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Schaible MJ, Todd ZR, Cangi EM, Harman CE, Hughson KHG, Stelmach K. Chapter 3: The Origins and Evolution of Planetary Systems. Astrobiology 2024; 24:S57-S75. [PMID: 38498821 DOI: 10.1089/ast.2021.0127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
The materials that form the diverse chemicals and structures on Earth-from mountains to oceans and biological organisms-all originated in a universe dominated by hydrogen and helium. Over billions of years, the composition and structure of the galaxies and stars evolved, and the elements of life, CHONPS, were formed through nucleosynthesis in stellar cores. Climactic events such as supernovae and stellar collisions produced heavier elements and spread them throughout the cosmos, often to be incorporated into new, more metal-rich stars. Stars typically form in molecular clouds containing small amounts of dust through the collapse of a high-density core. The surrounding nebular material is then pulled into a protoplanetary disk, from which planets, moons, asteroids, and comets eventually accrete. During the accretion of planetary systems, turbulent mixing can expose matter to a variety of different thermal and radiative environments. Chemical and physical changes in planetary system materials occur before and throughout the process of accretion, though many factors such as distance from the star, impact history, and level of heating experienced combine to ultimately determine the final geophysical characteristics. In Earth's planetary system, called the Solar System, after the orbits of the planets had settled into their current configuration, large impacts became rare, and the composition of and relative positions of objects became largely fixed. Further evolution of the respective chemical and physical environments of the planets-geosphere, hydrosphere, and atmosphere-then became dependent on their local geochemistry, their atmospheric interactions with solar radiation, and smaller asteroid impacts. On Earth, the presence of land, air, and water, along with an abundance of important geophysical and geochemical phenomena, led to a habitable planet where conditions were right for life to thrive.
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Affiliation(s)
- Micah J Schaible
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Zoe R Todd
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, USA
| | - Eryn M Cangi
- Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | | | - Kynan H G Hughson
- School of Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Kamil Stelmach
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
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Yuan Q, Li M, Desch SJ, Ko B, Deng H, Garnero EJ, Gabriel TSJ, Kegerreis JA, Miyazaki Y, Eke V, Asimow PD. Moon-forming impactor as a source of Earth's basal mantle anomalies. Nature 2023; 623:95-99. [PMID: 37914947 DOI: 10.1038/s41586-023-06589-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 08/30/2023] [Indexed: 11/03/2023]
Abstract
Seismic images of Earth's interior have revealed two continent-sized anomalies with low seismic velocities, known as the large low-velocity provinces (LLVPs), in the lowermost mantle1. The LLVPs are often interpreted as intrinsically dense heterogeneities that are compositionally distinct from the surrounding mantle2. Here we show that LLVPs may represent buried relics of Theia mantle material (TMM) that was preserved in proto-Earth's mantle after the Moon-forming giant impact3. Our canonical giant-impact simulations show that a fraction of Theia's mantle could have been delivered to proto-Earth's solid lower mantle. We find that TMM is intrinsically 2.0-3.5% denser than proto-Earth's mantle based on models of Theia's mantle and the observed higher FeO content of the Moon. Our mantle convection models show that dense TMM blobs with a size of tens of kilometres after the impact can later sink and accumulate into LLVP-like thermochemical piles atop Earth's core and survive to the present day. The LLVPs may, thus, be a natural consequence of the Moon-forming giant impact. Because giant impacts are common at the end stages of planet accretion, similar mantle heterogeneities caused by impacts may also exist in the interiors of other planetary bodies.
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Affiliation(s)
- Qian Yuan
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA.
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
| | - Mingming Li
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Steven J Desch
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Byeongkwan Ko
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
- Department of Earth and Environmental Sciences, Michigan State University, East Lansing, MI, USA
| | - Hongping Deng
- Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai, China
| | - Edward J Garnero
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | | | | | - Yoshinori Miyazaki
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Vincent Eke
- Institute for Computational Cosmology, Department of Physics, Durham University, Durham, UK
| | - Paul D Asimow
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
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'Super-puff' planet is one of the fluffiest worlds ever found. Nature 2023; 622:673. [PMID: 37853197 DOI: 10.1038/d41586-023-03222-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
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O'Callaghan J. This is what Earth's continents will look like in 250 million years. Nature 2023; 622:20. [PMID: 37749342 DOI: 10.1038/d41586-023-03005-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
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Fei H, Ballmer MD, Faul U, Walte N, Cao W, Katsura T. Variation in bridgmanite grain size accounts for the mid-mantle viscosity jump. Nature 2023; 620:794-799. [PMID: 37407826 PMCID: PMC10447242 DOI: 10.1038/s41586-023-06215-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/12/2023] [Indexed: 07/07/2023]
Abstract
A viscosity jump of one to two orders of magnitude in the lower mantle of Earth at 800-1,200-km depth is inferred from geoid inversions and slab-subducting speeds. This jump is known as the mid-mantle viscosity jump1,2. The mid-mantle viscosity jump is a key component of lower-mantle dynamics and evolution because it decelerates slab subduction3, accelerates plume ascent4 and inhibits chemical mixing5. However, because phase transitions of the main lower-mantle minerals do not occur at this depth, the origin of the viscosity jump remains unknown. Here we show that bridgmanite-enriched rocks in the deep lower mantle have a grain size that is more than one order of magnitude larger and a viscosity that is at least one order of magnitude higher than those of the overlying pyrolitic rocks. This contrast is sufficient to explain the mid-mantle viscosity jump1,2. The rapid growth in bridgmanite-enriched rocks at the early stage of the history of Earth and the resulting high viscosity account for their preservation against mantle convection5-7. The high Mg:Si ratio of the upper mantle relative to chondrites8, the anomalous 142Nd:144Nd, 182W:184W and 3He:4He isotopic ratios in hot-spot magmas9,10, the plume deflection4 and slab stagnation in the mid-mantle3 as well as the sparse observations of seismic anisotropy11,12 can be explained by the long-term preservation of bridgmanite-enriched rocks in the deep lower mantle as promoted by their fast grain growth.
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Affiliation(s)
- Hongzhan Fei
- Bayerisches Geoinstitut, Universität Bayreuth, Bayreuth, Germany.
- Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, School of Earth Sciences, Zhejiang University, Hangzhou, China.
| | - Maxim D Ballmer
- Department of Earth Sciences, University College London, London, UK
| | - Ulrich Faul
- Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nicolas Walte
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany
| | - Weiwei Cao
- Conditions Extrêmes et Matériaux: Haute Température et Irradiation (CEMHTI), Orléans, France
| | - Tomoo Katsura
- Bayerisches Geoinstitut, Universität Bayreuth, Bayreuth, Germany
- Center for High Pressure Science and Technology Advanced Research, Beijing, China
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Perotti G, Christiaens V, Henning T, Tabone B, Waters LBFM, Kamp I, Olofsson G, Grant SL, Gasman D, Bouwman J, Samland M, Franceschi R, van Dishoeck EF, Schwarz K, Güdel M, Lagage PO, Ray TP, Vandenbussche B, Abergel A, Absil O, Arabhavi AM, Argyriou I, Barrado D, Boccaletti A, Caratti O Garatti A, Geers V, Glauser AM, Justannont K, Lahuis F, Mueller M, Nehmé C, Pantin E, Scheithauer S, Waelkens C, Guadarrama R, Jang H, Kanwar J, Morales-Calderón M, Pawellek N, Rodgers-Lee D, Schreiber J, Colina L, Greve TR, Östlin G, Wright G. Water in the terrestrial planet-forming zone of the PDS 70 disk. Nature 2023; 620:516-520. [PMID: 37488359 PMCID: PMC10432267 DOI: 10.1038/s41586-023-06317-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/13/2023] [Indexed: 07/26/2023]
Abstract
Terrestrial and sub-Neptune planets are expected to form in the inner (less than 10 AU) regions of protoplanetary disks1. Water plays a key role in their formation2-4, although it is yet unclear whether water molecules are formed in situ or transported from the outer disk5,6. So far Spitzer Space Telescope observations have only provided water luminosity upper limits for dust-depleted inner disks7, similar to PDS 70, the first system with direct confirmation of protoplanet presence8,9. Here we report JWST observations of PDS 70, a benchmark target to search for water in a disk hosting a large (approximately 54 AU) planet-carved gap separating an inner and outer disk10,11. Our findings show water in the inner disk of PDS 70. This implies that potential terrestrial planets forming therein have access to a water reservoir. The column densities of water vapour suggest in-situ formation via a reaction sequence involving O, H2 and/or OH, and survival through water self-shielding5. This is also supported by the presence of CO2 emission, another molecule sensitive to ultraviolet photodissociation. Dust shielding, and replenishment of both gas and small dust from the outer disk, may also play a role in sustaining the water reservoir12. Our observations also reveal a strong variability of the mid-infrared spectral energy distribution, pointing to a change of inner disk geometry.
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Affiliation(s)
- G Perotti
- Max Planck Institute for Astronomy, Heidelberg, Germany.
| | | | - Th Henning
- Max Planck Institute for Astronomy, Heidelberg, Germany
| | - B Tabone
- Université Paris-Saclay, CNRS, Institut d'Astrophysique Spatiale, Orsay, France
| | - L B F M Waters
- Department of Astrophysics/IMAPP, Radboud University, Nijmegen, the Netherlands
- SRON Netherlands Institute for Space Research, Leiden, the Netherlands
| | - I Kamp
- Kapteyn Astronomical Institute, Rijksuniversiteit Groningen, Groningen, the Netherlands
| | - G Olofsson
- Department of Astronomy, Stockholm University, AlbaNova University Center, Stockholm, Sweden
| | - S L Grant
- Max-Planck Institut für Extraterrestrische Physik (MPE), Garching, Germany
| | - D Gasman
- Institute of Astronomy, KU Leuven, Leuven, Belgium
| | - J Bouwman
- Max Planck Institute for Astronomy, Heidelberg, Germany
| | - M Samland
- Max Planck Institute for Astronomy, Heidelberg, Germany
| | - R Franceschi
- Max Planck Institute for Astronomy, Heidelberg, Germany
| | - E F van Dishoeck
- Max-Planck Institut für Extraterrestrische Physik (MPE), Garching, Germany
- Leiden Observatory, Leiden University, Leiden, the Netherlands
| | - K Schwarz
- Max Planck Institute for Astronomy, Heidelberg, Germany
| | - M Güdel
- Max Planck Institute for Astronomy, Heidelberg, Germany
- Dept. of Astrophysics, University of Vienna, Vienna, Austria
- ETH Zürich, Institute for Particle Physics and Astrophysics, Zürich, Switzerland
| | - P-O Lagage
- Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, Gif-sur-Yvette, France
| | - T P Ray
- Dublin Institute for Advanced Studies, Dublin, Ireland
| | | | - A Abergel
- Université Paris-Saclay, CNRS, Institut d'Astrophysique Spatiale, Orsay, France
| | - O Absil
- STAR Institute, Université de Liège, Liège, Belgium
| | - A M Arabhavi
- Kapteyn Astronomical Institute, Rijksuniversiteit Groningen, Groningen, the Netherlands
| | - I Argyriou
- Institute of Astronomy, KU Leuven, Leuven, Belgium
| | - D Barrado
- Centro de Astrobiología (CAB), CSIC-INTA, Villanueva de la Cañada, Spain
| | - A Boccaletti
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, Meudon, France
| | - A Caratti O Garatti
- Dublin Institute for Advanced Studies, Dublin, Ireland
- INAF - Osservatorio Astronomico di Capodimonte, Napoli, Italy
| | - V Geers
- UK Astronomy Technology Centre, Royal Observatory Edinburgh, Edinburgh, UK
| | - A M Glauser
- ETH Zürich, Institute for Particle Physics and Astrophysics, Zürich, Switzerland
| | - K Justannont
- Chalmers University of Technology, Onsala Space Observatory, Onsala, Sweden
| | - F Lahuis
- SRON Netherlands Institute for Space Research, Groningen, the Netherlands
| | - M Mueller
- Kapteyn Astronomical Institute, Rijksuniversiteit Groningen, Groningen, the Netherlands
| | - C Nehmé
- Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, Gif-sur-Yvette, France
| | - E Pantin
- Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, Gif-sur-Yvette, France
| | - S Scheithauer
- Max Planck Institute for Astronomy, Heidelberg, Germany
| | - C Waelkens
- Institute of Astronomy, KU Leuven, Leuven, Belgium
| | - R Guadarrama
- Dept. of Astrophysics, University of Vienna, Vienna, Austria
| | - H Jang
- Department of Astrophysics/IMAPP, Radboud University, Nijmegen, the Netherlands
| | - J Kanwar
- Kapteyn Astronomical Institute, Rijksuniversiteit Groningen, Groningen, the Netherlands
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
- TU Graz, Fakultät für Mathematik, Physik und Geodäsie, Graz, Austria
| | - M Morales-Calderón
- Centro de Astrobiología (CAB), CSIC-INTA, Villanueva de la Cañada, Spain
| | - N Pawellek
- Dept. of Astrophysics, University of Vienna, Vienna, Austria
| | - D Rodgers-Lee
- Dublin Institute for Advanced Studies, Dublin, Ireland
| | - J Schreiber
- Max Planck Institute for Astronomy, Heidelberg, Germany
| | - L Colina
- Centro de Astrobiología (CAB, CSIC-INTA), Carretera de Ajalvir, Torrejón de Ardoz, Spain
| | - T R Greve
- DTU Space, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - G Östlin
- Department of Astronomy, Oskar Klein Centre, Stockholm University, Stockholm, Sweden
| | - G Wright
- UK Astronomy Technology Centre, Royal Observatory Edinburgh, Edinburgh, UK
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Planet or failed star? A mysterious object blurs the line. Nature 2023; 615:564. [PMID: 36918639 DOI: 10.1038/d41586-023-00749-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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Deamer D, Cary F, Damer B. Urability: A Property of Planetary Bodies That Can Support an Origin of Life. Astrobiology 2022; 22:889-900. [PMID: 35675644 DOI: 10.1089/ast.2021.0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The concept of habitability is now widely used to describe zones in a solar system in which planets with liquid water can sustain life. Because habitability does not explicitly incorporate the origin of life, this article proposes a new word-urability-which refers to the conditions that allow life to begin. The utility of the word is tested by applying it to combinations of multiple geophysical and geochemical factors that support plausible localized zones that are conducive to the chemical reactions and molecular assembly processes required for the origin of life. The concept of urable worlds, planetary bodies that can sustain an arising of life, is considered for bodies in our own solar system and exoplanets beyond.
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Affiliation(s)
- David Deamer
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, California, USA
| | - Francesca Cary
- Hawai'i Institute of Geophysics and Planetology, University of Hawai'i at Mānoa, Honolulu, Hawaii, USA
| | - Bruce Damer
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, California, USA
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Miyazaki Y, Korenaga J. Inefficient Water Degassing Inhibits Ocean Formation on Rocky Planets: An Insight from Self-Consistent Mantle Degassing Models. Astrobiology 2022; 22:713-734. [PMID: 35235378 DOI: 10.1089/ast.2021.0126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
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. We find that planets with low H2O/CO2 ratios would not have a sufficient amount of surface water to develop water oceans immediately after magma ocean solidification, and the majority of the water inventory would be retained in the mantle during their subsequent evolution regardless of planetary size. This is because oceanless planets are likely to operate under stagnant lid convection, and for such planets, dehydration stiffening of the depleted lithospheric mantle would limit the rate of mantle degassing. In contrast, a significant fraction of CO2 would already be degassed during magma ocean solidification. With a strong greenhouse effect, all surface water would exist as vapor, and water oceans may be absent throughout planetary evolution. Volatile concentrations in the bulk silicate Earth are close to the threshold amount for ocean formation, so if Venus shared similar concentrations, small differences in solar radiation may explain the divergent evolutionary paths of Earth and Venus.
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Affiliation(s)
- Yoshinori Miyazaki
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, USA
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
| | - Jun Korenaga
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, USA
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Abstract
Recent observations of the potentially habitable planets TRAPPIST-1 e, f, and g suggest that they possess large water mass fractions of possibly several tens of weight percent of water, even though the host star's activity should drive rapid atmospheric escape. These processes can photolyze water, generating free oxygen and possibly desiccating the planet. After the planets formed, their mantles were likely completely molten with volatiles dissolving and exsolving from the melt. To understand these planets and prepare for future observations, the magma ocean phase of these worlds must be understood. To simulate these planets, we have combined existing models of stellar evolution, atmospheric escape, tidal heating, radiogenic heating, magma-ocean cooling, planetary radiation, and water-oxygen-iron geochemistry. We present MagmOc, a versatile magma-ocean evolution model, validated against the rocky super-Earth GJ 1132b and early Earth. We simulate the coupled magma-ocean atmospheric evolution of TRAPPIST-1 e, f, and g for a range of tidal and radiogenic heating rates, as well as initial water contents between 1 and 100 Earth oceans. We also reanalyze the structures of these planets and find they have water mass fractions of 0-0.23, 0.01-0.21, and 0.11-0.24 for planets e, f, and g, respectively. Our model does not make a strong prediction about the water and oxygen content of the atmosphere of TRAPPIST-1 e at the time of mantle solidification. In contrast, the model predicts that TRAPPIST-1 f and g would have a thick steam atmosphere with a small amount of oxygen at that stage. For all planets that we investigated, we find that only 3-5% of the initial water will be locked in the mantle after the magma ocean solidified.
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Affiliation(s)
- Patrick Barth
- Centre for Exoplanet Science, University of St Andrews, St Andrews, UK
- SUPA, School of Physics & Astronomy, University of St Andrews, St Andrews, UK
- Max Planck Institute for Astronomy, Heidelberg, Germany
| | | | - Rory Barnes
- Astronomy Department, University of Washington, Seattle, Washington, USA
- NASA Virtual Planetary Laboratory Lead Team, USA
| | - Lena Noack
- Freie Universität Berlin, Institute of Geological Sciences, Berlin, Germany
| | - Paul Mollière
- Max Planck Institute for Astronomy, Heidelberg, Germany
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Klindžić D, Stam DM, Snik F, Keller CU, Hoeijmakers HJ, van Dam DM, Willebrands M, Karalidi T, Pallichadath V, van Dijk CN, Esposito M. LOUPE: observing Earth from the Moon to prepare for detecting life on Earth-like exoplanets. Philos Trans A Math Phys Eng Sci 2021; 379:20190577. [PMID: 33222648 PMCID: PMC7739899 DOI: 10.1098/rsta.2019.0577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
LOUPE, the Lunar Observatory for Unresolved Polarimetry of the Earth, is a small, robust spectro-polarimeter for observing the Earth as an exoplanet. Detecting Earth-like planets in stellar habitable zones is one of the key challenges of modern exoplanetary science. Characterizing such planets and searching for traces of life requires the direct detection of their signals. LOUPE provides unique spectral flux and polarization data of sunlight reflected by Earth, the only planet known to harbour life. These data will be used to test numerical codes to predict signals of Earth-like exoplanets, to test algorithms that retrieve planet properties, and to fine-tune the design and observational strategies of future space observatories. From the Moon, LOUPE will continuously see the entire Earth, enabling it to monitor the signal changes due to the planet's daily rotation, weather patterns and seasons, across all phase angles. Here, we present both the science case and the technology behind LOUPE's instrumental and mission design. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades'.
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Affiliation(s)
- D. Klindžić
- Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS, Delft, The Netherlands
- Leiden Observatory, Leiden University, PO Box 9513, 2300 RA, Leiden, The Netherlands
| | - D. M. Stam
- Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS, Delft, The Netherlands
| | - F. Snik
- Leiden Observatory, Leiden University, PO Box 9513, 2300 RA, Leiden, The Netherlands
| | - C. U. Keller
- Leiden Observatory, Leiden University, PO Box 9513, 2300 RA, Leiden, The Netherlands
| | - H. J. Hoeijmakers
- Center for Space and Habitability (CSH), University of Bern, Gesellschaftsstrasse 6 (G6), 3012 Bern, Switzerland
| | - D. M. van Dam
- Leiden Observatory, Leiden University, PO Box 9513, 2300 RA, Leiden, The Netherlands
| | - M. Willebrands
- Leiden Observatory, Leiden University, PO Box 9513, 2300 RA, Leiden, The Netherlands
| | - T. Karalidi
- Department of Physics, UCF, 4111 Libra Drive, Physical Sciences Building 430, Orlando, FL, USA
| | - V. Pallichadath
- Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS, Delft, The Netherlands
| | - C. N. van Dijk
- cosine Remote Sensing, Oosteinde 36, 2361 HE Warmond, The Netherlands
| | - M. Esposito
- cosine Remote Sensing, Oosteinde 36, 2361 HE Warmond, The Netherlands
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Haqq-Misra J, Kopparapu RK, Schwieterman E. Observational Constraints on the Great Filter. Astrobiology 2020; 20:572-579. [PMID: 32364797 DOI: 10.1089/ast.2019.2154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The search for spectroscopic biosignatures with the next generation of space telescopes could provide observational constraints on the abundance of exoplanets with signs of life. An extension of this spectroscopic characterization of exoplanets is the search for observational evidence of technology, known as technosignatures. Current mission concepts that would observe biosignatures from ultraviolet to near-infrared wavelengths could place upper limits on the fraction of planets in the Galaxy that host life, although such missions tend to have relatively limited capabilities of constraining the prevalence of technosignatures at mid-infrared wavelengths. Yet searching for technosignatures alongside biosignatures would provide important knowledge about the future of our civilization. If planets with technosignatures are abundant, then we can increase our confidence that the hardest step in planetary evolution-the Great Filter-is probably in our past. But if we find that life is commonplace while technosignatures are absent, then this would increase the likelihood that the Great Filter awaits to challenge us in the future.
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Affiliation(s)
| | | | - Edward Schwieterman
- Blue Marble Space Institute of Science, Seattle, Washington
- University of California at Riverside, Riverside, California
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Chaves Torres L, Kaur G, Melbourne LA, Pancost RD. Selective chemical degradation of silica sinters of the Taupo Volcanic Zone (New Zealand). Implications for early Earth and Astrobiology. Geobiology 2019; 17:449-464. [PMID: 31020785 DOI: 10.1111/gbi.12340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 02/26/2019] [Accepted: 03/21/2019] [Indexed: 06/09/2023]
Abstract
Most organic matter (OM) on Earth occurs as kerogen-like materials, that is naturally formed macromolecules insoluble with standard organic solvents. The formation of this insoluble organic matter (IOM) is a topic of much interest, especially when it limits the detection of compounds of geomicrobiological interest. For example, studies that search for biomarker evidence of life on early Earth or other planets usually use solvent-based extractions. This leaves behind a pool of OM as unexplored post-extraction residues, potentially containing diagnostic biomarkers. Since the IOM has an enhanced potential for preservation compared to soluble OM, analysing IOM-released biomarkers can also provide even deeper insights into the ecology of ancient settings, with implications for early Earth and Astrobiology investigations. Here, we analyse the prokaryotic lipid biosignature within soluble and IOM of the Taupo Volcanic Zone (TVZ) silica sinters, which are key analogues in the search for life. We apply sequential solvent extractions and a selective chemical degradation upon the post-solvent extraction residue. Moreover, we compare the IOM from TVZ sinters to analogous studies on peat and marine sediments to assess patterns in OM insolubilisation across the geosphere. Consistent with previous work, we find significant but variable proportions-1%-45% of the total prokaryotic lipids recovered-associated with IOM fractions. This occurs even in recently formed silica sinters, likely indicating inherent cell insolubility. Moreover, archaeal lipids seem more prone to insolubilisation as compared to the bacterial analogues, which might enhance their preservation and also bias overall biomarkers interpretation. These observations are similar to those observed in other settings, confirming that even in a setting where the OM derives predominantly from prokaryotic sources, patterns of IOM formation/occurrence are conserved. Differences with other settings, however, such as the occurrence of archaeol in IOM fractions, could be indicative of different mechanisms for IOM formation that merit further exploration.
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Affiliation(s)
- Lidia Chaves Torres
- Organic Geochemistry Unit, School of Chemistry, University of Bristol, Bristol, UK
- Cabot Institute, University of Bristol, Bristol, UK
| | - Gurpreet Kaur
- Organic Geochemistry Unit, School of Chemistry, University of Bristol, Bristol, UK
- Cabot Institute, University of Bristol, Bristol, UK
| | - Leanne A Melbourne
- Organic Geochemistry Unit, School of Chemistry, University of Bristol, Bristol, UK
- Cabot Institute, University of Bristol, Bristol, UK
| | - Richard D Pancost
- Organic Geochemistry Unit, School of Chemistry, University of Bristol, Bristol, UK
- Cabot Institute, University of Bristol, Bristol, UK
- School of Earth Sciences, University of Bristol, Bristol, UK
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15
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Lammer H, Sproß L, Grenfell JL, Scherf M, Fossati L, Lendl M, Cubillos PE. The Role of N 2 as a Geo-Biosignature for the Detection and Characterization of Earth-like Habitats. Astrobiology 2019; 19:927-950. [PMID: 31314591 DOI: 10.1089/ast.2018.1914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Since the Archean, N2 has been a major atmospheric constituent in Earth's atmosphere. Nitrogen is an essential element in the building blocks of life; therefore, the geobiological nitrogen cycle is a fundamental factor in the long-term evolution of both Earth and Earth-like exoplanets. We discuss the development of Earth's N2 atmosphere since the planet's formation and its relation with the geobiological cycle. Then we suggest atmospheric evolution scenarios and their possible interaction with life-forms: first for a stagnant-lid anoxic world, second for a tectonically active anoxic world, and third for an oxidized tectonically active world. Furthermore, we discuss a possible demise of present Earth's biosphere and its effects on the atmosphere. Since life-forms are the most efficient means for recycling deposited nitrogen back into the atmosphere at present, they sustain its surface partial pressure at high levels. Also, the simultaneous presence of significant N2 and O2 is chemically incompatible in an atmosphere over geological timescales. Thus, we argue that an N2-dominated atmosphere in combination with O2 on Earth-like planets within circumstellar habitable zones can be considered as a geo-biosignature. Terrestrial planets with such atmospheres will have an operating tectonic regime connected with an aerobic biosphere, whereas other scenarios in most cases end up with a CO2-dominated atmosphere. We conclude with implications for the search for life on Earth-like exoplanets inside the habitable zones of M to K stars.
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Affiliation(s)
- Helmut Lammer
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
| | - Laurenz Sproß
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
- 2Institute of Physics, University of Graz, Graz, Austria
| | - John Lee Grenfell
- 3Department of Extrasolar Planets and Atmospheres, German Aerospace Center, Institute of Planetary Research, Berlin, Germany
| | - Manuel Scherf
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
| | - Luca Fossati
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
| | - Monika Lendl
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
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16
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LeRoy MA, Gill BC. Evidence for the development of local anoxia during the Cambrian SPICE event in eastern North America. Geobiology 2019; 17:381-400. [PMID: 30729650 DOI: 10.1111/gbi.12334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 10/20/2018] [Accepted: 01/05/2019] [Indexed: 06/09/2023]
Abstract
The later Cambrian Steptoean Positive Carbon Isotope Excursion (SPICE) event was an episode marked by pronounced changes to the global biogeochemical cycles of carbon and sulfur and significant extinctions on several paleocontinents including Laurentia (North America). While the exact cause(s) of these events remains debated, various lines of evidence suggest an increase in the areal extent of anoxia at the seafloor was a likely feature. Here, we explore whether changes in local oxygenation accompanied the onset of the SPICE in southern Laurentia using cores of the Nolichucky and Eau Claire Formations from Ohio and Kentucky, USA, that represent a transect into the Rome Trough/Conasauga intrashelf basin. At our study locations, the initial positive δ13 C shift of the SPICE occurs in conjunction with increases in the abundance and δ34 S of sedimentary pyrite. Further local redox conditions, tracked using iron speciation analysis, indicate anoxic conditions developed at the two proximal locations after the start of the paired isotopic excursions. However, the location near the basin center shows no indication for anoxia before or during the onset of the SPICE. While this signal may reflect the structure of local redox conditions within the basin, with the development of anoxia limited to the basin margins, we argue that authigenic iron enrichments were muted by sedimentary dilution and/or the enhanced authigenesis of iron-bearing sheet silicates near the basin center, masking the signal for anoxia there. Regardless of the areal extent of anoxia within the basin, in either scenario the timing of the development of anoxic bottom waters was concurrent with local faunal turnover, features broadly consistent with a global expansion of anoxia playing a role in driving the isotopic trends and extinctions observed during the event.
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Affiliation(s)
- Matthew A LeRoy
- Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - Benjamin C Gill
- Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
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17
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Abstract
Considerable data and analysis support the detection of one or more supernovae (SNe) at a distance of about 50 pc, ∼2.6 million years ago. This is possibly related to the extinction event around that time and is a member of a series of explosions that formed the Local Bubble in the interstellar medium. We build on previous work, and propagate the muon flux from SN-initiated cosmic rays from the surface to the depths of the ocean. We find that the radiation dose from the muons will exceed the total present surface dose from all sources at depths up to 1 km and will persist for at least the lifetime of marine megafauna. It is reasonable to hypothesize that this increase in radiation load may have contributed to a newly documented marine megafaunal extinction at that time.
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Affiliation(s)
- Adrian L Melott
- 1 Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas
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18
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Ward LM, Stamenković V, Hand K, Fischer WW. Follow the Oxygen: Comparative Histories of Planetary Oxygenation and Opportunities for Aerobic Life. Astrobiology 2019; 19:811-824. [PMID: 31188035 DOI: 10.1089/ast.2017.1779] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Aerobic respiration-the reduction of molecular oxygen (O2) coupled to the oxidation of reduced compounds such as organic carbon, ferrous iron, reduced sulfur compounds, or molecular hydrogen while conserving energy to drive cellular processes-is the most widespread and bioenergetically favorable metabolism on Earth today. Aerobic respiration is essential for the development of complex multicellular life; thus the presence of abundant O2 is an important metric for planetary habitability. O2 on Earth is supplied by oxygenic photosynthesis, but it is becoming more widely understood that abiotic processes may supply meaningful amounts of O2 on other worlds. The modern atmosphere and rock record of Mars suggest a history of relatively high O2 as a result of photochemical processes, potentially overlapping with the range of O2 concentrations used by biology. Europa may have accumulated high O2 concentrations in its subsurface ocean due to the radiolysis of water ice at its surface. Recent modeling efforts suggest that coexisting water and O2 may be common on exoplanets, with confirmation from measurements of exoplanet atmospheres potentially coming soon. In all these cases, O2 accumulates through abiotic processes-independent of water-oxidizing photosynthesis. We hypothesize that abiogenic O2 may enhance the habitability of some planetary environments, allowing highly energetic aerobic respiration and potentially even the development of complex multicellular life which depends on it, without the need to first evolve oxygenic photosynthesis. This hypothesis is testable with further exploration and life-detection efforts on O2-rich worlds such as Mars and Europa, and comparison to O2-poor worlds such as Enceladus. This hypothesis further suggests a new dimension to planetary habitability: "Follow the Oxygen," in which environments with opportunities for energy-rich metabolisms such as aerobic respiration are preferentially targeted for investigation and life detection.
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Affiliation(s)
- Lewis M Ward
- 1 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California
| | - Vlada Stamenković
- 2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Kevin Hand
- 2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Woodward W Fischer
- 1 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California
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19
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NAKAMURA E, KUNIHIRO T, OTA T, SAKAGUCHI C, TANAKA R, KITAGAWA H, KOBAYASHI K, YAMANAKA M, SHIMAKI Y, BEBOUT GE, MIURA H, YAMAMOTO T, MALKOVETS V, GROKHOVSKY V, KOROLEVA O, LITASOV K. Hypervelocity collision and water-rock interaction in space preserved in the Chelyabinsk ordinary chondrite. Proc Jpn Acad Ser B Phys Biol Sci 2019; 95:165-177. [PMID: 30971619 PMCID: PMC6541723 DOI: 10.2183/pjab.95.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/04/2019] [Indexed: 06/01/2023]
Abstract
A comprehensive geochemical study of the Chelyabinsk meteorite reveals further details regarding its history of impact-related fragmentation and melting, and later aqueous alteration, during its transit toward Earth. We support an ∼30 Ma age obtained by Ar-Ar method (Beard et al., 2014) for the impact-related melting, based on Rb-Sr isotope analyses of a melt domain. An irregularly shaped olivine with a distinct O isotope composition in a melt domain appears to be a fragment of a silicate-rich impactor. Hydrogen and Li concentrations and isotopic compositions, textures of Fe oxyhydroxides, and the presence of organic materials located in fractures, are together consistent with aqueous alteration, and this alteration could have pre-dated interaction with the Earth's atmosphere. As one model, we suggest that hypervelocity capture of the impact-related debris by a comet nucleus could have led to shock-wave-induced supercritical aqueous fluids dissolving the silicate, metallic, and organic matter, with later ice sublimation yielding a rocky rubble pile sampled by the meteorite.
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Affiliation(s)
- Eizo NAKAMURA
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Tak KUNIHIRO
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Tsutomu OTA
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Chie SAKAGUCHI
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Ryoji TANAKA
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Hiroshi KITAGAWA
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Katsura KOBAYASHI
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Masahiro YAMANAKA
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Yuri SHIMAKI
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Gray E. BEBOUT
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
- Department of Earth and Environmental Sciences, Lehigh University, Bethlehem, PA, U.S.A.
| | - Hitoshi MIURA
- Graduate School of Natural Sciences, Nagoya City University, Nagoya, Japan
| | - Tetsuo YAMAMOTO
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Vladimir MALKOVETS
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Tottori, Japan
| | - Victor GROKHOVSKY
- Institute of Physics and Technology, Ural Federal University, Yekaterinburg, Russia
| | - Olga KOROLEVA
- Institute of Mineralogy, Ural Branch of the Russian Academy of Sciences, Miass, Russia
- South-Ural State University, Chelyabinsk, Russia
| | - Konstantin LITASOV
- V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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20
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YOSHIDA N. Formation of the first generation of stars and blackholes in the Universe. Proc Jpn Acad Ser B Phys Biol Sci 2019; 95:17-28. [PMID: 30643093 PMCID: PMC6395782 DOI: 10.2183/pjab.95.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 10/23/2018] [Indexed: 06/09/2023]
Abstract
Modern sky surveys using large ground-based telescopes have discovered a variety of celestial objects. Prominent structures such as galaxies and galaxy clusters are found virtually everywhere, and their collective distribution forms the large-scale structure of the Universe. It is thought that all of the rich content in the present-day Universe developed through gravitational amplification of primeval density fluctuations generated in the very early phase of cosmic evolution. The standard theoretical model based on an array of recent observations accurately predicts the physical conditions in the early Universe, and powerful super-computers allow us to simulate in detail the formation and evolution of cosmic structure to the present epoch. We review recent progress in the study on the first generation of stars and blackholes. We focus on the physics of early structure formation, while identifying several key issues and open questions. Finally, we discuss prospects for future observations of the first stars, galaxies and blackholes.
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Affiliation(s)
- Naoki YOSHIDA
- Department of Physics, School of Science, The University of Tokyo, Tokyo, Japan
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS, The University of Tokyo, Chiba, Japan
- Research Center for the Early Universe, The University of Tokyo, Tokyo, Japan
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21
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Ozaki K, Reinhard CT, Tajika E. A sluggish mid-Proterozoic biosphere and its effect on Earth's redox balance. Geobiology 2019; 17:3-11. [PMID: 30281196 PMCID: PMC6585969 DOI: 10.1111/gbi.12317] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/27/2018] [Indexed: 05/20/2023]
Abstract
The possibility of low but nontrivial atmospheric oxygen (O2 ) levels during the mid-Proterozoic (between 1.8 and 0.8 billion years ago, Ga) has important ramifications for understanding Earth's O2 cycle, the evolution of complex life and evolving climate stability. However, the regulatory mechanisms and redox fluxes required to stabilize these O2 levels in the face of continued biological oxygen production remain uncertain. Here, we develop a biogeochemical model of the C-N-P-O2 -S cycles and use it to constrain global redox balance in the mid-Proterozoic ocean-atmosphere system. By employing a Monte Carlo approach bounded by observations from the geologic record, we infer that the rate of net biospheric O2 production was 3 . 5 - 1.1 + 1.4 Tmol year-1 (1σ), or ~25% of today's value, owing largely to phosphorus scarcity in the ocean interior. Pyrite burial in marine sediments would have represented a comparable or more significant O2 source than organic carbon burial, implying a potentially important role for Earth's sulphur cycle in balancing the oxygen cycle and regulating atmospheric O2 levels. Our statistical approach provides a uniquely comprehensive view of Earth system biogeochemistry and global O2 cycling during mid-Proterozoic time and implicates severe P biolimitation as the backdrop for Precambrian geochemical and biological evolution.
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Affiliation(s)
- Kazumi Ozaki
- School of Earth and Atmospheric SciencesGeorgia Institute of TechnologyAtlantaGeorgia
- NASA Astrobiology InstituteAlternative Earths TeamMountain ViewCalifornia
- NASA Postdoctoral ProgramUniversities Space Research AssociationColumbiaMaryland
- Present address:
Department of Environmental ScienceToho UniversityChibaJapan
| | - Christopher T. Reinhard
- School of Earth and Atmospheric SciencesGeorgia Institute of TechnologyAtlantaGeorgia
- NASA Astrobiology InstituteAlternative Earths TeamMountain ViewCalifornia
| | - Eiichi Tajika
- Department of Earth and Planetary ScienceGraduate School of ScienceThe University of TokyoBunkyo‐kuJapan
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22
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Yoshiya K, Sato T, Omori S, Maruyama S. The Birthplace of Proto-Life: Role of Secondary Minerals in Forming Metallo-Proteins through Water-Rock Interaction of Hadean Rocks. ORIGINS LIFE EVOL B 2018; 48:373-393. [PMID: 30945039 DOI: 10.1007/s11084-019-09571-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 02/22/2019] [Indexed: 10/27/2022]
Abstract
The surface of Hadean Earth was mainly covered with three types of rocks-komatiite, KREEP basalt and anorthosite-which were remarkably different from those on the modern Earth. The water-rock interaction between these rocks and water provided a highly reducing environment and formed secondary minerals on the surface of the rocks that are important for producing metallo-enzymes for the emergence of primordial life. Previous studies suggested a correlation between the active site of metallo-enzymes and sulfide minerals based on the affinity of their structures, but they did not discuss the origin of metallic elements contained in these minerals which is critical to understanding where life began. We investigated secondary minerals formed through water-rock interactions of komatiite in a subaerial geyser system, then discussed the relationship between the active site of metallo-enzymes and secondary minerals. Instead of komatiite, we used serpentinite collected from the Hakuba Happo area, Nagano Prefecture in central-north Japan, which is thought to be a modern analog for the Hadean environment. We found several minor minerals, such as magnetite, chromite, pyrite and pentlandite in addition to serpentine minerals. Pentlandite has not been mentioned in previous studies as one of the candidates that could supply important metallic elements to build metallo-enzymes. It has been shown to be a catalyst for hydrogen generation possibly, because of structural similarity to the active site of hydrogenases. We consider the possibility that nickel-iron sulfide, pentlandite, could be important minerals for the origin of life. In addition, we estimated what kinds of minor minerals would be obtained from the water-rock interaction of these rocks using thermodynamic calculations. KREEP basalt contains a large amount of iron and it could be useful for producing metallo-enzymes, especially ferredoxins-electron transfer enzymes, which may have assisted in the emergence of life.
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Affiliation(s)
- Kazumi Yoshiya
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan.
| | - Tomohiko Sato
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Soichi Omori
- The Open University of Japan, 2-11 Wakaba, Mihama-ku, Chiba, 261- 8586, Japan
| | - Shigenori Maruyama
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
- Novosibirsk State University, Novosibirsk, 630090, Russia
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23
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Abstract
In previous experiments that simulated conditions on primordial volcanic islands, we demonstrated the abiotic formation of hydrophobic porphyrins. The present study focused on the question whether such porphyrins can be metalated by prebiotically plausible metal ion sources. We used water-insoluble octaethylporphyrin (H2oep) as a model compound. Experiments were conducted in a nitrogen atmosphere under cyclic wet-dry conditions in order to simulate the fluctuating environment in prebiotic rock pools. Wetting-drying proved to be a crucial factor. Significant yields of the metalloporphyrins (20-78% with respect to H2oep) were obtained from the soluble salts MCl2 (M = Mg, Fe, Co, Ni and Cu) in freshwater. Even almost insoluble minerals and rocks metalated the porphyrin. Basalt (an iron source, 11% yield), synthetic jaipurite (CoS, 33%) and synthetic covellite (CuS, 57%) were most efficient. Basalt, magnetite and FeCl2 gave considerably higher yields in artificial seawater than in freshwater. From iron sources, the highest yields, however, were obtained in an acidic medium (hydrochloric acid with an initial pH of 2.1). Under these conditions, iron meteorites also metalated the porphyrin. Acidic conditions were considered because they are known to occur during eruptions on volcanic islands. Octaethylporphyrinatomagnesium(II) did not form in acidic medium and was unstable towards dissolved Fe2+. It is therefore questionable whether magnesium porphyrins, i.e. possible ancestors of chlorophyll, could have accumulated in primordial rock pools. However, abiotically formed ancestors of the modern cofactors heme (Fe), B12 (Co), and F430 (Ni) may have been available to hypothetical protometabolisms and early organisms.
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Affiliation(s)
- Hannes Lukas Pleyer
- Department of Bioinorganic Chemistry and Chemical Evolution, Institute of Chemistry, University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
| | - Henry Strasdeit
- Department of Bioinorganic Chemistry and Chemical Evolution, Institute of Chemistry, University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
| | - Stefan Fox
- Department of Bioinorganic Chemistry and Chemical Evolution, Institute of Chemistry, University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany.
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24
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Nguyen DT, Fujihara A. Chiral Recognition in Cold Gas-Phase Cluster Ions of Carbohydrates and Tryptophan Probed by Photodissociation. ORIGINS LIFE EVOL B 2018; 48:395-406. [PMID: 30953250 DOI: 10.1007/s11084-019-09574-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/19/2019] [Indexed: 12/20/2022]
Abstract
Chiral recognition between tryptophan (Trp) and carbohydrates such as D-glucose (D-Glc), methyl-α-D-glucoside (D-glucoside), D-maltose, and D-cellobiose in cold gas-phase cluster ions was investigated as a model for chemical evolution in interstellar molecular clouds using a tandem mass spectrometer containing a cold ion trap. The photodissociation mass spectra of cold gas-phase clusters that contained Na+, Trp enantiomers, and D-maltose showed that Na+(D-Glc) was formed via the glycosidic bond cleavage of D-maltose from photoexcited homochiral Na+(D-Trp)(D-maltose), while the dissociation did not occur in heterochiral Na+(L-Trp)(D-maltose). The enantiomer-selective dissociation was also observed in the case of D-cellobiose. The enantiomer-selective glycosidic bond cleavage of disaccharides suggested that photoexcited D-Trp could prevent chemical evolution of sugar chains from D-enantiomer of carbohydrates in molecular clouds. The spectra of gas-phase clusters that contained Na+, Trp enantiomers, and D-Glc indicated that enantiomer-selective protonation of L-Trp from D-Glc could induce enantiomeric excess via collision-activated dissociation of the protonated L-Trp. In the case of protonated clusters, photoexcited H+(L-Trp) dissociated via Cα-Cβ bond cleavage in the presence of D-Glc or D-glucoside, where the excited states of H+(L-Trp) contributed to the enantiomer-selective reaction in the clusters. These enantiomer selectivities in cold gas-phase clusters indicated that chirality of a molecule induced enantiomeric excess of other molecules via enantiomer-selective reactions in molecular clouds.
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Affiliation(s)
- Doan Thuc Nguyen
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Osaka, 599-8531, Japan
| | - Akimasa Fujihara
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Osaka, 599-8531, Japan.
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25
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Abstract
As evident from the nearby examples of Proxima Centauri and TRAPPIST-1, Earth-sized planets in the habitable zone of low-mass stars are common. Here, we focus on such planetary systems and argue that their (oceanic) tides could be more prominent due to stronger tidal forces. We identify the conditions under which tides may exert a significant positive influence on biotic processes including abiogenesis, biological rhythms, nutrient upwelling, and stimulating photosynthesis. We conclude our analysis with the identification of large-scale algal blooms as potential temporal biosignatures in reflectance light curves that can arise indirectly as a consequence of strong tidal forces. Key Words: Tidal effects-Abiogenesis-Biological clocks-Planetary habitability-Temporal biosignatures. Astrobiology 18, 967-982.
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Affiliation(s)
- Manasvi Lingam
- 1 Harvard-Smithsonian Center for Astrophysics , Cambridge, Massachusetts
- 2 John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts
| | - Abraham Loeb
- 1 Harvard-Smithsonian Center for Astrophysics , Cambridge, Massachusetts
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26
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Gebauer S, Grenfell JL, Lehmann R, Rauer H. Evolution of Earth-like Planetary Atmospheres around M Dwarf Stars: Assessing the Atmospheres and Biospheres with a Coupled Atmosphere Biogeochemical Model. Astrobiology 2018; 18:856-872. [PMID: 30035637 DOI: 10.1089/ast.2017.1723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Earth-like planets orbiting M dwarfs are prominent targets when searching for life outside the Solar System. We apply our Coupled Atmosphere Biogeochemical model to investigate the coupling between the biosphere, geosphere, and atmosphere in order to gain insight into the atmospheric evolution of Earth-like planets orbiting M dwarfs and to understand the processes affecting biosignatures and climate on such worlds. This is the first study applying an automated chemical pathway analysis quantifying the production and destruction pathways of molecular oxygen (O2) for an Earth-like planet with an Archean O2 concentration orbiting in the habitable zone of the M dwarf star AD Leonis, which we take as a type-case of an active M dwarf. The main production arises in the upper atmosphere from carbon dioxide photolysis followed by catalytic hydrogen oxide radical (HOx) reactions. The strongest destruction does not take place in the troposphere, as was the case in Gebauer et al. ( 2017 ) for an early Earth analog planet around the Sun, but instead in the middle atmosphere where water photolysis is the strongest. Results further suggest that these atmospheres are in absolute terms less destructive for O2 than for early Earth analog planets around the Sun despite higher concentrations of reduced gases such as molecular hydrogen, methane, and carbon monoxide. Hence smaller amounts of net primary productivity are required to oxygenate the atmosphere due to a change in the atmospheric oxidative capacity, driven by the input stellar spectrum resulting in shifts in the intrafamily HOx partitioning. Under the assumption that an atmosphere of an Earth-like planet survived and evolved during the early high-activity phase of an M dwarf to an Archean-type composition, a possible "Great Oxidation Event," analogous to that on Early Earth, would have occurred earlier in time after the atmospheric composition was reached, assuming the same atmospheric O2 sources and sinks as on early Earth. Key Words: Earth-like-Oxygen-M dwarf stars-Atmosphere-Biogeochemistry-Photochemistry-Biosignatures-Earth-like planets. Astrobiology 18, 856-872.
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Affiliation(s)
- S Gebauer
- 1 Zentrum für Astronomie und Astrophysik (ZAA), Technische Universität Berlin (TUB) , Berlin, Germany
- 2 Institut für Planetenforschung (PF) , Abteilung Eaxtrasolare Planeten und Atmosphären (EPA), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - J L Grenfell
- 2 Institut für Planetenforschung (PF) , Abteilung Eaxtrasolare Planeten und Atmosphären (EPA), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - R Lehmann
- 3 Alfred-Wegener Institut , Helmholtz-Zentrum für Polar- und Meeresforschung, Potsdam, Germany
| | - H Rauer
- 1 Zentrum für Astronomie und Astrophysik (ZAA), Technische Universität Berlin (TUB) , Berlin, Germany
- 2 Institut für Planetenforschung (PF) , Abteilung Eaxtrasolare Planeten und Atmosphären (EPA), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
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Abstract
The potential habitability of an exoplanet is traditionally assessed by determining whether its orbit falls within the circumstellar "habitable zone" of its star, defined as the distance at which water could be liquid on the surface of a planet (Kopparapu et al., 2013 ). Traditionally, these limits are determined by radiative-convective climate models, which are used to predict surface temperatures at user-specified levels of greenhouse gases. This approach ignores the vital question of the (bio)geochemical plausibility of the proposed chemical abundances. Carbon dioxide is the most important greenhouse gas in Earth's atmosphere in terms of regulating planetary temperature, with the long-term concentration controlled by the balance between volcanic outgassing and the sequestration of CO2 via chemical weathering and sedimentation, as modulated by ocean chemistry, circulation, and biological (microbial) productivity. We developed a model that incorporates key aspects of Earth's short- and long-term biogeochemical carbon cycle to explore the potential changes in the CO2 greenhouse due to variance in planet size and stellar insolation. We find that proposed changes in global topography, tectonics, and the hydrological cycle on larger planets result in proportionally greater surface temperatures for a given incident flux. For planets between 0.5 and 2 R⊕, the effect of these changes results in average global surface temperature deviations of up to 20 K, which suggests that these relationships must be considered in future studies of planetary habitability. Key Words: Planets-Atmospheres-Carbon dioxide-Biogeochemistry. Astrobiology 18, 469-480.
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Affiliation(s)
- Andrew J Rushby
- 1 NASA Ames Research Center , Moffett Field, California, USA
- 2 School of Environmental Science, University of East Anglia , Norwich, UK
| | - Martin Johnson
- 2 School of Environmental Science, University of East Anglia , Norwich, UK
- 3 Centre for Environment, Fisheries and Aquaculture Sciences , Lowestoft, UK
| | | | - Andrew J Watson
- 5 College of Life and Environmental Sciences, University of Exeter , Exeter, UK
| | - Mark W Claire
- 6 School of Earth and Environmental Sciences, University of St. Andrews , St. Andrews, UK
- 7 Centre for Exoplanet Science, University of St. Andrews , St. Andrews, UK
- 8 Blue Marble Space Institute of Science , Seattle, Washington, USA
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Meadows VS, Arney GN, Schwieterman EW, Lustig-Yaeger J, Lincowski AP, Robinson T, Domagal-Goldman SD, Deitrick R, Barnes RK, Fleming DP, Luger R, Driscoll PE, Quinn TR, Crisp D. The Habitability of Proxima Centauri b: Environmental States and Observational Discriminants. Astrobiology 2018; 18:133-189. [PMID: 29431479 PMCID: PMC5820795 DOI: 10.1089/ast.2016.1589] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 09/04/2017] [Indexed: 05/21/2023]
Abstract
Proxima Centauri b provides an unprecedented opportunity to understand the evolution and nature of terrestrial planets orbiting M dwarfs. Although Proxima Cen b orbits within its star's habitable zone, multiple plausible evolutionary paths could have generated different environments that may or may not be habitable. Here, we use 1-D coupled climate-photochemical models to generate self-consistent atmospheres for several evolutionary scenarios, including high-O2, high-CO2, and more Earth-like atmospheres, with both oxic and anoxic compositions. We show that these modeled environments can be habitable or uninhabitable at Proxima Cen b's position in the habitable zone. We use radiative transfer models to generate synthetic spectra and thermal phase curves for these simulated environments, and use instrument models to explore our ability to discriminate between possible planetary states. These results are applicable not only to Proxima Cen b but to other terrestrial planets orbiting M dwarfs. Thermal phase curves may provide the first constraint on the existence of an atmosphere. We find that James Webb Space Telescope (JWST) observations longward of 10 μm could characterize atmospheric heat transport and molecular composition. Detection of ocean glint is unlikely with JWST but may be within the reach of larger-aperture telescopes. Direct imaging spectra may detect O4 absorption, which is diagnostic of massive water loss and O2 retention, rather than a photosynthetic biosphere. Similarly, strong CO2 and CO bands at wavelengths shortward of 2.5 μm would indicate a CO2-dominated atmosphere. If the planet is habitable and volatile-rich, direct imaging will be the best means of detecting habitability. Earth-like planets with microbial biospheres may be identified by the presence of CH4-which has a longer atmospheric lifetime under Proxima Centauri's incident UV-and either photosynthetically produced O2 or a hydrocarbon haze layer. Key Words: Planetary habitability and biosignatures-Planetary atmospheres-Exoplanets-Spectroscopic biosignatures-Planetary science-Proxima Centauri b. Astrobiology 18, 133-189.
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Affiliation(s)
- Victoria S. Meadows
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
| | - Giada N. Arney
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
- Planetary Systems Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland
| | - Edward W. Schwieterman
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
- NASA Postdoctoral Program, Universities Space Research Association, Columbia, Maryland
- Department of Earth Sciences, University of California at Riverside, Riverside, California
| | - Jacob Lustig-Yaeger
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
| | - Andrew P. Lincowski
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
| | - Tyler Robinson
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
- Department of Astronomy and Astrophysics, University of California, Santa Cruz, California
| | - Shawn D. Domagal-Goldman
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
- Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland
| | - Russell Deitrick
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
| | - Rory K. Barnes
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
| | - David P. Fleming
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
| | - Rodrigo Luger
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
| | - Peter E. Driscoll
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
- Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC
| | - Thomas R. Quinn
- Astronomy Department, University of Washington, Seattle, Washington
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
| | - David Crisp
- NASA Astrobiology Institute—Virtual Planetary Laboratory Lead Team, USA
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
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Cabrol NA. The Coevolution of Life and Environment on Mars: An Ecosystem Perspective on the Robotic Exploration of Biosignatures. Astrobiology 2018; 18:1-27. [PMID: 29252008 PMCID: PMC5779243 DOI: 10.1089/ast.2017.1756] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/27/2017] [Indexed: 05/09/2023]
Abstract
Earth's biological and environmental evolution are intertwined and inseparable. This coevolution has become a fundamental concept in astrobiology and is key to the search for life beyond our planet. In the case of Mars, whether a coevolution took place is unknown, but analyzing the factors at play shows the uniqueness of each planetary experiment regardless of similarities. Early Earth and early Mars shared traits. However, biological processes on Mars, if any, would have had to proceed within the distinctive context of an irreversible atmospheric collapse, greater climate variability, and specific planetary characteristics. In that, Mars is an important test bed for comparing the effects of a unique set of spatiotemporal changes on an Earth-like, yet different, planet. Many questions remain unanswered about Mars' early environment. Nevertheless, existing data sets provide a foundation for an intellectual framework where notional coevolution models can be explored. In this framework, the focus is shifted from planetary-scale habitability to the prospect of habitats, microbial ecotones, pathways to biological dispersal, biomass repositories, and their meaning for exploration. Critically, as we search for biosignatures, this focus demonstrates the importance of starting to think of early Mars as a biosphere and vigorously integrating an ecosystem approach to landing site selection and exploration. Key Words: Astrobiology-Biosignatures-Coevolution of Earth and life-Mars. Astrobiology 18, 1-27.
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Abstract
Biological public goods are broadly shared within an ecosystem and readily available. They appear to be widespread and may have played important roles in the history of life on Earth. Of particular importance to events in the early history of life are the roles of public goods in the merging of genomes, protein domains and even cells. We suggest that public goods facilitated the origin of the eukaryotic cell, a classic major evolutionary transition. The recognition of genomic public goods challenges advocates of a direct graph view of phylogeny, and those who deny that any useful phylogenetic signal persists in modern genomes. Ecological spillovers generate public goods that provide new ecological opportunities.This article is part of the themed issue 'Reconceptualizing the origins of life'.
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Affiliation(s)
- James O McInerney
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9PL, UK
| | - Douglas H Erwin
- Department of Paleobiology, MRC-121, Smithsonian Institution, Washington, DC, USA
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31
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Abstract
It is observed that hypervelocity space dust, which is continuously bombarding Earth, creates immense momentum flows in the atmosphere. Some of this fast space dust inevitably will interact with the atmospheric system, transferring energy and moving particles around, with various possible consequences. This paper examines, with supporting estimates, the possibility that by way of collisions the Earth-grazing component of space dust can facilitate planetary escape of atmospheric particles, whether they are atoms and molecules that form the atmosphere or larger-sized particles. An interesting outcome of this collision scenario is that a variety of particles that contain telltale signs of Earth's organic story, including microbial life and life-essential molecules, may be "afloat" in Earth's atmosphere. The present study assesses the capability of this space dust collision mechanism to propel some of these biological constituents into space. Key Words: Hypervelocity space dust-Collision-Planetary escape-Atmospheric constituents-Microbial life. Astrobiology 17, 1274-1282.
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Affiliation(s)
- Arjun Berera
- School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
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32
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Affiliation(s)
- Sara B Stone
- Planetary Health Alliance, Cambridge, MA 02139, USA
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33
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Pizzarello S, Shock E. Carbonaceous Chondrite Meteorites: the Chronicle of a Potential Evolutionary Path between Stars and Life. ORIGINS LIFE EVOL B 2017; 47:249-260. [PMID: 28078499 DOI: 10.1007/s11084-016-9530-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/01/2016] [Indexed: 10/20/2022]
Abstract
The biogenic elements, H, C, N, O, P and S, have a long cosmic history, whose evolution can still be observed in diverse locales of the known universe, from interstellar clouds of gas and dust, to pre-stellar cores, nebulas, protoplanetary discs, planets and planetesimals. The best analytical window into this cosmochemical evolution as it neared Earth has been provided so far by the small bodies of the Solar System, some of which were not significantly altered by the high gravitational pressures and temperatures that accompanied the formation of larger planets and may carry a pristine record of early nebular chemistry. Asteroids have delivered such records, as their fragments reach the Earth frequently and become available for laboratory analyses. The Carbonaceous Chondrite meteorites (CC) are a group of such fragments with the further distinction of containing abundant organic materials with structures as diverse as kerogen-like macromolecules and simpler compounds with identical counterparts in Earth's biosphere. All have revealed a lineage to cosmochemical synthetic regimes. Several CC show that asteroids underwent aqueous alteration of their minerals or rock metamorphism but may yet yield clues to the reactivity of organic compounds during parent-body processes, on asteroids as well as larger ocean worlds and planets. Whether the exogenous delivery by meteorites held an advantage in Earth's molecular evolution remains an open question as many others regarding the origins of life are. Nonetheless, the natural samples of meteorites allow exploring the physical and chemical processes that might have led to a selected chemical pool amenable to the onset of life. Graphical Abstract ᅟ.
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Affiliation(s)
- Sandra Pizzarello
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA.
| | - Everett Shock
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA
- School of Earth & Space Exploration, Arizona State University, Tempe, AZ, 85218, USA
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34
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Abstract
If properly interpreted, the impact record of the Moon, Earth's nearest neighbour, can be used to gain insights into how the Earth has been influenced by impacting events since its formation ~4.5 billion years (Ga) ago. However, the nature and timing of the lunar impactors - and indeed the lunar impact record itself - are not well understood. Of particular interest are the ages of lunar impact basins and what they tell us about the proposed "lunar cataclysm" and/or the late heavy bombardment (LHB), and how this impact episode may have affected early life on Earth or other planets. Investigations of the lunar impactor population over time have been undertaken and include analyses of orbital data and images; lunar, terrestrial, and other planetary sample data; and dynamical modelling. Here, the existing information regarding the nature of the lunar impact record is reviewed and new interpretations are presented. Importantly, it is demonstrated that most evidence supports a prolonged lunar (and thus, terrestrial) bombardment from ~4.2 to 3.4 Ga and not a cataclysmic spike at ~3.9 Ga. Implications for the conditions required for the origin of life are addressed.
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Affiliation(s)
- Nicolle E B Zellner
- Department of Physics, Albion College, 611 E. Porter St, Albion, MI, 49224, USA.
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35
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Carneiro CEA, Stabile AC, Gomes FP, da Costa ACS, Zaia CTBV, Zaia DAM. Interaction, at Ambient Temperature and 80 °C, between Minerals and Artificial Seawaters Resembling the Present Ocean Composition and that of 4.0 Billion Years Ago. ORIGINS LIFE EVOL B 2017; 47:323-343. [PMID: 27783188 DOI: 10.1007/s11084-016-9524-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 10/14/2016] [Indexed: 11/30/2022]
Abstract
Probably one of the most important roles played by minerals in the origin of life on Earth was to pre-concentrate biomolecules from the prebiotic seas. There are other ways to pre concentrate biomolecules such as wetting/drying cycles and freezing/sublimation. However, adsorption is most important. If the pre-concentration did not occur-because of degradation of the minerals-other roles played by them such as protection against degradation, formation of polymers, or even as primitive cell walls would be seriously compromised. We studied the interaction of two artificial seawaters with kaolinite, bentonite, montmorillonite, goethite, ferrihydrite and quartz. One seawater has a major cation and anion composition similar to that of the oceans of the Earth 4.0 billion years ago (ASW 4.0 Ga). In the other, the major cations and anions are an average of the compositions of the seawaters of today (ASWT). When ASWT, which is rich in Na+ and Cl-, interacted with bentonite and montmorrilonite structural collapse occurred on the 001 plane. However, ASW 4.0 Ga, which is rich in Mg2+ and SO42-, did not induce this behavior. When ASW 4.0 Ga was reacted with the minerals for 24 h at room temperature and 80 °C, the release of Si and Al to the fluid was below 1 % of the amount in the minerals-meaning that dissolution of the minerals did not occur. In general, minerals adsorbed Mg2+ and K+ from the ASW 4.0 Ga and these cations could be used for the formation of polymers. Also, when the minerals were mixed with ASW 4.0 Ga at 80 °C and ASWT at room temperature or 80 °C it caused the precipitation of CaSO4∙2H2O and halite, respectively. Finally, further experiments (adsorption, formation of polymers, protection of molecules against degradation, primitive cell wall formation) performed under the conditions described in this paper will probably be more representative of what happened on the prebiotic Earth.
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Affiliation(s)
- Cristine E A Carneiro
- Laboratório de Química Prebiótica, Departamento de Química-CCE, Universidade Estadual de Londrina, Londrina, PR, 86051-990, Brazil
| | - Antonio C Stabile
- Laboratório de Química Prebiótica, Departamento de Química-CCE, Universidade Estadual de Londrina, Londrina, PR, 86051-990, Brazil
| | - Frederico P Gomes
- Departamento de Agronomia-CCA, Universidade Estadual de Maringa, Maringá, PR, 87020-900, Brazil
| | - Antonio C S da Costa
- Departamento de Agronomia-CCA, Universidade Estadual de Maringa, Maringá, PR, 87020-900, Brazil
| | - Cássia T B V Zaia
- Departamento de Ciências Fisiológicas-CCB, Universidade Estadual de Londrina, Londrina, PR, 86051-990, Brazil
| | - Dimas A M Zaia
- Laboratório de Química Prebiótica, Departamento de Química-CCE, Universidade Estadual de Londrina, Londrina, PR, 86051-990, Brazil.
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36
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Munegumi T. Epimerization of Alanyl-Alanine Induced by γ-Rays Irradiation in Aqueous Solutions. ORIGINS LIFE EVOL B 2017; 47:69-82. [PMID: 27245350 DOI: 10.1007/s11084-016-9507-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 04/16/2016] [Indexed: 10/21/2022]
Abstract
Living organisms have homochiral L-amino acids in proteins and homochiral D-mononucleotides in nucleic acids. The chemical evolutionary process to protein homochirality has been discussed for many years. Although many scenarios have been proposed for homochirality in the monomeric compounds, homochirality in amino acids and mononucleotides does not always guarantee homochirality in polypeptides and polynucleotides. Integrated scenarios containing the pathways from monomer to polymer should be proposed because in the pathways oligomers and polymers as well as monomers racemize (or epimerize), degrade, and condense. This research addresses epimerization and degradation of dipeptides under γ-rays irradiation by a cobalt-60 (60Co) radiation source. The different rate constants of epimerization between diastereomeric dipeptides in the research suggest that the potential pathway toward homochirality could be much more complex.
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Affiliation(s)
- Toratane Munegumi
- Naruto University of Education, Naruto, Japan.
- Oyama National College of Technology, Oyama, Japan.
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37
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Tessera M. Research program for a search of the origin of Darwinian evolution : Research program for a vesicle-based model of the origin of Darwinian evolution on prebiotic early Earth. ORIGINS LIFE EVOL B 2017; 47:57-68. [PMID: 26968859 DOI: 10.1007/s11084-016-9482-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 02/24/2016] [Indexed: 10/22/2022]
Abstract
The search for origin of 'life' is made even more complicated by differing definitions of the subject matter, although a general consensus is that an appropriate definition should center on Darwinian evolution (Cleland and Chyba 2002). Within a physical approach which has been defined as a level-4 evolution (Tessera and Hoelzer 2013), one mechanism could be described showing that only three conditions are required to allow natural selection to apply to populations of different system lineages. This approach leads to a vesicle- based model with the necessary properties. Of course such a model has to be tested. Thus, after a brief presentation of the model an experimental program is proposed that implements the different steps able to show whether this new direction of the research in the field is valid and workable.
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Affiliation(s)
- Marc Tessera
- , 2 avenue du 11 novembre 1918, 92190, Meudon, France.
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Gebauer S, Grenfell JL, Stock JW, Lehmann R, Godolt M, von Paris P, Rauer H. Evolution of Earth-like Extrasolar Planetary Atmospheres: Assessing the Atmospheres and Biospheres of Early Earth Analog Planets with a Coupled Atmosphere Biogeochemical Model. Astrobiology 2017; 17:27-54. [PMID: 28103105 DOI: 10.1089/ast.2015.1384] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Understanding the evolution of Earth and potentially habitable Earth-like worlds is essential to fathom our origin in the Universe. The search for Earth-like planets in the habitable zone and investigation of their atmospheres with climate and photochemical models is a central focus in exoplanetary science. Taking the evolution of Earth as a reference for Earth-like planets, a central scientific goal is to understand what the interactions were between atmosphere, geology, and biology on early Earth. The Great Oxidation Event in Earth's history was certainly caused by their interplay, but the origin and controlling processes of this occurrence are not well understood, the study of which will require interdisciplinary, coupled models. In this work, we present results from our newly developed Coupled Atmosphere Biogeochemistry model in which atmospheric O2 concentrations are fixed to values inferred by geological evidence. Applying a unique tool (Pathway Analysis Program), ours is the first quantitative analysis of catalytic cycles that governed O2 in early Earth's atmosphere near the Great Oxidation Event. Complicated oxidation pathways play a key role in destroying O2, whereas in the upper atmosphere, most O2 is formed abiotically via CO2 photolysis. The O2 bistability found by Goldblatt et al. ( 2006 ) is not observed in our calculations likely due to our detailed CH4 oxidation scheme. We calculate increased CH4 with increasing O2 during the Great Oxidation Event. For a given atmospheric surface flux, different atmospheric states are possible; however, the net primary productivity of the biosphere that produces O2 is unique. Mixing, CH4 fluxes, ocean solubility, and mantle/crust properties strongly affect net primary productivity and surface O2 fluxes. Regarding exoplanets, different "states" of O2 could exist for similar biomass output. Strong geological activity could lead to false negatives for life (since our analysis suggests that reducing gases remove O2 that masks its biosphere over a wide range of conditions). Key Words: Early Earth-Proterozoic-Archean-Oxygen-Atmosphere-Biogeochemistry-Photochemistry-Biosignatures-Earth-like planets. Astrobiology 16, 27-54.
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Affiliation(s)
- S Gebauer
- 1 Zentrum für Astronomie und Astrophysik (ZAA), Technische Universität Berlin (TUB) , Berlin, Germany
- 2 Institut für Planetenforschung (PF) , Deutsches Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - J L Grenfell
- 2 Institut für Planetenforschung (PF) , Deutsches Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - J W Stock
- 3 Instituto de Astrofísica de Andalucía-CSIC , Granada, Spain
| | - R Lehmann
- 4 Alfred-Wegener Institut Helmholtz-Zentrum für Polar- und Meeresforschung , Potsdam, Germany
| | - M Godolt
- 2 Institut für Planetenforschung (PF) , Deutsches Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - P von Paris
- 5 Université de Bordeaux , LAB, UMR 5804, Floirac, France
- 6 CNRS, LAB , UMR 5804, Floirac, France
| | - H Rauer
- 1 Zentrum für Astronomie und Astrophysik (ZAA), Technische Universität Berlin (TUB) , Berlin, Germany
- 2 Institut für Planetenforschung (PF) , Deutsches Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
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Dehant V, Asael D, Baland RM, Baludikay BK, Beghin J, Belza J, Beuthe M, Breuer D, Chernonozhkin S, Claeys P, Cornet Y, Cornet L, Coyette A, Debaille V, Delvigne C, Deproost MH, De WInter N, Duchemin C, El Atrassi F, François C, De Keyser J, Gillmann C, Gloesener E, Goderis S, Hidaka Y, Höning D, Huber M, Hublet G, Javaux EJ, Karatekin Ö, Kodolanyi J, Revilla LL, Maes L, Maggiolo R, Mattielli N, Maurice M, McKibbin S, Morschhauser A, Neumann W, Noack L, Pham LBS, Pittarello L, Plesa AC, Rivoldini A, Robert S, Rosenblatt P, Spohn T, Storme JY, Tosi N, Trinh A, Valdes M, Vandaele AC, Vanhaecke F, Van Hoolst T, Van Roosbroek N, Wilquet V, Yseboodt M. PLANET TOPERS: Planets, Tracing the Transfer, Origin, Preservation, and Evolution of their ReservoirS. ORIGINS LIFE EVOL B 2016; 46:369-384. [PMID: 27337974 DOI: 10.1007/s11084-016-9488-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/21/2016] [Indexed: 11/25/2022]
Abstract
The Interuniversity Attraction Pole (IAP) 'PLANET TOPERS' (Planets: Tracing the Transfer, Origin, Preservation, and Evolution of their Reservoirs) addresses the fundamental understanding of the thermal and compositional evolution of the different reservoirs of planetary bodies (core, mantle, crust, atmosphere, hydrosphere, cryosphere, and space) considering interactions and feedback mechanisms. Here we present the first results after 2 years of project work.
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Affiliation(s)
- V Dehant
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium.
| | - D Asael
- Université de Liège (Ulg), 4000, Liège 1, Belgium
| | - R M Baland
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | | | - J Beghin
- Université de Liège (Ulg), 4000, Liège 1, Belgium
| | - J Belza
- Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Universiteit Ghent (Ughent), Ghent, Belgium
| | - M Beuthe
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - D Breuer
- Deutsche Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | | | - Ph Claeys
- Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Y Cornet
- Université de Liège (Ulg), 4000, Liège 1, Belgium
| | - L Cornet
- Université de Liège (Ulg), 4000, Liège 1, Belgium
| | - A Coyette
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - V Debaille
- Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - C Delvigne
- Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - M H Deproost
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - N De WInter
- Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - C Duchemin
- Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - F El Atrassi
- Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - C François
- Université de Liège (Ulg), 4000, Liège 1, Belgium
| | - J De Keyser
- Belgian Institute for Space Aeronomy (BISA), Brussels, Belgium
| | - C Gillmann
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - E Gloesener
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - S Goderis
- Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Y Hidaka
- Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - D Höning
- Deutsche Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - M Huber
- Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - G Hublet
- Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - E J Javaux
- Université de Liège (Ulg), 4000, Liège 1, Belgium
| | - Ö Karatekin
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - J Kodolanyi
- Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | | | - L Maes
- Belgian Institute for Space Aeronomy (BISA), Brussels, Belgium
| | - R Maggiolo
- Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - N Mattielli
- Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - M Maurice
- Deutsche Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - S McKibbin
- Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - A Morschhauser
- Deutsche Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - W Neumann
- Deutsche Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - L Noack
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - L B S Pham
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - L Pittarello
- Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - A C Plesa
- Deutsche Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - A Rivoldini
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - S Robert
- Belgian Institute for Space Aeronomy (BISA), Brussels, Belgium
| | - P Rosenblatt
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - T Spohn
- Deutsche Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - J -Y Storme
- Université de Liège (Ulg), 4000, Liège 1, Belgium
| | - N Tosi
- Deutsche Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany
| | - A Trinh
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | - M Valdes
- Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - A C Vandaele
- Belgian Institute for Space Aeronomy (BISA), Brussels, Belgium
| | | | - T Van Hoolst
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
| | | | - V Wilquet
- Belgian Institute for Space Aeronomy (BISA), Brussels, Belgium
| | - M Yseboodt
- Royal Observatory of Belgium (ROB), 3 Avenue Circulaire, B-1180, Brussels, Belgium
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40
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Hoffman PF. Cryoconite pans on Snowball Earth: supraglacial oases for Cryogenian eukaryotes? Geobiology 2016; 14:531-542. [PMID: 27422766 DOI: 10.1111/gbi.12191] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 04/29/2016] [Indexed: 05/22/2023]
Abstract
Geochemical, paleomagnetic, and geochronological data increasingly support the Snowball Earth hypothesis for Cryogenian glaciations. Yet, the fossil record reveals no clear-cut evolutionary bottleneck. Climate models and the modern cryobiosphere offer insights on this paradox. Recent modeling implies that Snowball continents never lacked ice-free areas. Wind-blown dust from these areas plus volcanic ash were trapped by snow on ice sheets and sea ice. At a Snowball onset, sea ice was too thin to flow and ablative ice was too cold for dust retention. After a few millenia, sea ice reached 100 s of meters in thickness and began to flow as a 'sea glacier' toward an equatorial ablation zone. At first, dust advected to the ablative surface was recycled by winds, but as the surface warmed with rising CO2 , dust aka cryoconite began to accumulate. As a sea glacier has no terminus, cryoconite saturated the surface. It absorbed solar radiation, supported cyanobacterial growth, and sank to an equilibrium depth forming holes and decameter-scale pans of meltwater. As meltwater production rose, drainages developed, connecting pans to moulins, where meltwater was flushed into the subglacial ocean. Flushing cleansed the surface, creating a stabilizing feedback. If the dust flux rose, cryoconite was removed; if the dust flux waned, cryoconite accumulated. In addition to cyanobacteria, modern cryoconite holes are inhabited by green algae, fungi, protists, and certain metazoans. On Snowball Earth, cryoconite pans provided stable interconnected habitats for eukaryotes tolerant of fresh to brackish cold water on an ablation surface 60 million km2 in area. Flushing and burial of organic matter was a potential source of atmospheric oxygen. Dominance of green algae among Ediacaran eukaryotic primary producers is a possible legacy of Cryogenian cryoconite pans, but a schizohaline ocean-supraglacial freshwater and subglacial brine-may have exerted selective stress on early metazoans, or impeded their evolution.
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Affiliation(s)
- P F Hoffman
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA.
- School of Earth and Ocean Sciences, University of Victoria, Victoria, BC, Canada.
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41
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Abstract
In this work various factors on the habitability were considered, focusing on conditions irrespective of the central star's radiation, to see the role of specific planetary body related effects. These so called planetary factors were evaluated to identify those trans-domain issues where important information is missing but good chance exit to be filled by new knowledge that might be gained in the next decade(s). Among these strategic knowledge gaps, specific issues are listed, like occurrence of radioactive nucleides in star forming regions, models to estimate the existence of subsurface liquid water from bulk parameters plus evolutionary context of the given system, estimation on the existence of redox gradient depending on the environment type etc. These issues require substantial improvement of modelling and statistical handling of various cases, as "planetary environment types". Based on our current knowledge it is probable that subsurface habitability is at least as frequent, or more frequent than surface habitability. Unfortunately it is more difficult from observations to infer conditions for subsurface habitability, but specific argumentation might help with indirect ways, which might result in new methods to approach habitability in general.
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Affiliation(s)
- A Kereszturi
- Research Centre for Astronomy and Earth Sciences, Csatkai u. 6-8, 9400, Sopron, Hungary.
| | - L Noack
- Royal Observatory of Belgium, Avenue Circulaire 3, 1180, Brussels, Belgium
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42
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43
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Abstract
The notion of self-regulating mantle convection, in which heat loss from the surface is constantly adjusted to follow internal radiogenic heat production, has been popular for the past six decades since Urey first advocated the idea. Thanks to its intuitive appeal, this notion has pervaded the solid earth sciences in various forms, but approach to a self-regulating state critically depends on the relation between the thermal adjustment rate and mantle temperature. I show that, if the effect of mantle melting on viscosity is taken into account, the adjustment rate cannot be sufficiently high to achieve self-regulation, regardless of the style of mantle convection. The evolution of terrestrial planets is thus likely to be far from thermal equilibrium and be sensitive to the peculiarities of their formation histories. Chance factors in planetary formation are suggested to become more important for the evolution of planets that are more massive than Earth.
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Affiliation(s)
- Jun Korenaga
- Department of Geology and Geophysics, Yale University, P.O. Box 208109, New Haven, CT 06520-8109, USA.
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Domagal-Goldman SD, Wright KE, Adamala K, Arina de la Rubia L, Bond J, Dartnell LR, Goldman AD, Lynch K, Naud ME, Paulino-Lima IG, Singer K, Walther-Antonio M, Abrevaya XC, Anderson R, Arney G, Atri D, Azúa-Bustos A, Bowman JS, Brazelton WJ, Brennecka GA, Carns R, Chopra A, Colangelo-Lillis J, Crockett CJ, DeMarines J, Frank EA, Frantz C, de la Fuente E, Galante D, Glass J, Gleeson D, Glein CR, Goldblatt C, Horak R, Horodyskyj L, Kaçar B, Kereszturi A, Knowles E, Mayeur P, McGlynn S, Miguel Y, Montgomery M, Neish C, Noack L, Rugheimer S, Stüeken EE, Tamez-Hidalgo P, Imari Walker S, Wong T. The Astrobiology Primer v2.0. Astrobiology 2016; 16:561-653. [PMID: 27532777 PMCID: PMC5008114 DOI: 10.1089/ast.2015.1460] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 06/06/2016] [Indexed: 05/09/2023]
Affiliation(s)
- Shawn D Domagal-Goldman
- 1 NASA Goddard Space Flight Center , Greenbelt, Maryland, USA
- 2 Virtual Planetary Laboratory , Seattle, Washington, USA
| | - Katherine E Wright
- 3 University of Colorado at Boulder , Colorado, USA
- 4 Present address: UK Space Agency, UK
| | - Katarzyna Adamala
- 5 Department of Genetics, Cell Biology and Development, University of Minnesota , Minneapolis, Minnesota, USA
| | | | - Jade Bond
- 7 Department of Physics, University of New South Wales , Sydney, Australia
| | | | | | - Kennda Lynch
- 10 Division of Biological Sciences, University of Montana , Missoula, Montana, USA
| | - Marie-Eve Naud
- 11 Institute for research on exoplanets (iREx) , Université de Montréal, Montréal, Canada
| | - Ivan G Paulino-Lima
- 12 Universities Space Research Association , Mountain View, California, USA
- 13 Blue Marble Space Institute of Science , Seattle, Washington, USA
| | - Kelsi Singer
- 14 Southwest Research Institute , Boulder, Colorado, USA
| | | | - Ximena C Abrevaya
- 16 Instituto de Astronomía y Física del Espacio (IAFE) , UBA-CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Rika Anderson
- 17 Department of Biology, Carleton College , Northfield, Minnesota, USA
| | - Giada Arney
- 18 University of Washington Astronomy Department and Astrobiology Program , Seattle, Washington, USA
| | - Dimitra Atri
- 13 Blue Marble Space Institute of Science , Seattle, Washington, USA
| | | | - Jeff S Bowman
- 19 Lamont-Doherty Earth Observatory, Columbia University , Palisades, New York, USA
| | | | | | - Regina Carns
- 22 Polar Science Center, Applied Physics Laboratory, University of Washington , Seattle, Washington, USA
| | - Aditya Chopra
- 23 Planetary Science Institute, Research School of Earth Sciences, Research School of Astronomy and Astrophysics, The Australian National University , Canberra, Australia
| | - Jesse Colangelo-Lillis
- 24 Earth and Planetary Science, McGill University , and the McGill Space Institute, Montréal, Canada
| | | | - Julia DeMarines
- 13 Blue Marble Space Institute of Science , Seattle, Washington, USA
| | | | - Carie Frantz
- 27 Department of Geosciences, Weber State University , Ogden, Utah, USA
| | - Eduardo de la Fuente
- 28 IAM-Departamento de Fisica, CUCEI , Universidad de Guadalajara, Guadalajara, México
| | - Douglas Galante
- 29 Brazilian Synchrotron Light Laboratory , Campinas, Brazil
| | - Jennifer Glass
- 30 School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia , USA
| | | | | | - Colin Goldblatt
- 33 School of Earth and Ocean Sciences, University of Victoria , Victoria, Canada
| | - Rachel Horak
- 34 American Society for Microbiology , Washington, DC, USA
| | | | - Betül Kaçar
- 36 Harvard University , Organismic and Evolutionary Biology, Cambridge, Massachusetts, USA
| | - Akos Kereszturi
- 37 Research Centre for Astronomy and Earth Sciences , Hungarian Academy of Sciences, Budapest, Hungary
| | - Emily Knowles
- 38 Johnson & Wales University , Denver, Colorado, USA
| | - Paul Mayeur
- 39 Rensselaer Polytechnic Institute , Troy, New York, USA
| | - Shawn McGlynn
- 40 Earth Life Science Institute, Tokyo Institute of Technology , Tokyo, Japan
| | - Yamila Miguel
- 41 Laboratoire Lagrange, UMR 7293, Université Nice Sophia Antipolis , CNRS, Observatoire de la Côte d'Azur, Nice, France
| | | | - Catherine Neish
- 43 Department of Earth Sciences, The University of Western Ontario , London, Canada
| | - Lena Noack
- 44 Royal Observatory of Belgium , Brussels, Belgium
| | - Sarah Rugheimer
- 45 Department of Astronomy, Harvard University , Cambridge, Massachusetts, USA
- 46 University of St. Andrews , St. Andrews, UK
| | - Eva E Stüeken
- 47 University of Washington , Seattle, Washington, USA
- 48 University of California , Riverside, California, USA
| | | | - Sara Imari Walker
- 13 Blue Marble Space Institute of Science , Seattle, Washington, USA
- 50 School of Earth and Space Exploration and Beyond Center for Fundamental Concepts in Science, Arizona State University , Tempe, Arizona, USA
| | - Teresa Wong
- 51 Department of Earth and Planetary Sciences, Washington University in St. Louis , St. Louis, Missouri, USA
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45
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Osinski GR, Ferrière L. Shatter cones: (Mis)understood? Sci Adv 2016; 2:e1600616. [PMID: 27532050 PMCID: PMC4975556 DOI: 10.1126/sciadv.1600616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
Meteorite impact craters are one of the most common geological features in the solar system. An impact event is a near-instantaneous process that releases a huge amount of energy over a very small region on a planetary surface. This results in characteristic changes in the target rocks, from vaporization and melting to solid-state effects, such as fracturing and shock metamorphism. Shatter cones are distinctive striated conical fractures that are considered unequivocal evidence of impact events. They are one of the most used and trusted shock-metamorphic effects for the recognition of meteorite impact structures. Despite this, there is still considerable debate regarding their formation. We show that shatter cones are present in several stratigraphic settings within and around impact structures. Together with the occurrence of complete and "double" cones, our observations are most consistent with shatter cone formation due to tensional stresses generated by scattering of the shock wave due to heterogeneities in the rock. On the basis of field mapping, we derive the relationship D sc = 0.4 D a, where D sc is the maximum spatial extent of in situ shatter cones, and D a is the apparent crater diameter. This provides an important, new, more accurate method to estimate the apparent diameter of eroded complex craters on Earth. We have reestimated the diameter of eight well-known impact craters as part of this study. Finally, we suggest that shatter cones may reduce the strength of the target, thus aiding crater collapse, and that their distribution in central uplifts also records the obliquity of impact.
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Affiliation(s)
- Gordon R. Osinski
- Centre for Planetary Science and Exploration, University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
- Department of Earth Sciences and Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 5B7, Canada
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46
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Lenardic A, Crowley JW, Jellinek AM, Weller M. The Solar System of Forking Paths: Bifurcations in Planetary Evolution and the Search for Life-Bearing Planets in Our Galaxy. Astrobiology 2016; 16:551-559. [PMID: 27355842 DOI: 10.1089/ast.2015.1378] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- A Lenardic
- 1 Department of Earth Sciences, Rice University , Houston, Texas, USA
| | - J W Crowley
- 2 Department of Earth and Planetary Sciences, Harvard University , Cambridge, Massachusetts, USA
| | - A M Jellinek
- 3 Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia , Vancouver, Canada
| | - M Weller
- 1 Department of Earth Sciences, Rice University , Houston, Texas, USA
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47
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Luo G, Ono S, Beukes NJ, Wang DT, Xie S, Summons RE. Rapid oxygenation of Earth's atmosphere 2.33 billion years ago. Sci Adv 2016; 2:e1600134. [PMID: 27386544 PMCID: PMC4928975 DOI: 10.1126/sciadv.1600134] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 04/20/2016] [Indexed: 05/18/2023]
Abstract
Molecular oxygen (O2) is, and has been, a primary driver of biological evolution and shapes the contemporary landscape of Earth's biogeochemical cycles. Although "whiffs" of oxygen have been documented in the Archean atmosphere, substantial O2 did not accumulate irreversibly until the Early Paleoproterozoic, during what has been termed the Great Oxygenation Event (GOE). The timing of the GOE and the rate at which this oxygenation took place have been poorly constrained until now. We report the transition (that is, from being mass-independent to becoming mass-dependent) in multiple sulfur isotope signals of diagenetic pyrite in a continuous sedimentary sequence in three coeval drill cores in the Transvaal Supergroup, South Africa. These data precisely constrain the GOE to 2.33 billion years ago. The new data suggest that the oxygenation occurred rapidly-within 1 to 10 million years-and was followed by a slower rise in the ocean sulfate inventory. Our data indicate that a climate perturbation predated the GOE, whereas the relationships among GOE, "Snowball Earth" glaciation, and biogeochemical cycling will require further stratigraphic correlation supported with precise chronologies and paleolatitude reconstructions.
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Affiliation(s)
- Genming Luo
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, E25-608, Cambridge, MA 02139, USA
- State Key Laboratory of Biogeology and Environmental Geology, and School of Earth Science, China University of Geosciences, Wuhan 430074, People’s Republic of China
- Corresponding author. (G.L.); (R.E.S.)
| | - Shuhei Ono
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, E25-608, Cambridge, MA 02139, USA
| | - Nicolas J. Beukes
- DST-NRF (Department of Science and Technology–National Research Foundation) Centre of Excellence for Integrated Mineral and Energy Resource Analysis, Department of Geology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa
| | - David T. Wang
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, E25-608, Cambridge, MA 02139, USA
| | - Shucheng Xie
- State Key Laboratory of Biogeology and Environmental Geology, and School of Earth Science, China University of Geosciences, Wuhan 430074, People’s Republic of China
| | - Roger E. Summons
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, E25-608, Cambridge, MA 02139, USA
- Corresponding author. (G.L.); (R.E.S.)
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Meech KJ, Yang B, Kleyna J, Hainaut OR, Berdyugina S, Keane JV, Micheli M, Morbidelli A, Wainscoat RJ. Inner solar system material discovered in the Oort cloud. Sci Adv 2016; 2:e1600038. [PMID: 27386512 PMCID: PMC4928888 DOI: 10.1126/sciadv.1600038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/30/2016] [Indexed: 05/31/2023]
Abstract
We have observed C/2014 S3 (PANSTARRS), a recently discovered object on a cometary orbit coming from the Oort cloud that is physically similar to an inner main belt rocky S-type asteroid. Recent dynamical models successfully reproduce the key characteristics of our current solar system; some of these models require significant migration of the giant planets, whereas others do not. These models provide different predictions on the presence of rocky material expelled from the inner solar system in the Oort cloud. C/2014 S3 could be the key to verifying these predictions of the migration-based dynamical models. Furthermore, this object displays a very faint, weak level of comet-like activity, five to six orders of magnitude less than that of typical ice-rich comets on similar Orbits coming from the Oort cloud. For the nearly tailless appearance, we are calling C/2014 S3 a Manx object. Various arguments convince us that this activity is produced by sublimation of volatile ice, that is, normal cometary activity. The activity implies that C/2014 S3 has retained a tiny fraction of the water that is expected to be present at its formation distance in the inner solar system. We may be looking at fresh inner solar system Earth-forming material that was ejected from the inner solar system and preserved for billions of years in the Oort cloud.
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Affiliation(s)
- Karen J. Meech
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
| | - Bin Yang
- European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago, Chile
| | - Jan Kleyna
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
| | - Olivier R. Hainaut
- European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
| | - Svetlana Berdyugina
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
- Kiepenheuer Institut fuer Sonnenphysik, Schoeneckstrasse 6, 79104 Freiburg, Germany
| | - Jacqueline V. Keane
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
| | - Marco Micheli
- Space Situational Awareness (SSA)–Near Earth Objects (NEO) Coordination Centre, European Space Agency, 00044 Frascati (RM), Italy
- SpaceDyS s.r.l., 56023 Cascina (Pl), Italy
- Istituto Nazionale di Astrofisica (INAF)–Istituto di Astrofisica e Planetologia Spaziali (IAPS), 00133 Roma (RM), Italy
| | - Alessandro Morbidelli
- Laboratoire Lagrange, UMR 7293, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Cöte d’Azur, Boulevard de l’Observatoire, 06304 Nice Cedex 4, France
| | - Richard J. Wainscoat
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
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Ward LM, Kirschvink JL, Fischer WW. Timescales of Oxygenation Following the Evolution of Oxygenic Photosynthesis. ORIGINS LIFE EVOL B 2016; 46:51-65. [PMID: 26286084 DOI: 10.1007/s11084-015-9460-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 08/06/2015] [Indexed: 01/12/2023]
Abstract
Among the most important bioenergetic innovations in the history of life was the invention of oxygenic photosynthesis-autotrophic growth by splitting water with sunlight-by Cyanobacteria. It is widely accepted that the invention of oxygenic photosynthesis ultimately resulted in the rise of oxygen by ca. 2.35 Gya, but it is debated whether this occurred more or less immediately as a proximal result of the evolution of oxygenic Cyanobacteria or whether they originated several hundred million to more than one billion years earlier in Earth history. The latter hypothesis involves a prolonged period during which oxygen production rates were insufficient to oxidize the atmosphere, potentially due to redox buffering by reduced species such as higher concentrations of ferrous iron in seawater. To examine the characteristic timescales for environmental oxygenation following the evolution of oxygenic photosynthesis, we applied a simple mathematical approach that captures many of the salient features of the major biogeochemical fluxes and reservoirs present in Archean and early Paleoproterozoic surface environments. Calculations illustrate that oxygenation would have overwhelmed redox buffers within ~100 kyr following the emergence of oxygenic photosynthesis, a geologically short amount of time unless rates of primary production were far lower than commonly expected. Fundamentally, this result arises because of the multiscale nature of the carbon and oxygen cycles: rates of gross primary production are orders of magnitude too fast for oxygen to be masked by Earth's geological buffers, and can only be effectively matched by respiration at non-negligible O2 concentrations. These results suggest that oxygenic photosynthesis arose shortly before the rise of oxygen, not hundreds of millions of years before it.
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Affiliation(s)
- Lewis M Ward
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, 91125, USA.
| | - Joseph L Kirschvink
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, 91125, USA
| | - Woodward W Fischer
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, 91125, USA
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Abstract
It has been widely reported that Jupiter has a profound role in shielding the terrestrial planets from comet impacts in the Solar System, and that a jovian planet is a requirement for the evolution of life on Earth. To evaluate whether jovians, in fact, shield habitable planets from impacts (a phenomenon often referred to as the "Jupiter as shield" concept), this study simulated the evolution of 10,000 particles in each of the jovian inter-planet gaps for the cases of full-mass and embryo planets for up to 100 My. The results of these simulations predict a number of phenomena that not only discount the "Jupiter as shield" concept, they also predict that in a Solar System like ours, large gas giants like Saturn and Jupiter had a different, and potentially even more important, role in the evolution of life on our planet by delivering the volatile-laden material required for the formation of life. The simulations illustrate that, although all particles occupied "non-life threatening" orbits at their onset of the simulations, a significant fraction of the 30,000 particles evolved into Earth-crossing orbits. A comparison of multiple runs with different planetary configurations revealed that Jupiter was responsible for the vast majority of the encounters that "kicked" outer planet material into the terrestrial planet region, and that Saturn assisted in the process far more than has previously been acknowledged. Jupiter also tends to "fix" the aphelion of planetesimals at its orbit irrespective of their initial starting zones, which has the effect of slowing their passages through the inner Solar System, and thus potentially improving the odds of accretion of cometary material by terrestrial planets. As expected, the simulations indicate that the full-mass planets perturb many objects into the deep outer Solar System, or eject them entirely; however, planetary embryos also did this with surprising efficiency. Finally, the simulations predict that Jupiter's capacity to shield or intercept Earth-bound comets originating in the outer Solar System is poor, and that the importance of jovian planets on the formation of life is not that they act as shields, but rather that they deliver life-enabling volatiles to the terrestrial planets.
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Affiliation(s)
- Kevin R Grazier
- Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
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