Pub Date : 2021-12-15DOI: 10.1017/s1473550421000367
Octavio A. Chon-Torres, K. Szocik
Astrotheology is presented as a discipline of study that manages to complement theology and science. It considers that each one has its own role and that as long as there is no reductionism that wants to monopolize the place of the other, fluid communication between both is possible. Therefore, it is worth examining epistemologically astrotheology in the light of astrobiology. To achieve this, we will highlight the aspect of experience in order to relate it to transdisciplinarity.
{"title":"A brief epistemological discussion of astrotheology in the light of astrobiology","authors":"Octavio A. Chon-Torres, K. Szocik","doi":"10.1017/s1473550421000367","DOIUrl":"https://doi.org/10.1017/s1473550421000367","url":null,"abstract":"\u0000 Astrotheology is presented as a discipline of study that manages to complement theology and science. It considers that each one has its own role and that as long as there is no reductionism that wants to monopolize the place of the other, fluid communication between both is possible. Therefore, it is worth examining epistemologically astrotheology in the light of astrobiology. To achieve this, we will highlight the aspect of experience in order to relate it to transdisciplinarity.","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43803574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-12-14DOI: 10.1017/s1473550421000355
L. D. da Silva
We present an alternative equation to estimate the probable number N of self-conscious intelligent technological societies (SCITSs) within the radius of the observable universe. This equation has only one poorly-known factor, Pc, the SCITS's formation probability, which can be estimated within an uncertainty by a factor of 102 (10−11 ≤ Pc ≤ 10−9) by applying the restriction imposed by Fermi's Paradox. The SCITS's formation rate for a typical spiral galaxy is then estimated as ≈1 civ Gyr−1. For a very optimistic maximum life expectancy ≈108 yr, the conclusion is that two civilizations never coexist in the same galaxy. Our estimated values for Pc are compatible with current biological and astrophysical evidences. We also propose an alternative astrosociological classification scheme which enables us to speculate about possible evolutionary paths for SCITSs in the universe. The so-called ‘Closed Bottle Neck’ (CBN) scenario suggests that civilizations are no exit evolutionary ways. We argue that simply there would not be interstellar travels nor Galaxy colonization or a Galactic Club. Thus Fermi's Paradox results eliminated, and the perspectives about the future of our own civilization may not be positive.
{"title":"Self-conscious intelligent technological societies in the universe: a simple direct approach to probable astrosociological realistic scenarios","authors":"L. D. da Silva","doi":"10.1017/s1473550421000355","DOIUrl":"https://doi.org/10.1017/s1473550421000355","url":null,"abstract":"\u0000 We present an alternative equation to estimate the probable number N of self-conscious intelligent technological societies (SCITSs) within the radius of the observable universe. This equation has only one poorly-known factor, Pc, the SCITS's formation probability, which can be estimated within an uncertainty by a factor of 102 (10−11 ≤ Pc ≤ 10−9) by applying the restriction imposed by Fermi's Paradox. The SCITS's formation rate for a typical spiral galaxy is then estimated as ≈1 civ Gyr−1. For a very optimistic maximum life expectancy ≈108 yr, the conclusion is that two civilizations never coexist in the same galaxy. Our estimated values for Pc are compatible with current biological and astrophysical evidences. We also propose an alternative astrosociological classification scheme which enables us to speculate about possible evolutionary paths for SCITSs in the universe. The so-called ‘Closed Bottle Neck’ (CBN) scenario suggests that civilizations are no exit evolutionary ways. We argue that simply there would not be interstellar travels nor Galaxy colonization or a Galactic Club. Thus Fermi's Paradox results eliminated, and the perspectives about the future of our own civilization may not be positive.","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48289181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-12-01DOI: 10.1017/S1473550421000276
H. Changela, E. Chatzitheodoridis, André Antunes, D. Beaty, Kristian Bouw, J. Bridges, K. Capova, C. Cockell, C. Conley, E. Dadachova, T. D. Dallas, S. de Mey, C. Dong, A. Ellery, M. Ferus, B. Foing, Xiaohui Fu, K. Fujita, Yangting Lin, S. Jheeta, L. Hicks, Sen Hu, Á. Kereszturi, Alexandros Krassakis, Yang Liu, J. Oberst, J. Michalski, P. M. Ranjith, T. Rinaldi, D. Rothery, Hector A. Stavrakakis, L. Selbmann, R. K. Sinha, Alian Wang, K. Williford, Z. Váci, J. Vago, M. Waltemathe, J. E. Hallsworth
Mars exploration motivates the search for extraterrestrial life, the development of space technologies, and the design of human missions and habitations. Here, we seek new insights and pose unresolved questions relating to the natural history of Mars, habitability, robotic and human exploration, planetary protection, and the impacts on human society. Key observations and findings include: – high escape rates of early Mars' atmosphere, including loss of water, impact present-day habitability; – putative fossils on Mars will likely be ambiguous biomarkers for life; – microbial contamination resulting from human habitation is unavoidable; and – based on Mars' current planetary protection category, robotic payload(s) should characterize the local martian environment for any life-forms prior to human habitation. Some of the outstanding questions are: – which interpretation of the hemispheric dichotomy of the planet is correct; – to what degree did deep-penetrating faults transport subsurface liquids to Mars' surface; – in what abundance are carbonates formed by atmospheric processes; – what properties of martian meteorites could be used to constrain their source locations; – the origin(s) of organic macromolecules; – was/is Mars inhabited; – how can missions designed to uncover microbial activity in the subsurface eliminate potential false positives caused by microbial contaminants from Earth; – how can we ensure that humans and microbes form a stable and benign biosphere; and – should humans relate to putative extraterrestrial life from a biocentric viewpoint (preservation of all biology), or anthropocentric viewpoint of expanding habitation of space? Studies of Mars' evolution can shed light on the habitability of extrasolar planets. In addition, Mars exploration can drive future policy developments and confirm (or put into question) the feasibility and/or extent of human habitability of space.
{"title":"Mars: new insights and unresolved questions","authors":"H. Changela, E. Chatzitheodoridis, André Antunes, D. Beaty, Kristian Bouw, J. Bridges, K. Capova, C. Cockell, C. Conley, E. Dadachova, T. D. Dallas, S. de Mey, C. Dong, A. Ellery, M. Ferus, B. Foing, Xiaohui Fu, K. Fujita, Yangting Lin, S. Jheeta, L. Hicks, Sen Hu, Á. Kereszturi, Alexandros Krassakis, Yang Liu, J. Oberst, J. Michalski, P. M. Ranjith, T. Rinaldi, D. Rothery, Hector A. Stavrakakis, L. Selbmann, R. K. Sinha, Alian Wang, K. Williford, Z. Váci, J. Vago, M. Waltemathe, J. E. Hallsworth","doi":"10.1017/S1473550421000276","DOIUrl":"https://doi.org/10.1017/S1473550421000276","url":null,"abstract":"\u0000 Mars exploration motivates the search for extraterrestrial life, the development of space technologies, and the design of human missions and habitations. Here, we seek new insights and pose unresolved questions relating to the natural history of Mars, habitability, robotic and human exploration, planetary protection, and the impacts on human society. Key observations and findings include:\u0000\u0000 \u0000 –\u0000 high escape rates of early Mars' atmosphere, including loss of water, impact present-day habitability;\u0000 \u0000 \u0000 –\u0000 putative fossils on Mars will likely be ambiguous biomarkers for life;\u0000 \u0000 \u0000 –\u0000 microbial contamination resulting from human habitation is unavoidable; and\u0000 \u0000 \u0000 –\u0000 based on Mars' current planetary protection category, robotic payload(s) should characterize the local martian environment for any life-forms prior to human habitation.\u0000 \u0000 \u0000 Some of the outstanding questions are:\u0000\u0000 \u0000 –\u0000 which interpretation of the hemispheric dichotomy of the planet is correct;\u0000 \u0000 \u0000 –\u0000 to what degree did deep-penetrating faults transport subsurface liquids to Mars' surface;\u0000 \u0000 \u0000 –\u0000 in what abundance are carbonates formed by atmospheric processes;\u0000 \u0000 \u0000 –\u0000 what properties of martian meteorites could be used to constrain their source locations;\u0000 \u0000 \u0000 –\u0000 the origin(s) of organic macromolecules;\u0000 \u0000 \u0000 –\u0000 was/is Mars inhabited;\u0000 \u0000 \u0000 –\u0000 how can missions designed to uncover microbial activity in the subsurface eliminate potential false positives caused by microbial contaminants from Earth;\u0000 \u0000 \u0000 –\u0000 how can we ensure that humans and microbes form a stable and benign biosphere; and\u0000 \u0000 \u0000 –\u0000 should humans relate to putative extraterrestrial life from a biocentric viewpoint (preservation of all biology), or anthropocentric viewpoint of expanding habitation of space?\u0000 \u0000 \u0000 Studies of Mars' evolution can shed light on the habitability of extrasolar planets. In addition, Mars exploration can drive future policy developments and confirm (or put into question) the feasibility and/or extent of human habitability of space.","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48500391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-11-19DOI: 10.1017/s1473550421000331
Saúl A. Villafañe-Barajas, M. Colín-García
Since their discovery, submarine hydrothermal vent systems have been pointed out as important places where chemical evolution on Earth could have occurred; and their role in the process has been highlighted. Similarly, some hypotheses have considered these systems in origin of life scenarios. In this way, many experiments have been developed, and the knowledge about these systems has increased. Due to their complexity, many experimental simulations have only included a few of the geochemical variables present in these environments, pressure and temperature. Other main variables have hardly been included, such as mineralogy, thermal and pH gradients, dissolved ions and/or redox reactions. As it has been understood, the dynamism and heterogeneity of these environments are huge, and it comprises different scales, from single vents to full hydrothermal fields. However, the vast majority of experiments focus on a specific part of these systems and do not include salinity, mineralogy and pH gradients. For this reason, in this paper, we pointed out some considerations about how this dynamism can be interpreted, and included in some models, as well their importance in prebiotic chemistry experiments and their extrapolations regarding the hypothesis about the origins of life.
{"title":"Submarine hydrothermal vent systems: the relevance of dynamic systems in chemical evolution and prebiotic chemistry experiments","authors":"Saúl A. Villafañe-Barajas, M. Colín-García","doi":"10.1017/s1473550421000331","DOIUrl":"https://doi.org/10.1017/s1473550421000331","url":null,"abstract":"\u0000 Since their discovery, submarine hydrothermal vent systems have been pointed out as important places where chemical evolution on Earth could have occurred; and their role in the process has been highlighted. Similarly, some hypotheses have considered these systems in origin of life scenarios. In this way, many experiments have been developed, and the knowledge about these systems has increased. Due to their complexity, many experimental simulations have only included a few of the geochemical variables present in these environments, pressure and temperature. Other main variables have hardly been included, such as mineralogy, thermal and pH gradients, dissolved ions and/or redox reactions. As it has been understood, the dynamism and heterogeneity of these environments are huge, and it comprises different scales, from single vents to full hydrothermal fields. However, the vast majority of experiments focus on a specific part of these systems and do not include salinity, mineralogy and pH gradients. For this reason, in this paper, we pointed out some considerations about how this dynamism can be interpreted, and included in some models, as well their importance in prebiotic chemistry experiments and their extrapolations regarding the hypothesis about the origins of life.","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46893926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-11-16DOI: 10.1017/s1473550421000343
S. Waters, S. Ledford, A. Wacker, Sonali Verma, Bianca Serda, J. McKaig, J. Varelas, Patrick Nicoll, K. Venkateswaran, David J. Smith
Bacillus pumilus SAFR-032, an endospore-forming bacterial strain, was investigated to determine its methylation pattern (methylome) change, compared to ground control, after direct exposure to space conditions onboard the International Space Station (ISS) for 1.5 years. The resulting ISS-flown and non-flown strains were sequenced using the Nanopore MinION and an in-house method and pipeline to identify methylated positions in the genome. Our analysis indicated genomic variants and m6A methylation increased in the ISS-flown SAFR-032. To complement the broader omics investigation and explore phenotypic changes, ISS-flown and non-flown strains were compared in a series of laboratory-based chamber experiments using an X-ray irradiation source (doses applied at 250, 500, 750, 1000 and 1250 Gy); results show a potentially higher survival fraction of ISS-flown DS2 at the two highest exposures. Taken together, results from this study document lasting changes to the genome by methylation, potentially triggered by conditions in spaceflight, with functional consequences for the resistance of bacteria to stressors expected on long-duration missions beyond low Earth orbit.
{"title":"Long-read sequencing reveals increased occurrence of genomic variants and adenosine methylation in Bacillus pumilus SAFR-032 after long-duration flight exposure onboard the International Space Station","authors":"S. Waters, S. Ledford, A. Wacker, Sonali Verma, Bianca Serda, J. McKaig, J. Varelas, Patrick Nicoll, K. Venkateswaran, David J. Smith","doi":"10.1017/s1473550421000343","DOIUrl":"https://doi.org/10.1017/s1473550421000343","url":null,"abstract":"\u0000 Bacillus pumilus SAFR-032, an endospore-forming bacterial strain, was investigated to determine its methylation pattern (methylome) change, compared to ground control, after direct exposure to space conditions onboard the International Space Station (ISS) for 1.5 years. The resulting ISS-flown and non-flown strains were sequenced using the Nanopore MinION and an in-house method and pipeline to identify methylated positions in the genome. Our analysis indicated genomic variants and m6A methylation increased in the ISS-flown SAFR-032. To complement the broader omics investigation and explore phenotypic changes, ISS-flown and non-flown strains were compared in a series of laboratory-based chamber experiments using an X-ray irradiation source (doses applied at 250, 500, 750, 1000 and 1250 Gy); results show a potentially higher survival fraction of ISS-flown DS2 at the two highest exposures. Taken together, results from this study document lasting changes to the genome by methylation, potentially triggered by conditions in spaceflight, with functional consequences for the resistance of bacteria to stressors expected on long-duration missions beyond low Earth orbit.","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49584303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-11-16DOI: 10.1017/s1473550421000318
A. Lockley, D. Visioni
{"title":"Detection of pre-industrial societies on exoplanets – ERRATUM","authors":"A. Lockley, D. Visioni","doi":"10.1017/s1473550421000318","DOIUrl":"https://doi.org/10.1017/s1473550421000318","url":null,"abstract":"","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48127004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-11-15DOI: 10.1017/S147355042100032X
M. Elvis
The controversial hypothesis that ‘Oumuamua (1I/2017 U1) was an alien craft dominated by a solar sail is considered using known physics for the two possible cases: controlled and uncontrolled flight. The reliability engineering challenges for an artefact designed to operate for ~105–106 year are also considerable. All three areas generate research programmes going forward. The uncontrolled case could be either ‘anonymous METI’ (messaging extraterrestrial intelligence) or ‘inadvertent METI’. In the controlled case the nature of the origin star, trajectory guidance from the origin star to the Sun, and the identity of a destination star are all undecided. The ‘controlled’ case has more strikes against it than the ‘uncontrolled’ case, but neither suffers a knock-out blow, as yet. Some of the issues turn out not to be major obstacles to the alien craft hypothesis, but others weaken the case for it. Most, however, imply new studies. Some of these, e.g. intercept missions for new interstellar objects, are concepts being developed, and will be of value whatever these objects turn out to be. Overall, these considerations show that a many-pronged, targeted, research programme can be built around the hypothesis that ‘Oumuamua is an alien craft. The considerations presented here can also be applied to other interstellar visitors, as well as to general discussions of interstellar travel.
{"title":"Research programmes arising from ‘Oumuamua considered as an alien craft","authors":"M. Elvis","doi":"10.1017/S147355042100032X","DOIUrl":"https://doi.org/10.1017/S147355042100032X","url":null,"abstract":"\u0000 The controversial hypothesis that ‘Oumuamua (1I/2017 U1) was an alien craft dominated by a solar sail is considered using known physics for the two possible cases: controlled and uncontrolled flight. The reliability engineering challenges for an artefact designed to operate for ~105–106 year are also considerable. All three areas generate research programmes going forward. The uncontrolled case could be either ‘anonymous METI’ (messaging extraterrestrial intelligence) or ‘inadvertent METI’. In the controlled case the nature of the origin star, trajectory guidance from the origin star to the Sun, and the identity of a destination star are all undecided. The ‘controlled’ case has more strikes against it than the ‘uncontrolled’ case, but neither suffers a knock-out blow, as yet. Some of the issues turn out not to be major obstacles to the alien craft hypothesis, but others weaken the case for it. Most, however, imply new studies. Some of these, e.g. intercept missions for new interstellar objects, are concepts being developed, and will be of value whatever these objects turn out to be. Overall, these considerations show that a many-pronged, targeted, research programme can be built around the hypothesis that ‘Oumuamua is an alien craft. The considerations presented here can also be applied to other interstellar visitors, as well as to general discussions of interstellar travel.","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47729007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-10-18DOI: 10.1017/s1473550421000240
C. Pacelli, A. Cassaro, M. Baqué, L. Selbmann, L. Zucconi, A. Maturilli, L. Botta, R. Saladino, U. Böttger, R. Demets, E. Rabbow, J. D. de Vera, S. Onofri
Mars is a primary target of astrobiological interest: its past environmental conditions may have been favourable to the emergence of a prebiotic chemistry and, potentially, biological activity. In situ exploration is currently underway at the Mars surface, and the subsurface (2 m depth) will be explored in the future ESA ExoMars mission. In this context, BIOlogy and Mars EXperiment was performed to evaluate the stability and detectability of organic biomarkers under space and Mars-like conditions. Our data suggested that some target molecules, namely melanin, azelaic acid and nucleic acids, can be detected even after 16 months exposure to Low Earth Orbit conditions by multidisciplinary approaches. We used the same techniques as onboard the ExoMars rover, as Raman and infrared spectroscopies and gas chromatograph-mass spectrometer, and polymerase chain reaction even if this is not planned for the imminent mission to Mars. These results should be taken into account for future Mars exploration.
{"title":"Fungal biomarkers are detectable in Martian rock-analogues after space exposure: implications for the search of life on Mars","authors":"C. Pacelli, A. Cassaro, M. Baqué, L. Selbmann, L. Zucconi, A. Maturilli, L. Botta, R. Saladino, U. Böttger, R. Demets, E. Rabbow, J. D. de Vera, S. Onofri","doi":"10.1017/s1473550421000240","DOIUrl":"https://doi.org/10.1017/s1473550421000240","url":null,"abstract":"\u0000 Mars is a primary target of astrobiological interest: its past environmental conditions may have been favourable to the emergence of a prebiotic chemistry and, potentially, biological activity. In situ exploration is currently underway at the Mars surface, and the subsurface (2 m depth) will be explored in the future ESA ExoMars mission. In this context, BIOlogy and Mars EXperiment was performed to evaluate the stability and detectability of organic biomarkers under space and Mars-like conditions. Our data suggested that some target molecules, namely melanin, azelaic acid and nucleic acids, can be detected even after 16 months exposure to Low Earth Orbit conditions by multidisciplinary approaches. We used the same techniques as onboard the ExoMars rover, as Raman and infrared spectroscopies and gas chromatograph-mass spectrometer, and polymerase chain reaction even if this is not planned for the imminent mission to Mars. These results should be taken into account for future Mars exploration.","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56973142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-09-03DOI: 10.1017/s1473550421000239
J. Genise
There are different criteria that are usually analysed independently before identifying a new trace fossil, such as morphological regularity, completeness, dispersion, recurrence and complexity, surface morphology, and context. The synthesis of these criteria, as utilized in paleosol ichnology, composes a protocol that is presented herein for the first time and can be used for testing the ichnogenicity of trace-like structures in any paleoenvironment of Earth or Mars. As a study case, the Martian ‘stick-like structures’ do not fulfil any of the requirements posed by this protocol to be postulated as trace fossils. The ichnogenicity test, focussed exclusively on morphology and context, is simpler but equally useful as the biogenicity ones. It may be applied in the future with other potential cases before carrying on more complex analyses or to evaluate the astrobiological interest of trace-like structures.
{"title":"Martian stick-like structures are not trace fossils: a new protocol for testing ichnogenicity synthesized from paleosol ichnology","authors":"J. Genise","doi":"10.1017/s1473550421000239","DOIUrl":"https://doi.org/10.1017/s1473550421000239","url":null,"abstract":"\u0000 There are different criteria that are usually analysed independently before identifying a new trace fossil, such as morphological regularity, completeness, dispersion, recurrence and complexity, surface morphology, and context. The synthesis of these criteria, as utilized in paleosol ichnology, composes a protocol that is presented herein for the first time and can be used for testing the ichnogenicity of trace-like structures in any paleoenvironment of Earth or Mars. As a study case, the Martian ‘stick-like structures’ do not fulfil any of the requirements posed by this protocol to be postulated as trace fossils. The ichnogenicity test, focussed exclusively on morphology and context, is simpler but equally useful as the biogenicity ones. It may be applied in the future with other potential cases before carrying on more complex analyses or to evaluate the astrobiological interest of trace-like structures.","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48165088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-09-02DOI: 10.1017/S1473550421000227
A. Brack
Abstract During 20 years, the European astrobiologists collaborated within EANA, the European Astrobiology Network Association, to help European researchers developing astrobiology programmes to share their knowledge, to foster their cooperation, to attract young scientists to this quickly evolving interactive field of research, and to explain astrobiology to the public at large. The experiment of Stanley Miller in 1953 launched the ambitious hope that chemists would be able to shed light on the origins of life by recreating a simple life form in a test tube. However, the dream has not yet been accomplished, despite the great volume of effort and innovation put forward by the scientific community.
{"title":"Astrobiology in Europe, 20 years of expectations","authors":"A. Brack","doi":"10.1017/S1473550421000227","DOIUrl":"https://doi.org/10.1017/S1473550421000227","url":null,"abstract":"Abstract During 20 years, the European astrobiologists collaborated within EANA, the European Astrobiology Network Association, to help European researchers developing astrobiology programmes to share their knowledge, to foster their cooperation, to attract young scientists to this quickly evolving interactive field of research, and to explain astrobiology to the public at large. The experiment of Stanley Miller in 1953 launched the ambitious hope that chemists would be able to shed light on the origins of life by recreating a simple life form in a test tube. However, the dream has not yet been accomplished, despite the great volume of effort and innovation put forward by the scientific community.","PeriodicalId":13879,"journal":{"name":"International Journal of Astrobiology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44015666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
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