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The given document is a list of various scientific articles and research papers related to topics such as Martian mineralogy, the habitability of Mars and Europa, the survival of bacteria in Martian conditions, the adaptation mechanisms of halophilic archaea, and the analysis of gene expression in different organisms. The articles cover a range of subjects including astrobiology, RNA sequencing, osmotic stress, and the effects of environmental factors on microbial life. The document provides a comprehensive collection of scientific literature that can be useful for library patrons conducting research on these specific topics. [Extracted from the article]

As the exploration of Mars and other worlds for signs of life has increased, the need for a common nomenclature and consensus has become significantly important for proper identification of nonterrestrial/non-Earth biology, biogenic structures, and chemical processes generated from biological processes. The fact that Earth is our single data point for all life, diversity, and evolution means that there is an inherent bias toward life as we know it through our own planet's history. The search for life "as we don't know it" then brings this bias forward to decision-making regarding mission instruments and payloads. Understandably, this leads to several top-level scientific, theoretical, and philosophical questions regarding the definition of life and what it means for future life detection missions. How can we decide on how and where to detect known and unknown signs of life with a single biased data point? What features could act as universal biosignatures that support Darwinian evolution in the geological context of nonterrestrial time lines? The purpose of this article is to generate an improved nomenclature for terrestrial features that have mineral/microbial interactions within structures and to confirm which features can only exist from life (biotic), features that are modified by biological processes (biogenic), features that life does not affect (abiotic), and properties that can exist or not regardless of the presence of biology (abiogenic). These four categories are critical in understanding and deciphering future returned samples from Mars, signs of potential extinct/ancient and extant life on Mars, and in situ analyses from ocean worlds to distinguish and separate what physical structures and chemical patterns are due to life and which are not. Moreover, we discuss hypothetical detection and preservation environments for extant and extinct life, respectively. These proposed environments will take into account independent active and ancient in situ detection prospects by using previous planetary exploration studies and discuss the geobiological implications within an astrobiological context. [ABSTRACT FROM AUTHOR]

Polygonal features in a ∼250 million-year-old Permian evaporitic deposit were investigated for their geological and organic content to test the hypothesis that they could preserve the signature of ancient habitable conditions and biological activity. Investigations on evaporitic rock were carried out as part of the MIne Analog Research (MINAR) project at Boulby Mine, the United Kingdom. The edges of the polygons have a higher clay content and contain higher abundances of minerals such as quartz and microcline, and clays such as illite and chlorite, compared with the interior of polygons, suggesting that the edges were preferred locations for the accumulation of weathering products during their formation. The mineral content and its strontium isotope ratio suggest that the material is from continental weathering at the borders of the Permian Zechstein Sea. The edges of the polygons contain material with mean δ13C and δ15N values of −20.8 and 5.3, respectively. Lipids, including alkanes and hopanes, were extracted from the interior and edges of the polygons, which are inferred to represent organic material entrained in the evaporites when they were formed. The presence of long-chain alkanes (C20–C35) that lack a carbon preference, low abundances of C23–C29 hopanes, and lack of marine, evaporitic, or thermal maturity indicators show that lipid biomarkers were, at least in part, potentially derived from a continental source and have not undergone significant thermal maturation since deposition. Lipid extractions using weak acids revealed significantly more lipids than those without acid, potentially indicating that encapsulation was not the only type of preservation mechanism occurring in Boulby salts. These data demonstrate the potential for ancient evaporites and their polygons to preserve information on local geological conditions, ancient habitability, and evidence of life. The data show that analogous martian evaporitic deposits are good targets for future life detection missions and the investigation of ancient martian habitability. [ABSTRACT FROM AUTHOR]

Hydrothermal vents, which are highly plausible habitable environments for life and of interest for some origin-of-life scenarios, may exist on icy moons such as Europa or Enceladus in addition to Earth. Some hydrothermal vent chimney structures are extremely porous and friable, making their reconstruction in the lab challenging (e.g., brucite or saponite in alkaline hydrothermal settings). Here, we present the results from our efforts to reconstruct a simplified chimney structure directly out of mineral powder using binder jet additive manufacturing. Olivine sand was chosen for this initial method development effort since it represents a naturally occurring seafloor material and is inexpensively available in large quantities in powder form. The crystal structure of olivine used for the print was not modified during the process, as confirmed by powder X-ray diffraction (XRD). To characterize the microstructure of our 3D printed precipitates, we used computed tomography (CT) X-ray scan techniques. We also evaluated a chimney precipitate from a sample collected from the Prony Hydrothermal Field (PHF), southern New Caledonia, an alkaline system driven by serpentinization with mineralogy composed of brucite and carbonates. While not directly comparable from a mineralogical point of view, the microstructure and porosity of both precipitates was similar, suggesting that our 3D printing technique may be a valuable tool for future astrobiology research on hydrothermal vent precipitates. [ABSTRACT FROM AUTHOR]

It is now routinely possible to sequence and recover microbial genomes from environmental samples. To the degree it is feasible to assign transcriptional and translational functions to these genomes, it should be possible, in principle, to largely understand the complete molecular inputs and outputs of a microbial community. However, gene-based tools alone are presently insufficient to describe the full suite of chemical reactions and small molecules that compose a living cell. Metabolomic tools have developed quickly and now enable rapid detection and identification of small molecules within biological and environmental samples. The convergence of these technologies will soon facilitate the detection of novel enzymatic activities, novel organisms, and potentially extraterrestrial life-forms on solar system bodies. This review explores the methodological problems and scientific opportunities facing researchers who hope to apply metabolomic methods in astrobiology-related fields, and how present challenges might be overcome. [ABSTRACT FROM AUTHOR]