The moons of Jupiter and Saturn, such as Europa and Enceladus, are strong candidates for the search for life outside of Earth. Together with the use of direct observational methods, physical and chemical processes that take place on icy moons may be studied on planetary field analogs, that is, on similar reachable locations on Earth. Fieldwork performed on planetary field analogs can test protocols and technology that may be applied on future space missions to extraterrestrial environments. The Arctic is a strong candidate for such studies. This study assesses a spectroscopic protocol for biosignature detection in the Arctic, as a proxy to icy moons. Samples of ice and the water underneath were collected by our team in different locations at and nearby Hudson Bay, Canada, and spectroscopic analysis detected the presence of humic acid in all the samples. On the contrary, biosignatures such as amino acids and beta-carotene may have been present in concentrations below the limit of detection of the equipment used. With proper optimization, it will be possible to implement this simple protocol that relies on lightweight equipment in future space missions to icy moons.

Revalorized olive waste impacts root microbiome.Root microbiome modulates plant-induced defense.Insect's exudate simulates the pest attack.The objective of this study was to investigate the combined effect of soil amendments and pest attack on plant-induced defense and their impact on a biological control agent's behavior. The effects of olive mill wastes revalorized through vermicomposting on the aboveground tri-trophic interactions among olive trees (Olea europaea), the olive seed-feeder, Prays oleae, and its natural predator, Chrysoperla carnea, were evaluated. The findings demonstrate that soil nitrogen and organic carbon levels, in conjunction with fungal diversity and functionality within olive roots, exert a significant influence on the volatile compounds emitted by the plant under attack that are most appealing to C. carnea. Moreover, the attractiveness of aerial volatiles was found to correlate with soil organic carbon content and the taxonomic and functional diversity of both bacteria and fungi in the olive root system. It is worthy of note that three particular volatile compounds, namely 5-hepten-2-one-6-methyl, acetic acid and nonanal, were consistently observed to attract C. carnea. These findings highlight the potential of soil amendments to enhance biological control strategies. Future research should prioritise the validation the greenhouse findings through large-scale field trials and the assessment of the practical applications of soil amendments in pest management programmes.

Although cicadas have traditionally been considered pests of little or no importance, in recent decades, an increase in damages is being recorded in olive groves of southern Spain. New agricultural practices that affect soil management are behind it. During 2024, intensive sampling has been carried out in an organic grove with herbaceous cover (VC2), and in a second one with mixed vegetation cover (VC1, in which the crushed remains of the annual pruning are added). In both ecological groves, inventories of the vegetation have been carried out, as well as intensive sampling in the olive canopy, with the densities of oviposition injuries being recorded and compared with respect to conventional management (CONV). The objectives of this study are to compare the three managements based on the density of oviposition injuries, to determine the priority areas for cicadas' oviposition within the trees; and to develop a sampling method to assess damage over large areas. The results show significant increases in the density of injuries in organic groves, with maximum values recorded in the olive grove with mixed cover. Oviposition injuries show an altitudinal gradient distribution, with maximum values in the lower zone of the trees. The factors involved are discussed.

The development of environmentally friendly control methods to mitigate the severe damages caused by Phytophthora cinnamomi in the Mediterranean climate-type ecosystems is essential. In this way, crop waste and by-products which represent between 13 and 65% of agriculture production, are a rich source of bioactive compounds with antifungal and biocide activity. The main objective of this work was to determine the biocide activity against P. cinnamomi of three organic extracts. These extracts enriched in bioactive compounds come from residues of asparagus (Asp) and olive crops (Oliv and OH, from fruits and leaves respectively). They were evaluated at two doses (0.15 and 0.10%) on the mycelial growth and sporangial production of P. cinnamomi by in vitro experiments. Mycelial growth and sporangial production were significant reduced from the three plant extracts at the two doses tested, reaching a total inhibition with Asp at both doses. In general, no phytotoxicity symptoms were observed on seed germination and plant development, except for a plant yield reduction in the substrate treated with Oliv and Asp at the highest dose. In experiments performed in artificially infested soil, Asp induced a reduction of chlamydospores viability greater than 75% compared to unamended soil. Additionally, in planta experiments showed a significant reduction in plant mortality in substrate amended with OH. These results suggest that soil application of Asp and OH can limit P. cinnamomi infectivity and survival, setting the first steps to develop a sustainable method to control the root disease based on agricultural waste circular economy.

In this study, we calculated the travel times of a thermal probe that descends through Europa's ice shell. The ice column is simplified to a conductive layer. Using a cellular automaton model, the descent of the probe was simulated by tracking temperature changes, with cell interaction dictated by heat conduction and cell state transition rules determined by cell temperatures. Validation tests, including a soil column simulation, and comparison with experimental data, support the reliability of the model. Simulations were performed with 2 different cell sizes, 19 constant probe temperatures, and 5 ice thermal conductivities. A smaller cell size ( Delta z=3 mm) produced shorter travel times (between 22 days for a probe temperature Tp=600K and similar to 4 years for Tp=280K) than a larger cell size ( Delta z=1 m), which produced travel times between 27 years ( Tp= 600K) and similar to 103 years ( Tp= 280K). The ice shell's thermal conductivity has a modest impact on descent times. The results are generally consistent with previous approaches that used more detailed probe engineering considerations. These results suggest that a probe relying solely on heat production may traverse Europa's conductive ice shell within a mission's timeframe.

Perchlorates have been found in the regolith of Mars and the Moon, in the ice of Europa, and in meteorites. Studying the processes of formation and destruction of these compounds is important both for understanding the geological and climatic evolution of a number of planets and bodies of the Solar System, and for assessing their habitability. To date, a number of processes for the synthesis of perchlorates under Martian conditions have been proposed, but these do not explain the perchlorate concentrations observed in the regolith and are not applicable to atmosphereless bodies, in particular Europa. We have studied the processes of synthesis and destruction of perchlorates during irradiation of ice and regolith models with high-energy electrons under conditions of low temperature (-50 degrees C) and in the absence of an atmosphere (at a pressure of 0.01 mbar). The data obtained indicate that perchlorates can be efficiently synthesized in the regolith of Mars and the surface layer of Europa ice under the influence of irradiation in the absence of a liquid phase or an atmosphere.

Subsurface exploration of ice-covered planets and moons presents communications challenges because of the need to communicate through kilometers of ice. The objective of this task is to develop the capability to wirelessly communicate through kilometers of ice and thus complement the potentially failure-prone tethers deployed behind an ice-penetrating probe on Ocean Worlds. In this paper, the preliminary work on the development of wireless deep-ice communication is presented and discussed. The communication test and acoustic attenuation measurements in ice have been made by embedding acoustic transceivers in glacial ice at the Matanuska Glacier, Anchorage, Alaska. Field test results show that acoustic communication is viable through ice, demonstrating the transmission of data and image files in the 13-18 kHz band over 100 m. The results suggest that communication over many kilometers of ice thickness could be feasible by employing reduced transmitting frequencies around 1 kHz, though future work is needed to better constrain the likely acoustic attenuation properties through a refrozen borehole.

Growing evidence of the potential habitability of Ocean Worlds across our solar system is motivating the advancement of technologies capable of detecting life as we know it-sharing a common ancestry or physicochemical origin with life on Earth-or don't know it, representing a distinct emergence of life different than our one known example. Here, we propose the Electronic Life-detection Instrument for Enceladus/Europa (ELIE), a solid-state single-molecule instrument payload that aims to search for life based on the detection of amino acids and informational polymers (IPs) at the parts per billion to trillion level. As a first proof-of-principle in a laboratory environment, we demonstrate the single-molecule detection of the amino acid L-proline at a 10 mu M concentration in a compact system. Based on ELIE's solid-state quantum electronic tunneling sensing mechanism, we further propose the quantum property of the HOMO-LUMO gap (energy difference between a molecule's highest energy-occupied molecular orbital and lowest energy-unoccupied molecular orbital) as a novel metric to assess amino acid complexity. Finally, we assess the potential of ELIE to discriminate between abiotically and biotically derived alpha-amino acid abundance distributions to reduce the false positive risk for life detection. Nanogap technology can also be applied to the detection of nucleobases and short sequences of IPs such as, but not limited to, RNA and DNA. Future missions may utilize ELIE to target preserved biosignatures on the surface of Mars, extant life in its deep subsurface, or life or its biosignatures in a plume, surface, or subsurface of ice moons such as Enceladus or Europa. One-Sentence Summary: A solid-state nanogap can determine the abundance distribution of amino acids, detect nucleic acids, and shows potential for detecting life as we know it and life as we don't know it.

The surface morphology of airless, ice-covered moons of the outer solar system, such as Europa, Enceladus, and Callisto, is not well known at centimeter- to meter-scales. Ice and snow erode differently on such worlds in part because sublimation is the dominant process. On Earth, ice penitentes have been observed in sublimation-driven environments, and may provide a guide for similar formations on ice-covered worlds. Penitentes are blade-like snow features observed on Earth in high-altitude, low-latitude snowfields. Models of penitente formation on Earth break down within the free-molecular regime of airless bodies, leaving a major gap in understanding whether such morphologies can form on their surfaces. To investigate the morphologic evolution of icy bodies, we developed a Sublimation Monte Carlo (SMC) model that enables a numerical approach to modeling exosphere-surface interactions at free-molecular conditions. The SMC model uses Monte Carlo tracking of molecules emitted from the surface to determine the net molecular interchange that drives surface changes. We validated results against experiments, matching the evolution of pre-formed penitentes as they receded in height and became less pronounced. Our results reveal the importance of molecular redeposition on topology, indicating that the stable morphology of isothermal topographies is a planar morphology on regions of net sublimation, regardless of initial surface shape. A study of parametrically varying temperature profiles for sinusoidal penitentes resulted in the following requirement for penitente growth: the trough temperature must exceed the peak temperature by a threshold value, which notably depends on the surface aspect ratio and peak temperature.

Sodium chloride is expected to be found on many of the surfaces of icy moons like Europa and Ganymede. However, spectral identification remains elusive as the known NaCl-bearing phases cannot match current observations, which require higher number of water of hydration. Working at relevant conditions for icy worlds, we report the characterization of three hyperhydrated sodium chloride (SC) hydrates, and refined two crystal structures [2NaCl center dot 17H(2)O (SC8.5); NaCl center dot 13H(2)O (SC13)]. We found that the dissociation of Na+ and Cl- ions within these crystal lattices allows for the high incorporation of water molecules and thus explain their hyperhydration. This finding suggests that a great diversity of hyperhydrated crystalline phases of common salts might be found at similar conditions. Thermodynamic constraints indicate that SC8.5 is stable at room pressure below 235 K, and it could be the most abundant NaCl hydrate on icy moon surfaces like Europa, Titan, Ganymede, Callisto, Enceladus, or Ceres. The finding of these hyperhydrated structures represents a major update to the H2O-NaCl phase diagram. These hyperhydrated structures provide an explanation for the mismatch between the remote observations of the surface of Europa and Ganymede and previously available data on NaCl solids. It also underlines the urgent need for mineralogical exploration and spectral data on hyperhydrates at relevant conditions to help future icy world exploration by space missions.