1,519 results match your criteria Astrobiology[Journal]

Tardigrade Survival Limits in High-Speed Impacts-Implications for Panspermia and Collection of Samples from Plumes Emitted by Ice Worlds.

Astrobiology 2021 May 11. Epub 2021 May 11.

Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury, UK.

The ability of tardigrades to survive impact shocks in the kilometer per second and gigapascal range was investigated. When rocks impact planetary surfaces, the impact speeds and shock pressures are in the kilometer per second and gigapascal range. This investigation tested whether tardigrades can survive in impacts typical of those that occur naturally in the Solar System. Read More

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Venus, an Astrobiology Target.

Astrobiology 2021 May 7. Epub 2021 May 7.

NASA Goddard Institute for Space Studies, New York, New York, USA.

We present a case for the exploration of Venus as an astrobiology target-(1) investigations focused on the likelihood that liquid water existed on the surface in the past, leading to the potential for the origin and evolution of life, (2) investigations into the potential for habitable zones within Venus' present-day clouds and Venus-like exo atmospheres, (3) theoretical investigations into how active aerobiology may impact the radiative energy balance of Venus' clouds and Venus-like atmospheres, and (4) application of these investigative approaches toward better understanding the atmospheric dynamics and habitability of exoplanets. The proximity of Venus to Earth, guidance for exoplanet habitability investigations, and access to the potential cloud habitable layer and surface for prolonged extended measurements together make the planet a very attractive target for near term astrobiological exploration. Read More

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Integrated Molar Absorptivity of Mid- and Far-Infrared Spectra of Glycine and Other Selected Amino Acids.

Astrobiology 2021 May;21(5):526-540

Actinium Chemical Research Institute, Rome, Italy.

A selection of five proteinogenic amino acids-glycine, isoleucine, phenylalanine, tyrosine, and tryptophan-were studied in the mid-infrared and in the far-infrared with the purpose to facilitate the search and identification of these astrobiologically and astrochemically relevant molecules in space environments. The molar extinction coefficients (ɛ) of all mid- and far-infrared bands were determined as well as the integrated molar absorptivities (ψ). The mid-infrared spectra of the five selected amino acids were recorded also at three different temperatures from -180°C to ambient temperature to +200°C. Read More

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Revival of Anhydrobiotic Cyanobacterium Biofilms Exposed to Space Vacuum and Prolonged Dryness: Implications for Future Missions beyond Low Earth Orbit.

Astrobiology 2021 May;21(5):541-550

Department of Biology, University of Rome Tor Vergata, Rome, Italy.

Dried biofilms of sp. CCMEE 029 were revived after a 672-day exposure to space vacuum outside the International Space Station during the EXPOSE-R2 space mission. After retrieval, they were air-dried stored for 3. Read More

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Investigation of Venus Cloud Aerosol and Gas Composition Including Potential Biogenic Materials via an Aerosol-Sampling Instrument Package.

Astrobiology 2021 Apr 30. Epub 2021 Apr 30.

Centre National d'Études Spatiales (CNES), Toulouse, France.

A lightweight, low-power instrument package to measure, both (1) the local gaseous environment and (2) the composition and microphysical properties of attendant venusian aerosols is presented. This Aerosol-Sampling Instrument Package (ASIP) would be used to explore cloud chemical and possibly biotic processes on future aerial missions such as multiweek balloon missions and on short-duration (<1 h) probes on Venus and potentially on other cloudy worlds such as Titan, the Ice Giants, and Saturn. A quadrupole ion-trap mass spectrometer (QITMS; Madzunkov and Nikolić, 25:1841-1852, 2014) fed alternately by (1) an aerosol separator that injects only aerosols into a vaporizer and mass spectrometer and (2) the pure aerosol-filtered atmosphere, achieves the compositional measurements. Read More

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as an Opportunistic Fungal Pathogen on Plants Grown on board the International Space Station.

Astrobiology 2021 Apr 29. Epub 2021 Apr 29.

NASA Exploration Research and Technology Programs, Kennedy Space Center, Florida, USA.

A plant production system called Veggie was launched to the International Space Station (ISS) in 2014. In late 2015, during the growth of cv. 'Profusion' in the Veggie hardware, plants developed chlorosis, leaf curling, fungal growth that damaged leaves and stems, and eventually necrosis. Read More

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Respiration Measurements of Individual Tardigrades of the Species cf as a Function of Temperature and Salinity and Termination of Anhydrobiosis.

Astrobiology 2021 Apr 29. Epub 2021 Apr 29.

Department of Science and Environment, Roskilde University, Roskilde, Denmark.

Numerous studies have demonstrated that tardigrades in a resting state (tun state) are very resistant to exceptional stress levels in comparison with the resistance observed in multicellular organisms in general. The types of stress include desiccation and radiation, which are also relevant in astrobiological research, and therefore, tardigrades are used as multicellular model organisms. For example, tardigrades have been investigated in the TARSE, TARDIS, RoTaRad, and TARDIKISS projects; their survival has been evaluated according to stressful conditions that prevail in low earth orbit, including the effects of cosmic radiation and microgravity. Read More

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Biogeographical Modeling of Alien Worlds.

Astrobiology 2021 Apr 27. Epub 2021 Apr 27.

Division of Epidemiology, The New York State Psychiatric Institute at Columbia University, New York Psychiatric Institute, New York, USA.

In this article, we partially quantify the biological potential of an exoplanet. We employ a variety of biogeographical analyses, placing biological evolution in the context of the geological evolution of the planet as a whole. Terrestrial (as in Earthly) biodiversity is tightly constrained in terms of species richness by its environment. Read More

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Theoretical Constraints Imposed by Gradient Detection and Dispersal on Microbial Size in Astrobiological Environments.

Manasvi Lingam

Astrobiology 2021 Apr 26. Epub 2021 Apr 26.

Department of Aerospace, Physics and Space Science, Florida Institute of Technology, Melbourne, Florida, USA.

The capacity to sense gradients efficiently and acquire information about the ambient environment confers many advantages such as facilitating movement toward nutrient sources or away from toxic chemicals. The amplified dispersal evinced by organisms endowed with motility is possibly beneficial in related contexts. Hence, the connections between information acquisition, motility, and microbial size are explored from an explicitly astrobiological standpoint. Read More

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Earth-like Habitable Environments in the Subsurface of Mars.

Astrobiology 2021 Apr 15. Epub 2021 Apr 15.

German Aerospace Center (DLR) Institute of Planetary Research, Berlin, Germany.

In Earth's deep continental subsurface, where groundwaters are often isolated for >10 to 10 years, energy released by radionuclides within rock produces oxidants and reductants that drive metabolisms of non-photosynthetic microorganisms. Similar processes could support past and present life in the martian subsurface. Sulfate-reducing microorganisms are common in Earth's deep subsurface, often using hydrogen derived directly from radiolysis of pore water and sulfate derived from oxidation of rock-matrix-hosted sulfides by radiolytically derived oxidants. Read More

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Optimizing Chiral Selectivity in Practical Life-Detection Instruments.

Astrobiology 2021 May 20;21(5):505-510. Epub 2021 Apr 20.

Division of Earth and Ecosystem Sciences, Desert Research Institute, Las Vegas, Nevada, USA.

Preferential uptake of either levorotatory (L) or dextrorotatory (D) enantiomer of a chiral molecule is a potential planetary life-detection method. On Earth, bacteria, as a rule, metabolize D-sugars and L-amino acids. Here, we use growth experiments to identify exceptions to the rule and their potential impact on the method's reliability. Read More

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Uninhabitable and Potentially Habitable Environments on Mars: Evidence from Meteorite ALH 84001.

Allan H Treiman

Astrobiology 2021 Apr 15. Epub 2021 Apr 15.

Lunar and Planetary Institute / Universities Space Research Association, Houston, Texas, USA.

The martian meteorite ALH 84001 formed before ∼4.0 Ga, so it could have preserved information about habitability on early Mars and habitability since then. ALH 84001 is particularly important as it contains carbonate (and other) minerals that were deposited by liquid water, raising the chance that they may have formed in a habitable environment. Read More

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Life on Mars: Independent Genesis or Common Ancestor?

Alfonso F Davila

Astrobiology 2021 Apr 13. Epub 2021 Apr 13.

NASA Ames Research Center, Exobiology Branch, Moffett Field, California, USA.

The possibility of biological transfer between planetary bodies is seldom factored into life detection strategies, although the actuality of such an event would have profound implications for how we interpret potential biosignatures found on other worlds. This article addresses the possibility of life on Mars in the context of a biological transfer and an independent genesis of life. The phylogenetic tree of life on Earth is used as a blueprint to interpret evidence of life and as a guideline to determine the likelihood that potential biosignatures could be expressed by martian organisms. Read More

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Quantifying Preservation Potential: Lipid Degradation in a Mars-Analog Circumneutral Iron Deposit.

Astrobiology 2021 Apr 8. Epub 2021 Apr 8.

Department of Earth Science and Engineering, Impacts and Astromaterials Research Centre, Imperial College London, London, United Kingdom.

Comparisons between the preservation potential of Mars-analog environments have historically been qualitative rather than quantitative. Recently, however, laboratory-based artificial maturation combined with kinetic modeling techniques have emerged as a potential means by which the preservation potential of solvent-soluble organic matter can be quantified in various Mars-analog environments. These methods consider how elevated temperatures, pressures, and organic-inorganic interactions influence the degradation of organic biomarkers post-burial. Read More

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Water Activities of Acid Brine Lakes Approach the Limit for Life.

Astrobiology 2021 Apr 5. Epub 2021 Apr 5.

Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland.

Water activity is an important characteristic for describing unusual waters and is a determinant of habitability for microorganisms. However, few empirical studies of water activity have been done for natural waters exhibiting an extreme chemistry. Here, we investigate water activity for acid brines from Western Australia and Chile with pH as low as 1. Read More

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Reactive Oxygen Species in Emulated Martian Conditions and Their Effect on the Viability of the Unicellular Alga .

Astrobiology 2021 Apr 5. Epub 2021 Apr 5.

Instituto de Nanociencia y Nanotecnología (INN), CNEA-CONICET, Centro Atómico Bariloche, San Carlos de Bariloche, Argentina.

Formation of oxygen-based free radicals from photochemical decomposition of hydrogen peroxide (HO) on Mars may be a key factor in the potential survival of terrestrial-like organisms on the red planet. Martian conditions that generate reactive oxygen species involve the decomposition of HO at temperatures of around 278 K under relatively high doses of C-band ultraviolet radiation (UVC). This process is further amplified by the presence of iron oxides and perchlorates. Read More

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Constraints for Use of Ultraviolet Spectropolarimetry to Detect Chiral Amino Acids from Comets.

Astrobiology 2021 Apr 1. Epub 2021 Apr 1.

Universidad Complutense de Madrid, Madrid, Spain.

Life is pervasive on planet Earth, but whether life is ubiquitous in the Galaxy and sustainable over timescales comparable to stellar evolution is unknown. Evidence suggests that life first appeared on Earth more than 3.77 Gyr ago, during a period of heavy meteoric bombardment. Read More

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Assessment of Isoprene as a Possible Biosignature Gas in Exoplanets with Anoxic Atmospheres.

Astrobiology 2021 Apr 1. Epub 2021 Apr 1.

Department of Earth, Atmospheric, and Planetary Sciences, MIT, Cambridge, Massachusetts, USA.

The search for possible biosignature gases in habitable exoplanet atmospheres is accelerating, although actual observations are likely years away. This work adds isoprene, CH, to the roster of biosignature gases. We found that isoprene geochemical formation is highly thermodynamically disfavored and has no known abiotic false positives. Read More

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Taxonomic Characterization and Microbial Activity Determination of Cold-Adapted Microbial Communities in Lava Tube Ice Caves from Lava Beds National Monument, a High-Fidelity Mars Analogue Environment.

Astrobiology 2021 May 1;21(5):613-627. Epub 2021 Apr 1.

Department of Natural Resource Sciences, McGill Space Institute, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada.

Martian lava tube caves resulting from a time when the planet was still volcanically active are proposed to contain deposits of water ice, a feature that may increase microbial habitability. In this study, we taxonomically characterized and directly measured metabolic activity of the microbial communities that inhabit lava tube ice from Lava Beds National Monument, an analogue environment to martian lava tubes. We investigated whether this environment was habitable to microorganisms by determining their taxonomic diversity, metabolic activity, and viability using both culture-dependent and culture-independent techniques. Read More

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Degradation of Amino Acids on Mars by UV Irradiation in the Presence of Chloride and Oxychlorine Salts.

Astrobiology 2021 Mar 30. Epub 2021 Mar 30.

Department of Chemistry, Tufts University, Medford, Massachusetts, USA.

The degradation of glycine (Gly), proline (Pro), and tryptophan (Trp) was studied under simulated Mars conditions during UV-driven production of oxychlorines and compared under Mars ambient and humid conditions, as films, and with addition of sodium chloride (NaCl), sodium chlorate (NaClO), and sodium perchlorate (NaClO) salts. It was shown that glycine sustained no significant destruction in either of the non-salt samples under Mars ambient or humid conditions. However, its degradation increased in the presence of any of the three salts and under both conditions though more under humid conditions. Read More

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Perchlorate Salts Exert a Dominant, Deleterious Effect on the Structure, Stability, and Activity of α-Chymotrypsin.

Astrobiology 2021 Apr;21(4):405-412

Centre for Astrobiology, SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom.

The presence of perchlorate ions on Mars raises the question of how these ions influence the biochemistry of any contaminant life introduced into the martian environment, or what selection pressures perchlorate ions exert on any environment that contains these ions, such as the Atacama Desert. In this study, we investigated the structure, stability, and enzyme activity of the model enzyme α-chymotrypsin in the presence of five Mars relevant salts, MgSO, MgCl, Mg(ClO), Ca(ClO), and NaClO. We found that all the perchlorate salts reduced the enzyme activity of α-chymotrypsin in a concentration-dependent manner, with Mg(ClO) and Ca(ClO) having the greatest effect. Read More

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Experimental Investigation of the Formation of Formaldehyde by Hadean and Noachian Impacts.

Astrobiology 2021 Apr;21(4):413-420

Department of Earth Science, Tohoku University, Sendai, Japan.

Formaldehyde (FA) is an important precursor in the abiotic synthesis of major biomolecules including amino acids, sugars, and nucleobases. Thus, spontaneous formation of prebiotic FA must have been crucial for the chemical origin of life. The frequent impacts of meteorites and asteroids on Hadean Earth have been considered one of the abiotic synthetic processes of organic compounds. Read More

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Interactions Between Iron Sulfide Minerals and Organic Carbon: Implications for Biosignature Preservation and Detection.

Astrobiology 2021 May 29;21(5):587-604. Epub 2021 Mar 29.

Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA.

Microbe-mineral interactions can produce unique composite materials, which can preserve biosignatures. Geological evidence suggests that iron sulfide (Fe-S) minerals are abundant in the subsurface of Mars. On Earth, the formation of Fe-S minerals is driven by sulfate-reducing microorganisms (SRM) that produce reactive sulfide. Read More

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Understanding Hypervelocity Sampling of Biosignatures in Space Missions.

Astrobiology 2021 Apr 19;21(4):421-442. Epub 2021 Mar 19.

Department of Astronomy and Carl Sagan Institute, Cornell University, Ithaca, New York, USA.

The atomic-scale fragmentation processes involved in molecules undergoing hypervelocity impacts (HVIs; defined as 3 km/s) are challenging to investigate via experiments and still not well understood. This is particularly relevant for the consistency of biosignals from small-molecular-weight neutral organic molecules obtained during solar system robotic missions sampling atmospheres and plumes at hypervelocities. Experimental measurements to replicate HVI effects on neutral molecules are challenging, both in terms of accelerating uncharged species and isolating the multiple transition states over very rapid timescales (1 ps). Read More

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A Drake Equation for Alien Artifacts.

James Benford

Astrobiology 2021 Mar 18. Epub 2021 Mar 18.

Microwave Sciences, Lafayette, California, USA.

I propose a version of the Drake equation to include searching for alien artifacts, which may be located on the Moon, Earth Trojans, and Earth co-orbital objects. The virtue of searching for artifacts is their lingering endurance in space, long after they go dead. I compare a search for extraterrestrial artifacts (SETA) strategy with the existing listening to stars search for extraterrestrial intelligence (SETI) strategy. Read More

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ExoMars Mars Organic Molecule Analyzer (MOMA) Laser Desorption/Ionization Mass Spectrometry (LDI-MS) Analysis of Phototrophic Communities from a Silica-Depositing Hot Spring in Yellowstone National Park, USA.

Astrobiology 2021 Mar 16. Epub 2021 Mar 16.

Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, USA.

The Mars Organic Molecule Analyzer (MOMA) is a key scientific instrument on the ExoMars Rover mission. MOMA is designed to detect and characterize organic compounds, over a wide range of volatility and molecular weight, in samples obtained from up to 2 m below the martian surface. Thorough analog sample studies are required to best prepare to interpret MOMA data collected on Mars. Read More

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Impact of UV Radiation on the Raman Signal of Cystine: Implications for the Detection of S-rich Organics on Mars.

Astrobiology 2021 May 10;21(5):566-574. Epub 2021 Mar 10.

Muséum National d'Histoire Naturelle, Institut de Minéralogie, Physique des Matériaux et Cosmochimie, CNRS UMR 7590, Sorbonne Université, Paris, France.

Traces of life may have been preserved in ancient martian rocks in the form of molecular fossils. Yet the surface of Mars is continuously exposed to intense UV radiation detrimental to the preservation of organics. Because the payload of the next rovers going to Mars to seek traces of life will comprise Raman spectroscopy tools, laboratory simulations that document the effect of UV radiation on the Raman signal of organics appear critically needed. Read More

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Ancient Oil as a Source of Carbonaceous Matter in 1.88-Billion-Year-Old Gunflint Stromatolites and Microfossils.

Astrobiology 2021 Mar 8. Epub 2021 Mar 8.

Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA.

The 1.88-billion-year-old Gunflint carbonaceous microfossils are renowned for their exceptional morphological and chemical preservation, attributed to early and rapid entombment in amorphous silica. The carbonaceous matter lining and partly filling filamentous and spherical structures is interpreted to be indigenous, representing thermally altered relicts of cellular material ( kerogen). Read More

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Martian Magmatic Clay Minerals Forming Vesicles: Perfect Niches for Emerging Life?

Astrobiology 2021 May 8;21(5):605-612. Epub 2021 Mar 8.

Muséum National d'Histoire Naturelle, Institut de Minéralogie, Physique des Matériaux et Cosmochimie, CNRS UMR 7590, Sorbonne Université, CNRS, Paris, France.

Mars was habitable in its early history, but the consensus is that it is quite inhospitable today, in particular because its modern climate cannot support stable liquid water at the surface. Here, we report the presence of magmatic Fe/Mg clay minerals within the mesostasis of the martian meteorite NWA 5790, an unaltered 1.3 Ga nakhlite archetypal of the martian crust. Read More

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Morphological and Spectral Diversity of the Clay-Bearing Unit at the ExoMars Landing Site Oxia Planum.

Astrobiology 2021 Apr 1;21(4):464-480. Epub 2021 Mar 1.

ENSL, CNRS, LGL-TPE, University of Lyon, Lyon, France.

The European Space Agency and Roscosmos' ExoMars rover mission, which is planned to land in the Oxia Planum region, will be dedicated to exobiology studies at the surface and subsurface of Mars. Oxia Planum is a clay-bearing site that has preserved evidence of long-term interaction with water during the Noachian era. Fe/Mg-rich phyllosilicates have previously been shown to occur extensively throughout the landing area. Read More

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