Astrobiology最新文献

{"title":"In Memoriam: David Hochberg (1957-2023).","authors":"Celia Blanco, Thomas Buhse, Pedro Cintas, Isabel Herreros, Jean-Claude Micheau, Federico Morán, Juan Pérez-Mercader, Josep M Ribó, Michael Stich, Cristóbal Viedma","doi":"10.1089/ast.2024.0030","DOIUrl":"https://doi.org/10.1089/ast.2024.0030","url":null,"abstract":"","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141454954","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 Concept of Life on Venus Informs the Concept of Habitability.","authors":"Charles S Cockell, John E Hallsworth, Sean McMahon, Stephen R Kane, Peter M Higgins","doi":"10.1089/ast.2023.0106","DOIUrl":"10.1089/ast.2023.0106","url":null,"abstract":"<p><p>An enduring question in astrobiology is how we assess extraterrestrial environments as being suitable for life. We suggest that the most reliable assessments of the habitability of extraterrestrial environments are made with respect to the empirically determined limits to known life. We discuss qualitatively distinct categories of habitability: <i>empirical habitability</i> that is constrained by the observed limits to biological activity; <i>habitability</i> sensu stricto, which is defined with reference to the known or unknown limits to the activity of all known organisms; and <i>habitability</i> sensu lato (habitability in the broadest sense), which is circumscribed by the limit of all possible life in the universe, which is the most difficult (and perhaps impossible) to determine. We use the cloud deck of Venus, which is temperate but incompatible with known life, as an example to elaborate and hypothesize on these limits.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"628-634"},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141154912","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":"Astrobiology by Gavriil Tikhov.","authors":"Charles S Cockell","doi":"10.1089/ast.2024.0036","DOIUrl":"https://doi.org/10.1089/ast.2024.0036","url":null,"abstract":"","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 6","pages":"643-668"},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141449503","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":"Exploiting the Unique Biology of <i>Caenorhabditis elegans</i> to Launch Neurodegeneration Studies in Space.","authors":"Tatyana Itkin, Ksenia Unger, Yair Barak, Amit Yovel, Liya Stekolshchik, Linoy Ego, Yana Aydinov, Yoram Gerchman, Amir Sapir","doi":"10.1089/ast.2023.0096","DOIUrl":"https://doi.org/10.1089/ast.2023.0096","url":null,"abstract":"<p><p>The 21st century is likely to be the first century in which large-scale short- and long-term space missions become common. Accordingly, an ever-increasing body of research is focusing on understanding the effects of current and future space expeditions on human physiology in health and disease. Yet the complex experimental environment, the small number of participants, and the high cost of space missions are among the primary factors that hinder a better understanding of the impact of space missions on human physiology. The goal of our research was to develop a cost-effective, compact, and easy-to-manipulate system to address questions related to human health and disease in space. This initiative was part of the Ramon SpaceLab program, an annual research-based learning program designed to cultivate high school students' involvement in space exploration by facilitating experiments aboard the International Space Station (ISS). In the present study, we used the nematode <i>Caenorhabditis elegans</i> (<i>C. elegans</i>), a well-suited model organism, to investigate the effect of space missions on neurodegeneration-related processes. Our study specifically focused on the level of aggregation of Huntington's disease-causing polyglutamine stretch-containing (PolyQ) proteins in <i>C. elegans</i> muscles, the canonical system for studying neurodegeneration in this organism. We compared animals expressing PolyQ proteins grown onboard the ISS with their genetically identical siblings grown on Earth and observed a significant difference in the number of aggregates between the two populations. Currently, it is challenging to determine whether this effect stems from developmental or morphological differences between the cultures or is a result of life in space. Nevertheless, our results serve as a proof of concept and open a new avenue for utilizing <i>C. elegans</i> to address various open questions in space studies, including the effects of space conditions on the onset and development of neurodegenerative diseases.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 6","pages":"579-589"},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141449504","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":"Exoplanet Innovators Interview: Sara Seager Interviews Ignas Snellen.","authors":"Sara Seager","doi":"10.1089/ast.2024.0044","DOIUrl":"10.1089/ast.2024.0044","url":null,"abstract":"","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"635-642"},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141247112","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":"Quantifying the Potential for Nitrate-Dependent Iron Oxidation on Early Mars: Implications for the Interpretation of Gale Crater Organics.","authors":"Lucas M Fifer, Michael L Wong","doi":"10.1089/ast.2023.0109","DOIUrl":"10.1089/ast.2023.0109","url":null,"abstract":"<p><p>Geological evidence and atmospheric and climate models suggest habitable conditions occurred on early Mars, including in a lake in Gale crater. Instruments aboard the Curiosity rover measured organic compounds of unknown provenance in sedimentary mudstones at Gale crater. Additionally, Curiosity measured nitrates in Gale crater sediments, which suggests that nitrate-dependent Fe²⁺ oxidation (NDFO) may have been a viable metabolism for putative martian life. Here, we perform the first quantitative assessment of an NDFO community that could have existed in an ancient Gale crater lake and quantify the long-term preservation of biological necromass in lakebed mudstones. We find that an NDFO community would have the capacity to produce cell concentrations of up to 10⁶ cells mL^-1, which is comparable to microbes in Earth's oceans. However, only a concentration of <10⁴ cells mL^-1, due to organisms that inefficiently consume less than 10% of precipitating nitrate, would be consistent with the abundance of organics found at Gale. We also find that meteoritic sources of organics would likely be insufficient as a sole source for the Gale crater organics, which would require a separate source, such as abiotic hydrothermal or atmospheric production or possibly biological production from a slowly turning over chemotrophic community.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"590-603"},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141157262","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":"Sharp Rise in Cosmic Ray Irradiation of Organisms on Earth Caused by a Nearby SN Shockwave Passage.","authors":"A A Shchepkin, G I Vasilyev, V M Ostryakov, A K Pavlov","doi":"10.1089/ast.2023.0126","DOIUrl":"10.1089/ast.2023.0126","url":null,"abstract":"<p><p>The work considers the modelling of nearby supernova (SN) effects on Earth's biosphere via cosmic rays (CRs) accelerated by shockwaves. The rise of the radiation background on Earth resulted from the external irradiation by CR high-energy particles and internal radiation in organisms by the decay of cosmogenic ¹⁴C is evaluated. We have taken into account that the CR flux near Earth goes up steeply when the shockwave crosses the Solar System, while in previous works the CR transport was considered as purely diffusive. Our simulations demonstrate a high rise of the external ionization of the environments at Earth's surface by atmospheric cascade particles that penetrate the first 70-100 m of water depth. Also, the cosmogenic ¹⁴C decay is able to irradiate the entire biosphere and deep ocean organisms. We analyzed the probable increase in mutation rate and estimated the distance between Earth and an SN, where the lethal effects of irradiation are possible. Our simulations demonstrate that for SN energy of around 10⁵¹ erg the lethal distance could be ∼18 pc.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"604-612"},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140891210","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":"Rebuilding the Habitable Zone from the Bottom up with Computational Zones.","authors":"Caleb Scharf, Olaf Witkowski","doi":"10.1089/ast.2023.0035","DOIUrl":"10.1089/ast.2023.0035","url":null,"abstract":"<p><p>Computation, if treated as a set of physical processes that act on information represented by states of matter, encompasses biological systems, digital systems, and other constructs and may be a fundamental measure of living systems. The opportunity for biological computation, represented in the propagation and selection-driven evolution of information-carrying organic molecular structures, has been partially characterized in terms of planetary habitable zones (HZs) based on primary conditions such as temperature and the presence of liquid water. A generalization of this concept to computational zones (CZs) is proposed, with constraints set by three principal characteristics: capacity (including computation rates), energy, and instantiation (or substrate, including spatial extent). CZs naturally combine traditional habitability factors, including those associated with biological function that incorporate the chemical milieu, constraints on nutrients and free energy, as well as element availability. Two example applications are presented by examining the fundamental thermodynamic work efficiency and Landauer limit of photon-driven biological computation on planetary surfaces and of generalized computation in stellar energy capture structures (a.k.a. Dyson structures). It is suggested that CZs that involve nested structures or substellar objects could manifest unique observational signatures as cool far-infrared emitters. While these latter scenarios are entirely hypothetical, they offer a useful, complementary introduction to the potential universality of CZs.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"613-627"},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141295433","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":"Exoplanet Innovators Interview: Sara Seager Interviews Diana Valencia.","authors":"Sara Seager","doi":"10.1089/ast.2024.0025","DOIUrl":"https://doi.org/10.1089/ast.2024.0025","url":null,"abstract":"","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":"24 5","pages":"570-576"},"PeriodicalIF":4.2,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141070522","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":"Abiotic Ribose Synthesis Under Aqueous Environments with Various Chemical Conditions.","authors":"Chinatsu Ono, Sako Sunami, Yuka Ishii, Hyo-Joong Kim, Takeshi Kakegawa, Steven A Benner, Yoshihiro Furukawa","doi":"10.1089/ast.2023.0071","DOIUrl":"10.1089/ast.2023.0071","url":null,"abstract":"<p><p>Ribose is the defining sugar in ribonucleic acid (RNA), which is often proposed to have carried the genetic information and catalyzed the biological reactions of the first life on Earth. Thus, abiological processes that yield ribose under prebiotic conditions have been studied for decades. However, aqueous environments required for the formation of ribose from materials available in quantity under geologically reasonable models, where the ribose formed is not immediately destroyed, remain unclear. This is due in large part to the challenge of analysis of carbohydrates formed under a wide range of aqueous conditions. Thus, the formation of ribose on prebiotic Earth has sometimes been questioned. We investigated the quantitative effects of pH, temperature, cation, and the concentrations of formaldehyde and glycolaldehyde on the synthesis of diverse sugars, including ribose. The results suggest a range of conditions that produce ribose and that ribose could have formed in constrained aquifers on prebiotic Earth.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"489-497"},"PeriodicalIF":4.2,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140847856","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}