEN radiometer to measure how much light was absorbed by the dust at different wavelengths.
The objective of having the two main instruments at two different locations was observe the dust lifting events from different perspectives.
During the campaign, we observed a large number of dust devils (many more than 10) and dust lifting events produced by wind gusts (over 10). For each dust lifting, we recorded the dust devil distance, the size, duration and direction. To do this, we marked out concentric circles with radii of 25, 50, 75, 100, 125 and 150 m on the ground. This information along with the videos made by the cameras, helped us to establish the amount of dust lifted by the dust devil as well as their distances from the instruments. All the data collected for each event was key to establish the RDS and SIS capabilities for dust lifting characterisation on Mars.
The first two days of the campaign were characterised by high dust-loading conditions and frequent formations of dust lifting events produced by dust devils or wind gusts. During these two days, each dust lifting event registered by the cameras was also detected by RDS and SIS, with signals showing a sharp peak at the time when the event passed within the sensors field of view. Preliminary analysis suggests that we can infer from RDS and SIS signals the difference between dust lifting events produced by dust devils and those produced by wind gusts – an important result for the observations on Mars.
Figure 3. Map indicating the location selected for carrying out the field campaign in the southern part of Makgadikgadi Salt Pans (red square) and the village Rakops (black square) where different lodges are available.
The third day of campaign had to be cancelled due to rain. This resulted in a lower dust-loading conditions in the following days, and thus the amount of dust lifted by vortices or wind gusts was smaller compared to the first two days.
Upon return to BIUST in Palapye on 6 October, we held a seminar for staff and students titled Atmospheric science on Mars: from Earth analogues to future planetary networks.
In summary, the campaign was a complete success. Our observations have demonstrated the capability of the RDS and SIS sensors to detect and characterise dust devils on Mars. The analysis of the signals along with the information acquired by the other instruments will allow us to quantitatively establish the sensors limit of detection. In addition, the rainy episode offered us the chance to study dust lifting events in different aerosol loading conditions.
20-EPN2-046: Characterising dust lifting events using the ground-based Mars-2020-RDS and ExoMars-2022-SIS radiometers
Visit by Daniel Toledo, INTA (Spain) to TA1.5 AU Makgadikgadi Salt Pans (Botswana). Dates of visit: 29 September – 06 October 2021
Report Summary:
On Mars, the airborne dust is a critical factor that drives the weather and climate of the planet. Dust devils are thought to account for the ~50 % of the total dust budget, and they represent a continuous source of dust, present even outside the dust storms period. For these reasons they have been proposed as the main mechanism able to sustain the observed dust haze of the martian atmosphere. However, additional dust devil surveys covering long diurnal periods are needed to place quantitative constraints on the cycles of these events. In this regard, the present and future observations of the Radiation and Dust Sensor (RDS) and the Sun Irradiance Sensor (SIS), which are part of NASA Mars 2020 and ESA/Roscosmos ExoMars 2022 missions, offer a unique opportunity to monitoring dust devils at high temporal resolution from sunrise to sunset, and with an excellent spatial coverage.
The main goal of the field campaign in the Makgadikgadi Salts Pans (20-EPN2-065) was to study dust lifting events using the spare units of RDS and SIS. During the campaign (29 Sept to 6 Oct 2021), a large number of dust devils (>10) and dust lifting events produced by wind gusts (>10) were observed by RDS and SIS sensors. For each case, information on distance, size, temporal duration and direction was registered. This information along with observations made by other instruments (e.g. wind speed and direction), have allowed us to study the potential RDS and SIS capabilities for dust lifting characterisation on Mars.
20-EPN2-046: Investigating molecular and isotopic fingerprints of life on Greenland Ice Sheet (GrIS) cryo-ecosystems with astrobiological interest for icy worlds.
Visit by Laura Sánchez-García, Centro de Astrobiología (INTA-CSIC), Madrid, Spain, to TA1.4 AU Greenland Kangerlussuaq Field Site (Greenland). Dates of visit: 19-25 July 2021
Report Summary:
Glacial systems are interesting for studying habitability and limits of life. They are extreme environments where indigenous microorganisms may survive prolonged exposure to sub-zero temperatures and background radiation for geological timescales. Glaciers and the surrounding cryo-environments (permafrost, glacial lakes, or melting streams) arise as relevant scenarios for studying the development of functional microbial cryo-ecosystems and may have implications in the search for past or extant life in icy worlds beyond the Earth. In the Solar System, Europa and Enceladus have been recognized as the icy worlds with highest likelihood to harbor life, largely because liquid water could be in contact with rocks. Both satellites are believed to contain a global ocean of salty water under a rigid icy crust that would provide the scenario for an interaction between briny water and rocks, and the conditions for life to arise.
The permanent Greenland Ice Sheet (GrIS) represents a possible analog of such icy worlds, constituting an important long-term repository of psychrophilic microorganisms. Around the GrIS, different formations such as glacial lakes, permafrost, or further peat soils represent diverse degree of succession upon the influence of the GrIS and its thermal destabilisation.
We propose investigating molecular and isotopic lipid biomarkers of microorganisms inhabiting different cryo-ecosystems at and around the GrIS to obtain clues of a potential life development on analogous extraterrestrial cold environments (ice sheet), and learning how ecosystems evolves (biological succession) when the ice cover retreats and gets exposed to the atmosphere (glacier-melting streams, bedrock-erosion sediments, lake sediments, glacial soils).
