Astrobiology最新文献

{"title":"Chapter 8: Searching for Life Beyond Earth.","authors":"Luoth Chou, Natalie Grefenstette, Schuyler Borges, Tristan Caro, Enrico Catalano, Chester E Harman, Jordan McKaig, Chinmayee Govinda Raj, Gareth Trubl, Amber Young","doi":"10.1089/ast.2021.0104","DOIUrl":"10.1089/ast.2021.0104","url":null,"abstract":"<p><p>The search for life beyond Earth necessitates a rigorous and comprehensive examination of biosignatures, the types of observable imprints that life produces. These imprints and our ability to detect them with advanced instrumentation hold the key to our understanding of the presence and abundance of life in the universe. Biosignatures are the chemical or physical features associated with past or present life and may include the distribution of elements and molecules, alone or in combination, as well as changes in structural components or physical processes that would be distinct from an abiotic background. The scientific and technical strategies used to search for life on other planets include those that can be conducted <i>in situ</i> to planetary bodies and those that could be observed remotely. This chapter discusses numerous strategies that can be employed to look for biosignatures directly on other planetary bodies using robotic exploration including those that have been deployed to other planetary bodies, are currently being developed for flight, or will become a critical technology on future missions. Search strategies for remote observations using current and planned ground-based and space-based telescopes are also described. Evidence from spectral absorption, emission, or transmission features can be used to search for remote biosignatures and technosignatures. Improving our understanding of biosignatures, their production, transformation, and preservation on Earth can enhance our search efforts to detect life on other planets.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 S1","pages":"S164-S185"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140157506","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":"Foreword to the Astrobiology Primer 3.0.","authors":"Lucas Mix","doi":"10.1089/ast.2023.0116","DOIUrl":"10.1089/ast.2023.0116","url":null,"abstract":"","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 S1","pages":"S1-S3"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140157508","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 Is Uncertain: Inherent Variability Exhibited by Organisms, and at Higher Levels of Biological Organization.","authors":"Joseph W Bull","doi":"10.1089/ast.2023.0094","DOIUrl":"10.1089/ast.2023.0094","url":null,"abstract":"<p><p>Organisms act stochastically. A not uncommon view in the ecological literature is that this is mainly due to the observer having insufficient information or a stochastic environment-and not partly because organisms themselves respond with inherent unpredictability. In this study, I compile the evidence that contradicts that view. Organisms generate uncertainty internally, which results in irreducible stochastic responses. I consider why: for instance, stochastic responses are associated with greater adaptability to changing environments and resource availability. Over longer timescales, biologically generated uncertainty influences behavior, evolution, and macroecological processes. Indeed, it could be stated that organisms are systems <i>defined</i> by the internal generation, magnification, and record-keeping of uncertainty as inputs to responses. Important practical implications arise if organisms can indeed be defined by an association with specific classes of inherent uncertainty: not least that isolating those signatures then provides a potential means for detecting life, for considering the forms that life could theoretically take, and for exploring the wider limits to how life might become distributed. These are all fundamental goals in astrobiology.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"318-327"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139728871","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":"Considerations for Detecting Organic Indicators of Metabolism on Enceladus.","authors":"Laura M Barge, Gregory P Fournier","doi":"10.1089/ast.2023.0074","DOIUrl":"10.1089/ast.2023.0074","url":null,"abstract":"<p><p>Enceladus is of interest to astrobiology and the search for life since it is thought to host active hydrothermal activity and habitable conditions. It is also possible that the organics detected on Enceladus may indicate an active prebiotic or biotic system; in particular, the conditions on Enceladus may favor mineral-driven protometabolic reactions. When including metabolism-related biosignatures in Enceladus mission concepts, it is necessary to base these in a clearer understanding of how these signatures could also be produced prebiotically. In addition, postulating which biological metabolisms to look for on Enceladus requires a non-Earth-centric approach since the details of biological metabolic pathways are heavily shaped by adaptation to geochemical conditions over the planet's history. Creating metabolism-related organic detection objectives for Enceladus missions, therefore, requires consideration of how metabolic systems may operate differently on another world, while basing these speculations on observed Earth-specific microbial processes. In addition, advances in origin-of-life research can play a critical role in distinguishing between interpretations of any future organic detections on Enceladus, and the discovery of an extant prebiotic system would be a transformative astrobiological event in its own right.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 3","pages":"328-338"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140179222","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":"Fluorescence Microscopy with Deep UV, Near UV, and Visible Excitation for <i>In Situ</i> Detection of Microorganisms.","authors":"Noel Case, Nikki Johnston, Jay Nadeau","doi":"10.1089/ast.2023.0020","DOIUrl":"10.1089/ast.2023.0020","url":null,"abstract":"<p><p>We report a simple, inexpensive design of a fluorescence microscope with light-emitting diode (LED) excitation for detection of labeled and unlabeled microorganisms in mineral substrates. The use of deep UV (DUV) excitation with visible emission requires no specialized optics or slides and can be implemented easily and inexpensively using an oblique illumination geometry. DUV excitation (<280 nm) is preferable to near UV (365 nm) for avoidance of mineral autofluorescence. When excited with DUV, unpigmented bacteria show two emission peaks: one in the near UV ∼320 nm, corresponding to proteins, and another peak in the blue to green range, corresponding to flavins and/or reduced nicotinamide adenine dinucleotide (NADH). Many commonly used dyes also show secondary excitation peaks in the DUV, with identical emission spectra and quantum yields as their primary peak. However, DUV fails to excite key biosignature molecules, especially chlorophyll in cyanobacteria. Visible excitation (violet to blue) also results in less mineral autofluorescence than near UV, and most autofluorescence in the minerals seen here is green, so that red dyes and red autofluorescence of chlorophyll and porphyrins are readily distinguished. The pairing of DUV and near UV or visible excitation, with emission across the visible, represents the most thorough approach to detection of labeled and unlabeled bacteria in soil and rock.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 3","pages":"300-317"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10979697/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140179223","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":"Chapter 1: The Astrobiology Primer 3.0.","authors":"Micah J Schaible, Nadia Szeinbaum, G Ozan Bozdag, Luoth Chou, Natalie Grefenstette, Stephanie Colón-Santos, Laura E Rodriguez, M J Styczinski, Jennifer L Thweatt, Zoe R Todd, Alberto Vázquez-Salazar, Alyssa Adams, M N Araújo, Thiago Altair, Schuyler Borges, Dana Burton, José Alberto Campillo-Balderas, Eryn M Cangi, Tristan Caro, Enrico Catalano, Kimberly Chen, Peter L Conlin, Z S Cooper, Theresa M Fisher, Santiago Mestre Fos, Amanda Garcia, D M Glaser, Chester E Harman, Ninos Y Hermis, M Hooks, K Johnson-Finn, Owen Lehmer, Ricardo Hernández-Morales, Kynan H G Hughson, Rodrigo Jácome, Tony Z Jia, Jeffrey J Marlow, Jordan McKaig, Veronica Mierzejewski, Israel Muñoz-Velasco, Ceren Nural, Gina C Oliver, Petar I Penev, Chinmayee Govinda Raj, Tyler P Roche, Mary C Sabuda, George A Schaible, Serhat Sevgen, Pritvik Sinhadc, Luke H Steller, Kamil Stelmach, J Tarnas, Frank Tavares, Gareth Trubl, Monica Vidaurri, Lena Vincent, Jessica M Weber, Maggie Meiqi Weng, Regina L Wilpiszeki, Amber Young","doi":"10.1089/ast.2021.0129","DOIUrl":"10.1089/ast.2021.0129","url":null,"abstract":"<p><p>The Astrobiology Primer 3.0 (ABP3.0) is a concise introduction to the field of astrobiology for students and others who are new to the field of astrobiology. It provides an entry into the broader materials in this supplementary issue of <i>Astrobiology</i> and an overview of the investigations and driving hypotheses that make up this interdisciplinary field. The content of this chapter was adapted from the other 10 articles in this supplementary issue and thus represents the contribution of all the authors who worked on these introductory articles. The content of this chapter is not exhaustive and represents the topics that the authors found to be the most important and compelling in a dynamic and changing field.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 S1","pages":"S4-S39"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140157497","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":"Chapter 11: Astrobiology Education, Engagement, and Resources.","authors":"M J Styczinski, D M Glaser, M Hooks, T Z Jia, K Johnson-Finn, G A Schaible, M J Schaible","doi":"10.1089/ast.2021.0098","DOIUrl":"10.1089/ast.2021.0098","url":null,"abstract":"<p><p>Although astrobiology is a relatively new field of science, the questions it seeks to answer (<i>e.g.,</i> \"What is life?\" \"What does life require?\") have been investigated for millennia. In recent decades, formal programs dedicated specifically to the science of astrobiology have been organized at academic, governmental, and institutional scales. Constructing educational programs around this emerging science relies on input from broad expertise and backgrounds. Because of the interdisciplinary nature of this field, career pathways in astrobiology often begin in more specific fields such as astronomy, geology, or biology, and unlike many other sciences, typically involve substantial training outside one's primary discipline. The recent origin of astrobiology as a field of science has led to strong collaborations with education research in the development of astrobiology courses and offers a unique instructional laboratory for further pedagogical studies. This chapter is intended to support students, educators, and early career scientists by connecting them to materials and opportunities that the authors and colleagues have found advantageous. Annotated lists of relevant programs and resources are included as a series of appendices in the supplementary material.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 S1","pages":"S216-S227"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140157499","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":"Chapter 2: What Is Life?","authors":"Stephanie Colón-Santos, Alberto Vázquez-Salazar, Alyssa Adams, José Alberto Campillo-Balderas, Ricardo Hernández-Morales, Rodrigo Jácome, Israel Muñoz-Velasco, Laura E Rodriguez, Micah J Schaible, George A Schaible, Nadia Szeinbaum, Jennifer L Thweatt, Gareth Trubl","doi":"10.1089/ast.2021.0116","DOIUrl":"10.1089/ast.2021.0116","url":null,"abstract":"<p><p>The question \"What is life?\" has existed since the beginning of recorded history. However, the scientific and philosophical contexts of this question have changed and been refined as advancements in technology have revealed both fine details and broad connections in the network of life on Earth. Understanding the framework of the question \"What is life?\" is central to formulating other questions such as \"Where else could life be?\" and \"How do we search for life elsewhere?\" While many of these questions are addressed throughout the Astrobiology Primer 3.0, this chapter gives historical context for defining life, highlights conceptual characteristics shared by all life on Earth as well as key features used to describe it, discusses why it matters for astrobiology, and explores both challenges and opportunities for finding an informative operational definition.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 S1","pages":"S40-S56"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140157500","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":"Planetary Protection Knowledge Gap Closure Enabling Crewed Missions to Mars.","authors":"James A Spry, Bette Siegel, Corien Bakermans, David W Beaty, Mary-Sue Bell, James N Benardini, Rosalba Bonaccorsi, Sarah L Castro-Wallace, David A Coil, Athena Coustenis, Peter T Doran, Lori Fenton, David P Fidler, Brian Glass, Stephen J Hoffman, Fathi Karouia, Joel S Levine, Mark L Lupisella, Javier Martin-Torres, Rakesh Mogul, Karen Olsson-Francis, Sandra Ortega-Ugalde, Manish R Patel, David A Pearce, Margaret S Race, Aaron B Regberg, Petra Rettberg, John D Rummel, Kevin Y Sato, Andrew C Schuerger, Elliot Sefton-Nash, Matthew Sharkey, Nitin K Singh, Silvio Sinibaldi, Perry Stabekis, Carol R Stoker, Kasthuri J Venkateswaran, Robert R Zimmerman, Maria-Paz Zorzano-Mier","doi":"10.1089/ast.2023.0092","DOIUrl":"10.1089/ast.2023.0092","url":null,"abstract":"<p><p>As focus for exploration of Mars transitions from current robotic explorers to development of crewed missions, it remains important to protect the integrity of scientific investigations at Mars, as well as protect the Earth's biosphere from any potential harmful effects from returned martian material. This is the discipline of planetary protection, and the Committee on Space Research (COSPAR) maintains the consensus international policy and guidelines on how this is implemented. Based on National Aeronautics and Space Administration (NASA) and European Space Agency (ESA) studies that began in 2001, COSPAR adopted principles and guidelines for human missions to Mars in 2008. At that point, it was clear that to move from those qualitative provisions, a great deal of work and interaction with spacecraft designers would be necessary to generate meaningful quantitative recommendations that could embody the intent of the Outer Space Treaty (Article IX) in the design of such missions. Beginning in 2016, COSPAR then sponsored a multiyear interdisciplinary meeting series to address planetary protection \"knowledge gaps\" (KGs) with the intent of adapting and extending the current robotic mission-focused Planetary Protection Policy to support the design and implementation of crewed and hybrid exploration missions. This article describes the outcome of the interdisciplinary COSPAR meeting series, to describe and address these KGs, as well as identify potential paths to gap closure. It includes the background scientific basis for each topic area and knowledge updates since the meeting series ended. In particular, credible solutions for KG closure are described for the three topic areas of (1) microbial monitoring of spacecraft and crew health; (2) natural transport (and survival) of terrestrial microbial contamination at Mars, and (3) the technology and operation of spacecraft systems for contamination control. The article includes a KG data table on these topic areas, which is intended to be a point of departure for making future progress in developing an end-to-end planetary protection requirements implementation solution for a crewed mission to Mars. Overall, the workshop series has provided evidence of the feasibility of planetary protection implementation for a crewed Mars mission, given (1) the establishment of needed zoning, emission, transport, and survival parameters for terrestrial biological contamination and (2) the creation of an accepted risk-based compliance approach for adoption by spacefaring actors including national space agencies and commercial/nongovernment organizations.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 3","pages":"230-274"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140179225","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":"Hardware Development for Plant Cultivation Allowing <i>In Situ</i> Fluorescence Analysis of Calcium Fluxes in Plant Roots Under Microgravity and Ground-Control Conditions.","authors":"Magnus Rath, Michaela Dümmer, Jens Hauslage, Christian Liemersdorf, Christoph Forreiter","doi":"10.1089/ast.2023.0038","DOIUrl":"10.1089/ast.2023.0038","url":null,"abstract":"<p><p>Maintaining an optimal leaf and stem orientation to yield a maximum photosynthetic output is accomplished by terrestrial plants using sophisticated mechanisms to balance their orientation relative to the Earth's gravity vector and the direction of sunlight. Knowledge of the signal transduction chains of both gravity and light perception and how they influence each other is essential for understanding plant development on Earth and plant cultivation in space environments. However, <i>in situ</i> analyses of cellular signal transduction processes in weightlessness, such as live cell imaging of signaling molecules using confocal fluorescence microscopy, require an adapted experimental setup that meets the special requirements of a microgravity environment. In addition, investigations under prolonged microgravity conditions require extensive resources, are rarely accessible, and do not allow for immediate sample preparation for the actual microscopic analysis. Therefore, supply concepts are needed that ensure both the viability of the contained plants over a longer period of time and an unhindered microscopic analysis in microgravity. Here, we present a customized supply unit specifically designed to study gravity-induced Ca²⁺ mobilization in roots of <i>Arabidopsis thaliana</i>. The unit can be employed for ground-based experiments, in parabolic flights, on sounding rockets, and probably also aboard the International Space Station.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 3","pages":"275-282"},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140179224","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}