Astrobiology最新文献

{"title":"Information Transmission via Molecular Communication in Astrobiological Environments.","authors":"Manasvi Lingam","doi":"10.1089/ast.2023.0069","DOIUrl":"10.1089/ast.2023.0069","url":null,"abstract":"<p><p>The ubiquity of information transmission via molecular communication between cells is comprehensively documented on Earth; this phenomenon might even have played a vital role in the origin(s) and early evolution of life. Motivated by these considerations, a simple model for molecular communication entailing the diffusion of signaling molecules from transmitter to receiver is elucidated. The channel capacity <i>C</i> (maximal rate of information transmission) and an optimistic heuristic estimate of the actual information transmission rate <math><mi>ℐ</mi></math> are derived for this communication system; the two quantities, especially the latter, are demonstrated to be broadly consistent with laboratory experiments and more sophisticated theoretical models. The channel capacity exhibits a potentially weak dependence on environmental parameters, whereas the actual information transmission rate may scale with the intercellular distance <i>d</i> as <math><mi>ℐ</mi></math> ∝ <i>d</i>^-4 and could vary substantially across settings. These two variables are roughly calculated for diverse astrobiological environments, ranging from Earth's upper oceans (<i>C</i> ∼ 3.1 × 10³ bits/s; <math><mi>ℐ</mi></math> ∼ 4.7 × 10^-2 bits/s) and deep sea hydrothermal vents (<i>C</i> ∼ 4.2 × 10³ bits/s; <math><mi>ℐ</mi></math> ∼ 1.2 × 10^-1 bits/s) to the hydrocarbon lakes and seas of Titan (<i>C</i> ∼ 3.8 × 10³ bits/s; <math><mi>ℐ</mi></math> ∼ 2.6 × 10^-1 bits/s).</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138796043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biosignature Detection and MinION Sequencing of Antarctic Cryptoendoliths After Exposure to Mars Simulation Conditions.","authors":"Catherine Maggiori, Miguel Angel Fernández-Martínez, Louis-Jacques Bourdages, Laura Sánchez-García, Mercedes Moreno-Paz, Jesús Manuel Sobrado, Daniel Carrizo, Álvaro Vicente-Retortillo, Jacqueline Goordial, Lyle G Whyte","doi":"10.1089/ast.2023.0025","DOIUrl":"10.1089/ast.2023.0025","url":null,"abstract":"<p><p>In the search for life in our Solar System, Mars remains a promising target based on its proximity and similarity to Earth. When Mars transitioned from a warmer, wetter climate to its current dry and freezing conditions, any putative extant life probably retreated into habitable refugia such as the subsurface or the interior of rocks. Terrestrial cryptoendolithic microorganisms (<i>i.e.,</i> those inhabiting rock interiors) thus represent possible modern-day Mars analogs, particularly those from the hyperarid McMurdo Dry Valleys in Antarctica. As DNA is a strong definitive biosignature, given that there is no known abiotic chemistry that can polymerize nucleobases, we investigated DNA detection with MinION sequencing in Antarctic cryptoendoliths after an ∼58-sol exposure in MARTE, a Mars environmental chamber capable of simulating martian temperature, pressure, humidity, ultraviolet (UV) radiation, and atmospheric composition, in conjunction with protein and lipid detection. The MARTE conditions resulted in changes in community composition and DNA, proteins, and cell membrane-derived lipids remained detectable postexposure. Of the multitude of extreme environmental conditions on Mars, UV radiation (specifically UVC) is the most destructive to both cells and DNA. As such, we further investigated if a UVC exposure corresponding to ∼278 martian years would impede DNA detection via MinION sequencing. The MinION was able to successfully detect and sequence DNA after this UVC radiation exposure, suggesting its utility for life detection in future astrobiology missions focused on finding relatively recently exposed biomarkers inside possible martian refugia.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139048282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Sulfur-Rich Microbial Organic Matter in Jurassic Carbonates Using Laser-Assisted Mass Spectrometry.","authors":"Siveen Thlaijeh, Kevin Lepot, Yvain Carpentier, Armelle Riboulleau, Dumitru Duca, Marin Vojkovic, Anuradha Tewari, Johan Sarazin, Mathilde Bon, Nicolas Nuns, Nicolas Tribovillard, Cristian Focsa","doi":"10.1089/ast.2023.0008","DOIUrl":"10.1089/ast.2023.0008","url":null,"abstract":"<p><p>Laser desorption-ionization mass spectrometry (MS) shows great potential for <i>in situ</i> molecular analysis of planetary surfaces and microanalysis of space-returned samples or (micro)fossils. Coupled with pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) in ESA's ExoMars project, this technique could help assess further the origin of sulfur-bearing organic matter (OM) recently detected on Mars. To unravel this potential, we analyzed sulfurized microbial OM from ca. 150 million year-old carbonates with laser desorption-ionization mass spectrometry (single- and two-step: LDI-MS and L2MS), in comparison with time-of-flight secondary-ion mass spectrometry (ToF-SIMS), gas chromatography-mass spectrometry (GC-MS), and Py-GC-MS. We show that LDI-MS and L2MS readily detect sulfur-bearing moieties such as (alkyl)thiophenes and (alkyl)benzothiophenes. The mineral matrix, however, made the identification of sulfur-bearing molecules challenging in our L2MS experiment. The dominance of small aromatic hydrocarbons (≤14 carbons) in the LDI-MS and L2MS of the extracted soluble and insoluble OM and of the bulk rock is consistent with the low thermal maturity of the sediment and contrasts with the predominance of larger polycyclic aromatic structures commonly observed in meteorites with these techniques. We detected inorganic ions, in particular VO⁺, in demineralized OM that likely originate from geoporphyrins, which derive from chlorophylls during sediment diagenesis. Finally, insoluble OM yielded distinct compositions compared with extracted soluble OM, with a greater abundance of ions of mass-to-charge ratio (<i>m</i>/<i>z</i>) over 175 and additional N-moieties. This highlights the potential of laser-assisted MS to decipher the composition of macromolecular OM, in particular to investigate the preservation of biomacromolecules in microfossils. Studies comparing diverse biogenic and abiogenic OM are needed to further assess the use of this technique to search for biosignatures.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138796037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Future of the Search for Life: Workshop Report.","authors":"Marc Neveu, Richard Quinn, Laura M Barge, Kathleen L Craft, Christopher R German, Stephanie Getty, Christopher Glein, Macarena Parra, Aaron S Burton, Francesca Cary, Andrea Corpolongo, Lucas Fifer, Andrew Gangidine, Diana Gentry, Christos D Georgiou, Zaid Haddadin, Craig Herbold, Aila Inaba, Seán F Jordan, Hemani Kalucha, Pavel Klier, Kas Knicely, An Y Li, Patrick McNally, Maëva Millan, Neveda Naz, Chinmayee Govinda Raj, Peter Schroedl, Jennifer Timm, Ziming Yang","doi":"10.1089/ast.2022.0158","DOIUrl":"10.1089/ast.2022.0158","url":null,"abstract":"<p><p>The 2-week, virtual Future of the Search for Life science and engineering workshop brought together more than 100 scientists, engineers, and technologists in March and April 2022 to provide their expert opinion on the interconnections between life-detection science and technology. Participants identified the advances in measurement and sampling technologies they believed to be necessary to perform <i>in situ</i> searches for life elsewhere in our Solar System, 20 years or more in the future. Among suggested measurements for these searches, those pertaining to three potential indicators of life termed \"dynamic disequilibrium,\" \"catalysis,\" and \"informational polymers\" were identified as particularly promising avenues for further exploration. For these three indicators, small breakout groups of participants identified measurement needs and knowledge gaps, along with corresponding constraints on sample handling (acquisition and processing) approaches for a variety of environments on Enceladus, Europa, Mars, and Titan. Despite the diversity of these environments, sample processing approaches all tend to be more complex than those that have been implemented on missions or envisioned for mission concepts to date. The approaches considered by workshop breakout groups progress from nondestructive to destructive measurement techniques, and most involve the need for fluid (especially liquid) sample processing. Sample processing needs were identified as technology gaps. These gaps include technology and associated sampling strategies that allow the preservation of the thermal, mechanical, and chemical integrity of the samples upon acquisition; and to optimize the sample information obtained by operating suites of instruments on common samples. Crucially, the interplay between science-driven life-detection strategies and their technological implementation highlights the need for an unprecedented level of payload integration and extensive collaboration between scientists and engineers, starting from concept formulation through mission deployment of life-detection instruments and sample processing systems.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139477715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Origin and Early Evolution of Life: Homochirality Emergence in Prebiotic Environments.","authors":"Carolina Chieffo, Anastasiia Shvetsova, Fryni Skorda, Augustin Lopez, Michele Fiore","doi":"10.1089/ast.2023.0007","DOIUrl":"10.1089/ast.2023.0007","url":null,"abstract":"<p><p>Homochirality is one of the signatures of life. Numerous geological and prebiotic chemistry studies have proved that disordered soups containing small organic molecules, gases, liquids, and minerals (such as those containing phosphorous) yielded racemic mixtures of building blocks for biomolecule assembly. Polymers obtained from these bricks should have been enantiopure with functional properties similar to modern biomolecules or heterochiral with some functions such as catalyzing a chemical transformation unspecifically. Up until now, no clues have been found as to how symmetry breaking occurred. In this review, we highlight the principal achievements regarding the emergence of homochirality during the prebiotic synthesis of building blocks. Furthermore, we tried to focus on approaches based on prebiotic systems chemistry (bottom-up) and laboratory scales to simulate plausible prebiotic messy environments for the emergence of life. We aim with this review to assemble, even partially, the puzzle pieces of the origin of life regarding the relevant phenomenon of homochiral symmetry breaking.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49673807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Life Detection and Microbial Biomarker Profiling with Signs of Life Detector-Life Detector Chip During a Mars Drilling Simulation Campaign in the Hyperarid Core of the Atacama Desert.","authors":"Mercedes Moreno-Paz, Rita Sofia Dos Santos Severino, Laura Sánchez-García, Juan Manuel Manchado, Miriam García-Villadangos, Jacobo Aguirre, Miguel Angel Fernández-Martínez, Daniel Carrizo, Linda Kobayashi, Arwen Dave, Kim Warren-Rhodes, Alfonso Davila, Carol R Stoker, Brian Glass, Víctor Parro","doi":"10.1089/ast.2021.0174","DOIUrl":"10.1089/ast.2021.0174","url":null,"abstract":"<p><p>The low organic matter content in the hyperarid core of the Atacama Desert, together with abrupt temperature shifts and high ultraviolet radiation at its surface, makes this region one of the best terrestrial analogs of Mars and one of the best scenarios for testing instrumentation devoted to <i>in situ</i> planetary exploration. We have operated remotely and autonomously the SOLID-LDChip (Signs of Life Detector-Life Detector Chip), an antibody microarray-based sensor instrument, as part of a rover payload during the 2019 NASA Atacama Rover Astrobiology Drilling Studies (ARADS) Mars drilling simulation campaign. A robotic arm collected drilled cuttings down to 80 cm depth and loaded SOLID to process and assay them with LDChip for searching for molecular biomarkers. A remote science team received and analyzed telemetry data and LDChip results. The data revealed the presence of microbial markers from Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria, Firmicutes, and Cyanobacteria to be relatively more abundant in the middle layer (40-50 cm). In addition, the detection of several proteins from nitrogen metabolism indicates a pivotal role in the system. These findings were corroborated and complemented on \"returned samples\" to the lab by a comprehensive analysis that included DNA sequencing, metaproteomics, and a metabolic reconstruction of the sampled area. Altogether, the results describe a relatively complex microbial community with members capable of nitrogen fixation and denitrification, sulfur oxidation and reduction, or triggering oxidative stress responses, among other traits. This remote operation demonstrated the high maturity of SOLID-LDChip as a powerful tool for remote <i>in situ</i> life detection for future missions in the Solar System.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10825288/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71477512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Mission Simulating the Search for Life on Mars with Automated Drilling, Sample Handling, and Life Detection Instruments Performed in the Hyperarid Core of the Atacama Desert, Chile.","authors":"Carol R Stoker, Brian J Glass, Thomas R Stucky, Arwen I Dave, Linda T Kobayashi, Richard C Quinn, Mercedes Moreno-Paz, Laura Sánchez-García, Maria F Mora, Florian Kehl, Víctor Parro, Peter A Willis, Alfonso Davila, Eldar Noe Dobrea, Jon C Rask, Daniel Ricardo","doi":"10.1089/ast.2022.0055","DOIUrl":"10.1089/ast.2022.0055","url":null,"abstract":"<p><p>We report on a field demonstration of a rover-based drilling mission to search for biomolecular evidence of life in the arid core of the Atacama Desert, Chile. The KREX2 rover carried the Honeybee Robotics 1 m depth The Regolith and Ice Drill for Exploration of New Terrains (TRIDENT) drill and a robotic arm with scoop that delivered subsurface fines to three flight prototype instruments: (1) The Signs of Life Detector (SOLID), a protein and biomolecule analyzer based on fluorescence sandwich microarray immunoassay; (2) the Planetary <i>In Situ</i> Capillary Electrophoresis System (PISCES), an amino acid analyzer based on subcritical water extraction coupled to microchip electrophoresis analysis; and (3) a Wet Chemistry Laboratory cell to measure soluble ions using ion selective electrodes and chronopotentiometry. A California-based science team selected and directed drilling and sampling of three sites separated by hundreds of meters that included a light-toned basin area showing evidence of aqueous activity surrounded by a rocky desert pavement. Biosignatures were detected in basin samples collected at depths ranging from 20 to 80 cm but were not detected in the surrounding area. Subsurface stratigraphy of the units drilled was interpreted from drill sensor data as fine-scale layers of sand/clay sediments interspersed with layers of harder material in the basins and a uniform subsurface composed of course-to-fine sand in the surroundings. The mission timeline and number of commands sent to accomplish each activity were tracked. The deepest sample collected (80 cm) required 55 commands, including drilling and delivery to three instruments. Elapsed time required for drilling and sample handling was less than 3 hours to collect sample from 72 cm depth, including time devoted to recovery from a jammed drill. The experiment demonstrated drilling, sample transfer technologies, and instruments that accomplished successful detection of biomolecular evidence of life in one of the most biologically sparse environments on Earth.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10750310/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49673805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bridging Place-Based Astrobiology Education with Genomics, Including Descriptions of Three Novel Bacterial Species Isolated from Mars Analog Sites of Cultural Relevance.","authors":"Rebecca D Prescott, Yvonne L Chan, Eric J Tong, Fiona Bunn, Chiyoko T Onouye, Christy Handel, Chien-Chi Lo, Karen Davenport, Shannon Johnson, Mark Flynn, Jennifer A Saito, Herb Lee, Kaleomanuiwa Wong, Brittany N Lawson, Kayla Hiura, Kailey Sager, Mia Sadones, Ethan C Hill, Derek Esibill, Charles S Cockell, Rosa Santomartino, Patrick S G Chain, Alan W Decho, Stuart P Donachie","doi":"10.1089/ast.2023.0072","DOIUrl":"10.1089/ast.2023.0072","url":null,"abstract":"<p><p>Democratizing genomic data science, including bioinformatics, can diversify the STEM workforce and may, in turn, bring new perspectives into the space sciences. In this respect, the development of education and research programs that bridge genome science with \"place\" and world-views specific to a given region are valuable for Indigenous students and educators. Through a multi-institutional collaboration, we developed an ongoing education program and model that includes Illumina and Oxford Nanopore sequencing, free bioinformatic platforms, and teacher training workshops to address our research and education goals through a place-based science education lens. High school students and researchers cultivated, sequenced, assembled, and annotated the genomes of 13 bacteria from Mars analog sites with cultural relevance, 10 of which were novel species. Students, teachers, and community members assisted with the discovery of new, potentially chemolithotrophic bacteria relevant to astrobiology. This joint education-research program also led to the discovery of species from Mars analog sites capable of producing <i>N</i>-acyl homoserine lactones, which are quorum-sensing molecules used in bacterial communication. Whole genome sequencing was completed in high school classrooms, and connected students to funded space research, increased research output, and provided culturally relevant, place-based science education, with participants naming three novel species described here. Students at St. Andrew's School (Honolulu, Hawai'i) proposed the name <i>Bradyrhizobium prioritasuperba</i> for the type strain, BL16A^T, of the new species (DSM 112479^T = NCTC 14602^T). The nonprofit organization Kauluakalana proposed the name <i>Brenneria ulupoensis</i> for the type strain, K61^T, of the new species (DSM 116657^T = LMG = 33184^T), and Hawai'i Baptist Academy students proposed the name <i>Paraflavitalea speifideiaquila</i> for the type strain, BL16E^T, of the new species (DSM 112478^T = NCTC 14603^T).</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10750312/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138796020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>In Situ</i> Real-Time Monitoring for Aseptic Drilling: Lessons Learned from the Atacama Rover Astrobiology Drilling Studies Contamination Control Strategy and Implementation and Application to the Icebreaker Mars Life Detection Mission.","authors":"Rosalba Bonaccorsi, Brian Glass, Mercedes Moreno-Paz, Miriam García-Villadangos, Kimberley Warren-Rhodes, Victor Parro, Juan Manuel Manchado, Mary Beth Wilhelm, Christopher P McKay","doi":"10.1089/ast.2022.0133","DOIUrl":"10.1089/ast.2022.0133","url":null,"abstract":"<p><p>In 2019, the Atacama Rover Astrobiology Drilling Studies (ARADS) project field-tested an autonomous rover-mounted robotic drill prototype for a 6-Sol life detection mission to Mars (Icebreaker). ARADS drilled Mars-like materials in the Atacama Desert (Chile), one of the most life-diminished regions on Earth, where mitigating contamination transfer into life-detection instruments becomes critical. Our Contamination Control Strategy and Implementation (CCSI) for the Sample Handling and Transfer System (SHTS) hardware (drill, scoop and funnels) included out-of-simulation protocol testing (out-of-sim) for hardware decontamination and verification during the 6-Sol simulation (in-sim). The most effective five-step decontamination combined safer-to-use sterilants (3%_hydrogen-peroxide-activated 5%_sodium-hypochlorite), and <i>in situ</i> real-time verification by adenosine triphosphate (ATP) and Signs of Life Detector (SOLID) Fluorescence Immunoassay for characterization hardware bioburden and airborne contaminants. The 20- to 40-min protocol enabled a 4-log bioburden reduction down to <0.1 fmoles ATP detection limit (funnels and drill) to 0.2-0.7 fmoles (scoop) of total ATP. The (post-cleaning) hardware background was 0.3 to 1-2 attomoles ATP/cm² (cleanliness benchmark background values) equivalent to ca. 1-10 colony forming unit (CFU)/cm². Further, 60-100% of the in-sim hardware background was ≤3-4 bacterial cells/cm², the threshold limit for Class <7 aseptic operations. Across the six Sols, the flux of airborne contaminants to the drill sites was ∼5 and ∼22 amoles ATP/(cm²·day), accounting for an unexpectedly high Fluorescence Intensity (FI) signal (FI: ∼6000) against aquatic cyanobacteria, but negligible anthropogenic contribution. The SOLID immunoassay also detected microorganisms from multiple habitats across the Atacama Desert (anoxic, alkaline/acidic microenvironments in halite fields, playas, and alluvial fans) in both airborne and post-cleaning hardware background. Finally, the hardware ATP background was 40-250 times lower than the ATP in cores. Similarly, the FI peaks (FI_max) against the microbial taxa and molecular biomarkers detected in the post-cleaned hardware (FI: ∼1500-1600) were 5-10 times lower than biomarkers in drilled sediments, excluding significant interference with putative biomarker found in cores. Similar protocols enable the acquisition of contamination-free materials for ultra-sensitive instruments analysis and the integrity of scientific results. Their application can augment our scientific knowledge of the distribution of cryptic life on Mars-like grounds and support life-detection robotic and human-operated missions to Mars.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138827981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Atacama Rover Astrobiology Drilling Studies (ARADS) Project.","authors":"B Glass, D Bergman, V Parro, L Kobayashi, C Stoker, R Quinn, A Davila, P Willis, W Brinckerhoff, K Warren-Rhodes, M B Wilhelm, L Caceres, J DiRuggiero, K Zacny, M Moreno-Paz, A Dave, S Seitz, A Grubisic, M Castillo, R Bonaccorsi","doi":"10.1089/ast.2022.0126","DOIUrl":"10.1089/ast.2022.0126","url":null,"abstract":"<p><p>With advances in commercial space launch capabilities and reduced costs to orbit, humans may arrive on Mars within a decade. Both to preserve any signs of past (and extant) martian life and to protect the health of human crews (and Earth's biosphere), it will be necessary to assess the risk of cross-contamination on the surface, in blown dust, and into the near-subsurface (where exploration and resource-harvesting can be reasonably anticipated). Thus, evaluating for the presence of life and biosignatures may become a critical-path Mars exploration precursor in the not-so-far future, circa 2030. This Special Collection of papers from the Atacama Rover Astrobiology Drilling Studies (ARADS) project describes many of the scientific, technological, and operational issues associated with searching for and identifying biosignatures in an extreme hyperarid region in Chile's Atacama Desert, a well-studied terrestrial Mars analog environment. This paper provides an overview of the ARADS project and discusses in context the five other papers in the ARADS Special Collection, as well as prior ARADS project results.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10750311/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138486562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}