Astrobiology最新文献

{"title":"Experimental Models on the Prebiotic Formation of Biopolymer Building Blocks.","authors":"César Menor-Salván, Marta Ruiz-Bermejo","doi":"10.1177/15311074251365950","DOIUrl":"https://doi.org/10.1177/15311074251365950","url":null,"abstract":"<p><p>The scientific study of the origins of life is a deep pursuit that exists at the intersection of multiple disciplines. Prebiotic chemistry focuses on understanding how biopolymer building blocks such as amino acids, nucleotides, and sugars emerged and how their chemical and structural space evolves toward life (chemical evolution). Simulation experiments have been essential for exploring plausible pathways for the origin of building blocks under early Earth conditions and planetary environments. Key examples include the seminal Miller-Urey experiment and the polymerization of hydrogen cyanide. Research highlights the role of environmental cycles and geochemistry in shaping the prebiotic chemical space. These processes facilitated the condensation and stabilization of biopolymer precursors, particularly in terrestrial or small-pond scenarios. Noncanonical building blocks, including triazines and alternative amino acids, may have contributed to proto-biopolymer formation. This expands our understanding of chemical evolution. Despite significant progress, challenges remain, particularly in understanding nucleoside formation and the transition to modern biopolymers. This review provides a general overview of the prebiotic formation of biopolymer building blocks and examines both classic and seminal experiments and recent experimental approaches. Insights provided by extraterrestrial samples, such as carbonaceous meteorites and asteroids, also contribute to offering a comprehensive perspective on abiogenesis.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144820449","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":"Crystal Habits as Potential Biosignatures.","authors":"Scott M Perl, Ashley E Murphy, Chinmayee Govinda Raj, Stephanie C Santos, Mihaela Glamoclija, David Des Marais, Tori Hoehler, Svetlana Shkolyar, Sherry L Cady, Jen Blank, Alfonso Davila, Paulina Cortez, Ashleigh Burgess, Jon Lima-Zaloumis","doi":"10.1177/15311074251360767","DOIUrl":"10.1177/15311074251360767","url":null,"abstract":"<p><p>Our understanding of crystalline structures within terrestrial planetary analog environments can shed light on how these features can be interpreted on rocky planets and icy moons in our solar system. The ability to distinguish biogenic and abiotic components within the mineral, crystal, and structural features allows us to inform future life detection missions, science payloads, and instrument measurement resolutions. Moreover, having these terrestrial reference measurements in a review format allows the measurement rationale to be understood in the context of mission concepts and geomicrobiological assessment of life in extreme environments. From 2020 to 2022, this team contributed to NASA's Center for Life Detection, Life Detection Knowledge Base, where structural features in crystalline and crystal-centric sample analyses were reviewed and assessed for biogenic preservation potential. This article highlights the scientific rationale and astrobiological sample assessment of evaluation for crystal habits as a possible biosignature. This is to illustrate true and false positives of the standards of evidence for minerals and their associated crystal habits. Moreover, we illustrate how these efforts contribute to the overall assessment of this type of morphological evidence in extant and extinct life detection campaigns.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"525-536"},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144726964","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":"Resilience of Hybrid Bioelectrodes in an Ionizing Environment: A Space Simulation Study of <i>Limnospira indica</i> Under Gamma Radiation.","authors":"Nikolay Ryzhkov, Paul J Janssen, Artur Braun","doi":"10.1177/15311074251365212","DOIUrl":"10.1177/15311074251365212","url":null,"abstract":"<p><p>Cyanobacteria possess unique biological properties and the ability to perform life-sustaining processes, which make them useful for applications in space exploration and colonization. Their potential use in bioelectricity and fuel production has garnered significant interest. This study explores the effects of ionizing radiation on the cyanobacterium <i>Limnospira indica</i> used in bioelectrodes. This is an important consideration as radiation levels in space are significantly higher than those experienced on Earth with its protective atmosphere and magnetosphere. In an approximate space radiation simulation setting, using gamma radiation, living cells of <i>L. indica</i> strain PCC 8005 (formerly known as <i>Arthrospira</i> sp.) were interfaced as bioelectrodes with boron-doped diamond (BDD)-coated and fluorine-doped tin oxide (FTO)-coated glass substrates and exposed to ⁶⁰Co gamma rays at an acute dose rate of 136 Gy.h^-1 for up to 14 h; electrogenic abilities (<i>i.e.</i>, respiration current in the dark) were measured by chronoamperometry. <i>Limnospira indica</i>-based bioelectrodes did not exhibit statistically significant changes in current generation even under high doses of 1.9 kGy gamma rays as compared with non-exposed bioelectrodes. Under radiation, bare FTO electrodes performed better than BDD electrodes, but negative gamma-induced effects in bare BDD electrodes were mitigated by cyanobacteria. The stable current generation under high-dose highlights the potential of biophotoelectrochemical and biophotovoltaic cells in radiation-intensive environments and applications in space.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"584-600"},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144820450","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":"Sterilization of Stainless-Steel Surfaces Using Ultraviolet Radiation Produced by Light-Emitting Diodes.","authors":"Joseph Wood, Mariela Monge, Emily P Seto, Katherine Ratliff, Brian Ford, Denise Aslett, Ahmed Abdel-Hady, Lesley Mendez Sandoval","doi":"10.1177/15311074251365196","DOIUrl":"10.1177/15311074251365196","url":null,"abstract":"<p><p>Numerous studies have demonstrated that ultraviolet radiation in the C wavelength range produced by light-emitting diodes (UVC-LEDs) is effective for disinfection (<i>i.e.,</i> inactivation of vegetative bacteria and viruses). However, there are few efficacy data available to confirm its use as a sterilization technique (complete inactivation of bacterial spores). The present study evaluated the use of UVC-LED to achieve the sterilization of stainless-steel surfaces as a function of UVC dose and several other variables. Spores of <i>Bacillus atrophaeus</i> and two strains of <i>Bacillus pumilus</i> were used as indicator microorganisms. Results showed that the microorganism, spore loading, and inoculation method all affected whether complete inactivation was achieved. Under the tested conditions, sterilization of stainless-steel surfaces was achieved using UV-LED with doses that ranged from ∼4500 to 21,000 mJ/cm², and if spore deposition was low enough to prevent clumping and subsequent shielding. We found that spore deposition in which sterilization was achieved ranged from 2.9 to 6.2 log₁₀ colony-forming units/cm² and depended primarily on the microorganism/strain. Shielding of UV radiation diminished efficacy and may have also occurred from the presence of foreign material.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"550-562"},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144783364","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":"Introduction to the Life Detection Knowledge Base Project.","authors":"Tori M Hoehler, Alfonso Davila, Niki Parenteau, Richard Quinn, David Des Marais, Svetlana Shkolyar, Leslie Bebout, Steven Benner, Jennifer G Blank, William Brinckerhoff, Morgan Cable, Sherry Cady, Jennifer Eigenbrode, Richard Everroad, Stephanie Getty, Daniel Glavin, Stanislaw Gliniewicz, Heather Graham, Lindsay Hays, Linda Jahnke, Barbara Lafuente, Graham Lau, Owen Lehmer, Jon Lima-Zaloumis, Kennda Lynch, Ashley Murphy, Marc Neveu, Scott M Perl, J Hank Rainwater, Antonio Ricco, Andro Rios, Sanjoy Som, Mary Beth Wilhelm, Andrew Pohorille","doi":"10.1089/ast.2024.0107","DOIUrl":"10.1089/ast.2024.0107","url":null,"abstract":"","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"451-453"},"PeriodicalIF":3.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144493828","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":"Structural Biosignatures-A Category of Potential Biosignatures in the Life Detection Knowledge Base.","authors":"Svetlana Shkolyar, Leslie Bebout, Jennifer G Blank, Sherry L Cady, Barbara Cavalazzi, Elizabeth Corbin, Alfonso F Davila, David Des Marais, Martin Fisk, Keyron Hickman-Lewis, Jonathan Lima-Zaloumis, Nicola McLoughlin, Ashley E Murphy, Nora Noffke, Scott M Perl, Andrew Pohorille, Sally L Potter-McIntyre, J Hank Rainwater, Frances Westall","doi":"10.1089/ast.2024.0105","DOIUrl":"10.1089/ast.2024.0105","url":null,"abstract":"<p><p>The Life Detection Knowledge Base (LDKB) is part of the Life Detection Forum suite of web tools developed for life detection mission planners. This article details the development of one of its categories of biosignatures, the <i>Structure</i> category. The <i>Structure</i> category includes physical attributes of objects and their spatial relationships (e.g., orientation). Initial population of the LDKB <i>Structure</i> category performed during a Content Development Group (CDG) phase resulted in the selection of six high-priority biosignature themes for content development: crystal habits, microtunnels, Mesa Depression Relief structures (a sedimentary surface morphology), laminations, spheroids, and filaments. In populating content, it was concluded that environmental considerations are crucial to recognize structural biosignatures remotely for planetary exploration when not known <i>a priori</i>. CDG activity also revealed knowledge and technology gaps in identifying structural biosignatures. This included gaps in research on biological prevalence of structural features due to a lack of research on these topics and a gap in technologies for <i>in situ</i> surface imaging of potential structural biosignatures. In addition, the implementation of two functionalities in the tool (i.e., linking multiple lines of evidence within entries and including images to represent physical biosignature attributes) resulted directly from CDG activity. These improvements enhance the LDKB's ability to serve as a comprehensive repository for data on true biosignatures and their abiotic counterparts.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"482-497"},"PeriodicalIF":2.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144582941","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 Knowledge Base: A Community Tool for Knowledge Management and Representation.","authors":"Andrew Pohorille, Graham Lau, Stanislaw Gliniewicz, Alfonso Davila, Niki Parenteau, David Des Marais, Richard Quinn, Svetlana Shkolyar, Richard Everroad, Tori Hoehler","doi":"10.1089/ast.2024.0106","DOIUrl":"10.1089/ast.2024.0106","url":null,"abstract":"<p><p>The Life Detection Knowledge Base (LDKB; https://lifedetectionforum.com/ldkb) is a community-owned web resource that is designed to facilitate the infusion of astrobiology knowledge and expertise into the conceptualization and design of life detection missions. The aim of the LDKB is to gather and organize diverse knowledge from a range of fields into a common reference frame to support mission science risk assessment, specifically in terms of the potential for false positive and false negative results when pursuing a particular observation strategy. Within the LDKB, knowledge sourced from the primary scientific literature is organized according to (1) a taxonomic classification scheme in which potential biosignatures are defined at a uniform level of granularity that corresponds to observable physical or chemical quantities, qualities, or states; (2) a set of four standard assessment criteria, uniformly applied to each potential biosignature, that target the factors that contribute to false positive and false negative potential; and (3) a discourse format that utilizes customizable, user-defined \"arguments\" to represent the essential aspects of relevant scientific literature in terms of their specific bearing on one of the four assessment criteria, and thereby on false positive and false negative potential. By mapping available and newly emerging knowledge into this standardized framework, we can identify areas where the current state of knowledge supports a well-informed science risk assessment as well as critical knowledge gaps where focused research could help flesh out and mature promising life detection approaches.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"454-463"},"PeriodicalIF":2.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144473872","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 Knowledge Base: Assessment Criteria for Potential Biosignatures.","authors":"Niki Parenteau, Tori Hoehler, Alfonso Davila, Stephanie Getty, Graham Lau, Marc Neveu, Svetlana Shkolyar, David Des Marais, Andro Rios, Linda Jahnke, Leslie Bebout, Richard Quinn, Andrew Pohorille","doi":"10.1089/ast.2024.0104","DOIUrl":"10.1089/ast.2024.0104","url":null,"abstract":"<p><p>Astrobiology and the search for evidence of life beyond Earth are now key drivers for planetary science and astronomy missions. Efforts are underway to establish evaluative frameworks to interpret potential signs of life in returned data. However, there is a need for a \"before-the-fact\" system to assess mission science risk and the potential false negative and false positive results. The Life Detection Knowledge Base (LDKB) is a community-owned web tool that organizes the scientific literature and enables discourse and evaluation of potential biosignatures (defined to the same level of granularity) relative to a set of standard criteria. This article details the development of draft criteria and their utilization as an organizing basis for the LDKB and their vetting by the astrobiology community via two workshops. We report the incorporation of community feedback to generate a finalized set of criteria, which delineate contributing factors to the potential for false negative or false positive results in the search for evidence of life within and beyond our solar system.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"474-481"},"PeriodicalIF":2.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144599231","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":"Challenges and Opportunities in Using Amino Acids to Decode Carbonaceous Chondrite and Asteroid Parent Body Processes.","authors":"José C Aponte, Hannah L McLain, Daniel Saeedi, Amirali Aghazadeh, Jamie E Elsila, Daniel P Glavin, Jason P Dworkin","doi":"10.1089/ast.2025.0017","DOIUrl":"10.1089/ast.2025.0017","url":null,"abstract":"<p><p>Carbonaceous chondrite (CC) meteorites are fragments of planetesimals that hold clues about the early solar system's organic matter. Amino acids are key to life on Earth; thus their study from extraterrestrial samples may help identify signs of prebiotic chemistry and life on other planets and may reveal how life as we know it began. This study analyzed amino acid concentrations and distributions in 42 CC samples, including returned samples from asteroids Ryugu and Bennu, to investigate the relationship between amino acid composition and parent body processes. We performed a statistical analysis of the amino acid molecular distributions and abundances in the context of meteoritic hydrogen, carbon, nitrogen, and carbonate total contents to explore the links between these organic species and thermal and aqueous processing experienced in the parent bodies. We also evaluated whether meteoritic amino acid ratios can be used as anti-biosignatures, and we re-evaluated the links between l-isovaline enantiomeric excesses and parent body aqueous alteration. While some trends were observed, correlations between amino acid distributions and alteration proxies (H, C, N, carbonates, enantiomeric excess) were generally weak, which indicates the need for larger sample sets. Thermal metamorphism correlated with lower amino acid and elemental [hydrogen (H), carbon (C), and nitrogen (N)] abundances, consistent with diverse parent bodies or localized processing. Ryugu samples exhibited significant amino acid variations despite similar bulk elemental compositions due to parent body heterogeneity. No strong statistical correlations were found between amino acid concentrations and H, C, or N content, which diminishes the reliability of predictions of amino acid abundances based solely on observed elemental abundances. While Ryugu and Bennu may share a common, Ceres-like parent body, observed differences in chemical composition suggest diverse evolutionary pathways. Finally, principal component analysis of amino acid and elemental data revealed distinct groupings that place Ryugu samples in a potentially unique subgroup and Bennu within the C2-ung chondrite group. These findings underscore the need for further study of such materials, especially given our discovery of their distinct nature, and emphasizes the insights gleaned from the ability to analyze returned asteroid samples.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"437-449"},"PeriodicalIF":3.5,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144186425","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":"Artificial Intelligence-Enhanced Detection of Biogenicity Using Laboratory Specimens of Biologically and Microbially Induced Sedimentary Structures in a Controlled Experiment.","authors":"Florent Arrignon, Liza Alexandra Fernandez, Stéphanie Boulêtreau, Neil S Davies, Jessica Ferriol, Frédéric Julien, Joséphine Leflaive, Thierry Otto, Erwan Roussel, Johannes Steiger, Jean-Pierre Toumazet, Dov Corenblit","doi":"10.1089/ast.2024.0153","DOIUrl":"10.1089/ast.2024.0153","url":null,"abstract":"<p><p>The search for traces of life can be based on the detection of specific signatures produced by microorganisms on sedimentary rocks. Microbially induced sedimentary structures (MISSs) develop under specific physicochemical conditions that are likely to have potentially existed on Mars during the Noachian period. We designed an experiment under controlled laboratory conditions to explore the wide range variability in biogeomorphological responses of clay-sand substrates to the development of biological mats-including microbial mats-of different strains and biomasses, and an abiotic control. A 3D picture dataset based on the experiment was built using multi-image photogrammetry. Visual observations were combined with multivariate statistics on computed topographical variables to interpret the diversity in the resulting biotic and abiotic mud cracks. Finally, an artificial intelligence (AI) classifier based on convolutional neural networks was trained with the data. The resulting model predicted accurately not only the biotic-abiotic differences but also the differences between strains and biomasses of biotic treatments. Its results outperformed the blind human classification, even using only grayscale pictures. Class Activation Maps showed that AI followed several decision paths, not always like those of the human expert. Next steps are proposed for application of these models to <i>ex situ</i> biogeomorphological structures (fossil and modern MISS) on Earth's surface, to ultimately transpose them to a martian context.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"414-436"},"PeriodicalIF":3.5,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144186424","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}