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Several icy moons of the Solar system, such as Europa, harbor global oceans below their surfaces. It is conceivable that a number of exoplanetary bodies may also possess them. The presence of aqueous layers, partially or totally liquid, highly influences the bulk physical properties of these bodies, particularly the thermal state, and consequently, the geological activity and the potential habitability over time. In this work, we obtained experimental data to characterize the thermal budgets of aqueous environments in planetary bodies depending on the main solute composition, and we quantified the heat associated with water-rich materials’ phase transitions occurring during planetary evolution. We measured the heat capacity (Cp) and the sensible heat values of aqueous systems at several concentrations of sulfate, carbonate, chloride, ammonia, and methanol at low temperatures, and we calculated the latent heat associated with the phase transitions. Raman spectroscopy allowed us to identify the phases related to the Cp and enthalpy (ΔH) variations. We applied thermal functions to estimate the energy involved in the generation of oceans and other endogenous processes, recognizing the impact of heat transfer by both ice and brine slurries. Likewise, we calculated the heat associated with the formation of local liquid lenses, particularly below Europa’s surface, which is suggested by the presence of geological features such as Thera Macula. We propose that the calorimetric properties of the slurries of the studied salt- and volatile-systems may sustain the potential habitability of icy moons and support the formation of certain surface features, in particular due to the high latent heat density and the promotion of the exothermic local growth of ice blocks that can separate from the remaining liquid.

Planetary protection guidance for martian exploration has become a notable point of discussion over the last decade. This is due to increased scientific interest in the habitability of the red planet with updated techniques, missions becoming more attainable by smaller space agencies, and both the private sector and governments engaging in activities to facilitate commercial opportunities and human-crewed missions. The international standards for planetary protection have been developed through consultation with the scientific community and the space agencies by the Committee on Space Research's (COSPAR) Panel on Planetary Protection, which provides guidance for compliance with the Outer Space Treaty of 1967. In 2021, the Panel evaluated recent scientific data and literature regarding the planetary protection requirements for Mars and the implications of this on the guidelines. In this paper, we discuss the COSPAR Planetary Protection Policy for Mars, review the new scientific findings and discuss the next steps required to enable the next generation of robotic missions to Mars.

Microbial activity is a major contributor to the biogeochemical cycles that make up the life support system of planet Earth. A 613 m deep geomicrobiological perforation and a systematic multi-analytical characterization revealed an unexpected diversity associated with the rock matrix microbiome that operates in the subsurface of the Iberian Pyrite Belt (IPB). Members of 1 class and 16 genera were deemed the most representative microorganisms of the IPB deep subsurface and selected for a deeper analysis. The use of fluorescence in situ hybridization allowed not only the identification of microorganisms but also the detection of novel activities in the subsurface such as anaerobic ammonium oxidation (ANAMMOX) and anaerobic methane oxidation, the co-occurrence of microorganisms able to maintain complementary metabolic activities and the existence of biofilms. The use of enrichment cultures sensed the presence of five different complementary metabolic activities along the length of the borehole and isolated 29 bacterial species. Genomic analysis of nine isolates identified the genes involved in the complete operation of the light-independent coupled C, H, N, S and Fe biogeochemical cycles. This study revealed the importance of nitrate reduction microorganisms in the oxidation of iron in the anoxic conditions existing in the subsurface of the IPB, FP7 Ideas: European Research Council, Grant/Award Number: ERC Advanced Grant #250-350

Introduction. Understanding the origin and evolution of Phobos and Deimos is the goal of the coming Martian Moons eXploration mission (MMX) led by JAXA [1, 2, 3]. This mission will be launched in 2024 to the Martian system and return samples from Phobos. Before sample return operations, a rover of 25 kg approximately will be delivered to the surface carrying four instruments: a Raman spectrometer (RAX), a radiometer (miniRad), a stereo pair of cameras looking forwards (NavCams), and two cameras looking at the wheel-surface interface, (WheelCams) [4]. The RAX instrument. The RAman spectrometer for MMX, RAX, has been developed together by DLR, INTA/UVA, and JAXA/UTo [5]. It consists of three elements: I) The RAX Laser Assembly (RLA), which was originally designed for the RLS instrument of the ExoMars mission, and includes a laser emitting at 532 nm; II) The RAX Spectrometer Module (RSM), comprising a sophisticated confocal optical assembly and a CMOS detector that covers a spectral range of up to 4000 cm-1 with a spectral resolution of ̴ 10 cm-1; III) The Autofocus System (AFS) to measure with high precision at different positions onto the ground. RAX will in situ examine the minerals of the surface and their formation conditions at rover sampling spots. By analysing the vibrational modes of the substances, RAX will be capable to characterize the igneous phases, volatiles, organic species, and secondary alteration minerals at grain scale. RAX’s targets may be correlated, on the one hand to the orbital data to better approach the spatial distribution and stratigraphic relationship between the Phobos’ blue and red material units, and on the other hand to the mineral and rock types observed on the Mars’ surface by other Raman spectrometers to link their genesis (or not) (e.g. RLS [6], or Supercam [7]). The identified mineral assemblages can be used to determine whether Phobos is a captured asteroid rich in carbon and water, or is a remnant body of a giant impact to Mars. In addition, the information may also support the sample return selection and provide context information of the materials once they are in terrestrial laboratories. References. [1] T. Usui, et al., Space Sci. Rev. 216:49, 2020; [2] S. L. Murchie, D. T. Britt, C. M. Pieters., Space Science 102, 2014, 176–182; [3] C.M. Pieters, S. L. Murchie, N. Thomas, and D. Britt, Planetary and Space Science 102, 2014, 144-151; [4] P. Michel, et al., Earth, Planets and Space 74: 2, 2022; [5] Y. Cho et al., Earth, Planets and Space 73:232, 2021; [6] F. Rull et al., Astrobiology 17 (6-7), 2017, 627–654; [7] S. Maurice et al., Space Sci. Rev. 217, 2021.

IntroductionCO2 clathrate is one of the possible compounds in the crust of ice moons. The analysis of the data provided by the NASA Galileo mission revealed that the Jovian moons have both, the chemical and the physical conditions required for clathrate hydrates to be formed from the surface to deeper layers (Prieto-Ballesteros et al. 2005, Hand et al. 2006, Izquierdo-Ruiz et al. 2020).The study of the dielectric properties of water-related minerals is key to understand the results of future missions to Jupiter and its satellites. The JUICE (ESA) and Europa Clipper (NASA) missions will try to determine the internal subsurface structure of these Jovian icy moons with the radar instruments onboard: RIME and REASON respectively. These instruments will operate both at a frequency of 9 MHz, with capacity to penetrate from 1 to 30 km depth. REASON has an extra antenna of 60 MHz to explore shallow depths (that is, 300 m to 4.5 km).There are many works about the physical properties of clathrate hydrates (for instance: Sloan et al, 2007), but just a few of them are focused on their electrical properties in planetary conditions. Davidson (1973) and Davidson & Ripmeester (1978) determined the high frequency permittivity (εꚙ) of several clathrates, finding a value of 2.85 at 233 K for clathrates of simple guest molecules such as argon and nitrogen. This value increases over 7.7 for other guest molecules and structures such as ethylene oxide and acetone. So far, only Stern et al. (2021) investigated CO2- and CH4- clathrate hydrates to determine their electrical conductivity, but not their permittivity.In this work we present novel results for CO2 clathrate including a combined electrical conductivity and permittivity study. MethodologyWe use a stainless-steel high pressure chamber with an internal volume of 60 ml for the formation of clathrate hydrates. In this cell we mixed distillated water with CO2 gas at 30 bar of pressure.The conditions of temperature and pressure are recorded at fixed time intervals by sensors inserted into the cell during all the testing period. For the electrical measurements we used a Teflon cell inside the pressure chamber with two polished stainless steel electrodes. Data were taken in isothermal conditions, stabilizing the sample during 10 minutes at each temperature step, when the conductance (G) and parallel capacitance (Cp) were measured, in the frequency range from 20 Hz to 106 Hz in several steps using an LCR precision meter (IM3536-01 Hioki).The electrical measurements were taken at different temperatures inside the boundaries of the CO2 clathrate equilibrium curves, where several phases such as water, CO2 dissolved, CO2 gas, water ice, and/or CO2 clathrate, can co-exist, following the phase diagram H2O-CO2. We have performed in situ Raman spectroscopy through the sapphire window of the chamber, in order to determine the specific phases stabilized at each temperature step before collecting the electrical data measurement.. ResultsWe measured the electrical conductivity and real permittivity values for samples of 1) CO2 clathrate and, 2) water with CO2. The results allowed us to discriminate the presence of the CO2 clathrate phase respecting to other phases that could also be formed during the experiments.When CO2 clathrate is formed, the electrical characterization shows the conductivity and the real part of the permittivity constant with frequencies higher than 100 kHz, with smooth variation with the temperature. At 255 K the real permittivity (εꚙ) was 2.5, and the conductivity (σ) was 1.5·10-6 S/cm. Both obtained values are in good agreement with Stern et al. (2021).The conductivity and real permittivity of the two phases sample H2O+CO2 with no clathrate formation showed a steeper dependence with frequency and temperature in comparison with the CO2 clathrate. At 265 K, εꚙ was 1.5, and σ was 1.04·10-6 S/cm.The attenuation of the signal was calculated from the experimental values of conductivity and real permittivity according to the next equation (Petinelli et al., 2015) at 10 kHz.𝛼 ≅ 𝜎/(2𝑐𝜀0( √𝜀´))The attenuation showed clear differences between CO2 clathrate, icy water with dissolved CO2, and ice water itself, with attenuation obtained values of 10.99, 1.35 and 0.34 dB/km at 265 K, respectively. ConclusionsThe different phases of the H2O-CO2 system have appreciable differences in their electrical properties, which means that differences in the physical state could be identifiable by radar measurements. The possible relation with surface morphological features could eventually help to understand the geological activity of the moons, such as the mechanism of jets formation proposed for Europa (Shibley & Laughlin, 2021) or the formation of the double ridge structures (Culberg et al., 2022). AcknowledgmentsThis work was supported by the ESA contract 4000126441/19/ES/CM, and the MINECO Projects PID2019-107442RBC32, and PRE2020-093227. ReferencesPrieto-Ballesteros, O. et al. 2005 Icarus, 177, 491-505.// Hand, K. et al. 2006, Astrobiology Vol 6, 3. 463-482. // Izquierdo-Ruiz, F. et al. 2020 ACS Earth and Space Chemistry 2020 4 (11), 2121-2128 // Sloan Jr, E.D. et al. 2007. Clathrate Hydrates of Natural Gases (3rd ed.). CRC Press // Davidson, D.W. 1973 The Physical Chemistry of Water Vol2 115-234. // Davidson D.W. & Ripmeester J.A. 1978. Journal of Glaciology, 21, 33-49. // Stern L. A. et al. 2021, Geophysical Research Letters, 48 // Petinelli et al. 2015. Reviews of Geophysics 53, 593-641 // Shibley, N.C. & Laughlin, G. 2021. The Planetary Science Journal, 2:221 // Culberg et al. 2022. Nat Commun 13, 2007

The María de Maeztu Academy of the Centro de Astrobiología is a two year-long (2019-2020, 2020-2021), tailor-made capacity-building activity implemented within the frame of the “Maria de Maeztu” excellence programme. It aims to strengthen and develop new capacities and stimulate the training of young researchers. The first edition of the transdisciplinary challenges is a training activity of the María de Maeztu Academy intended to develope new skills and generating relevant scientific-technical solutions in the field of Astrobiology. The training program started in September 2021 by forming teams with volunteers from different CAB and INTA departments and different areas of expertise. Throughout 2020-2021, several periodic reviews of the proposals were carried out, passing different milestones and receiving expert comments in each evaluation. Then, the CAB’s MdM Executive Committee decided to financially support the four teams to develop the proposed projects in the 2021/2022 academic year, until the end of the María de Maeztu programme. One of those challenges is “NEXT (iN situ EXploration of planeTary objects): EUROPA” and its objective is to identify the optimal Raman technique for the exploration of the surface of Jupiter´s moon Europa in future missions: conducting tests of various Raman techniques (using both commercial and flight models) on representative samples from Europa characterizing these samples with the different Raman techniques generating a database of pros and cons of each technique, which can minimize risks and optimize expected results Figure 1 - “NEXT (iN situ EXploration of planeTary objects): EUROPA” logo In the search for life on other bodies within the Solar System, the top candidates are the icy moons, including Saturn’s moon Enceladus and Europa. These icy moons are target of study as they will help us in the task of assessing possible habitability zones in our neighborhood. The choice of instruments that can answer these questions and also allow us to understand other factors is key. Raman spectroscopy has the versatility to be used to obtain those answers. It has been widely used in the analysis of terrestrial and planetary samples due to its advantages in rapid and non-destructive analysis of the mineralogy and mineral chemistry of rock and/or soil samples. For planetary explorations it exhibits great potentials for unambiguous phase identification due to its narrow and non-overlapping peak profiles, fast analysis without sample preparations, robust behavior and low mass, etc. To achieve the stated objectives, a work plan has been established in different stages, subdivided into three phases: Samples preparation Tests conduction of various Raman techniques on the samples (first is carried out exclusively at the INTA facilities and in the second, the collaborating laboratories will take part) Analysis of the test results and database generation of pros and cons of each technique The samples prepared consist in a saline solution with a molecular organic component. The salt used was MgSO4 that was detected by the Galileo mission [1]. The organic molecule selected was the amino-acid alanine. This amino-acid was discovering in several meteorites as the Murchison meteorite [2]. The sample solutions were prepared with proportions in weight of 5, 10 and 17 % for the salt, and 0.5, 1.0 and 1.5 for the alanine. The following figures show the multisamples compositions of the nine samples (1 to 9), as a result of the prepared sample vials. Figure 2 - Multisamples concentrations Figure 3 - Prepared multisamples vials In the second phase, the prepared samples will be analysed in liquid and frozen state with different Raman technologies in four laboratories including the ExoMars RLS [3] Flight Spare model located at INTA. RLS [4] was the first Raman spectrometer qualified for space applications. This phase will be completed in June 2022. The laboratories where the tests will take place together with the Raman technology to be tested are as follows: Centro de Astrobiología (CAB): iHR550 Horiba with an in-situ 532nm laser and portable i-Raman BWTEK with an in-situ 532nm laser INTA: ExoMars RLS Flight Spare (in-situ visible green laser). GSE (control and scientific analysis) automated by SW University of Valladolid: Raman in-situ Exemplar® Plus LS High Performance Spectrometer with an 785nm (IR) laser and Raman with remote pulsed laser Instituto de Micro y Nanotecnología (IMN): LabRaman HR with two possibilities: 532 nm Solid State Diode Laser and 632 nm (HeNe) Solid State Diode Laser Figure 4 - portable i-Raman BWTEK at CAB facilities Figure 5 - RLS Flight Spare Model at INTA facilities With all the information provided by the Raman tests with Raman technology, an analysis of the results will be carried out in July 2022 and conclusions will be issued on the different techniques used to determine and argue which technology (remote or in-situ Raman technology, which excitation laser wavelength: visible / infrared spectrum) would be the most suitable for meet the scientific requirements to address whether life exists or has ever existed in Europa. [1] Thomas B. McCord, Gary B. Hansen, Jean-Philippe Combe, Paul Hayne, Hydrated minerals on Europa’s surface: An improved look from the Galileo NIMS investigation, Icarus, Volume 209, Issue 2, 2010, Pages 639-650 [2] Engel, M., Nagy, B. Distribution and enantiomeric composition of amino acids in the Murchison meteorite. Nature 296, 837–840 (1982) [3] Rull, F., et al, The Raman Laser Spectrometer for the ExoMars Rover Mission to Mars, Astrobiology, 2017, vol. 17(6-7), 627-654 [4] Moral, A.G., et al, A Raman Spectrometer for the ExoMars 2020 Rover, European Planetary Science Congress 2017, 17-22 September, 2017, Riga Latvia, id. EPSC2017-1001

Introducction JAXA’s MMX (Martian Moons eXploration) mission, to be launched in 2024, will study both Martian satellites, for several years, and will drop a small rover to Phobos, to explore its surface [1]. As part of this rover scientific payload, it will be placed a Raman spectrometer, the RAX Instrument (Raman Spectrometer for MMX). The RAX will be able to analyse the mineral composition of the Phobos regolithe surface with in-situ measurements, complementing the Japanese Sample Return mission, and helping to reveal the nature and distribution of materials on the Martian Moon’s surface, and ultimately its origin and evolution [2]. The RAX instrument [3] has been designed, manufactured, integrated and tested by an international consortium led by DLR (Germany), with significant contributions from JAXA & University of Tokyo (Japan), and INTA-CAB-UVa (Spain). One of the Spanish contributions to RAX, will be the instrument Verification Target, a small piece of PET (polyethylene terephthalate) attached to MMX spacecraft, to be used before launch, and during cruise; for spectral instrument performances verification on-ground and just before the rover release to Phobos. Figure 1. RAX Verification Target design proposed by INTA-CAB-UVa Experimental Thanks to previous expertise of the UVa-INTA group with PET material, used on the Raman Laser Spectrometer (RLS) Calibration Target [4] for ESA’s ExoMars mission; and SuperCam Calibration Target [5] for NASA Mars2020; a newly design-deuterated PET material, decreasing the PET fluorescence background, and adding new Raman bands with respect to ordinary PET [6] has been developed, manufactured, characterized and space-qualified for MMX-RAX mission by INTA-CAB-UVa; so it was proposed as candidate the RAX Verification Target. Figure 2. RAX Verification Target Flight batch for qualification/acceptance Results and discussion During the session, a detailed description of different tests carried out for the space qualification of the deuterated material, will be shown. And how the final performances with respect to other commercial PETs have been improved; and so, how the final verification-calibration of the Raman instrument has been optimized. Acknowledgements INTA’s internal I+D+I project IDMats; and MICINN grants PID2019-107442RB-C32 & PID2019-107442RB-C31 References [1] Michel P. et al. (2022) Earth, Planets and Space 74, 2. [2] Hagelschuer, T. et al. (2019) 70th Int. Astronautical Congress, 2019. [3] Hagelschuer, T. et al. (2022) 73th Int. Astronautical Congress. [4] López-Reyes, G. et al. (2020) Journal of Raman Spectroscopy, 1-13 [5] Manrique, J.A. et al. (2020) Space Sci Rev, 216:138 [6] Mora, J. et al (2020) Acta Astronaut. 167 (2020) 360–373

Perseverance's Mars Environmental Dynamics Analyzer (MEDA) is collecting data at Jezero Crater, characterizing the physical processes in the lowest layer of the atmosphere as no previous instrument did before. Here we show that temperature measurements at four heights capture the response of the atmospheric surface layer to multiple phenomena. We observe the transition from a stable nighttime thermal inversion to a diurnal, highly turbulent convective regime, with large vertical thermal gradients, and where local surface properties (such as Thermal Inertia) play an essential role. Recording multiple daily optical depths yielded higher aerosol concentrations in the morning than in the afternoon. Measured wind patterns are mainly driven by local topography, with a small contribution from regional winds. Daily and seasonal variability of relative humidity shows a complex hydrologic cycle. These observations raise new puzzles in which changes in surface albedo and thermal inertia may play an influential role. On a larger scale, surface pressure shows typical signatures of gravity waves and baroclinic eddies in a part of the seasonal cycle characterized before as low wave activity. These observations, combined and simultaneous, show the rich Jezero’s meteorology, and unveil the diversity of processes driving change on today’s Martian surface.

Hydrothermal systems, commonly developed in volcanic calderas, play an important role on the type and location of the post-caldera volcanic activity. The hydrothermal alteration and mineral precipitation can modify the physical properties and mechanical behaviour of the affected rocks, with the progressive alteration facilitating the occurrence of phreatic or hydrothermal explosive eruptions. Deception Island (South Shetland Islands) is one of the most active volcanoes in Antarctica, with more than 20 eruptions and three documented unrest periods over the past two centuries. The island consists of a composite volcano with an 8.5 x 10 km centrally located caldera dated at c. 8,300 years, according to paleomagnetic data, and 3,980 ± 125 calibrated years before the present (cal yr BP) based on tephrochronology, sedimentological studies and 14C dating. After the caldera-forming event, volcanic activity has been characterized by monogenetic magmatic and phreatomagmatic eruptions located around the caldera rim. Also, a hydrothermal system developed in the Port Foster area, although no detailed study has been done so far. The aim of this work is to shed further light in the dynamics of Deception Island hydrothermal system by studying several representative samples of magmatic rocks. A detailed petrographic study and a characterization of primary and secondary minerals have been carried out. The presence of secondary minerals and the palagonite alteration in the Fumarole Bay Formation suggest that the alteration of the samples took place under conditions of low water/rock ratios, basic pH and temperatures below 200 °C. The secondary minerals from the Basaltic Shield Formation samples may be indicative of fluids with temperatures higher than 200 °C and richer in CO2. Finally, the physical changes observed in the samples of this study lead to the conclusion that the investigated areas of the Fumarole Bay Formation are more likely to host hydrothermal or phreatic explosive eruptions, compared to the Basaltic Shield Formation zones.This research is part of POLARCSIC research initiatives and was partially funded by the MINECO grants POSVOLDEC(CTM2016-79617-P)(AEI/FEDER-UE) and VOLGASDEC (PGC2018-095693-B-I00)(AEI/FEDER, UE) and the grant PID2020-114876GB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and, as appropriate, by “ERDF A way of making Europe”, by the “European Union” or by the “European Union NextGenerationEU/PRTR”. This research is also supported by the PREDOCS-UB grant.

The aim of the European Space Agency’s ExoMars rover mission is to search for potential traces of present or past life in the swallow subsurface (2m depth) of Mars. The ExoMars rover mission relies on a suite of analytical instruments envisioned to identify organic compounds with biological value (biomarkers) associated with a mineralogical matrix in a highly oxidative environment. We investigated the feasibility of detecting basic organics (linear and branched lipid molecules) with Raman laser spectroscopy, an instrument onboard the ExoMars rover, when exposed to oxidant conditions. We compared the detectability of six lipid molecules (alkanes, alkanols, fatty acid, and isoprenoid) before and after an oxidation treatment (15 days with hydrogen peroxide), with and without mineral matrix support (amorphous silica rich vs. iron rich). Raman and infrared spectrometry was combined with gas chromatography–mass spectrometry to determine detection limits and technical constraints. We observed different spectral responses to degradation depending on the lipid molecule and mineral substrate, with the silica-rich material showing better preservation of organic signals. These findings will contribute to the interpretation of Raman laser spectroscopy results on cores from the ExoMars rover landing site, the hydrated silica-enriched delta fan on Cogoon Vallis (Oxia Planum)., Proyecto MINECO Retos de la Sociedad. Ref. ESP2017-87690-C3-1-R

In this work, we have analyzed natural samples collected at three hydrothermal areas of Iceland by Raman spectroscopy. The studied high-latitude regions are considered environmentally and mineralogically appropriate Martian analogues since they are rich in weathered basalts that have been altered by hydrothermalism to mineral phases such as silica, clay minerals, sulfates, oxides, and sulfur. The main objective of this work was to assess the relation of the spectroscopic signatures of alteration to hydrothermal processes and biomediation, considering previous studies focused on the detection of lipid biomarkers in the same samples. The recorded Raman spectra, taken with optical parameters similar to the ExoMars 2022 Raman spectrometer, showed structural modifications in all secondary minerals in the form of peak shifts (in the case of sulfur and clay minerals), changes in the relative ratio intensity (in anatase) and/or shape broadening (in sulfates and hematite). These results reveal the suitability of Raman spectroscopy to examine areas rich in water-altered minerals, where a mixture of crystalline and amorphous phases can co-exist. The detection of silica is singularly interesting since, on the one hand, it can imply the past existence of hydrothermal hot springs rich in nutrient and redox gradients and, on the other hand, provides excellent matrix for biosignature preservation. The data can be helpful as an astrobiological database for the forthcoming missions to Mars, where potential upwelling groundwater systems could have altered the mineral phases in a similar way to that observed in this work.

Detecting evidence of life on other planetary bodies requires a certain understanding of known biomarkers and their chemical nature, preservation potential, or biological specificity. In a planetary search for life, carbonates are of special interest due to their known association with life as we know it. On Earth, carbonates serve as an invaluable paleogeochemical archive of fossils of up to billions of years old. Here, we investigated biomarker profiles on three Chilean Triassic–Jurassic sedimentary records regarding our search for signs of past and present life over ∼200 Ma. A multianalytical platform that combines lipid-derived biomarkers, metaproteomics, and a life detector chip (LDChip) is considered in the detection of biomolecules with different perdurability and source-diagnosis potential. The combined identification of proteins with positive LDChip inmunodetections provides metabolic information and taxonomic affiliation of modern/subrecent biosignatures. Molecular and isotopic analysis of more perdurable hydrocarbon cores allows for the identification of general biosources and dominant autotrophic pathways over time, as well as recreation of prevailing redox conditions over ∼200 Ma. We demonstrate how extraterrestrial life detection can benefit from the use of different biomarkers to overcome diagnosis limitations due to a lack of specificity and/or alteration over time. Our findings have implications for future astrobiological missions to Mars. This work has been funded by the Spanish Ministry of Science and Innovation and Fondo Europeo de Desarrollo Regional (MICINN/FEDER) through the projects Nr. RYC2018-023943-I (L.S.-G.), RYC-2014-19446 (D.C.), RTI2018-094368-B-I00 (V.P.), and ESP2017-89053-C2-1-P (O.P.-B.). The Project Nr. MDM-2017-0737 Unidad de Excelencia “María de Maeztu”- Centro de Astrobiología (CSIC-INTA) was funded by the Spanish State Research Agency (AEI). M.A.L. was supported by a Juan de la Cierva postdoctoral fellowship (FJC2018-037246-I). Peerreview

The upcoming JUpiter ICy moons Explorer (JUICE) (ESA) and Europa Clipper (NASA) missions will perform detailed observations of the giant gaseous planet Jupiter and three of its largest moons (Ganymede, Callisto, and Europa). A series of experiments was performed to measure the thermal conductivity and calorimetry of macroscopic frozen salt solutions of particular interest in Jovian icy moons. The following salts were investigated: Na-chloride (NaCl), Mg-sulphate (MgSO4), sodium sulphate (Na2SO4), and Magnesium chloride (MgCl2). Measurements were performed at atmospheric pressure and temperatures from 0 to -70ºC in a climatic chamber. Temperature and thermal conductivity were measured during the course of the experiments. A small sample of the liquid salt-water solution was set aside for the calorimetry measurements. A side effect of the measurements is that they served to spot phase changes in the ice mixtures with high sensitivity. An important result is that, the phase changes observed in the standard calorimetric tests, could be monitored in situ with high sensitivity in the thermal conductivity measurements. Indeed, when a phase change occurs, a large peak appeared in the thermal conductivity values as the result of the natural heat release that accompanied the phase change.

Ceres, dwarf planet of the main asteroid belt, is considered a relic ocean world since the Dawn mission discovered evidences of aqueous alteration and cryovolcanic activity [1]. Unexpectedly, a variety of ammonium-rich minerals were identified on its surface, including phyllosilicates, carbonates, and chlorides [2]. Although from the Dawn’s VIR spectroscopic data it was not possible to specify the exact type of phyllosilicates observed, montmorillonite is considered a good candidate owing to its ability to incorporate NH4+ in its interlayers [3]. Ammonium-rich phases are usually found at greater distances from the Sun. Hence, the study on their stability at environmental conditions relevant to Ceres’ interior and of its regolith can help elucidate certain ambiguities concerning the provenance of its precursor materials. In this study, it was investigated the changes in the spectroscopic signatures of the clay mineral montmorillonite after (a) being immersed in ammonium chloride aqueous solution and, subsequently, (b) washed with deionized water. After each treatment, samples were submitted to different environmental conditions relevant to the surface of Ceres. For one experiment, they were frozen overnight at 193 K, and then subjected to 10-5 bar for up to 4 days in a Telstar Cryodos lyophilizer. For the other, they were placed inside the Planetary Atmospheres and Surfaces Chamber (PASC) [4] for 1 day at 100 K and 5.10-8 bar. The combination of different techniques, i.e., Raman and IR spectroscopies, XRD, and SEM/EDX, assisted the assignment of the bands to each particular molecule. In this regard, the signatures of the mineral external surface were distinguished from the interlayered NH4+ cations. The degree of compaction of the samples resulted crucial on their stability and spectroscopic response, being stiff smectites more resistant to low temperatures and vacuum conditions. In ground clay minerals, a decrease in the basal space with a redshift of the interlayered NH4+ IR band was measured after just 1 day of being exposed to vacuum conditions. Acknowledgments This work was supported by the Spanish MINECO projects ESP2017-89053-C2-1-P and PID2019-107442RB-C32, and the AEI project MDM‐2017‐0737 Unidad de Excelencia “María de Maeztu”. References [1] De Sanctis et al., Space Sci. Rev. 216, 60, 2020 [2] Raponi et al., Icarus 320, 83, 2019 [3] Borden and Giese, Clays Clay Miner. 49, 444, 2001 [4] Mateo-Marti et al., Life 9, 72, 2019

ESA and NASA will launch two missions to explore the main Galilean moons of Jupiter in the coming years, JUpiter ICy moons Explorer-JUICE and Europa Clipper, respectively. Both missions will be able to determine the distribution of the potential habitable zone in the upper dozens of kilometers of the ice bodies by using onboard radar instruments [Bruzzone et al. 2013, Grasset et al., 2013, Phillips and Pappalardo 2014, Aglyamov et al. 2017]. Considering the possible presence of mixtures of water with salts, volatiles, and clays in the ice and liquid layers, we performed laboratory experiments to obtain the electrical properties of these chemical systems at solid and liquid state, and at different pressure conditions (Table 1). The results that we present at the conference will facilitate the interpretation of the future data received from the radar sensors. We measured the dielectric properties of these samples with a BDS80 Broadband Dielectric Spectroscopy system (Novocontrol), which allows working in a frequency range from 1 Hz to 10 MHz and temperatures from 143 to 323 K. Both, real permittivity (ε´) and electric conductivity (σ) were measured at 0.1 MPa while cooling the samples in temperature steps of 10 K. From these data, we calculated the activation energy and the attenuation of the radar wave depending on the chemical composition, the temperature of the sample, and the frequency of the applied electric field [Petrenko and Whitworth 1999, Pettinelli et al. 2015]. Conductivity measurements at high pressure were carried out using a modification of a chamber used previously for planetary simulation experiments (Muñoz-Iglesias et al. 2019). It is based on a stainless steel cylinder, which has different access on the bases and along the main body. Pressurization of the sample is carried out by water or gas from one access at the chamber base, while a sapphire window is at the opposite side for visual control and spectral analysis. Connections throughout the body of the cylinder are for the thermocouple, the pressure gauge and a special one to plug in the electrical sensor. The key feature is the plug for in-situ conductivity measurements with feed through wires connected to the probe, made of two Pt electrodes placed in a PTFE structure in order to maintain the configuration and to ensure the distance between electrodes (around 500 micrometers). Both electrodes have connections to isolated copper wires, which pass through the cell body to be connected to the signal transducer and the computer to record the data. Acknowledgements This work was supported by the ESA contract number 4000126441/19/ES/CM. We thank Anezina Solomonidou for assistance in the project proposal. References Aglyamov et al. (2017) Bright prospects for radar detection of Europa’s ocean, Icarus, 281, 334-337. Bruzzone et al. (2013) RIME: Radar for Icy moon Exploration, IEEE International Geoscience and Remote Sensing Symposium - IGARSS, Melbourne, 3907-3910. Grasset et al. (2013). Jupiter Icy moons explorer (JUICE): an ESA mission to orbit Ganymede and to characterise the Jupiter system. Planet. Space Sci. 78, 1-21 Muñoz-Iglesias et al. (2019). Experimental Petrology to Understand Europa's Crust. JGR-Planets 124, 2660-2678 Phillips and Pappalardo (2014). Europa Clipper mission concept: exploring Jupiter’s ocean moon. Eos Trans. AGU 95, 165-167. Pettinelli et al. (2015) Dielectric properties of Jovian satellite ice analogs for subsurface radar exploration: A review. Reviews of Geophysics, 53, 593-641.

Nunataks are permanent ice-free rocky peaks that project above ice caps in polar regions, thus being exposed to extreme climatic conditions throughout the year. They undergo extremely low temperatures and scarcity of liquid water in winter, while receiving high incident and reflected (albedo) UVA-B radiation in summer. Here, we investigate the geomicrobiology of the permanently exposed lithic substrates of nunataks from Livingston Island (South Shetlands, Antarctic Peninsula), with focus on prokaryotic community structure and their main metabolic traits. Contrarily to first hypothesis, an extensive sampling based on different gradients and multianalytical approaches demonstrated significant differences for most geomicrobiological parameters between the bedrock, soil, and loose rock substrates, which overlapped any other regional variation. Brevibacillus genus dominated on bedrock and soil substrates, while loose rocks contained a diverse microbial community, including Actinobacteria, Alphaproteobacteria and abundant Cyanobacteria inhabiting the milder and diverse microhabitats within. Archaea, a domain never described before in similar Antarctic environments, were also consistently found in the three substrates, but being more abundant and potentially more active in soils. Stable isotopic ratios of total carbon (δ 13C) and nitrogen (δ 15N), soluble anions concentrations, and the detection of proteins involved in key metabolisms via the Life Detector Chip (LDChip), suggest that microbial primary production has a pivotal role in nutrient cycling at these exposed areas with limited deposition of nutrients. Detection of stress-resistance proteins, such as molecular chaperons, suggests microbial molecular adaptation mechanisms to cope with these harsh conditions. Since early Mars may have encompassed analogous environmental conditions as the ones found in these Antarctic nunataks, our study also contributes to the understanding of the metabolic features and biomarker profiles of a potential Martian microbiota, as well as the use of LDChip in future life detection missions. This project has been funded by the Spanish Ministry of Science and Innovation (MICINN)/European Regional Development Fund (FEDER) project no. RTI2018-094368-B-I00; the European Research Council Consolidator grant no. 818602; and the Spanish State Research Agency (AEI) project no. MDM-2017-0737, Unidad de Excelencia “María de Maeztu” to Centro de Astrobiología.

ExoMars mission is ESA’s greatest commitment to reach the Red Planet in 2023 (ExoMars will take off in September 2022 and the lander will reach Mars in June 2023). ExoMars2022 aims to search for past/present life traces on Mars and to investigate the geochemical and environmental evolution of Mars. To fulfil these objectives, the Rosalind Franklin rover will be equipped with a large quantity of instruments that will allow to select and collect samples up to 2 meters in depth through a drill. Once samples are collected, the rover Sample Preparation and Distribution System will crush the samples and deliver the powdered material within the Analytical Laboratory Drawer (ALD). MicroOmega, MOMA and Raman Laser Spectrometer (RLS) are the three key scientific instruments included in ALD that will perform combined analysis to extract the most information about composition of Mars subsurface RLS is a Raman spectrometer which provides a powerful tool for identification and characterization of minerals and biomarkers. The instrument is made up from several units: a laser for samples excitation, an internal optical head (iOH) which collects the Raman signal returned by the sample and forward to through the Spectrometer Unit where it is diffracted and projected to a CCD. All the mentioned operations are controlled by ICEU, (Instrument-Control & Excitation-Unit) a sophisticated custom electronic box designed to support an autonomous software control based on an exclusive hardware architecture composed by a FPGA (where low level drivers are hosted), a LEON2 (where Application Software (ASW) is running) and associated peripherals will be used by SW to perform assigned tasks. Therefore, RLS ASW purpose is to command and control all RLS critical elements, such as the optical head focusing mechanism, the CCD imager, and thermal control for both CCD (in order to keep it cool) and laser source (to warm it until its working temperature). In order to obtain the maximum scientific performance at the Mars surface while optimizing the limited operation opportunities for RLS, according to the Rover Reference Surface Mission, and solving the technical difficulties intrinsic to space instrumentation, the RLS team has developed an advanced embedded software in a custom-hardware-architecture that provides an automated control of all RLS subsystems as well as post-processing capabilities to perform prompt in-situ analysis of Raman spectra. In addition, it also includes the logic to perform automated Raman acquisitions and applying post-processing algorithm to adapt the sample acquisition parameter of every sample spot under analysis, reducing the sample fluorescence, removing undesired spikes due to Cosmic Ray impacts and by calculating the acquisition integration time. The objective of those algorithms is to maximize the Raman signal intensity of the acquired spectra, avoiding saturation level on the detector. The RLS ASW, commands the autofocus system to guarantee that iOH is optimally focused in the accurate acquisition position over the sample. This is part of the AF algorithm function which allows effective Raman signal collection by maximizing the SNR. Finally, RLS manages communications with Rover’s MMS (Mission Management SW) implementing ‘CANopen Controller IP Core’ protocol.

Cyanobacteria are ecologically versatile microorganisms inhabiting most environments, ranging from marine systems to arid deserts. Although they possess several pathways for light-independent energy generation, until now their ecological range appeared to be restricted to environments with at least occasional exposure to sunlight. Here we present molecular, microscopic, and metagenomic evidence that cyanobacteria predominate in deep subsurface rock samples from the Iberian Pyrite Belt Mars analog (southwestern Spain). Metagenomics showed the potential for a hydrogen-based lithoautotrophic cyanobacterial metabolism. Collectively, our results suggest that they may play an important role as primary producers within the deep-Earth biosphere. Our description of this previously unknown ecological niche for cyanobacteria paves the way for models on their origin and evolution, as well as on their potential presence in current or primitive biospheres in other planetary bodies, and on the extant, primitive, and putative extraterrestrial biospheres., This work was supported by the European Research Council Advanced Grant ERC250350-IPBSL, and the Spanish Ministerio de Economía y Competitividad/Fondo Europeo de Desarrollo Regional Grants AYA2011-24803 and ESP2015-69540-R. F.P.-S. is currently funded by the Spanish Ministerio de Economía y Competitividad/Fondo Europeo de Desarrollo Regional Grant CTM2016-80095-C2-1-R.

Mineralogy is the key to understanding the origin of Phobos and its position in the evolution of the Solar System. In situ Raman spectroscopy on Phobos is an important tool to achieve the scientific objectives of the Martian Moons eXploration (MMX) mission, and maximize the scientific merit of the sample return by characterizing the mineral composition and heterogeneity of the surface of Phobos. Conducting in situ Raman spectroscopy in the harsh environment of Phobos requires a very sensitive, compact, lightweight, and robust instrument that can be carried by the compact MMX rover. In this context, the Raman spectrometer for MMX (i.e., RAX) is currently under development via international collaboration between teams from Japan, Germany, and Spain. To demonstrate the capability of a compact Raman system such as RAX, we built an instrument that reproduces the optical performance of the flight model using commercial off-the-shelf parts. Using this performance model, we measured mineral samples relevant to Phobos and Mars, such as anhydrous silicates, carbonates, and hydrous minerals. Our measurements indicate that such minerals can be accurately identified using a RAX-like Raman spectrometer. We demonstrated a spectral resolution of approximately 10 cm−1, high enough to resolve the strongest olivine Raman bands at ~ 820 and ~ 850 cm−1, with highly sensitive Raman peak measurements (e.g., signal-to-noise ratios up to 100). These results strongly suggest that the RAX instrument will be capable of determining the minerals expected on the surface of Phobos, adding valuable information to address the question of the moon’s origin, heterogeneity, and circum-Mars material transport. Graphical Abstract

Maritime Antarctica is a climate-sensitive region that has experienced a continuous increase of temperature over the last 50 years. This phenomenon accelerates glacier retreat and promotes the exposure of ice-covered surfaces, triggering physico-chemical alteration of the ground and subsequent soil formation. Here, we studied the biogeochemical composition and evolution extent of soil on three recently exposed peninsulas (Fildes, Barton and Potter) on Southwest (SW) King George Island (KGI). Nine soil samples were analyzed for their lipid biomarkers, stable isotope composition, bulk geochemistry and mineralogy. Their biomarkers profiles were compared to those of local fresh biomass of microbial mats (n = 3) and vegetation (1 moss, 1 grass, and 3 lichens) to assess their contribution to the soil organic matter (SOM). The molecular and isotopic distribution of lipids in the soil samples revealed contributions to the SOM dominated by biogenic sources, mostly vegetal (i.e. odd HMW n-alkanes distributions and generally depleted δ13C ratios). Microbial sources were also present to a lesser extent (i.e. even LMW n-alkanes and n-alkanoic acids, heptadecane, 1-alkenes, 9-octadecenoic acid, or iso/anteiso 15: 0 and 17:0 alkanoic acids). Additional contribution from petrogenic sources (bedrock erosion-derived hydrocarbons) was also considered although found to be minor. Results from mineralogy (relative abundance of plagioclases and virtual absence of clay minerals) and bulk geochemistry (low chemical weathering indexes) suggested little chemical alteration of the original geology. This together with the low content of total nitrogen and organic carbon, as well as moderate microbial activity in the soils, confirmed little edaphological development on the recently-exposed KGI surfaces. This study provides molecular and isotopic fingerprints of SOM composition in young Antarctic soils, and contributes to the understanding of soil formation and biogeochemistry in this unexplored region which is currently being affected by thermal destabilization. This study was partially funded by the Instituto Antartico Uruguayo (IAU) and by the Spanish Agencia Estatal de Investigacion (AEI) and Fondo Europeo de Desarrollo Regional (FEDER), through the projects RYC-2014-19446 and ESP2017-87690-C3-3-R (D. Carrizo), ESP201789053-C2-1-P (O. Prieto-Ballesteros), RYC2018-023943-I (L. SanchezGarcia), and MDM-2017-0737 Unidad de Excelencia Maria de Maeztu -Centro de Astrobiología (INTA-CSIC). Sonia Vega acknowledges to the Comunidad de Madrid for a pre-doctoral contract (PEJD-2018-PRE/TIC8497). Eduardo Juri and the crew members from the Artigas Base (BCAA) are acknowledge for their filed assistance. Peerreview

Producción Científica, The Raman laser spectrometer (RLS) instrument onboard the Rosalind Franklin rover of the ExoMars 2022 mission will analyze powdered samples on Mars to search for traces of life. To prepare for the mission, the RLS scientific team has developed the RLS ExoMars Simulator (RLS Sim), a flexible model of RLS that operates similarly to the actual instrument, both in laboratory and field conditions, while also emulating the rover operational constraints in terms of sample distribution that are relevant to the Raman analysis. This system can operate autonomously to perform RLS-representative analysis in one or several samples, making it very useful to perform heavy experimental tasks that would otherwise be impossible using a flight-representative model of the instrument. In this work, we introduce the current configuration of the RLS Sim that has incorporated new hardware elements such as the RAman Demonstrator 1 (RAD1) spectrometer with the objective of approaching its performance to that of the actual RLS instrument. To evaluate the scientific capability of the RLS Sim, we have compared it with a replica model of RLS, the RLS Flight Spare (FS). Several acquisition aspects have been evaluated based on the analysis of select samples, assessing the performance in terms of spectral range and resolution and also studying several issues related to the evolution of signal-to-noise ratio (SNR) with different acquisition parameters, especially the number of accumulations. This performance analysis has shown that the RLS Sim in its updated configuration will be a key model to perform support science for the ExoMars mission and the RLS instrument on the Rosalind Franklin rover. Designed to work intensively, the use of the RLS Sim in combination with the RLS FS will facilitate maximizing the scientific return of the RLS spectrometer during Martian operations., Secretaría de Estado de Investigación, Desarrollo e Innovación (grant PID2019-107442RBC31), European Union’s Horizon 2020 research and innovation program (grant 687302)

Thermal properties of frozen salt solutions are crucial to interpret the JUpiter ICy moons Explorer (JUICE) (ESA) and Europa Clipper (NASA) missions, which will be launched in the upcoming years to make detailed observations of the giant gaseous planet Jupiter and three of its largest moons (Ganymede, Callisto, and Europa) due to the scarcity of experimental measurements. Therefore, we have conducted a set of experiments to measure and study the thermal conductivity and calorimetry of macroscopic frozen salt solutions of particular interest in these regions, including Na-chloride (NaCl), Mg-sulphate (MgSO4), sodium sulphate (Na2SO4), and Magnesium chloride (MgCl2). A climatic chamber has been used to mimic the cryogenic conditions in the Jovian Icy Moons. Measurements were performed at atmospheric pressure and temperatures from 0 to -70ºC. Temperature and thermal conductivity were measured during the course of the experiments. A side effect of these measurements is that they served to spot phase changes in the ice mixtures. A small sample of the liquid salt-water solution was set aside for the calorimetry measurements. These experiments and the measurements of thermal conductivity and calorimetry will be valuable to constrain the chemical composition, physical state, and temperature of the upper layers of the icy crusts of Ganymede, Callisto, and Europa (please see abstracts EPSC Muñoz Iglesias et al. 2020 and EPSC Solomonidou et al. 2020).

Dawn mission sensors detected pervasive Mg and NH4 phyllosilicates mixed with a dark mineral component, probably magnetite, on Ceres’ surface, and observed Na and Mg carbonates locally associated to impact structures [1-4]. Ceres’ crust is mainly composed by different phases of silicates, water and salts. Stephan et al. [5] suggest that the NH4-phyllosilicate is also one of the most representative components in the crust, while the distribution of water as ice or liquid is dependent on the depth. Recent models show that Ceres precursors and the differentiated crust have suffered aqueous alteration and porosity reduction during its evolution, in which silicates and water have physically and chemically interacted [6]. To understand the exchanges between water and the rock particles we are performing a set of experiments simulating the thermal evolution of two systems: 1) montmorillonite clays in liquid water; 2) montmorillonite clays in brine solutions. NH4-montmorillonite is obtained in the laboratory by cation substitution method [7] from the montmorillonite (Gonzales County, Texas, USA) ((Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2·nH2O). The resulting smectite was checked and characterized by XRD, IR and Raman spectroscopy. In the first set of experiments 1.5 wt% of both, the original and the NH4-montmorillonite, were suspended in liquid water and placed into a pressure cell. In order to simulate the conditions in the ice-rich crust, systems were cooled down to 263 K for 24 hours. After that, the samples were heated up to room temperature. During the heating of our first tests with pure water, just when the ice started to melt at 272 K, we observed shifts from 1 to 2.8 bar in the case of the montmorillonite, and to 2.6 bar when working with the NH4-enriched clay. In the second set of experiments, the protocol was repeated, but the original montmorillonite was suspended in an eutectic solution of NaCl (23 wt %). It also showed a pressure shift near the eutectic temperature of the solution 251 K from 1 to 1.5 bar. We interpret these pressure shifts as the effect of a positive volume change of the system, in which the reduction of the water volume by melting is overcompensated by the smectite swelling, even at the low clay quantities we are using in these experiments. When the phyllosilicate freezes, the interlayer distance is reduced [8] and the molecules of water release. This effect is reversible if the clay is in an aqueous environment. The number of molecules inserted between layers depends on the cation in the clay. The Na+ present in the original montmorillonite has the capability to incorporate more than 12 molecules of water [8]. Experiments done so far with NH4-smectites suggest that its facility to swell is lower in the NH4-montmorillonite than in the original montmorillonite [9]. From the laboratory results, we can argue that the interaction between water-smectite during thermal evolution of Ceres’ crust could yield interesting geological effects such as the clay dehydration by freezing, the precipitation of salts from brines when swelling occurs or the generation of stresses by the deformation of the materials. References: [1] Ammannito et al., 2016. Science, 353, issue 6503 aaf4279. [2] De Sanctis et al., 2015. Nature, 528, 241-244. [3] Longobardo et al., 2017. Icarus, .318, .205-211. [4] Stein et al, 2019. Icarus, .320, 188-201. [5] Stephan et al., 2017 Icarus 318 , 111-123 [6] Neumann et al., 2020 Astronomy & Astrophysics 633, A117 [7] Gautier et al., 2010. Applied Clay Science, 49 (3), 247-254. [8] Madsen F. T. and Muller-Vonmoos. 1989 Applied clay science 4 (2), 143-156. [9] Norrish and Rausel-Colom, 1962 Clay minerals bull. 5, 9-16.

The study area (148.155 km2, Figure 1) is located in the southern equatorial region of Mars, approximately centered at 26.0° S and 6.5° E. Although subjected to extensive surface erosion, this heavily cratered region, selected as a representative section of the densely cratered highlands [1], still shows evident signs of past water erosion in the form of valley networks that regularly dissect the surface. As such, is an ideal area to study the role of water in modifying the surface of the Martian highlands. The top elevation of the mapped region is located in the central and eastern areas, reaching a maximum elevation of 2,606 meters above the Martian datum (a.m.d.). The points of lower elevation in the area are locally inside impact craters (-678 m a.m.d.). We found two unusually large impact craters. One is at the northeast, about 180 km in diameter, and only its southern half is inside the area. The other is at the southeast, irregularly shaped, and 116 km in diameter. The topography in the mapped region is also defined by two large valley network systems which carve the surface flowing from south to north, and surround the positive relief at each flank. We have produced a 1:500.000 scale geomorphological map with unprecedented detail, using ArcGIS 10.3 Desktop Software (ESRI) to draw and compiled a combination of a mosaic of hi-resolution CTX images, complemented by available Context Camera (CTX) images for cover gaps [2], a mosaic composed by MOLA and HRSC topography [3], and THEMIS-IR day imagery [4]. We mapped the main morphological units to contribute to the understanding of the hydrology ofthis understudied region of Mars. We mainly focus on describing eleven different morphological unitsand four geomorphic features (Figure 2), related to the past presence of water, as both ice and liquid,to allow us to characterize the past environment and eventually to identify their presence andpersistence. Among these units we would like to highlight the watershed unit, formed by incisions on thesurface that we interpret as evidence of aqueous activity, in which water came from channels thatflowed by the runoff wall unit. We differentiate a few types of impact craters, highlighting the invertedcrater unit and the sediment-filled impact crater unit, both filled up with sedimentary materials maybesourced by paleo-lakes. We differentiate two ejecta units related to liquid and ice water reservoirs;and a polygonal ridged unit and a knobby terrain unit associated with permafrost environments. Acknowledgments: This research is a contribution of the Project ”MarsFirstWater”, EuropeanResearch Council, Consolidator Grant no. 818602. Authors also thank the Agencia Estatal deInvestigación (AEI) project no. MDM-2017-0737 Unidad de Excelencia ”María de Maeztu”, and ReyJuan Carlos University. References: [1] Forsberg-Taylor, et al., (2004). Journal of Geophysical Research: Planets, 109(E5). [2] Fergason R.L. et al. (2018) Astrogeology PDS Annex, USGS. [3] Dickson J.L. et al. (2018)49th LPSC, Abstract#2083. [4] Christensen, P. R et al. (2004). Space Science Reviews, 110 (1), 85–130.

In the coming years The JUpiter ICy moons Explorer (JUICE) (ESA) and Europa Clipper (NASA) missions will study the icy crusts of the main Galilean moons of Jupiter. They will use the penetrating radars RIME and REASON, which will work at wave frequency ranges able to penetrate up to 9 and 30 Km depth respectively, in combination with other instruments [Bruzzone et al. 2013, Aglyamov et al. 2017]. In this regard, we have started a set of experiments to study the electrical properties of materials at low temperatures with the aim to help with the interpretation obtained from the level of attenuation of the radar waves. Ultimately, they will be useful to constrain the chemical composition, physical state and temperature of the upper layers of the icy crusts of Ganymede, Callisto and Europa (please see abstracts EPSC González Díaz et al. 2020 and EPSC Solomonidou et al. 2020). The first set of experiments have been done in a high-pressure chamber equipped with pressure and temperature sensors in direct contact with the sample and a large sapphire window which allows textural and spectroscopic analyses. We have characterized aqueous solutions with salts (MgSO4, NaCl, MgCl2, Mg(ClO4)2, Na2CO3), volatiles (CO2) and clays (nontronite, montmorillonite) at temperatures down to 223 K and pressures up to 60 MPa. Samples were studied by pressure-temperature (P-T) cycles in two ways: (a) first freezing the solution and pressurizing it (TPPT method) and (b) first pressurizing the solution and then freezing it (PTTP method), in order to examine textural and grain size heterogeneities and fracture formation depending on the method of formation. The cooling of the samples led to the final formation of water ice, hydrated salts and clathrate hydrates. Raman spectroscopy was used to control the mineral assemblages and understand better the crust environments and processes that can explain the resulting values, like the appearance of supercooled brines, amorphous phases and recrystallizations during the P-T cycles. We measured the dielectric properties of these samples with a BDS80 Broadband Dielectric Spectroscopy system (Novocontrol) which allows to work in a frequency range from 1 Hz to 10 MHz and temperatures from 143 to 323 K. Both permittivity and electric conductivity were measured at 0.1 MPa while cooling the samples in temperature steps of 10 K. From these data we estimated, on the one hand, the activation energy for motion of the electric charges of each solution, and on the other hand, the attenuation of the radar wave depending on the chemical composition and the temperature of the sample, and the frequency of the electric field applied [Pettinelli et al. 2015]. The already obtained novel data will be used as reference for a second set of experiments, consisting on the same dielectric properties’ characterization but, in this set, samples will be also subjected to high pressure conditions. References Aglyamov et al. (2017) Bright prospects for radar detection of Europa’s ocean, Icarus, 281, 334-337. Bruzzone et al. (2013) RIME: Radar for Icy moon Exploration, IEEE International Geoscience and Remote Sensing Symposium - IGARSS, Melbourne, 3907-3910. Pettinelli et al. (2015) Dielectric properties of Jovian satellite ice analogs for subsurface radar exploration: A review, Reviews of Geophysics, 53, 593-641.

Introduction The Raman Laser Spectrometer (RLS) [1] is one of the Pasteur Payload instruments belonging to the analytical suite onboard the ExoMars’ Rosalind Franklin Rover that will perform Raman spectroscopy on samples extracted from the Martian subsoil for a definitive identification and characterization of minerals and biosignatures [2] in order to address the question of whether life has ever existed on Mars. At the whole life cycle of the instrument, quite testing campaigns are accomplished with the flight and flight-representative models (RLS FM, FS and EQM). Outcomes from some of them, mainly the ones dedicated to get functional and performance capacities of the instrument, may be very useful as reference results during the operations phase in Mars and, also, to learn about the instrument itself (possible design improvements, ageing influence, etc.). But all these outcome data is not easy to manage, on the one hand because lots of telemetries and parameters are generated during each test and, on the other hand because it is very important to have into account the specific conditions for each test. So, for RLS, the need to archive properly all this data, including test conditions, and to ease its analysis led to the challenge of developing a tool for scientist and engineers to handle this outcome, so that they can easy access to data and compare results from different tests and modes and perform long-term analysis of the RLS instrument scientific and technical performance. In this context, RASTA (RLS Archive and Supporting Tool for Analysis) has been conceived as a solution for managing all the RLS data generating during different on-ground test campaigns) in addition to those that will be generated by the RLS FM during operations at Mars surface. RASTA (RLS Archive and Supporting Tool for Analysis) The overall RASTA architecture is shown in Figure 1. RASTA has 3 main elements: RASTA-Parsers, RASTA-DB (Database) and RASTA-MS (Matlab® Scripts). Therefore, RASTA tool consists in a structural and relational database and several parser files that allow to analyze the data generated by the instrument and insert the raw data into RASTA-DB. Once all of the above is done, the users can consult the available data to perform their engineering or science analysis using the user-oriented RASTA-MS (Matlab® Scripts). As depicted in Figure 1, RLS sessions act inside the RASTA architecture as the input files, which could be found in two formats: RLS IDAT (Instrument Data Analysis Tool) .rls files: for ground session performed with the End-to-end Ground Testing Framework [3] as EGSE. Those sessions are generated by RLS IDAT, a software tool that can be used for the reception, decodification, calibration and verification of the TMs (science and housekeeping) generated by the RLS instrument. PDS4 (Planetary Data System, version 4) files for ground and flight sessions performed with the Rover different models: Rover OBC (onboard computer) inside ATB (ExoMars rover Avionic Test Bench), GTM (ExoMars rover Ground Test Module) or PFM (ExoMars rover Proto-flight Model). PDS4 [4] is the official archive system for the ExoMars Mission data. Figure 1- RASTA architecture diagram According to the type of the RLS session input files, the RASTA-Parser extracts the relevant data and stores it into the RASTA-DB. RASTA-DB is a relational open source database developed in SQL language hosted on a server, for allowing ‘read permission’ access to RLS scientists’ and engineers’ community. In order to properly archive each RLS data, a dedicated metadata file is linked to the data provided, so that every aspect of the session like: test purpose, test sequence, mission phase or environment conditions could be addressed to the RASTA-Parsers, before the session is committed into RASTA-DB. Finally, in order to support the users’ analysis, a software library based on Matlab® language has been developed. This library consists of: Low-level library: implementing basic searches in RASTA-DB. Use cases: specific analysis, implemented as sets of calls to ‘Basic scripts’ plus some additional logics or math. The main feature of the tool is that the users can develop their own Matlab® custom analyses by calling the basic ones as ‘building-blocks’ for implementing their analyses. Conclusion RASTA provides a solution for archiving and supporting the analysis of the large amounts of data generated by RLS in its multiple campaigns performed not only in ground, but also during Mars operation in the coming years. It is a powerful tool to do long term analysis of scientific and engineering performance across different sessions of different RLS models. Acknowledgements MINECO grants ESP2014-56138-C3-1-R, ESP2014-56138-C3-2-R, ESP2107-87690-C3-1-R, ESP2107-87690-C3-3-R. References [1] Moral, A.G., et al, A Raman Spectrometer for the ExoMars 2020 Rover, European Planetary Science Congress 2017, 17-22 September, 2017, Riga Latvia, id. EPSC2017-1001. [2] Rull, F., et al, The Raman Laser Spectrometer for the ExoMars Rover Mission to Mars, Astrobiology, 2017, vol. 17(6-7), 627-654. [3] J. Zafra et al., End-to-end Ground Testing Framework for Raman Laser Spectrometer (RLS) on board Exomars 2020, in Simulation and EGSE for Space Programmes- sesp 2019. [4] Jet Propulsion Laboratory California Institute of Technology Pasadena, California, Planetary Data System Standards Reference, Version 1.14.0, may 22, 2020.

The ExoMars Rosalind Franklin rover is scheduled to land in Oxia Planum, at the outlet of Coogoon Valles, in 2023. The site is located in the western Arabia Terra region, the most gradual transition of the planetary topographic dichotomy, also considered to be one of the oldest terrains of Mars (Davis et al., 2016). Despite the high potential of the area as a promising location to search for ancient life, some aspects of its regional geologic context remain elusive. The extremely complex hydrologic history of Coogoon Valles system (Molina et al., 2017) is one example of the difficulty in addressing its geologic record. The Arabia Terra surface is extensively modified, and the paucity of valley networks (Figure 1A) and the presence of many inverted structures (Hynek et al., 2010; Davis et al., 2016; Davis et al., 2019) seem to indicate a widespread denudation. Besides, some of the phyllosilicate-bearing light-toned layered materials found in the area could have been formed by weathered airborne transported volcanic tuffs or ashes, that may cover older features. The absence of obvious volcanic edifices near the study area, that could be a source for these materials (Kerber et al., 2012), does not exclude the presence of yet undiscovered volcanic sources in the vicinity. Some crater-like structures, which lack typical features of impact origin, could have been formed by tectonics, groundwater, thermokarst, or volcanic collapses (or a combination of all; Figure 2). Their morphology favors a volcanic origin (Molina et al., 2019), perhaps similar to the plain-style calderas described to the NE of Arabia Terra (Figure 2; Michalski and Bleacher, 2013). The distribution of relatively small water- and volcanic-related features in the region provides additional evidence for processes that are difficult to assess on a regional scale. We have performed a grid-based mapping (Ramsdale et al., 2017; Voelker and Ramsdale, 2019) in two perpendicular study areas that overlap in the landing site area (Figure 1). The northern study area was separated into 2,171 grids (each 20x20 km, yellow in Figure 1B). It follows the dichotomy scarp from the landing site until reaching the plain-style calderas to the northeast (Michalski and Bleacher, 2013). Here we looked for features related to volcanic and thermokarstic activity as depressions pits, flows, and ridges. The other study area (2,563 grids, white in Figure 1B) transverses the dichotomy from the landing site southbound to Sinus Sabaeus in the Noachian highlands, where records of fluvial activity are much more prevalent (Robas et al., 2019). In this case, we looked for modified craters and various water-related features. In addition to that, we mapped further landforms found in both study areas, as knob fields, light-toned deposits, and channels. To identify the different features we used the global mosaic composed of CTX images (Malin et al., 2007; Dickson et al., 2018), a topographic mosaic from MOLA and HRSC data (Smith et al. 2001; Jaumann, R. et al. 2007; Fergason et al., 2018), and the quantitative THEMIS-derived global thermal inertia mosaic (Christensen et al., 2004, 2013). Acknowledgments: This research is a contribution of the Project ”MarsFirstWater”, European Research Council Consolidator Grant no. 818602. The authors also thank the Agencia Estatal de Investigación (AEI) project no. MDM-2017-0737 Unidad de Excelencia ”María de Maeztu”, and Rey Juan Carlos University. References: Christensen P. R. et al., Space Sci Rev. 110, 85–130 (2004). Christensen P. R., R. L. Fergason, C. S. Edwards, J. Hill, in LPSC, 44, No. 1719, id. 2822 (2013). Davis J. M., M. Balme, P. M. Grindrod, R. M. E. Williams, S. Gupta, Geology. 44, 847–850 (2016). Davis J.M. et al, J Geophys Res Planets. 124(7), 1913–1934. (2019). Dickson J. L. , L. A. Kerber, C. I. Fassett, B. L. Ehlmann, in LPSC, 49, No. 2083, id. 2480 (2018). Fergason R. , T. Hare, J. Laura, Astrogeology PDS Annex, US Geological Survey (2018). Hynek B. M., M. Beach, M. R. T. Hoke, J Geophys Res Planets. 115 (2010). Jaumann R. et al., Planet Space Sci. 55, 928–952 (2007). Malin M. C. et al., Journal of Geophysical Research: Planets, 112, E5 (2018). Michalski J. R. , J. E. Bleacher, Nature. 502, 47–52 (2013). Molina A. et al., Icarus. 293, 27–44 (2017). Molina A., O. Prieto-Ballesteros, I. López, C. Robas, A. G. Fairén, in EANA Conf., 282577 (2019). Ramsdale J. D. et al., Planet Space Sci. 140, 49–61 (2017). Robas C., A. Molina, I. López, O. Prieto-Ballesteros, A. G. Fairén, in EANA Conf., 280888 (2019). Voelker M., J. D. Ramsdale, in Planetary Cartography and GIS, H. Hargitai, Ed. (Springer International Publishing, Cham, 2019), pp. 293–302.

The presence of organic matter in lacustrine mudstone sediments at Gale crater was revealed by the Mars Science Laboratory Curiosity rover, which also identified smectite clay minerals. Analogue experiments on phyllosilicates formed under low temperature aqueous conditons have illustrated that these are excellent reservoirs to host organic compounds against the harsh surface conditions of Mars. Here, we evaluate whether the capacity of smectites to preserve organic compounds can be influenced by a short exposure to different diagenetic fluids. We analyzed the stability of glycine embedded within nontronite samples previously exposed to either acidic or alkaline fluids (hereafter referred to as "treated nontronites") under Mars-like surface conditions. Analyses performed using multiple techniques showed higher photodegradation of glycine in the acid-treated nontronite, triggered by decarboxylation and deamination processes. In constrast, our experiments showed that glycine molecules were preferably incorporated by ion exchange in the interlayer region of the alkali-treated nontronite, conferring them a better protection against the external conditions. Our results demonstrate that smectite previously exposed to fluids with different pH values influences how glycine is adsorbed into their interlayer regions, affecting their potential for preservation of organic compounds under contemporary Mars surface conditions. The research leading to these results is a contribution from the Projects "icyMARS" and "MarsFirstWater", funded by the European Research Council, Starting Grant no. 307496 and Consolidator Grant no. 818602, respectively, to AGF. We acknowledge to S. Galvez-Martinez for help and support during XPS measurements and the technical staff of the Unidad de Tecnicas Geologicas (Universidad Complutense de Madrid) for the XRD measurements. This Project has been partially supported by Unidad de Excelencia "Maria de Maeztu", MDM-2017-0737, Centro de Astrobiologia (INTA-CSIC), OPB is supported by project ESP2017-89053-C2-1-P and EMM by project ESP2017-89053-C2-2-P. Peer review

The JUpiter ICy moons Explorer (JUICE) (ESA) and Europa Clipper (NASA) missions will be launched in the next decade in order to spend a number of years making detailed observations of the giant gaseous planet Jupiter and three of its largest moons, Ganymede, Callisto, and Europa. The focus of both missions is to scrutinize the nature of these icy moons and characterize the conditions that may have led to the emergence of habitable environment for life. A particular aspect of both JUICE and Europa Clipper missions is the exploration of the icy crusts, which comprises a new and very focused objective for outer solar system missions. A good example however of such investigations has been presented by Cassini’s RADAR instrument. One of JUICE’s tasks is to characterize the structure and properties of the ice shell by probing the subsurface of Ganymede down to a depth of a few kilometers. An additional task of JUICE’s ice penetrating RIME and Clipper’s radar REASON is to obtain profiles of subsurface thermal, compositional, and structural horizons down to a maximum depth of 1 to 9 km depending on the crust’s properties. However, the interpretation of radar sounding experiments relies on the ability to decipher the backscattering patterns. The icy moons of Jupiter have been reported to be efficient backscatters of cm-wavelength radiations, showing polarization effects that must be due to factors other than the only single scattering process at the space-body surface interface. The identification of the characteristics of the backscattering radiation results from the superposition of backscattering layers with different electrical properties as a function of depth. Amongst the properties likely to modify the backscattering efficiency are: the amount of silicate (partial absorbers), the ice salinity, and the distribution of cracks present in the layer (inhomogeneity of the medium at size scales comparable to the radar wavelengths). Consequently, direct measurements of the dielectric values (electrical conductivity and permittivity) of an icy layer with properties controlled in the lab could unveil the backscattering efficiency of the sample. We provide here the first version of a database of measurements, following a number of laboratory experiments made at CAB-CSIC-INTA, in collaboration with UCM and CSIC-ITEFI (Please see abstracts EPSC Muñoz-Iglesias et al. and EPSC Gonzalez-Díaz et al.), collected and classified based on the parameters and properties of the different ice samples, which are manufactured to resemble the Jovian moon ice compositions. During the experiments, different conditions of T and P were applied and the recorded measurements of electrical properties were collected in this database of ‘ice behavior’. Since the next remote sensing data are not expected anytime before the arrival of JUICE and Europa Clipper (around 2030), the database provides us with the opportunity to compare with the current literature and the data available for the Jovian icy moons from previous missions, but also add information that is currently missing and relate that information to relative surface processes. The ice database would facilitate the interpretation of future radar sounding measurements, providing a better constrain on the true nature of ices of the surfaces of JUICE’s and Europa Clipper’s future targets.

SuperCam is a highly integrated remote-sensing instrumental suite for NASA’s Mars 2020 mission. It consists of a co-aligned combination of Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), Visible and In frared Spectroscopy (VISIR), together with sound recording (MIC) and high-magnification imaging techniques (RMI). They provide information on the mineralogy, geochemistry and mineral context around the Perseverance Rover. The calibration of this complex suite is a major challenge. Not only does each technique require its own standards or references, their combination also introduces new requirements to obtain optimal scientific output. Elemental composition, molecular vibrational features, fluorescence, morphology and texture provide a full picture of the sample with spectral information that needs to be co-aligned, correlated, and individually calibrated. The resulting hardware includes different kinds of targets, each one covering different needs of the instrument. Standards for imaging calibration, geological samples for mineral identification and chemometric calculations or spectral references to calibrate and eval uate the health of the instrument, are all included in the SuperCam Calibration Target (SCCT). The system also includes a specifically designed assembly in which the samples are mounted. This hardware allows the targets to survive the harsh environmental condi tions of the launch, cruise, landing and operation on Mars during the whole mission. Here we summarize the design, development, integration, verification and functional testing of the SCCT. This work includes some key results obtained to verify the scientific outcome of the SuperCam system., Proyecto MINECO Retos de la Sociedad. Ref. ESP2017-87690-C3-1-R

The ExoMars rover, scheduled to be launched in 2020, will be equipped with a novel and diverse payload. It will also include a drill to collect subsurface samples (from 0- to 2-m depth) and deliver them to the rover analytical laboratory, where it will be possible to perform combined science between instruments. For the first time, the exact same sample target areas will be investigated using complementary analytical methods—infrared spectrometry, Raman spectrometry, and laser desorption mass spectrometry—to establish mineralogical and organic chemistry composition. Fundamental for implementing this cooperative science strategy is the Raman Laser Spectrometer (RLS) calibration target (CT). The RLS CT features a polyethylene terephthalate disk used for RLS calibration and verification of the instrument during the mission. In addition, special patterns have been recorded on the RLS CT disk that the other instruments can detect and employ to determine their relative position. In this manner, the RLS CT ensures the spatial correlation between the three analytical laboratory instruments: MicrOmega, RLS, and MOMA. The RLS CT has been subjected to a series of tests to qualify it for space utilization and to characterize its behavior during the mission. The results from the joint work performed by the RLS and MicrOmega instrument teams confirm the feasibility of the “combined science” approach envisioned for ExoMars rover operations, whose science return is optimized when complementing the RLS and MicrOmega joint analysis with the autonomous RLS operation., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737); Spanish Ministerio de Economía y Competitividad (MINECO) under references ESP2014‐56138‐C3‐2‐R and ESP2107‐87690‐C3‐1‐R.

We present the hypothesis that microorganisms can change the freezing/melting curve of cold salty solutions by protein expression, as it is known that proteins can affect the liquid-to-ice transition, an ability that could be of ecological advantage for organisms on Earth and on Mars. We tested our hypothesis by identifying a suitable candidate, the well-known psycrophile and halotolerant bacteria Rhodococcus sp. JG3, and analyzing its response in culture conditions that included specific hygroscopic salts relevant to Mars-that is, highly concentrated magnesium perchlorate solutions of 20 wt % and 50 wt % Mg(ClO4)2 at both end members of the eutectic concentration (44 wt %)-and subfreezing temperatures (263 K and 253 K). Using a combination of techniques of molecular microbiology and aqueous geochemistry, we evaluated the potential roles of proteins over- or underexpressed as important players in different mechanisms for the adaptability of life to cold environments. We recorded the changes observed by micro-differential scanning calorimetry. Unfortunately, Rhodococcus sp. JG3 did not show our hypothesized effect on the melting characteristics of cold Mg-perchlorate solutions. However, the question remains as to whether our novel hypothesis that halophilic/psychrophilic bacteria or archaea can alter the freezing/melting curve of salt solutions could be validated. The null result obtained after analyzing just one case lays the foundation to continue the search for proteins produced by microorganisms that thrive in very cold, high-saline solutions, which would involve testing different microorganisms with different salt components. The immediate implications for the habitability of Mars are discussed., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)

Organic chemistry is ubiquitous in the Solar System, and both Mars and a number of icy satellites of the outer Solar System show substantial promise for having hosted or hosting life. Here, we propose a novel astrobiologically focused instrument suite that could be included as scientific payload in future missions to Mars or the icy moons: the Complex Molecules Detector, or CMOLD. CMOLD is devoted to determining different levels of prebiotic/biotic chemical and structural targets following a chemically general approach (i.e., valid for both terrestrial and nonterrestrial life), as well as their compatibility with terrestrial life. CMOLD is based on a microfluidic block that distributes a liquid suspension sample to three instruments by using complementary technologies: (1) novel microscopic techniques for identifying ultrastructures and cell-like morphologies, (2) Raman spectroscopy for detecting universal intramolecular complexity that leads to biochemical functionality, and (3) bioaffinity-based systems (including antibodies and aptamers as capture probes) for finding life-related and nonlife-related molecular structures. We highlight our current developments to make this type of instruments flight-ready for upcoming Mars missions: the Raman spectrometer included in the science payload of the ESAs Rosalind Franklin rover (Raman Laser Spectrometer instrument) to be launched in 2022, and the biomarker detector that was included as payload in the NASA Icebreaker lander mission proposal (SOLID instrument). CMOLD is a robust solution that builds on the combination of three complementary, existing techniques to cover a wide spectrum of targets in the search for (bio)chemical complexity in the Solar System., This work has been funded by the project “MarsFirstWater,” European Research Council Consolidator grant number 818602 to Alberto G. Fairén; the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER program projects no. ESP2015-69540-R, RTI2018-094368-B-I00, BIO2016-79618-R, and ESP2017-89053-C2-1-P; With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)