Astrobiology最新文献

{"title":"Setting the Stage: The Early History of the Solar System.","authors":"Antígona Segura, Rachel L Smith, Myriam Telus, Edward Schwieterman, Rachel Osten, Sukrit Ranjan","doi":"10.1177/15311074261454247","DOIUrl":"10.1177/15311074261454247","url":null,"abstract":"<p><p>This article reviews the early history of our solar system from an astrobiological perspective and presents evidence from meteorites and astronomical observations. The purpose is to trace the formation of key molecules that participated in the building blocks of life. The Sun and its planetary system started from a section of a molecular cloud that collapsed into a protoplanetary disk. In the center of the protoplanetary disk, the protosun heated the surrounding material. The dust and gas inherited from the cloud remained pristine farther away from the protostar, while new compounds were created in the gas and on the icy mantles of the dust. The dust accreted into pebbles, pebbles formed planetesimals, and planetesimals collided and accreted pebbles to create planets. Meanwhile, the protosun became the Sun when its core reached the pressure and temperature required to transform hydrogen into helium. During this process, the Sun emitted high-energy radiation and particles that impacted the chemistry in the disk and the early evolution of the terrestrial planets.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"510-529"},"PeriodicalIF":2.3,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148270050","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":"Viking's Astrobiological Legacy: A Philosophical Framework for Searching for Molecular Biosignatures.","authors":"Denise Kathleen Buckner, Mary Beth Wilhelm","doi":"10.1177/15311074261464717","DOIUrl":"10.1177/15311074261464717","url":null,"abstract":"<p><p>James Lovelock was the first to lay out a physical and chemical basis for searching for life beyond Earth, based on the observation that the molecular features and patterns in classes of organics differ for compounds formed through biological versus nonbiological processes. This approach shaped the Viking molecular analysis experiment designed to search for organics, including potential signs of extinct or extant life, and it still remains fundamentally viable today. In the five decades since Viking, many missions have uncovered new information about the martian organic inventory, geological landscape, and changes to habitability over time, while advances in organic geochemistry on Earth enabled scientists to identify even more differences between biotic and abiotic organics, solidifying the utility of Lovelock's physical and chemical approach in the search for extraterrestrial life. Key Words: Search for Mars' Organics-Mars-Biosignatures-Life detection-Biomarkers. Astrobiology 26, 72S-78S.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"72S-78S"},"PeriodicalIF":2.3,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148359193","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":"Biological Validation and Agnostic Experiments for Extant and Extinct Microbial Life within the Martian Subsurface.","authors":"Scott M Perl, Charles S Cockell, Woodward W Fischer, Sunanda Sharma, Karen G Lloyd, Mary Beth Wilhelm, Frank A Corsetti, Tina Treude, Jared Leadbetter, Donato Giovannelli, Christine M Foreman, Kevin Freedman, Kennda Lynch, Martin Homann, Sanjoy M Som, Laurence Wilson, Suniti Karunatillake, Henrik Drake, Kathryn Bywaters, Jill Mikucki, Aaron J Celestian, Pin Chen, Lisa Guan, Yadira Ibarra, Justin Boland, Sona Hosseini, Phillipe L Tosi, Devan M Nisson, Ashley Murphy, Madeline Garner, Federico Thei, Michele Biondi, Paul Propster","doi":"10.1177/15311074261464716","DOIUrl":"10.1177/15311074261464716","url":null,"abstract":"<p><p>Over the last several decades, investigations of Earth's subsurface and other extremely low-biomass systems have refined our understanding of the environmental limits of life, driven by methodological advances that permit agnostic life detection of biology and their respective physical biosignatures and chemical biomarkers. These advances enable mission concepts centered on microbiological processes that facilitate identification of both active life and preserved biosignatures through measurements of metabolism and associated biochemical markers that, on Mars, are more likely to be retained below the surface. Terrestrially, although biological processes can exert a significant influence on Earth's crust, the presence of habitable conditions does not necessarily imply the existence of cellular life. The Viking missions constituted the first direct life-detection experiments on Mars but produced equivocal outcomes, prompting subsequent exploration strategies to emphasize surface habitability rather than direct biological testing. Leveraging progress in subsurface microbiology and planetary exploration, we contend that Mars missions are now poised to shift toward direct tests for extant microbial activity in the subsurface, with metabolic processes serving as a broadly applicable indicator of life.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"26 1_suppl","pages":"156S-171S"},"PeriodicalIF":2.3,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148444158","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 Role of Chemical Sensors, Microfluidics, and Analytical Microsystems in Future Mars Exploration.","authors":"Samuel P Kounaves, Antonio J Ricco","doi":"10.1177/15311074261464023","DOIUrl":"10.1177/15311074261464023","url":null,"abstract":"<p><p>The Viking Mars mission raised intriguing questions about Mars' surface chemistry. More than three decades later, an array of small electrochemical sensors included on the Phoenix Mars lander provided a key insight: Perchlorate, chlorine's most highly oxidized form, was present at surprisingly high concentrations in the regolith. This has implications for Mars' geochemistry, habitability, potential to support microbial life, and human exploration; as a strong oxidant, it might also help explain the destruction of organic compounds on the martian surface. Here, we examine the role of chemical sensors in the exploration of Mars and a critical allied enabling technology, microfluidics, from Phoenix to the present day and beyond. Enormous technological advances in microtechnologies, targeting terrestrial applications from everyday consumer electronics to wearable medical diagnostic devices, are just now beginning to be adapted and harnessed to support planetary science and discovery. These advances are poised to revolutionize how much can be learned using robust systems with unimaginably small requirements for size, weight, and power, making them compatible with small, potentially lower-cost delivery to the martian surface on hard landers, impactors, penetrators, and even rotorcraft.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"94S-101S"},"PeriodicalIF":2.3,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148337576","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":"Chemical and Physical Evolution of the Crust.","authors":"Wriju Chowdhury, Dustin Trail, Mike Ackerson","doi":"10.1177/15311074261452816","DOIUrl":"10.1177/15311074261452816","url":null,"abstract":"<p><p>The topography and chemical composition of Earth's early crust likely shaped the conditions under which self-replicating biomolecules emerged. The stability of these molecules depended on dynamic interactions across Earth's interior and surface, from the core to the atmosphere. Tracing the origin of a biosphere on Earth requires understanding its transformation from an initially uninhabitable planet into a temperate world with a stable crust, active rock recycling, volatile cycling, and surface oceans. These features are closely linked to plate tectonics, a process unique to Earth in our solar system. Before the onset of modern plate tectonics, Earth evolved from a global magma ocean (∼4.5 Ga) into a differentiated planet with a primordial crust, mantle, and core. The co-evolution of the lithosphere, hydrosphere, and atmosphere played a fundamental role in establishing surface conditions suitable for life. Here, we review current perspectives on the evolution of tectonic regimes from Earth's formation (∼4.567 Ga) to the emergence of mobile-lid tectonics and the implications for crustal environments that may have supported the origin of life.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"549-564"},"PeriodicalIF":2.3,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148154921","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":"Assessing the Earliest Evidence for Life in the Geologic and Genomic Records.","authors":"Elizabeth A Bell, Gregory P Fournier","doi":"10.1177/15311074261454242","DOIUrl":"10.1177/15311074261454242","url":null,"abstract":"<p><p>Both the geologic and genomic records provide information on the earliest history of terrestrial life. Despite the challenges inherent to the fragmentary and highly metamorphosed earliest rock record, microfossils as old as ∼3.5 billion years (Ga) and potential morphological and isotopic traces in earlier rocks suggest the origin and diversification of life within the planet's first billion years. This is consistent with a growing body of evidence for liquid water in Earth's surface or near-surface environment by around 4.3 Ga, which provides at least one requirement of habitability. Genomic evidence further informs our understanding of early life, including some aspects of its environment, physiology, and metabolism. In addition, ancestral proteome reconstruction and molecular clocks provide clues to the nature and timing of the last universal common ancestor (LUCA), although the latter methodology remains challenging and highly uncertain. Improved molecular clock methods may be able to better constrain the timing of LUCA and the divergence of the major domains of extant life, while further interrogation of the earliest geologic and geochemical records may be able to reveal even earlier evidence for an inhabited planet.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"633-643"},"PeriodicalIF":2.3,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148026363","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":"Experimental Evidence for a Microbial Origin of Reduction Spots in Red Beds on Earth-and Mars?","authors":"Sev Zielinska, Naomi Felton, Philip B Vixseboxse, Sean McMahon","doi":"10.1177/15311074261464015","DOIUrl":"10.1177/15311074261464015","url":null,"abstract":"<p><p>The Perseverance rover recently discovered sedimentary rocks reddened by ferric oxides and peppered with bleached spots lacking these oxides. Some of these spots are associated with phosphate, iron sulfide minerals, and organic matter and are regarded as \"potential biosignatures,\" suggestive of microbial iron- and sulfate-reduction and organic matter oxidation. Similar millimeter-centimeter-scale \"reduction spots\" occur in many ancient red beds on Earth. Although terrestrial reduction spots are widely considered biogenic, the available evidence is not decisive, and the proposed microbial mechanism of spot formation has not been tested experimentally. Here, we report a successful laboratory demonstration of bleached spot formation in ferruginous sediment. Millimeter-centimeter-scale rounded bleached spots appeared within weeks on the underside of anaerobic sand-ferrihydrite slurries inoculated with microbial communities from the reducing zones of Winogradsky columns, originally seeded with soil and pondwater. The spatial and temporal distribution of observed bleaching events, which did not occur in sterile controls, is best explained by a microbially induced process, and DNA sequencing confirms that bacteria of iron-reducing genera (e.g., <i>Paradesulfitobacterium</i>) are abundant in the bleached areas. These results strongly support the longstanding hypothesis that microbial colonies can indeed generate visibly bleached reduction spots in ferruginous sediments and rocks. Further experiments are needed to establish whether and how nonbiological processes can mimic these features and to search for features that disambiguate biogenic and abiogenic reduction spots.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"485-491"},"PeriodicalIF":2.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148300779","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":"Can Pareto Optimality Be Evidence of Life?","authors":"Niall Rodgers, Corentin C Loron, H James Cleaves, Mark A van Zuilen, Sean McMahon","doi":"10.1177/15311074261464011","DOIUrl":"10.1177/15311074261464011","url":null,"abstract":"<p><p>Biological evolution confronts situations in which the modification of a trait to improve the performance of one function may diminish the performance of another. Similar trade-offs occur in economics and engineering, where they are evaluated with the concept of Pareto optimality. \"Pareto optimal\" solutions are solutions such that performance cannot be improved for any task without sacrificing performance for another task. Solutions outside the <i>Pareto optimal</i> set are likely to be uncompetitive in that they could be improved without negative consequences. Biologists have argued that optimization for multiple biological functions restricts the variety of evolutionarily stable phenotypes to a Pareto set within traitspace, while promoting diversity within this set. Here, we consider whether evidence for such optimality could serve as evidence of life in astrobiology. We propose that objects whose properties lie demonstrably within a region constrained by trade-offs between biologically relevant functions are more likely to be biogenic; examples discussed here include bacterial morphology, mycelial networks, and the selection of molecules. Conversely, objects with comparable characteristics to known forms of life that exist outside the relevant Pareto set are less likely to be biological. We conclude that the detection of Pareto optimality may disclose functionality and, hence, biogenicity in unfamiliar materials.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"492-499"},"PeriodicalIF":2.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148300756","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":"Plasma and Thermal Processing Leading to Latitudinal and Temporal Variability of the Trapped O₂ at Europa and Ganymede.","authors":"Apurva V Oza, Robert E Johnson, Carl A Schmidt, Wendy M Calvin, Yuk L Yung","doi":"10.1177/15311074261460369","DOIUrl":"10.1177/15311074261460369","url":null,"abstract":"<p><p>We describe the physical processes that affect the formation, trapping, and outgassing of O₂ at Europa and Ganymede. Following Voyager measurements of their ambient magnetospheric plasmas, laboratory data indicated that the observed ions, which were mostly ejected from volcanic Io, would in turn impact and sputter their surfaces. This would decompose the ice and produce thin oxygen atmospheres. More than a decade later, Europa's O₂ atmosphere was inferred from observations of the O aurora, and \"condensed\" O₂ bands were observed in Ganymede's icy surface at 5773 and 6275 Å. More than another decade later, their atmospheres were shown to have a dusk/dawn enhancement, confirmed by recent Juno data. Although the incident plasma produces these observables, processes that occur within the topmost surface are still not well understood. Here, we note that the incident plasma particles produce a nonequilibrium defect density locally in the surface ice grains. Defect diffusion within these grains leads to the formation of voids and molecular products, some of which are volatile. Although some volatiles are released into the satellite atmospheres, others are trapped at defect sites or trapped in voids, which create gas bubbles whose lifetimes (in steady state) are limited by the plasma-induced destruction rate. Here, we discuss how trapping competes with the annealing of the radiation damage. We describe the differences observed at Europa and Ganymede and roughly determine the observed trend with latitude of O₂ bands observed on Ganymede's trailing hemisphere. This understanding is used to discuss the relative importance of \"condensed\" O₂ and O₂ adsorbed on regolith grains as atmospheric sources, accounting for dusk/dawn enhancements and temporal variability reported in \"condensed\" O₂ band depths. Since plasma-induced damage and thermal annealing timescales drive oxidant variability on icy moons (likely also Callisto, Dione, and Rhea), they can help determine volatile downwelling, a potentially metabolic source for their oceans, and upwelling of other trapped oxidants (e.g., CO₂), suggestive of ongoing geologic activity.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"472-484"},"PeriodicalIF":2.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148350536","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":"Regolith as a Refuge: Differential Survival of Bacteriophage Qβ in Mars Analog Environments.","authors":"Miguel Arribas Tiemblo, Alicia Rodríguez-Moreno, Felipe Gómez, Ester Lázaro","doi":"10.1177/15311074261459203","DOIUrl":"10.1177/15311074261459203","url":null,"abstract":"<p><p>Viruses are among the simplest biological entities capable of replication. Their robustness and adaptability make them relevant not only to terrestrial ecosystems but also to astrobiological exploration. As durable entities, they may persist in environments far harsher than those tolerable to cellular life and are likely candidates for forward contamination. To assess their relevance in planetary protection and as potential biomarkers, we investigated the preservation of bacteriophage Qβ, an RNA virus, in Mars analog environments using two commercial martian regolith simulants: Mars Global Simulant (MGS)-1 and Mojave Mars Simulant (MMS)-2. MMS-2, enriched in iron oxides, exhibited higher oxidative potential than MGS-1, which is mainly composed of basaltic material. Viral survival was assessed across variables that included time, temperature, concentration, and particle size. Our results show that inactivation in MGS-1 was primarily driven by adsorption, while in MMS-2, it was dominated by chemical oxidation. MGS-1 provided a more protective matrix that mitigated freeze-induced damage and shielded desiccated viral particles from ultraviolet (UV) B and UVC radiation. These findings highlight the importance of mineral composition in modulating viral persistence and suggest that regolith may act as both a barrier and a refuge. Understanding virus-mineral interactions is essential for assessing biosignature preservation, planetary protection, and the potential roles of viruses in the evolution and survival of life beyond Earth.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"443-457"},"PeriodicalIF":2.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148209952","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}