Astrobiology最新文献_第4页

Membrane-Spanning Molecular Lengths as an Agnostic Biosignature. 跨膜分子长度作为一种不可知论的生物标志。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-05-01 Epub Date: 2025-05-05 DOI: 10.1089/ast.2024.0125

Michael J Malaska, Hilda Sandström, Amy E Hofmann, Robert Hodyss, Linnea Rensmo, Mark van der Meulen, Martin Rahm, Morgan L Cable, Jonathan I Lunine

{"title":"Membrane-Spanning Molecular Lengths as an Agnostic Biosignature.","authors":"Michael J Malaska, Hilda Sandström, Amy E Hofmann, Robert Hodyss, Linnea Rensmo, Mark van der Meulen, Martin Rahm, Morgan L Cable, Jonathan I Lunine","doi":"10.1089/ast.2024.0125","DOIUrl":"10.1089/ast.2024.0125","url":null,"abstract":"We explore a hypothesis in which the detection of classes of lipid-like molecules with similar abundance-averaged lengths would constitute a biosignature for other worlds. This is based on the functional requirements of membrane molecules: they must have enough hydrophobic length to not diffuse away from the membrane, be capped by one or two hydrophilic polar groups, and also maintain a semipermeable membrane. Our hypothesis is that once membrane thickness is set in a biological system, it is very difficult to modify it, due to the necessity to redesign all the other associated molecules; the membrane thickness will be constant across all molecular classes that constitute membranes resulting from a common ancestor. In such a scenario, similar thickness values would thus constitute a biosignature and cross-correlate between different molecular classes. We tested this hypothesis by developing a simple method to use modeled lengths of lipid-like molecules to estimate the thicknesses of membranes formed by these molecules. We examined abundance patterns of four different classes of membrane molecules used by terrestrial life: fatty acids, glycerol dialkyl glycerol tetraether lipids, carotenoids, and ladderanes from microbial isolates and environmental samples, as well as abiotic samples of fatty acids. We found that the modeled cell membrane thicknesses from each of these molecular classes were similar and gave results consistent with the observed values. From these results, we propose that our approach provides a framework to identify potential membrane component molecules as an agnostic biosignature. The power of our approach is that our method enables multiple molecular classes to be compared and provides increasing confidence of a biological detection.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"25 5","pages":"367-389"},"PeriodicalIF":3.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143952863","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}

引用次数: 0

Applied Astrobiology: An Integrated Approach to the Future of Life in Space. 应用天体生物学：未来太空生活的综合方法。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-05-01 Epub Date: 2025-04-22 DOI: 10.1089/ast.2024.0156

Robin Wordsworth, Collin Cherubim, Shannon Nangle, Aaron Berliner, Esther Dyson, Peter Girguis, David Grinspoon, Rachel Harris, Ken Liu, Adam Marblestone, Chris Mason, Ryan Morhard, Dimitar D Sasselov, Sara Seager, Robert Wood, Peter Worden

引用次数: 0

Rosalind Franklin Society Proudly Announces the 2024 Award Recipient for Astrobiology. 罗莎琳德·富兰克林学会自豪地宣布2024年天体生物学奖得主。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-04-01 DOI: 10.1089/ast.2024.0037.rfs2024

Manasvi Lingam

引用次数: 0

Simple Lipids Form Stable Higher-Order Structures in Concentrated Sulfuric Acid. 简单脂类在浓硫酸中形成稳定的高阶结构。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-04-01 Epub Date: 2025-03-26 DOI: 10.1089/ast.2024.0124

Daniel Duzdevich, Collin Nisler, Janusz J Petkowski, William Bains, Caroline K Kaminsky, Jack W Szostak, Sara Seager

{"title":"Simple Lipids Form Stable Higher-Order Structures in Concentrated Sulfuric Acid.","authors":"Daniel Duzdevich, Collin Nisler, Janusz J Petkowski, William Bains, Caroline K Kaminsky, Jack W Szostak, Sara Seager","doi":"10.1089/ast.2024.0124","DOIUrl":"10.1089/ast.2024.0124","url":null,"abstract":"Venus has become a target of astrobiological interest because it is physically accessible to direct exploration, unlike exoplanets. So far this interest has been motivated not by the explicit expectation of finding life but rather by a desire to understand the limits of biology. The venusian surface is sterilizing, but the cloud deck includes regions with temperatures and pressures conventionally considered compatible with life. However, the venusian clouds are thought to consist of concentrated sulfuric acid. To determine if any fundamental features of life as we understand them here on Earth could in principle exist in these extreme solvent conditions, we tested several simple lipids for resistance to solvolysis and their ability to form structures in concentrated sulfuric acid. We find that single-chain saturated lipids with sulfate, alcohol, trimethylamine, and phosphonate head groups are resistant to sulfuric acid degradation at room temperature. Furthermore, we find that they form stable higher-order structures typically associated with lipid membranes, micelles, and vesicles. Finally, results from molecular dynamics simulations suggest a molecular explanation for the observed robustness of the lipid structures formed in concentrated sulfuric acid. We conclude with implications for the study of Venus as a target of experimental astrobiology.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"270-283"},"PeriodicalIF":3.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727633","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}

引用次数: 0

Traces of Bacterial Contribution to Calcite Weathering Detected by Statistical Characterizations of Surface Microtopography. 细菌对方解石风化作用的表面微地形统计特征分析。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-04-01 Epub Date: 2025-03-26 DOI: 10.1089/ast.2024.0084

Luca Stigliano, Karim Benzerara, Philippe Ackerer, Nicolas Menguy, Cynthia Travert, Fériel Skouri-Panet, Damien Daval

{"title":"Traces of Bacterial Contribution to Calcite Weathering Detected by Statistical Characterizations of Surface Microtopography.","authors":"Luca Stigliano, Karim Benzerara, Philippe Ackerer, Nicolas Menguy, Cynthia Travert, Fériel Skouri-Panet, Damien Daval","doi":"10.1089/ast.2024.0084","DOIUrl":"10.1089/ast.2024.0084","url":null,"abstract":"There is a crucial need to identify reliable imprints of microbe-mineral interactions to quantify the contribution of microorganisms to chemical weathering and detect traces of life in the geological record. Yet conventional methods based on qualitative descriptions of supposedly bioinduced etching features have often proven equivocal. Here, calcite dissolution experiments were carried out at various solution compositions, in the presence or absence of cyanobacterial biofilms. Nanoscale chemical and crystallographic characterizations failed to detect any distinctive biogenicity feature. Conversely, high-elevation regions at the calcite surface were detected through statistical characterizations of the microtopography, which made microbially weathered surfaces quantitatively distinguishable from their abiotic counterparts. Interestingly, the high-elevation regions that formed beneath clusters of microbial cells are at odds with the etching features that resemble cell morphologies and are usually sought as bioweathering markers. Atomic-scale stochastic simulations of the dissolution process suggested that these regions resulted from a local increase in fluid saturation state at the biofilm-mineral contact, which led to a localized reduction in dissolution rates. Overall, this study offers a new avenue for the nondestructive identification of bioweathering signatures in natural settings.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"296-308"},"PeriodicalIF":3.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143708238","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}

引用次数: 0

Spectroscopic Protocol for Biosignature Detection: Arctic Ice Samples as Analogs for Icy Moons. 生物签名检测的光谱协议：北极冰样品作为冰卫星的类似物。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-04-01 Epub Date: 2025-03-28 DOI: 10.1089/ast.2024.0131

Francisco Calapez, Rodrigo Dias, Rute Cesário, Bruno Pedras, João Canário, Zita Martins

{"title":"Spectroscopic Protocol for Biosignature Detection: Arctic Ice Samples as Analogs for Icy Moons.","authors":"Francisco Calapez, Rodrigo Dias, Rute Cesário, Bruno Pedras, João Canário, Zita Martins","doi":"10.1089/ast.2024.0131","DOIUrl":"10.1089/ast.2024.0131","url":null,"abstract":"The moons of Jupiter and Saturn, such as Europa and Enceladus, are strong candidates for the search for life outside of Earth. Together with the use of direct observational methods, physical and chemical processes that take place on icy moons may be studied on planetary field analogs, that is, on similar reachable locations on Earth. Fieldwork performed on planetary field analogs can test protocols and technology that may be applied on future space missions to extraterrestrial environments. The Arctic is a strong candidate for such studies. This study assesses a spectroscopic protocol for biosignature detection in the Arctic, as a proxy to icy moons. Samples of ice and the water underneath were collected by our team in different locations at and nearby Hudson Bay, Canada, and spectroscopic analysis detected the presence of humic acid in all the samples. On the contrary, biosignatures such as amino acids and β-carotene may have been present in concentrations below the limit of detection of the equipment used. With proper optimization, it will be possible to implement this simple protocol that relies on lightweight equipment in future space missions to icy moons.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"284-295"},"PeriodicalIF":3.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727635","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}

引用次数: 0

Humidity Enhancement in Dry Permafrost: The Effects of Temperature Cycles on Habitability. 干燥永久冻土的湿度增强：温度循环对可居住性的影响。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-03-28 DOI: 10.1089/ast.2024.0148

Michael T Mellon, Aldin F Aksay, Hanna G Sizemore, Christopher P McKay

{"title":"Humidity Enhancement in Dry Permafrost: The Effects of Temperature Cycles on Habitability.","authors":"Michael T Mellon, Aldin F Aksay, Hanna G Sizemore, Christopher P McKay","doi":"10.1089/ast.2024.0148","DOIUrl":"https://doi.org/10.1089/ast.2024.0148","url":null,"abstract":"The search for life in the solar system often focuses on water and on environments where habitable conditions exist, persistently or occasionally. In this search, dry permafrost (ice-free frozen soil) has received minimal attention. It was previously proposed that within martian dry permafrost the water activity (<math><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>w</mi></mrow></msub></mrow></math>, an essential property for habitability) could be enhanced by diurnal thermal cycles and water desorption from soil grains, but the details remain unexplored. We examined <math><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>w</mi></mrow></msub></mrow></math> in dry soil (which contained only vapor and adsorbed water) through experiments and numerical simulations and contrasted the results with a habitability threshold for terrestrial organisms (<math><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>w</mi></mrow></msub></mrow><mo> </mo><mo> </mo><mo>></mo><mo> </mo><mo> </mo><mn>0.6</mn></math>). We found that heating cycles in a soil raised <math><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>w</mi></mrow></msub></mrow></math>. As water vapor desorbs from warming soil grains, it diffuses toward cooler adjacent soil, where a fraction of this incoming vapor enhances the local <math><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>w</mi></mrow></msub></mrow></math>. In laboratory tests with loess and clay soils, we observed <math><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>w</mi></mrow></msub></mrow></math> to increase by 0.06-0.12. Extrapolating from laboratory to permafrost conditions by using numerical simulations, we found that some Antarctic soils can be boosted periodically into a habitable range. In contrast, the current martian climate is too dry or cold for this <math><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>w</mi></mrow></msub></mrow></math>-enhancement process to impact habitability. However, high-obliquity periods on Mars are analogous to the Antarctic case.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727631","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}

引用次数: 0

Tectonics and Surface Environments on Early Earth. 早期地球的构造和地表环境。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-03-26 DOI: 10.1089/ast.2024.0093

Jun Korenaga

引用次数: 0

How Habitable Are M Dwarf Exoplanets? Modeling Surface Conditions and Exploring the Role of Melanins in the Survival of Aspergillus niger Spores Under Exoplanet-Like Radiation. M矮系外行星有多适合居住？模拟地表条件并探索黑色素在类系外行星辐射下黑曲霉孢子存活中的作用。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-03-01 Epub Date: 2025-03-05 DOI: 10.1089/ast.2024.0023

Afonso Mota, Stella Koch, Daniel Matthiae, Nuno Santos, Marta Cortesão

{"title":"How Habitable Are M Dwarf Exoplanets? Modeling Surface Conditions and Exploring the Role of Melanins in the Survival of Aspergillus niger Spores Under Exoplanet-Like Radiation.","authors":"Afonso Mota, Stella Koch, Daniel Matthiae, Nuno Santos, Marta Cortesão","doi":"10.1089/ast.2024.0023","DOIUrl":"10.1089/ast.2024.0023","url":null,"abstract":"Exoplanet habitability remains a challenging field due to the large distances separating Earth from other stars. Using insights from biology and astrophysics, we studied the habitability of M dwarf exoplanets by modeling their surface temperature and flare ultraviolet (UV) and X-ray doses using the martian atmosphere as a shielding model. Analyzing the Proxima Centauri and TRAPPIST-1 systems, our models suggest that Proxima b and TRAPPIST-1 e are likeliest to have temperatures compatible with surface liquid water, as well as tolerable radiation environments. Results of the modeling were used as a basis for microbiology experiments to assess spore survival and germination of the melanin-rich fungus Aspergillus niger to exoplanet-like radiation (UV-C and X-rays). Results showed that A. niger spores can endure superflare events on M dwarf planets when shielded by a Mars-like atmosphere or by a thin layer of soil or water. Melanin-deficient spores suspended in a melanin-rich solution showed higher survival rates and germination efficiency when compared to melanin-free solutions. Overall, the models developed in this work establish a framework for microbiological research in habitability studies. Finally, we showed that A. niger spores can survive harsh radiation conditions of simulated exoplanets, which also emphasizes the importance of multifunctional molecules like melanins in radiation shielding beyond Earth.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"161-176"},"PeriodicalIF":3.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555576","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}

引用次数: 0

Ammonia or Methanol Would Enable Subsurface Liquid Water at the Martian South Pole. 氨或甲醇将使火星南极的地下液态水成为可能。

IF 3.5 3区物理与天体物理

Astrobiology Pub Date : 2025-03-01 Epub Date: 2025-02-17 DOI: 10.1089/ast.2024.0075

Isabel Egea-González, Christopher P McKay, John E Hallsworth, Alberto Jiménez-Díaz, Javier Ruiz

引用次数: 0