1,620 results match your criteria Astrobiology[Journal]

The Origin of Life: What Is the Question?

Astrobiology 2022 May 20. Epub 2022 May 20.

Laboratoire Biophysique et Évolution, UMR Chimie Biologie Innovation 8231, ESPCI Paris, Université PSL, CNRS, Paris, France.

The question of the origin of life is a tenacious question that challenges many branches of science but is also extremely multifaceted. While prebiotic chemistry and micropaleontology reformulate the question as that of explaining the appearance of life on Earth in the deep past, systems chemistry and synthetic biology typically understand the question as that of demonstrating the synthesis of novel living matter from nonliving matter independently of historical constraints. The objective of this contribution is to disentangle the different readings of the origin-of-life question found in science. Read More

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Catalytic Synthesis of Polyribonucleic Acid on Prebiotic Rock Glasses.

Astrobiology 2022 May 19. Epub 2022 May 19.

Foundation for Applied Molecular Evolution, Alachua, Florida, USA.

Reported here are experiments that show that ribonucleoside triphosphates are converted to polyribonucleic acid when incubated with rock glasses similar to those likely present 4.3-4.4 billion years ago on the Hadean Earth surface, where they were formed by impacts and volcanism. Read More

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Astrobiology 2018; 18(11): 1369-1374.


Astrobiology 2022 May 12. Epub 2022 May 12.

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Extremophiles in Earth's Deep Seas: A View Toward Life in Exo-Oceans.

Astrobiology 2022 May 12. Epub 2022 May 12.

Louisiana Universities Marine Consortium, Chauvin, Louisiana, USA.

Humanity's search for extraterrestrial life is a modern manifestation of the exploratory and curious nature that has led us through millennia of scientific discoveries. With the ongoing exploration of extraterrestrial bodies, the potential for discovery of extraterrestrial life has expanded. We may better inform this search through an understanding of how life persists and flourishes on Earth in a myriad of environmental extremes. Read More

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Science Autonomy for Ocean Worlds Astrobiology: A Perspective.

Astrobiology 2022 May 4. Epub 2022 May 4.

NASA Goddard Space Flight Center, Greenbelt, Maryland, USA.

Astrobiology missions to ocean worlds in our solar system must overcome both scientific and technological challenges due to extreme temperature and radiation conditions, long communication times, and limited bandwidth. While such tools could not replace ground-based analysis by science and engineering teams, machine learning algorithms could enhance the science return of these missions through development of autonomous science capabilities. Examples of science autonomy include onboard data analysis and subsequent instrument optimization, data prioritization (for transmission), and real-time decision-making based on data analysis. Read More

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Resolving the History of Life on Earth by Seeking Life As We Know It on Mars.

Astrobiology 2022 Apr 25. Epub 2022 Apr 25.

Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA.

An origin of Earth life on Mars would resolve significant inconsistencies between the inferred history of life and Earth's geologic history. Life utilizes amino acids, nucleic acids, and lipids for the metabolic, informational, and compartment-forming subsystems of a cell. Such building blocks may have formed simultaneously from cyanosulfidic chemical precursors in a planetary surface scenario involving ultraviolet light, wet-dry cycling, and volcanism. Read More

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The Radiation Environment of Ceres and Implications for Surface Sampling.

Astrobiology 2022 May 21;22(5):509-519. Epub 2022 Apr 21.

University of Hawaii at Manoa, Honolulu, Hawaii, USA.

Ceres is a large water-rich dwarf planet located within the asteroid belt. Its surface displays evidence of material sourced from a deep subsurface liquid brine layer within recent geologic time, making it a candidate ocean world with possible present-day activity. However, Ceres lacks a substantial atmosphere and likely does not possess a global magnetic field. Read More

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Freshwater and Evaporite Brine Compositions on Hadean Earth: Priming the Origins of Life.

Astrobiology 2022 Apr 21. Epub 2022 Apr 21.

Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, New York, USA.

The chemical composition of aqueous solutions during the Hadean era determined the availability of essential elements for prebiotic synthesis of the molecular building blocks of life. Here we conducted quantitative reaction path modeling of atmosphere-water-rock interactions over a range of environmental conditions to estimate freshwater and evaporite brine compositions. We then evaluated the solution chemistries for their potential to influence ribonucleotide synthesis and polymerization as well as protocell membrane stability. Read More

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Acritarch-like Microorganisms from the 1.9 Ga Gunflint Chert, Canada.

Astrobiology 2022 May 18;22(5):568-578. Epub 2022 Apr 18.

Department of Earth Sciences, University of Western Ontario, London, Canada.

Fossil evidence of eukaryotic life older than 1.8 Ga has long been debated because known fossils of that age usually lack cellular micro- and ultra-structures that bear strong affinities to eukaryotes. These include fossils of the ∼1. Read More

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Irradiation of Phenylalanine at 300 K by MeV Ions.

Astrobiology 2022 Apr 5;22(4):439-451. Epub 2022 Jan 5.

Physics Department, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, Brazil.

Phenylalanine (Phe) is an amino acid that has been identified in carbonaceous meteorites; its formation mechanism in space is unknown, and its radioresistance has been the subject of investigation. This work aims at studying, in the laboratory, the Phe radiolysis by cosmic analogues. The Phe destruction rate, at 300 K, is measured for H, He, and N ion beam irradiation in the 0. Read More

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Biogeochemical Characteristics of Earth's Volcanic Permafrost: An Analog of Extraterrestrial Environments.

Astrobiology 2022 Mar 23. Epub 2022 Mar 23.

Institute of Physicochemical and Biological Problems in Soil Science, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences," Pushchino, Russia.

This article describes a study of frozen volcanic deposits collected from volcanoes Tolbachik and Bezymianny on the Kamchatka Peninsula, Russia, and Deception Island volcano, Antarctica. In addition, we studied suprasnow ash layers deposited after the 2007 eruptions of volcanoes Shiveluch and Bezymianny on Kamchatka. The main objectives were to characterize the presence and survivability of thermophilic microorganisms in perennially frozen volcanic deposits. Read More

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Quantum Dots in Peroxidase-like Chemistry and Formamide-Based Hot Spring Synthesis of Nucleobases.

Astrobiology 2022 May 23;22(5):541-551. Epub 2022 Mar 23.

J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic.

Quantum dots (QDs) are usually seen as artificial semiconductor particles exhibiting optical and electronic properties interesting for nanotechnological applications. However, they may also play a role in prebiotic chemistry. Starting from zinc acetate, cadmium acetate, and mercaptosuccinic acid, we demonstrate the formation of ZnCd QDs upon UV irradiation in prebiotic liquid formamide. Read More

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Characterization of the Halochromic Gloeocapsin Pigment, a Cyanobacterial Biosignature for Paleobiology and Astrobiology.

Astrobiology 2022 Mar 25. Epub 2022 Mar 25.

Early Life Traces & Evolution-Astrobiology, UR Astrobiology, University of Liège, Liège, Belgium.

Ultraviolet (UV)-screening compounds represent a substantial asset for the survival of cyanobacteria in extreme environments exposed to high doses of UV radiations on modern and early Earth. Among these molecules, the halochromic pigment gloeocapsin remains poorly characterized and studied. In this study, we identified a gloeocapsin-producing cultivable cyanobacteria: the strain ULC007. Read More

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Remains Viable and Shows Morphological Changes under Anoxic (CO-Enriched) and Hypobaric (2.4 kPa) Atmospheric Conditions.

Astrobiology 2022 Mar 22. Epub 2022 Mar 22.

Department of Natural Science, St. Petersburg College, Clearwater, Florida, USA.

Potentially habitable zones have been discovered on Mars today in underground areas containing perchlorate brines. Understanding the low-pressure adaptations of microorganisms is essential in learning more about what life could potentially be found on Mars today or could have existed in the distant past. Many studies have looked at low-pressure adaptations in bacteria; however, studies aimed at understanding these adaptations in archaea are scarcer. Read More

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Interpreting Molecular and Isotopic Biosignatures in Methane-Derived Authigenic Carbonates in the Light of a Potential Carbon Cycle in the Icy Moons.

Astrobiology 2022 May 22;22(5):552-567. Epub 2022 Mar 22.

Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, Madrid, Spain.

Finding evidence of life beyond Earth is the aim of future space missions to icy moons. Icy worlds with an ocean underlying the icy crust and in contact with a rocky subsurface have great astrobiological interest due to the potential for water-rock interactions that may provide a source of nutrients necessary to sustain life. Such water-rock interactions in icy moons can be indirectly investigated using analogous environments on the deep seafloor on Earth. Read More

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Meteorites as Food Source on Early Earth: Growth, Selection, and Inhibition of a Microbial Community on a Carbonaceous Chondrite.

Astrobiology 2022 May 18;22(5):495-508. Epub 2022 Mar 18.

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

Meteoritic material accumulated on the surface of the anoxic early Earth during the Late Heavy Bombardment around 4.0 Gya and may have provided Earth's surface with extraterrestrial nutrients and energy sources. This research investigates the growth of an anaerobic microbial community from pond sediment on native and pyrolyzed (heat-treated) carbonaceous chondrite Cold Bokkeveld. Read More

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Science Objectives for Flagship-Class Mission Concepts for the Search for Evidence of Life at Enceladus.

Astrobiology 2022 Mar 15. Epub 2022 Mar 15.

Division of Space Science and Astrobiology, NASA Ames Research Center, Moffett Field, California, USA.

revealed that Saturn's Moon Enceladus hosts a subsurface ocean that meets the accepted criteria for habitability with bio-essential elements and compounds, liquid water, and energy sources available in the environment. Whether these conditions are sufficiently abundant and collocated to support life remains unknown and cannot be determined from data. However, thanks to the plume of oceanic material emanating from Enceladus' south pole, a new mission to Enceladus could search for evidence of life without having to descend through kilometers of ice. Read More

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Planetary Terrestrial Analogues Library Project: 3. Characterization of Samples With MicrOmega.

Astrobiology 2022 03 8;22(3):263-292. Epub 2022 Mar 8.

Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway.

The Planetary Terrestrial Analogues Library (PTAL) project aims at building and exploiting a database involving several analytical techniques, to help characterize the mineralogical evolution of terrestrial bodies, starting with Mars. Around 100 natural Earth rock samples have been collected from selected locations to gather a variety of analogs for martian geology, from volcanic to sedimentary origin with different levels of alteration. All samples are to be characterized within the PTAL project with different mineralogical and elemental analysis techniques, including techniques brought on actual and future instruments at the surface of Mars (near infrared [NIR] spectroscopy, Raman spectroscopy, and laser-induced breakdown spectroscopy). Read More

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Inefficient Water Degassing Inhibits Ocean Formation on Rocky Planets: An Insight from Self-Consistent Mantle Degassing Models.

Astrobiology 2022 Mar 1. Epub 2022 Mar 1.

Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, USA.

A sufficient amount of water is required at the surface to develop water oceans. A significant fraction of water, however, remains in the mantle during magma ocean solidification, and thus the existence of water oceans is not guaranteed even for exoplanets located in the habitable zone. To discuss the likelihood of ocean formation, we built two models to predict the rate of mantle degassing during the magma ocean stage and the subsequent solid-state convection stage. Read More

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A Review of the "Black Beauty" Martian Regolith Breccia and Its Martian Habitability Record.

Astrobiology 2022 Feb 25. Epub 2022 Feb 25.

Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom.

The regolith breccia Northwest Africa (NWA) 7034 and paired samples are unique meteorite representatives of the martian crust. They are water rich, lithologically varied, and preserve the oldest martian zircon grains yet discovered that formed 4500-4300 Ma. The meteorite thus provides us with an invaluable record of the crustal and environmental conditions on early Mars. Read More

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February 2022

Exploring Space via Astromycology: A Report on the CIFAR Programs and Inaugural Joint Meeting.

Astrobiology 2022 Feb 23. Epub 2022 Feb 23.

Department of Molecular Genetics, University of Toronto, Toronto, Canada.

"Fungi on Mars!": a popular news heading that piques public interest and makes scientists' blood boil. While such a statement is laden with misinformation and light on evidence, the search for past and present extraterrestrial life is an ongoing scientific effort. Moreover, it is one that is increasingly gaining momentum with the recent collection of martian rock cores from Jezero Crater by NASA's Perseverance rover. Read More

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February 2022

Synthesis of Phospholipids Under Plausible Prebiotic Conditions and Analogies with Phospholipid Biochemistry for Origin of Life Studies.

Astrobiology 2022 May 23;22(5):598-627. Epub 2022 Feb 23.

Université de Lyon, Université Claude Bernard Lyon 1, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, CPE, Villeurbanne, France.

Phospholipids are essential components of biological membranes and are involved in cell signalization, in several enzymatic reactions, and in energy metabolism. In addition, phospholipids represent an evolutionary and non-negligible step in life emergence. Progress in the past decades has led to a deeper understanding of these unique hydrophobic molecules and their most pertinent functions in cell biology. Read More

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Multiwavelength Ablation/Ionization and Mass Spectrometric Analysis of 1.88 Ga Gunflint Chert.

Astrobiology 2022 Apr 23;22(4):369-386. Epub 2022 Feb 23.

Space Research & Planetary Sciences (WP), Physics Institute, University of Bern, Bern, Switzerland.

The investigation of chemical composition on planetary bodies without significant sample processing is of importance for nearly every mission aimed at robotic exploration. Moreover, it is a necessary tool to achieve the longstanding goal of finding evidence of life beyond Earth, for example, possibly preserved microbial remains within martian sediments. Our Laser Ablation Ionization Mass Spectrometer (LIMS) is a compact time-of-flight mass spectrometer intended to investigate the elemental, isotope, and molecular composition of a wide range of solid samples, including e. Read More

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Screening the Survival of Cyanobacteria Under Perchlorate Stress. Potential Implications for Mars Resource Utilization.

Astrobiology 2022 Feb 22. Epub 2022 Feb 22.

Department of Animal Taxonomy and Ecology, Faculty of Biology, Adam Mickiewicz University in Poznań, Poznań, Poland.

Cyanobacteria are good candidates for various martian applications as a potential source of food, fertilizer, oxygen, and biofuels. However, the increased levels of highly toxic perchlorates may be a significant obstacle to their growth on Mars. Therefore, in the present study, 17 cyanobacteria strains that belong to Chroococcales, Chroococcidiopsidales, Nostocales, Oscillatoriales, Pleurocapsales, and Synechococcales were exposed to 0. Read More

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February 2022

Photochemical Synthesis of Ammonia and Amino Acids from Nitrous Oxide.

Astrobiology 2022 Apr 21;22(4):387-398. Epub 2022 Feb 21.

Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan.

Abiotic synthesis of ammonia (NH) and amino acids is important for the origin of life and early evolution. Ammonia and organic nitrogen species may be produced from nitrous oxide (NO), which is a second abundant nitrogen species in the atmosphere. Here, we report a new photochemical experiment and evaluate whether NO can be used as a nitrogen source for prebiotic synthesis in the atmosphere. Read More

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Infrared Spectral Intensities of Amine Ices, Precursors to Amino Acids.

Astrobiology 2022 Apr 15;22(4):452-461. Epub 2022 Feb 15.

Astrochemistry Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA.

Here, we address the paucity of infrared (IR) spectral data needed to quantify low-temperature experiments with amine ices, such as the formation of amino acids, by reporting new IR results on solid phases of methylamine (CHNH) and ethylamine (CHCHNH), precursors to glycine and alanine, respectively. Mid-IR band strengths and absorption coefficients for CHNH and CHCHNH, in both amorphous and crystalline forms, are presented, along with measurements of a density and refractive index (670 nm) for each. For these same compounds, we also have calculated IR optical constants, and they are being made available in electronic form. Read More

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Mineral Matrix Effects on Pyrolysis Products of Kerogens Infer Difficulties in Determining Biological Provenance of Macromolecular Organic Matter at Mars.

Astrobiology 2022 May 15;22(5):520-540. Epub 2022 Feb 15.

Department of Earth Science and Engineering, Imperial College London, London, UK.

Ancient martian organic matter is likely to take the form of kerogen-like recalcitrant macromolecular organic matter (MOM), existing in close association with reactive mineral surfaces, especially iron oxides. Detecting and identifying a biological origin for martian MOM will therefore be of utmost importance for life-detection efforts at Mars. We show that Type I and Type IV kerogens provide effective analogues for putative martian MOM of biological and abiological (meteoric) provenances, respectively. Read More

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Astrobiological Potential of Fe/Mg Smectites with Special Emphasis on Jezero Crater, Mars 2020 Landing Site.

Astrobiology 2022 May 15;22(5):579-597. Epub 2022 Feb 15.

School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.

Life is known to adapt in accordance with its surrounding environment and sustainable resources available to it. Since harsh conditions would have precluded any possible aerobic evolution of life at the martian surface, it is plausible that martian life, should it exist, would have evolved in such a way as to derive energy from more optimum resources. Iron is one of the most abundant elements present in the martian crust and occurs at about twice the amount present on Earth. Read More

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Duplex Formation and the Origins of Homochirality.

Astrobiology 2022 02;22(2):192-196

Department of Biomolecular Engineering, University of California, Santa Cruz, California, USA.

The roots of biological homochirality remain unknown despite decades of study. A commonly proposed path includes an initial small enantiomeric excess that was amplified over time, but a satisfactory source of the excess and a plausible amplification process have yet to be described. We propose here a route to oligonucleotide homochirality from unactivated racemic sources based upon the facts that duplex structures are inherently homochiral and their synthesis from strands of complementary string nucleotide subunits is both uncommonly rapid and exergonic. Read More

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February 2022

Integrated Molar Absorptivity of Mid- and Far-Infrared Spectra of Alanine and a Selection of Other Five Amino Acids of Astrobiological Relevance.

Astrobiology 2022 Apr 7;22(4):462-480. Epub 2022 Feb 7.

Actinium Chemical Research Institute, Rome, Italy.

Alanine and other five proteinogeninc amino acids produced quite easily in exogenous and/or endogenous prebiotic processes, that is, valine, serine, proline, glutamic acid, and aspartic acid (Ala, Val, Ser, Pro, Glu, and Asp, respectively) were studied in the mid- and far-infrared spectral range. This work is an extension of the previous one where other proteinogenic amino acids glycine, isoleucine, phenylalanine, tyrosine, and tryptophan (Gly, Ile, Phe, Tyr, and Trp, respectively) were studied in the mid-infrared and in the far-infrared with the purpose to facilitate the search and identification of these astrobiological and astrochemical relevant molecules in space environments. The molar extinction coefficients () of all mid- and far-infrared bands were determined as well as the integrated molar absorptivities (). Read More

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