Astrobiology最新文献

{"title":"A Comprehensive Radiobiological Characterization of Anhydrobiotic <i>Saccharomyces cerevisiae</i>.","authors":"Michel Lapointe, Sebastian Tattenberg, Camille Bélanger-Champagne, Stan Yen, Douglas Boreham, Cornelia Hoehr, Christopher Thome","doi":"10.1177/15311074261466922","DOIUrl":"10.1177/15311074261466922","url":null,"abstract":"<p><p>The anhydrobiotic (living without water) yeast <i>Saccharomyces cerevisiae</i> has gained considerable interest for its use in a variety of fields, from investigation of the biological effects of deep space radiation exposure to its utilization as a radiation dosimeter and its applicability in the study of preservation of microbial life in martian regolith. A complete radiobiological characterization of yeast during anhydrobiosis must be undertaken to ensure the informed interpretation of these works. This study investigated the radiobiological properties of a desiccated recombinational repair-deficient <i>rad51</i> knockout strain of <i>S. cerevisiae</i>. We focused on radiation tolerance, oxygen enhancement ratio (OER), and relative biological effectiveness (RBE). Desiccation-induced radioresistance was significantly higher compared with hydrated yeast; it required a threefold higher dose for an equivalent biological response. Desiccated yeast exhibited no OER, which indicates the absence of oxygen-dependent radiosensitization due to the lack of indirect damage pathways. RBE measurements for a 74 MeV proton beam (1.10 ± 0.01) and a neutron beam (12.2 ± 0.7) align with prior studies and demonstrate consistency between desiccated and hydrated systems when appropriately scaled. These findings support the use of the desiccated yeast model as a robust and translatable system for addressing fundamental questions in astrobiology and radiobiology.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"677-687"},"PeriodicalIF":2.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148410216","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":"Reactive Iron Mineral Phases on Mars: Implications for Organic Carbon Preservation.","authors":"Emily Bonsall, Eileen Tisdall, Christian Schröder","doi":"10.1177/15311074261475984","DOIUrl":"10.1177/15311074261475984","url":null,"abstract":"<p><p>It is estimated that ∼20% of organic carbon stored in sediments on Earth is bound to reactive iron minerals. They often occur as nanoparticulate or X-ray amorphous iron (hydr)oxides, which are challenging to identify with mineralogical techniques-especially those that require any type of heating, which also makes them susceptible to alteration in response to diagenetic processes. Reactive iron species have been identified on Mars in the form of nanophase ferric oxides in Gusev crater and at Meridiani Planum with Spirit's and Opportunity's Mössbauer spectrometers, respectively, and as Fe-rich amorphous material in Gale crater with Curiosity's CheMin X-ray diffraction channel. Here, we use the amount of reactive iron minerals and geochemical evidence for diagenetic processes to assess the relative preservation potential of sedimentary rocks at these three landing sites. Sedimentary rocks in Gale crater show the highest preservation potential, and organic carbon compounds have been identified in these rocks. Sedimentary rocks in Gusev crater show equally high preservation potential. However, reactive Fe minerals can also react with organic carbon when heat is added during pyrolysis and laser desorption. These effects need to be considered to determine accurately the organic carbon inventory measured during current and future missions as well as in returned samples.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"715-726"},"PeriodicalIF":2.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148757949","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":"IMPRESS: A Planetary Penetrator Network for Astrobiology, Prospecting, and Exploration of Mars.","authors":"Jan Spacek, Holden Alpern, Thomas Dineen, Janusz J Petkowski, Gabriella Rizzo, Steven A Benner, May Lui, Charles Cockell, Marshall Eubanks, Dirk Schulze-Makuch, Christopher Temby, Mitchell Richburg","doi":"10.1177/15311074261471218","DOIUrl":"10.1177/15311074261471218","url":null,"abstract":"<p><p>The International Mars Prospecting Ride-Share System (IMPRESS) is presented here as a scalable, democratized, and low-cost mission architecture for distributed measurements on the martian surface and in the shallow subsurface. IMPRESS is intended to prospect on Mars in advance of sample return and human exploration. Its primary objective is to survey Mars for extant life, but it also supports geophysical, soil chemistry, resource, and landing-site risk assessments. Instead of relying on soft landers and drilling systems, IMPRESS deploys swarms of planetary penetrators that use descent kinetic energy to emplace instruments 0.2-1 m below the surface. This architecture provides spatial coverage, measurement replication, and mission redundancy. This increases the chance of detecting unevenly distributed biosignatures and gives negative results stronger context. Small penetrator platforms with standardized design, power, and communication interfaces lower the cost per experiment. The probes operate as independent nodes within a network, which enables time-correlated atmospheric, seismic, and environmental measurements that support the broader Mars exploration campaign. Repeatable mission deployments can range from small rideshare implementations with tens of penetrators to larger dedicated campaigns with hundreds or more. We describe the IMPRESS mission architecture, penetrator platforms, compatible payload classes, and how distributed shallow-subsurface surveys reduce scientific and operational uncertainty before future Mars surface activities. Key Words: Planetary penetrators-Mars-Extant life-Planetary protection-Distributed exploration-Rideshare. Astrobiology, 26, 688-699.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"688-699"},"PeriodicalIF":2.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148560577","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":"<i>In Vitro</i>-Selected DNA Aptamers Enable Detection of the Ancestral Peptide 3C8Y in [FeFe]-Hydrogenase CpI and in Metal-Rich, Acidic Environments: Implications for Astrobiology.","authors":"Yolanda Blanco, Shuvankar Naskar, Ángeles Aguilera, María Fernández-Algar, Thomas Happe, Carlos Briones","doi":"10.1177/15311074261474801","DOIUrl":"10.1177/15311074261474801","url":null,"abstract":"<p><p>Selecting molecular biosignatures of unequivocal biological origin and sufficient complexity is essential for developing next-generation biosensors in astrobiology-driven missions. Among the most promising candidates are ancestral peptides, molecular relics that preserve functional signatures of early life. Here, we report the <i>in-vitro</i> selection and characterization of single-stranded DNA aptamers that specifically bind to the 15-amino acid 3C8Y peptide, derived from the [FeFe]-hydrogenase CpI of <i>Clostridium pasteurianum</i>. This ancestral peptide, a candidate biosignature of anaerobic metabolism, contains metal-binding cysteines associated with [FeS] clusters. Three DNA aptamers were selected through a Systematic Evolution of Ligands by EXponential Enrichment-based approach and subsequently validated using colorimetric ELONA assays. The aptamers exhibited high affinity (<i>K</i>_d in the low nanomolar range) and robust specificity toward both the synthetic 3C8Y peptide (compared with three structurally related peptides) and the heterologously expressed CpI protein in native and denatured states (relative to two other hydrogenases). Dual-aptamer sandwich ELONA confirmed the recognition of distinct binding sites, enabling sensitive detection of the peptide in both free and [FeS]-clustered states. Notably, the aptamers detected 3C8Y-containing targets in complex environmental samples from Río Tinto (Spain), a metal-rich acidic analog, but not in samples from less iron-abundant Icelandic geothermal sites, which are dominated by photosynthetic organisms that do not express CpI hydrogenases. These findings support the use of <i>in-vitro</i>-selected aptamers for label-free detection of oxygen-sensitive metalloproteins in complex matrices, with promising applications in astrobiology.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"700-714"},"PeriodicalIF":2.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148705312","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":"A Model of UV-Blue Absorbance in Bulk Liquid of Venusian Cloud Aerosols Is Consistent with Efficient Organic Absorbers at High Concentrations.","authors":"Jan Spacek, Paul B Rimmer, Janusz J Petkowski, Yeon Joo Lee","doi":"10.1177/15311074261477502","DOIUrl":"10.1177/15311074261477502","url":null,"abstract":"<p><p>At visible wavelengths, Venus appears serene and pale yellow. But since the 1920s, observers have noted high-contrast features in the ultraviolet. These features track the ∼4-day superrotation of the upper cloud deck and vary widely over time and space. The identity of the UV absorber(s)-active between at least 280 and 500 nm-remains unknown, as no proposed candidate fully matches all observational data. From remote observations of Venus, and accounting for light scattering by cloud droplets, we modeled the 365-455 nm decadic absorption coefficient, <math><mrow><mrow><msub><mrow><mi>a</mi></mrow><mi>λ</mi></msub></mrow></mrow></math>, of the bulk liquid that forms Venus's clouds. Assuming a uniform distribution in mode 1 and mode 2 particles across a 6 km layer below the cloud top at 65 km, we constrained the decadic absorption coefficient within the modeled range to a peak at <math><mrow><mrow><msub><mrow><mi>a</mi></mrow><mrow><mn>375</mn></mrow></msub></mrow></mrow></math> = 1278 cm^-1, equivalent to a decadic absorbance of <math><mrow><mrow><msub><mrow><mi>A</mi></mrow><mrow><mn>375</mn></mrow></msub></mrow></mrow></math> = 1278 for a 1 cm path length. This extremely high absorption coefficient implies the presence of a highly efficient absorber, for example, conjugated organics, at relatively high concentrations-for example, ∼12 g/L for porphyrin-type pigments with a representative peak molar absorption coefficient of ∼10⁵ M^-1cm^-1. Inorganic absorbers, typically below 10⁴ M^-1cm^-1, would either need to constitute a large portion of the aerosols or still not be sufficiently light-absorbing, even in pure form. We emphasize that all candidate absorbers must be evaluated against Venus's reflectance curve using (1) known molar absorption coefficients, (2) realistic atmospheric distributions, and (3) appropriate particle size distributions. The planned Rocket Lab mission will test the hypothesis of organics in Venus's clouds.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"727-739"},"PeriodicalIF":2.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148811951","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":"Wavelength Requirements for Life Detection via Reflected Light Spectroscopy of Rocky Exoplanets.","authors":"Joshua Krissansen-Totton, Anna Grace Ulses, Maxwell K Frissell, Samantha Gilbert-Janizek, Amber Young, Jacob Lustig-Yaeger, Tyler D Robinson, Stephanie Olson, Eleonora Alei, Giada Arney, Celeste Hagee, Chester Harman, Natalie Hinkel, Émilie Laflèche, Natasha Latouf, Avi Mandell, Mark M Moussa, Mary N Parenteau, Sukrit Ranjan, Blair Russell, Edward W Schwieterman, Clara Sousa-Silva, Armen Tokadjian, Nicholas Wogan","doi":"10.1177/15311074261477497","DOIUrl":"10.1177/15311074261477497","url":null,"abstract":"<p><p>Searching for signs of life is a primary goal of the Habitable Worlds Observatory (HWO). However, merely detecting oxygen, methane, or other widely discussed biosignatures is insufficient evidence for a biosphere. In parallel with biosignature detection, exoplanet life detection additionally requires characterization of the broader physicochemical context to evaluate planetary habitability and the plausibility that life could produce a particular biosignature in a given environment. Life detection further requires that we can confidently rule out photochemical or geological phenomena that can mimic life (i.e., \"false positives\"). Evaluating false-positive scenarios may require different observatory specifications than biosignature detection surveys. Here, we explore the coronagraph requirements for assessing habitability and for cautiously excluding known false-positive (and false-negative) scenarios for oxygen and methane, the two most widely discussed biosignatures for Earth-like exoplanets. We find that broad wavelength coverage ranging from the near ultraviolet (UV; 0.26 µm) and extending into the near infrared (NIR; 1.7 µm) is necessary to contextualize these potential biosignatures with HWO. The short-wavelength cutoff is driven by the need to identify Proterozoic-like biospheres via O₃, whereas the long-wavelength cutoff is driven by the need to contextualize O₂ and CH₄ biosignatures via constraints on carbon-bearing atmospheric species. The ability to obtain spectra with signal-to-noise ratios of 20-40 across this 0.26-1.7 µm range (assuming R = 7 UV, R = 140 VIS, and R = 70 NIR) is also required. While not every Earth-analog biosignature and false positive can be unambiguously identified with these capabilities-and the plausibility and contextual clues of many biosignature false positives remain an area of active research-our minimal spectral recommendations would enable a broad search for Earth-like life assuming such observations are achievable for a statistically meaningful number of HWO targets.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"740-760"},"PeriodicalIF":2.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148757669","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 Climate and Habitability of Tidally Locked Rocky Exoplanets.","authors":"Erica Bisesi, Giuseppe Murante, Jost von Hardenberg, José A Caballero, Michele Maris, Daniela Billi, Nicoletta La Rocca, Laura Silva","doi":"10.1177/15311074261479167","DOIUrl":"10.1177/15311074261479167","url":null,"abstract":"<p><p>Tidally locked exoplanets orbiting M dwarf stars are prime targets in the search for habitable worlds, yet their complex climate dynamics challenge conventional models of habitability. We homogeneously estimated the liquid-water habitability of exoplanets with the highest up-to-date Earth similarity index (ESI). We modified the climate model PLASIM to apply it to tidally locked exoplanets across a range of parameters. We systematically classified and compared potentially habitable exoplanets and selected among the ones featuring the highest ESI in the conservative sample of the Habitable Worlds Catalog, both relative to each other and as a function of atmospheric pressure. Our analysis revealed three main climate regimes: Snowball, Hot, and Eyeball planets-the latter having a warm and habitable substellar region with <i>T</i> > 273 K and a localized hydrological cycle. Although surface temperature generally increases with pressure, Eyeball planet climates remain stable in a wide pressure range. Complex atmospheric dynamics rules the behavior of the climate, highlighting the need for detailed climate simulations to guide future observations.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"761-784"},"PeriodicalIF":2.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148787457","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 Search for Life Elsewhere: Avoiding Hype and Fostering Public Understanding.","authors":"Danilo Albergaria, Marieke Baan, Jordan Bimm, Martin Devecka, Maria Cristina Fortuna, Thilina Heenatigala, Inge Loes Ten Kate, Anastasia Kokori, Juan Carlos Muñoz-Mateos, Julie Nekola Nováková, Tan Vu Nguyen, Iris Nijman, Erik Persson, Stephen Pompea, Marten Raaphorst, David Redeker, Pedro Russo, Ionica Smeets, Harrison B Smith, Gretchen Stahlman, Dallyce Vetter, Robert Massey, Tina Ibsen","doi":"10.1177/15311074261475082","DOIUrl":"https://doi.org/10.1177/15311074261475082","url":null,"abstract":"<p><p>The search for life beyond Earth presents unique challenges for science communication due to its interdisciplinary nature, the potential for groundbreaking discoveries, and the inherent uncertainties involved. The Lorentz Center workshop <i>Breaking News: We Found Extraterrestrial Life!</i> brought together scientists, historians, philosophers, science journalists, and press information officers to reflect on these challenges. The event took place from the 2nd to the 6th of September 2024 in Leiden, the Netherlands. The goal was to prepare the community for different future scenarios of life detection. Participants aimed to develop strategies to communicate research results properly with the public. We provide here a synthesis of the discussions and conclusions reached during the event. To summarize, effective communication about the search for life elsewhere requires balancing scientific rigor with public engagement. To build public trust and understanding, it is essential to set realistic expectations, avoid sensationalism, and promote transparency. By using clear and accessible language, addressing ethical considerations, and managing expectations, we can communicate the complexities of astrobiology research effectively to a broad audience. Additionally, fostering critical thinking, encouraging independent verification, and tailoring communication for different audiences can help ensure that astrobiology discoveries are understood, appreciated, and used responsibly.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"15311074261475082"},"PeriodicalIF":2.3,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148672978","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":"Insights into the Possible Composition of a Martian Biota.","authors":"J William Schopf","doi":"10.1177/15311074261464025","DOIUrl":"https://doi.org/10.1177/15311074261464025","url":null,"abstract":"<p><p>In the half-century since the Viking Mission's imaginative, trail-blazing effort to detect extant life on Mars, much has been learned about the current and past martian environment, the biology and ecology of Earth's present-day microbial biota, and Earth's most ancient fossils, a preserved record of life inhabiting environments much like those then prevalent on Mars. Earth's earliest known biota was entirely anaerobic-as would be expected of all lifeforms on Mars, whether past or present-composed of at least four principal lineages: sulfuretum microbes, photosynthetic bacteria, methanogenic archaea, and methanotrophic archaea. Given their existence on the early Earth, it seems reasonable to suggest that similar lineages might also have originated on Mars and, if so, might subsequently have coevolved with and adapted to the slowly changing martian environment to continue to be extant even to the present day.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"26 1_suppl","pages":"47S-52S"},"PeriodicalIF":2.3,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148444192","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 in the Martian Subsurface: Advancements in Microbial Metabolic Research under Mars Laboratory and Field-Analog Conditions since Viking.","authors":"Devan M Nisson, Rebecca L Mickol, Adam Robinson, Karen G Lloyd","doi":"10.1177/15311074261464014","DOIUrl":"10.1177/15311074261464014","url":null,"abstract":"<p><p>Following the Viking experiments in 1976, many of the original inferences of biological metabolism have been replicated via abiotic mechanisms we now know are plausible on Mars' surface. While in many cases subsequent experiments have cast doubt on whether Viking truly detected life, numerous other studies since Viking have greatly expanded our knowledge of life's limits and microbial metabolism. In particular, increased characterization of Earth's subsurface has revealed the astounding complexity and adaptability of life, highlighting chemically based metabolisms as potentially strong targets for future life detection missions. Over the same time frame, we have gained knowledge of putatively more habitable regions in Mars' subsurface, relative to the original Viking lander surface sites, that could host similar organisms. In this review, we discuss the wealth of knowledge concerning the habitability of zones across Mars' surface/subsurface, and we suggest specific microbial metabolisms that should be targeted in future life detection missions based on laboratory and field studies under analogous conditions on Earth and with consideration of recommendations from the larger Astrobiology community. The ability to leverage these advancements in subsurface research toward the incorporation of increased specificity in future life detection efforts is additionally discussed in the context of current Mars subsurface mission progress and planetary protection and defense concerns.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"53S-71S"},"PeriodicalIF":2.3,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148337509","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}