Astrobiology最新文献_第5页

Introducing the Collection of Papers from the Second Workshop on Habitability of the Venus Cloud Layer and Related Research. 介绍第二届金星云层可居住性及相关研究研讨会论文集。

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-04-01 DOI: 10.1089/ast.2024.2902

Sanjay S Limaye, James B Garvin

引用次数: 0

Chapter 9: Life as We Don't Know It. 第 9 章：我们不知道的生活。

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-03-01 DOI: 10.1089/ast.2021.0103

Natalie Grefenstette, Luoth Chou, Stephanie Colón-Santos, Theresa M Fisher, Veronica Mierzejewski, Ceren Nural, Pritvik Sinhadc, Monica Vidaurri, Lena Vincent, Maggie Meiqi Weng

{"title":"Chapter 9: Life as We Don't Know It.","authors":"Natalie Grefenstette, Luoth Chou, Stephanie Colón-Santos, Theresa M Fisher, Veronica Mierzejewski, Ceren Nural, Pritvik Sinhadc, Monica Vidaurri, Lena Vincent, Maggie Meiqi Weng","doi":"10.1089/ast.2021.0103","DOIUrl":"10.1089/ast.2021.0103","url":null,"abstract":"While Earth contains the only known example of life in the universe, it is possible that life elsewhere is fundamentally different from what we are familiar with. There is an increased recognition in the astrobiology community that the search for life should steer away from terran-specific biosignatures to those that are more inclusive to all life-forms. To start exploring the space of possibilities that life could occupy, we can try to dissociate life from the chemistry that composes it on Earth by envisioning how different life elsewhere could be in composition, lifestyle, medium, and form, and by exploring how the general principles that govern living systems on Earth might be found in different forms and environments across the Solar System. Exotic life-forms could exist on Mars or Venus, or icy moons like Europa and Enceladus, or even as a shadow biosphere on Earth. New perspectives on agnostic biosignature detection have also begun to emerge, allowing for a broader and more inclusive approach to seeking exotic life with unknown chemistry that is distinct from life as we know it on Earth.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140157507","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

Detectability of Surface Biosignatures for Directly Imaged Rocky Exoplanets. 直接成像岩质系外行星表面生物特征的可探测性。

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-03-01 Epub Date: 2024-02-19 DOI: 10.1089/ast.2023.0099

Schuyler R Borges, Gabrielle G Jones, Tyler D Robinson

{"title":"Detectability of Surface Biosignatures for Directly Imaged Rocky Exoplanets.","authors":"Schuyler R Borges, Gabrielle G Jones, Tyler D Robinson","doi":"10.1089/ast.2023.0099","DOIUrl":"10.1089/ast.2023.0099","url":null,"abstract":"Modeling the detection of life has never been more opportune. With next-generation space telescopes, such as the currently developing Habitable Worlds Observatory (HWO) concept, we will begin to characterize rocky exoplanets potentially similar to Earth. However, few realistic planetary spectra containing surface biosignatures have been paired with direct imaging telescope instrument models. Therefore, we use a HWO instrument noise model to assess the detection of surface biosignatures affiliated with oxygenic, anoxygenic, and nonphotosynthetic extremophiles. We pair the HWO telescope model to a one-dimensional radiative transfer model to estimate the required exposure times necessary for detecting each biosignature on planets with global microbial coverage and varying atmospheric water vapor concentrations. For modeled planets with 0-50% cloud coverage, we determine pigments and the red edge could be detected within 1000 hr (100 hr) at distances within 15 pc (11 pc). However, tighter telescope inner working angles (2.5 λ/D) would allow surface biosignature detection at further distances. Anoxygenic photosynthetic biosignatures could also be more easily detectable than nonphotosynthetic pigments and the photosynthetic red edge when compared against a false positive iron oxide slope. Future life detection missions should evaluate the influence of false positives on the detection of multiple surface biosignatures.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139911952","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

Correction to: Astrobiology 2023;23(12):1303-1336. Correction to：Astrobiology 2023;23(12):1303-1336.

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-03-01 DOI: 10.1089/ast.2022.0133.correx

引用次数: 0

Chapter 5: Major Biological Innovations in the History of Life on Earth. 第 5 章：地球生命史上的重大生物创新。

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-03-01 DOI: 10.1089/ast.2021.0119

G Ozan Bozdag, Nadia Szeinbaum, Peter L Conlin, Kimberly Chen, Santiago Mestre Fos, Amanda Garcia, Petar I Penev, George A Schaible, Gareth Trubl

{"title":"Chapter 5: Major Biological Innovations in the History of Life on Earth.","authors":"G Ozan Bozdag, Nadia Szeinbaum, Peter L Conlin, Kimberly Chen, Santiago Mestre Fos, Amanda Garcia, Petar I Penev, George A Schaible, Gareth Trubl","doi":"10.1089/ast.2021.0119","DOIUrl":"10.1089/ast.2021.0119","url":null,"abstract":"All organisms living on Earth descended from a single, common ancestral population of cells, known as LUCA-the last universal common ancestor. Since its emergence, the diversity and complexity of life have increased dramatically. This chapter focuses on four key biological innovations throughout Earth's history that had a significant impact on the expansion of phylogenetic diversity, organismal complexity, and ecospace habitation. First is the emergence of the last universal common ancestor, LUCA, which laid the foundation for all life-forms on Earth. Second is the evolution of oxygenic photosynthesis, which resulted in global geochemical and biological transformations. Third is the appearance of a new type of cell-the eukaryotic cell-which led to the origin of a new domain of life and the basis for complex multicellularity. Fourth is the multiple independent origins of multicellularity, resulting in the emergence of a new level of complex individuality. A discussion of these four key events will improve our understanding of the intertwined history of our planet and its inhabitants and better inform the extent to which we can expect life at different degrees of diversity and complexity elsewhere.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11071111/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140157503","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}

引用次数: 0

Chapter 4: A Geological and Chemical Context for the Origins of Life on Early Earth. 第 4 章：早期地球生命起源的地质和化学背景。

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-03-01 DOI: 10.1089/ast.2021.0139

Laura E Rodriguez, Thiago Altair, Ninos Y Hermis, Tony Z Jia, Tyler P Roche, Luke H Steller, Jessica M Weber

引用次数: 0

Chapter 8: Searching for Life Beyond Earth. 第 8 章：寻找地球之外的生命。

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-03-01 DOI: 10.1089/ast.2021.0104

Luoth Chou, Natalie Grefenstette, Schuyler Borges, Tristan Caro, Enrico Catalano, Chester E Harman, Jordan McKaig, Chinmayee Govinda Raj, Gareth Trubl, Amber Young

{"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":"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 in situ 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.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"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}

引用次数: 0

Foreword to the Astrobiology Primer 3.0. 天体生物学入门 3.0》前言。

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-03-01 DOI: 10.1089/ast.2023.0116

Lucas Mix

引用次数: 0

Considerations for Detecting Organic Indicators of Metabolism on Enceladus. 检测恩克拉多斯新陈代谢有机指标的考虑因素。

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-03-01 DOI: 10.1089/ast.2023.0074

Laura M Barge, Gregory P Fournier

{"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":"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.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"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}

引用次数: 0

Fluorescence Microscopy with Deep UV, Near UV, and Visible Excitation for In Situ Detection of Microorganisms. 利用深紫外、近紫外和可见光激发的荧光显微镜对微生物进行现场检测。

IF 4.2 3区物理与天体物理

Astrobiology Pub Date : 2024-03-01 DOI: 10.1089/ast.2023.0020

Noel Case, Nikki Johnston, Jay Nadeau

{"title":"Fluorescence Microscopy with Deep UV, Near UV, and Visible Excitation for In Situ 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":"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.","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":null,"pages":null},"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}

引用次数: 0