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Blankenship DD, Moussessian A, Chapin E, Young DA, Wesley Patterson G, Plaut JJ, Freedman AP, Schroeder DM, Grima C, Steinbrügge G, Soderlund KM, Ray T, Richter TG, Jones-Wilson L, Wolfenbarger NS, Scanlan KM, Gerekos C, Chan K, Seker I, Haynes MS, Barr Mlinar AC, Bruzzone L, Campbell BA, Carter LM, Elachi C, Gim Y, Hérique A, Hussmann H, Kofman W, Kurth WS, Mastrogiuseppe M, McKinnon WB, Moore JM, Nimmo F, Paty C, Plettemeier D, Schmidt BE, Zolotov MY, Schenk PM, Collins S, Figueroa H, Fischman M, Tardiff E, Berkun A, Paller M, Hoffman JP, Kurum A, Sadowy GA, Wheeler KB, Decrossas E, Hussein Y, Jin C, Boldissar F, Chamberlain N, Hernandez B, Maghsoudi E, Mihaly J, Worel S, Singh V, Pak K, Tanabe J, Johnson R, Ashtijou M, Alemu T, Burke M, Custodero B, Tope MC, Hawkins D, Aaron K, Delory GT, Turin PS, Kirchner DL, Srinivasan K, Xie J, Ortloff B, Tan I, Noh T, Clark D, Duong V, Joshi S, Lee J, Merida E, Akbar R, Duan X, Fenni I, Sanchez-Barbetty M, Parashare C, Howard DC, Newman J, Cruz MG, Barabas NJ, Amirahmadi A, Palmer B, Gawande RS, Milroy G, Roberti R, Leader FE, West RD, Martin J, Venkatesh V, Adumitroaie V, Rains C, Quach C, Turner JE, O’Shea CM, Kempf SD, Ng G, Buhl DP, Urban TJ. Radar for Europa Assessment and Sounding: Ocean to Near-Surface (REASON). SPACE SCIENCE REVIEWS 2024; 220:51. [PMID: 38948073 PMCID: PMC11211191 DOI: 10.1007/s11214-024-01072-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 04/29/2024] [Indexed: 07/02/2024]
Abstract
The Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is a dual-frequency ice-penetrating radar (9 and 60 MHz) onboard the Europa Clipper mission. REASON is designed to probe Europa from exosphere to subsurface ocean, contributing the third dimension to observations of this enigmatic world. The hypotheses REASON will test are that (1) the ice shell of Europa hosts liquid water, (2) the ice shell overlies an ocean and is subject to tidal flexing, and (3) the exosphere, near-surface, ice shell, and ocean participate in material exchange essential to the habitability of this moon. REASON will investigate processes governing this material exchange by characterizing the distribution of putative non-ice material (e.g., brines, salts) in the subsurface, searching for an ice-ocean interface, characterizing the ice shell's global structure, and constraining the amplitude of Europa's radial tidal deformations. REASON will accomplish these science objectives using a combination of radar measurement techniques including altimetry, reflectometry, sounding, interferometry, plasma characterization, and ranging. Building on a rich heritage from Earth, the moon, and Mars, REASON will be the first ice-penetrating radar to explore the outer solar system. Because these radars are untested for the icy worlds in the outer solar system, a novel approach to measurement quality assessment was developed to represent uncertainties in key properties of Europa that affect REASON performance and ensure robustness across a range of plausible parameters suggested for the icy moon. REASON will shed light on a never-before-seen dimension of Europa and - in concert with other instruments on Europa Clipper - help to investigate whether Europa is a habitable world.
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Affiliation(s)
| | - Alina Moussessian
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Elaine Chapin
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Duncan A. Young
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
| | | | - Jeffrey J. Plaut
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Adam P. Freedman
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Dustin M. Schroeder
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305 USA
- Department of Geophysics, Stanford University, Stanford, CA 94305 USA
| | - Cyril Grima
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
| | - Gregor Steinbrügge
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Krista M. Soderlund
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
| | - Trina Ray
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Thomas G. Richter
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
| | - Laura Jones-Wilson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | | | - Kirk M. Scanlan
- Geodesy & Earth Observation Division, DTU Space, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Christopher Gerekos
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
| | - Kristian Chan
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
- Department of Earth and Planetary Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78712 USA
| | - Ilgin Seker
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Mark S. Haynes
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | | | | | - Bruce A. Campbell
- Smithsonian Institution, Center for Earth & Planetary Studies, MRC 315, Washington, DC 20013-7012 USA
| | - Lynn M. Carter
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 USA
| | - Charles Elachi
- California Institute of Technology, Pasadena, CA 91125 USA
| | - Yonggyu Gim
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Alain Hérique
- University Grenoble Alpes, CNRS, CNES, IPAG, 38000 Grenoble, France
| | - Hauke Hussmann
- Institute of Planetary Research, German Aerospace Center, Berlin, Germany
| | - Wlodek Kofman
- University Grenoble Alpes, CNRS, CNES, IPAG, 38000 Grenoble, France
- Centrum Badan Kosmicznych Polskiej Akademii Nauk (CBK PAN), Warsaw, Poland
| | - William S. Kurth
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 USA
| | | | | | | | - Francis Nimmo
- Dept. Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064 USA
| | - Carol Paty
- Department of Earth Sciences, University of Oregon, Eugene, OR 97403 USA
| | | | - Britney E. Schmidt
- Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY USA
- Department of Astronomy, Cornell University, Ithaca, NY USA
| | - Mikhail Y. Zolotov
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 USA
| | | | - Simon Collins
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Harry Figueroa
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Mark Fischman
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Eric Tardiff
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Andy Berkun
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Mimi Paller
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | | | | | - Gregory A. Sadowy
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Kevin B. Wheeler
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Emmanuel Decrossas
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Yasser Hussein
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Curtis Jin
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Frank Boldissar
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Neil Chamberlain
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Brenda Hernandez
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Elham Maghsoudi
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Jonathan Mihaly
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 USA
| | - Shana Worel
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Vik Singh
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Kyung Pak
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Jordan Tanabe
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Robert Johnson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Mohammad Ashtijou
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Tafesse Alemu
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Michael Burke
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Brian Custodero
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Michael C. Tope
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - David Hawkins
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Kim Aaron
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | | | | | - Donald L. Kirchner
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 USA
| | - Karthik Srinivasan
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Julie Xie
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Brad Ortloff
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Ian Tan
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Tim Noh
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Duane Clark
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Vu Duong
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Shivani Joshi
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Jeng Lee
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Elvis Merida
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Ruzbeh Akbar
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Xueyang Duan
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Ines Fenni
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | | | - Chaitali Parashare
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Duane C. Howard
- Center for Quantum Computing, Amazon Web Services, Pasadena, CA 91125 USA
| | | | - Marvin G. Cruz
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | | | - Ahmadreza Amirahmadi
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Brendon Palmer
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Rohit S. Gawande
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Grace Milroy
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Rick Roberti
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Frank E. Leader
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Richard D. West
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Jan Martin
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Vijay Venkatesh
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Virgil Adumitroaie
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Christine Rains
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Cuong Quach
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | - Jordi E. Turner
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 USA
| | - Colleen M. O’Shea
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 USA
| | - Scott D. Kempf
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
| | - Gregory Ng
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
| | - Dillon P. Buhl
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
| | - Timothy J. Urban
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758 USA
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2
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Sahai N, LaRowe D, Senko JM. Bioenergetics of iron snow fueling life on Europa. Proc Natl Acad Sci U S A 2024; 121:e2316452121. [PMID: 38621125 PMCID: PMC11047109 DOI: 10.1073/pnas.2316452121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 03/11/2024] [Indexed: 04/17/2024] Open
Abstract
The main sources of redox gradients supporting high-productivity life in the Europan and other icy ocean world oceans were proposed to be photolytically derived oxidants, such as reactive oxygen species (ROS) from the icy shell, and reductants (Fe(II), S(-II), CH4, H2) from bottom waters reacting with a (ultra)mafic seafloor. Important roadblocks to maintaining life, however, are that the degree of ocean mixing to combine redox species is unknown, and ROS damage biomolecules. Here, we envisage a unique solution using an acid mine drainage (AMD)-filled pit lakes analog system for the Europan ocean, which previous models predicted to be acidic. We hypothesize that surface-generated ROS oxidize dissolved Fe(II) resulting in Fe(III) (hydr)oxide precipitates, that settle to the seafloor as "iron snow." The iron snow provides a respiratory substrate for anaerobic microorganisms ("breathing iron"), and limits harmful ROS exposure since they are now neutralized at the ice-water interface. Based on this scenario, we calculated Gibbs energies and maximal biomass productivities of various anaerobic metabolisms for a range of pH, temperatures, and H2 fluxes. Productivity by iron reducers was greater for most environmental conditions considered, whereas sulfate reducers and methanogens were more favored at high pH. Participation of Fe in the metabolic redox processes is largely neglected in most models of Europan biogeochemistry. Our model overcomes important conceptual roadblocks to life in icy ocean worlds and broadens the potential metabolic diversity, thus increasing total primary productivity, the diversity and volume of habitable environmental niches and, ultimately, the probability of biosignature detection.
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Affiliation(s)
- Nita Sahai
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, OH44325
- Department of Geosciences, The University of Akron, Akron, OH44325
- Department of Biology, The University of Akron, Akron, OH44325
- Integrated Biosciences Program, The University of Akron, Akron, OH44325
| | - Doug LaRowe
- Department of Earth Sciences, University of Southern California, Los Angeles, CA90089
| | - John M. Senko
- Department of Geosciences, The University of Akron, Akron, OH44325
- Department of Biology, The University of Akron, Akron, OH44325
- Integrated Biosciences Program, The University of Akron, Akron, OH44325
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3
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Szalay JR, Allegrini F, Ebert RW, Bagenal F, Bolton SJ, Fatemi S, McComas DJ, Pontoni A, Saur J, Smith HT, Strobel DF, Vance SD, Vorburger A, Wilson RJ. Oxygen production from dissociation of Europa's water-ice surface. NATURE ASTRONOMY 2024; 8:567-576. [PMID: 38798715 PMCID: PMC11111413 DOI: 10.1038/s41550-024-02206-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 01/17/2024] [Indexed: 05/29/2024]
Abstract
Jupiter's moon Europa has a predominantly water-ice surface that is modified by exposure to its space environment. Charged particles break molecular bonds in surface ice, thus dissociating the water to ultimately produce H2 and O2, which provides a potential oxygenation mechanism for Europa's subsurface ocean. These species are understood to form Europa's primary atmospheric constituents. Although remote observations provide important global constraints on Europa's atmosphere, the molecular O2 abundance has been inferred from atomic O emissions. Europa's atmospheric composition had never been directly sampled and model-derived oxygen production estimates ranged over several orders of magnitude. Here, we report direct observations of H2+ and O2+ pickup ions from the dissociation of Europa's water-ice surface and confirm these species are primary atmospheric constituents. In contrast to expectations, we find the H2 neutral atmosphere is dominated by a non-thermal, escaping population. We find 12 ± 6 kg s-1 (2.2 ± 1.2 × 1026 s-1) O2 are produced within Europa's surface, less than previously thought, with a narrower range to support habitability in Europa's ocean. This process is found to be Europa's dominant exogenic surface erosion mechanism over meteoroid bombardment.
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Affiliation(s)
- J. R. Szalay
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ USA
| | - F. Allegrini
- Southwest Research Institute, San Antonio, TX USA
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX USA
| | - R. W. Ebert
- Southwest Research Institute, San Antonio, TX USA
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX USA
| | - F. Bagenal
- Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO USA
| | - S. J. Bolton
- Southwest Research Institute, San Antonio, TX USA
| | - S. Fatemi
- Department of Physics, University of Umeå, Umeå, Sweden
| | - D. J. McComas
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ USA
| | - A. Pontoni
- Southwest Research Institute, San Antonio, TX USA
| | - J. Saur
- Institute of Geophysics and Meteorology, University of Cologne, Cologne, Germany
| | - H. T. Smith
- The Johns Hopkins University Applied Physics Laboratory, Baltimore, MD USA
| | | | - S. D. Vance
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - A. Vorburger
- Physics Institute, University of Bern, Bern, Switzerland
| | - R. J. Wilson
- Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO USA
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4
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Vance SD, Craft KL, Shock E, Schmidt BE, Lunine J, Hand KP, McKinnon WB, Spiers EM, Chivers C, Lawrence JD, Wolfenbarger N, Leonard EJ, Robinson KJ, Styczinski MJ, Persaud DM, Steinbrügge G, Zolotov MY, Quick LC, Scully JEC, Becker TM, Howell SM, Clark RN, Dombard AJ, Glein CR, Mousis O, Sephton MA, Castillo-Rogez J, Nimmo F, McEwen AS, Gudipati MS, Jun I, Jia X, Postberg F, Soderlund KM, Elder CM. Investigating Europa's Habitability with the Europa Clipper. SPACE SCIENCE REVIEWS 2023; 219:81. [PMID: 38046182 PMCID: PMC10687213 DOI: 10.1007/s11214-023-01025-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 11/03/2023] [Indexed: 12/05/2023]
Abstract
The habitability of Europa is a property within a system, which is driven by a multitude of physical and chemical processes and is defined by many interdependent parameters, so that its full characterization requires collaborative investigation. To explore Europa as an integrated system to yield a complete picture of its habitability, the Europa Clipper mission has three primary science objectives: (1) characterize the ice shell and ocean including their heterogeneity, properties, and the nature of surface-ice-ocean exchange; (2) characterize Europa's composition including any non-ice materials on the surface and in the atmosphere, and any carbon-containing compounds; and (3) characterize Europa's geology including surface features and localities of high science interest. The mission will also address several cross-cutting science topics including the search for any current or recent activity in the form of thermal anomalies and plumes, performing geodetic and radiation measurements, and assessing high-resolution, co-located observations at select sites to provide reconnaissance for a potential future landed mission. Synthesizing the mission's science measurements, as well as incorporating remote observations by Earth-based observatories, the James Webb Space Telescope, and other space-based resources, to constrain Europa's habitability, is a complex task and is guided by the mission's Habitability Assessment Board (HAB).
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Affiliation(s)
- Steven D. Vance
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Kathleen L. Craft
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD USA
| | - Everett Shock
- School of Earth & Space Exploration and School of Molecular Sciences, Arizona State University, Tempe, AZ USA
| | - Britney E. Schmidt
- Department of Astronomy and Department of Earth & Atmospheric Sciences, Cornell University, Ithaca, NY USA
| | - Jonathan Lunine
- Department of Astronomy and Department of Earth & Atmospheric Sciences, Cornell University, Ithaca, NY USA
| | - Kevin P. Hand
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - William B. McKinnon
- Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University in St. Louis, Saint Louis, MO USA
| | - Elizabeth M. Spiers
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA USA
| | - Chase Chivers
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA USA
- Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA USA
| | - Justin D. Lawrence
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA USA
- Honeybee Robotics, Altadena, CA USA
| | - Natalie Wolfenbarger
- Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin, Austin, TX USA
| | - Erin J. Leonard
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | | | | | - Divya M. Persaud
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Gregor Steinbrügge
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Mikhail Y. Zolotov
- School of Earth & Space Exploration and School of Molecular Sciences, Arizona State University, Tempe, AZ USA
| | | | | | | | - Samuel M. Howell
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | | | - Andrew J. Dombard
- Dept. of Earth and Environmental Sciences, University of Illinois Chicago, Chicago, USA
| | | | - Olivier Mousis
- Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille), Marseille, France
| | - Mark A. Sephton
- Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, Imperial College London, London, United Kingdom
| | | | - Francis Nimmo
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA USA
| | - Alfred S. McEwen
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - Murthy S. Gudipati
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Insoo Jun
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Xianzhe Jia
- Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI USA
| | - Frank Postberg
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
| | - Krista M. Soderlund
- Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin, Austin, TX USA
| | - Catherine M. Elder
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
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5
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Tan JSW, Salter TL, Watson JS, Waite JH, Sephton MA. Organic Biosignature Degradation in Hydrothermal and Serpentinizing Environments: Implications for Life Detection on Icy Moons and Mars. ASTROBIOLOGY 2023; 23:1045-1055. [PMID: 37506324 DOI: 10.1089/ast.2022.0144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
Evidence of liquid water is a primary indicator of habitability on the icy moons in our outer solar system as well as on terrestrial planets such as Mars. If liquid water-containing environments host life, some of its organic remains can be fossilized and preserved as organic biosignatures. However, inorganic materials may also be present and water-assisted organic-inorganic reactions can transform the organic architecture of biological remains. Our understanding of the fate of these organic remains can be assisted by experimental simulations that monitor the chemical changes that occur in microbial organic matter due to the presence of water and minerals. We performed hydrothermal experiments at temperatures between 100°C and 300°C involving lipid-rich microbes and natural serpentinite mineral mixtures generated by the subaqueous hydrothermal alteration of ultramafic rock. The products reveal what the signals of life may look like when subjected to water-organic-inorganic reactions. Straight- and branched-chain lipids in unaltered samples are joined by cyclization and aromatization products in hydrothermally altered samples. Hydrothermal reactions produce distinct products that are not present in the starting materials, including small, single-ring, heteroatomic, and aromatic compounds such as indoles and phenols. Hydrothermal reactions in the presence of serpentinite minerals lead to significant reduction of these organic structures and their replacement by diketopiperazines (DKPs) and dihydropyrazines (DHPs), which may be compounds that are distinct to organic-inorganic reactions. Given that the precursors of DKPs and DHPs are normally lost during early diagenesis, the presence of these compounds can be an indicator of coexisting recent life and hydrothermal processing in the presence of minerals. However, laboratory experiments reveal that the formation and preservation of these compounds can only occur within a distinct temperature window. Our findings are relevant to life detection missions that aim to access hydrothermal and serpentinizing environments in the subsurfaces of icy moons and Mars.
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Affiliation(s)
- Jonathan S W Tan
- Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, Imperial College London, London, United Kingdom
| | - Tara L Salter
- Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, Imperial College London, London, United Kingdom
| | - Jonathan S Watson
- Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, Imperial College London, London, United Kingdom
| | - J Hunter Waite
- Space Science and Engineering Division, Southwest Research Institute, San Antonio, Texas, USA
| | - Mark A Sephton
- Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, Imperial College London, London, United Kingdom
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6
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Villanueva GL, Hammel HB, Milam SN, Faggi S, Kofman V, Roth L, Hand KP, Paganini L, Stansberry J, Spencer J, Protopapa S, Strazzulla G, Cruz-Mermy G, Glein CR, Cartwright R, Liuzzi G. Endogenous CO 2 ice mixture on the surface of Europa and no detection of plume activity. Science 2023; 381:1305-1308. [PMID: 37733858 DOI: 10.1126/science.adg4270] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 08/22/2023] [Indexed: 09/23/2023]
Abstract
Jupiter's moon Europa has a subsurface ocean beneath an icy crust. Conditions within the ocean are unknown, and it is unclear whether it is connected to the surface. We observed Europa with the James Webb Space Telescope (JWST) to search for active release of material by probing its surface and atmosphere. A search for plumes yielded no detection of water, carbon monoxide, methanol, ethane, or methane fluorescence emissions. Four spectral features of carbon dioxide (CO2) ice were detected; their spectral shapes and distribution across Europa's surface indicate that the CO2 is mixed with other compounds and concentrated in Tara Regio. The 13CO2 absorption is consistent with an isotopic ratio of 12C/13C = 83 ± 19. We interpret these observations as indicating that carbon is sourced from within Europa.
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Affiliation(s)
- G L Villanueva
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - H B Hammel
- Association of Universities for Research in Astronomy, Washington, DC 20004, USA
| | - S N Milam
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - S Faggi
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
- American University, Washington, DC 20016, USA
| | - V Kofman
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
- American University, Washington, DC 20016, USA
| | - L Roth
- Royal Institute of Technology, Stockholm 104 50, Sweden
| | - K P Hand
- Jet Propulsion Laboratory, Pasadena, CA 91109, USA
| | - L Paganini
- NASA Headquarters, Washington, DC 20546, USA
| | - J Stansberry
- Space Telescope Science Institute, Baltimore, MD 21218, USA
| | - J Spencer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S Protopapa
- Southwest Research Institute, Boulder, CO 80302, USA
| | - G Strazzulla
- Osservatorio Astrofisico di Catania, Istituto Nazionale di Astrofisica, 95123 Catania, Italy
| | - G Cruz-Mermy
- Universite Paris-Sarclay, 91190 Gif-sur-Yvette, France
| | - C R Glein
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - R Cartwright
- Carl Sagan Center for Research, Search for Extraterrestrial Intelligence Institute, Mountain View, CA 94043, USA
| | - G Liuzzi
- Università degli Studi della Basilicata, 85100 Potenza, Italy
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7
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Roberts JH, McKinnon WB, Elder CM, Tobie G, Biersteker JB, Young D, Park RS, Steinbrügge G, Nimmo F, Howell SM, Castillo-Rogez JC, Cable ML, Abrahams JN, Bland MT, Chivers C, Cochrane CJ, Dombard AJ, Ernst C, Genova A, Gerekos C, Glein C, Harris CD, Hay HCFC, Hayne PO, Hedman M, Hussmann H, Jia X, Khurana K, Kiefer WS, Kirk R, Kivelson M, Lawrence J, Leonard EJ, Lunine JI, Mazarico E, McCord TB, McEwen A, Paty C, Quick LC, Raymond CA, Retherford KD, Roth L, Rymer A, Saur J, Scanlan K, Schroeder DM, Senske DA, Shao W, Soderlund K, Spiers E, Styczinski MJ, Tortora P, Vance SD, Villarreal MN, Weiss BP, Westlake JH, Withers P, Wolfenbarger N, Buratti B, Korth H, Pappalardo RT. Exploring the Interior of Europa with the Europa Clipper. SPACE SCIENCE REVIEWS 2023; 219:46. [PMID: 37636325 PMCID: PMC10457249 DOI: 10.1007/s11214-023-00990-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 07/20/2023] [Indexed: 08/29/2023]
Abstract
The Galileo mission to Jupiter revealed that Europa is an ocean world. The Galileo magnetometer experiment in particular provided strong evidence for a salty subsurface ocean beneath the ice shell, likely in contact with the rocky core. Within the ice shell and ocean, a number of tectonic and geodynamic processes may operate today or have operated at some point in the past, including solid ice convection, diapirism, subsumption, and interstitial lake formation. The science objectives of the Europa Clipper mission include the characterization of Europa's interior; confirmation of the presence of a subsurface ocean; identification of constraints on the depth to this ocean, and on its salinity and thickness; and determination of processes of material exchange between the surface, ice shell, and ocean. Three broad categories of investigation are planned to interrogate different aspects of the subsurface structure and properties of the ice shell and ocean: magnetic induction, subsurface radar sounding, and tidal deformation. These investigations are supplemented by several auxiliary measurements. Alone, each of these investigations will reveal unique information. Together, the synergy between these investigations will expose the secrets of the Europan interior in unprecedented detail, an essential step in evaluating the habitability of this ocean world.
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Affiliation(s)
| | | | - Catherine M Elder
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | | | | | | | - Ryan S Park
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Gregor Steinbrügge
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Francis Nimmo
- University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Samuel M Howell
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | | | - Morgan L Cable
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | | | | | | | - Corey J Cochrane
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | | | - Carolyn Ernst
- Johns Hopkins Applied Physics Laboratory, Laurel, MD, USA
| | | | | | | | | | - Hamish C F C Hay
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Paul O Hayne
- University of Colorado Boulder, Boulder, CO, USA
| | | | - Hauke Hussmann
- German Aerospace Center Institute of Planetary Research, Berlin, Germany
| | | | | | - Walter S Kiefer
- Lunar and Planetary Institute, University Space Research Association, Houston, TX, USA
| | | | | | | | - Erin J Leonard
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | | | | | | | | | | | | | - Carol A Raymond
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Kurt D Retherford
- Sapienza University of Rome, Rome, Italy
- University of Texas at San Antonio, San Antonio, TX, USA
| | - Lorenz Roth
- KTH Royal Institute of Technology, Stockholm, Sweden
| | - Abigail Rymer
- Johns Hopkins Applied Physics Laboratory, Laurel, MD, USA
| | | | | | | | - David A Senske
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Wencheng Shao
- University of California, Santa Cruz, Santa Cruz, CA, USA
| | | | | | - Marshall J Styczinski
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
- University of Washington, Seattle, WA, USA
| | - Paolo Tortora
- Alma Mater Studiorum - Università di Bologna, Bologna, Italy
| | - Steven D Vance
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | | | | | | | | | | | - Bonnie Buratti
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Haje Korth
- Johns Hopkins Applied Physics Laboratory, Laurel, MD, USA
| | - Robert T Pappalardo
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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8
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Weber JM, Marlin TC, Prakash M, Teece BL, Dzurilla K, Barge LM. A Review on Hypothesized Metabolic Pathways on Europa and Enceladus: Space-Flight Detection Considerations. Life (Basel) 2023; 13:1726. [PMID: 37629583 PMCID: PMC10456045 DOI: 10.3390/life13081726] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Enceladus and Europa, icy moons of Saturn and Jupiter, respectively, are believed to be habitable with liquid water oceans and therefore are of interest for future life detection missions and mission concepts. With the limited data from missions to these moons, many studies have sought to better constrain these conditions. With these constraints, researchers have, based on modeling and experimental studies, hypothesized a number of possible metabolisms that could exist on Europa and Enceladus if these worlds host life. The most often hypothesized metabolisms are methanogenesis for Enceladus and methane oxidation/sulfate reduction on Europa. Here, we outline, review, and compare the best estimated conditions of each moon's ocean. We then discuss the hypothetical metabolisms that have been suggested to be present on these moons, based on laboratory studies and Earth analogs. We also detail different detection methods that could be used to detect these hypothetical metabolic reactions and make recommendations for future research and considerations for future missions.
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Affiliation(s)
- Jessica M. Weber
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA (B.L.T.); (K.D.); (L.M.B.)
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9
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Qu Y, Yin Z, Kustatscher E, Nützel A, Peckmann J, Vajda V, Ivarsson M. Traces of Ancient Life in Oceanic Basalt Preserved as Iron-Mineralized Ultrastructures: Implications for Detecting Extraterrestrial Biosignatures. ASTROBIOLOGY 2023; 23:769-785. [PMID: 37222732 DOI: 10.1089/ast.2022.0075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Benefiting from their adaptability to extreme environments, subsurface microorganisms have been discovered in sedimentary and igneous rock environments on Earth and have been advocated as candidates in the search for extraterrestrial life. In this article, we study iron-mineralized microstructures in calcite-filled veins within basaltic pillows of the late Ladinian Fernazza group (Middle Triassic, 239 Ma) in Italy. These microstructures represent diverse morphologies, including filaments, globules, nodules, and micro-digitate stromatolites, which are similar to extant iron-oxidizing bacterial communities. In situ analyses including Raman spectroscopy have been used to investigate the morphological, elemental, mineralogical, and bond-vibrational modes of the microstructures. According to the Raman spectral parameters, iron minerals preserve heterogeneous ultrastructures and crystallinities, coinciding with the morphologies and precursor microbial activities. The degree of crystallinity usually represents a microscale gradient decreasing toward previously existing microbial cells, revealing a decline of mineralization due to microbial activities. This study provides an analog of possible rock-dwelling subsurface life on Mars or icy moons and advocates Raman spectroscopy as an efficient tool for in situ analyses. We put forward the concept that ultrastructural characteristics of minerals described by Raman spectral parameters corresponding to microscale morphologies could be employed as carbon-lean biosignatures in future space missions.
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Affiliation(s)
- Yuangao Qu
- Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Zongjun Yin
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China
| | - Evelyn Kustatscher
- Museum of Nature South Tyrol, Bozen/Bolzano, Italy
- Department für Geo- und Umweltwissenschaften, Paläontologie und Geobiologie, Ludwig-Maximilians-Universität, München, Germany
- SNSB-Bayerische Staatssammlung für Paläontologie und Geobiologie, München, Germany
| | - Alexander Nützel
- Department für Geo- und Umweltwissenschaften, Paläontologie und Geobiologie, Ludwig-Maximilians-Universität, München, Germany
- SNSB-Bayerische Staatssammlung für Paläontologie und Geobiologie, München, Germany
- GeoBio-Center, Ludwig-Maximilians-Universität München, München, Germany
| | - Jörn Peckmann
- Institute für Geologie, Centrum für Erdsystemforschung und Nachhaltigkeit, Universität Hamburg, Hamburg, Germany
| | - Vivi Vajda
- Department of Paleobiology, Swedish Museum of Natural History, Stockholm, Sweden
| | - Magnus Ivarsson
- Department of Paleobiology, Swedish Museum of Natural History, Stockholm, Sweden
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10
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Randolph-Flagg NG, Ely T, Som SM, Shock EL, German CR, Hoehler TM. Phosphate availability and implications for life on ocean worlds. Nat Commun 2023; 14:2388. [PMID: 37185347 PMCID: PMC10130162 DOI: 10.1038/s41467-023-37770-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 03/30/2023] [Indexed: 05/17/2023] Open
Abstract
Several moons in the outer solar system host liquid water oceans. A key next step in assessing the habitability of these ocean worlds is to determine whether life's elemental and energy requirements are also met. Phosphorus is required by all known life and is often limited to biological productivity in Earth's oceans. This raises the possibility that its availability may limit the abundance or productivity of Earth-like life on ocean worlds. To address this potential problem, here we calculate the equilibrium dissolved phosphate concentrations associated with the reaction of water and rocks-a key driver of ocean chemical evolution-across a broad range of compositional inputs and reaction conditions. Equilibrium dissolved phosphate concentrations range from 10-11 to 10-1 mol/kg across the full range of carbonaceous chondrite compositions and reaction conditions considered, but are generally > 10-5 mol/kg for most plausible scenarios. Relative to the phosphate requirements and uptake kinetics of microorganisms in Earth's oceans, such concentrations would be sufficient to support initially rapid cell growth and construction of global ocean cell populations larger than those observed in Earth's deep oceans.
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Affiliation(s)
- Noah G Randolph-Flagg
- Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, Mountain View, CA, USA.
- NASA Postdoctoral Program, Universities Space Research Association, Columbia, MD, USA.
- Blue Marble Space Institute of Science, Seattle, WA, USA.
| | - Tucker Ely
- NASA Postdoctoral Program, Universities Space Research Association, Columbia, MD, USA
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, USA
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Sanjoy M Som
- Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, Mountain View, CA, USA
- Blue Marble Space Institute of Science, Seattle, WA, USA
| | - Everett L Shock
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Christopher R German
- Dept. Geology and Geophysics, Woods Hole Oceanographic Institution Woods Hole, Falmouth, MA, USA
| | - Tori M Hoehler
- Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, Mountain View, CA, USA
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11
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Sanderink A, Klenner F, Zymak I, Žabka J, Postberg F, Lebreton JP, Gaubicher B, Charvat A, Abel B, Polášek M, Cherville B, Thirkell L, Briois C. OLYMPIA-LILBID: A New Laboratory Setup to Calibrate Spaceborne Hypervelocity Ice Grain Detectors Using High-Resolution Mass Spectrometry. Anal Chem 2023; 95:3621-3628. [PMID: 36753610 DOI: 10.1021/acs.analchem.2c04429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The coupling of an Orbitrap-based mass analyzer to the laser-induced liquid beam ion desorption (LILBID) technique has been investigated, with the aim to reproduce the mass spectra recorded by Cassini's Cosmic Dust Analyzer (CDA) in the vicinity of Saturn's icy moon Enceladus. LILBID setups are usually coupled with time-of-flight (TOF) mass analyzers, with a limited mass resolution (∼800 m/Δm). Thanks to the Orbitrap technology, we developed a unique analytical setup that is able to simulate hypervelocity ice grains' impact in the laboratory (at speeds in the range of 15-18 km/s) with an unprecedented high mass resolution of up to 150 000 m/Δm (at m/z 19 for a 500 ms signal duration). The results will be implemented in the LILBID database and will be useful for the calibration and future data interpretation of the Europa Clipper's SUrface Dust Analyzer (SUDA), which will characterize the habitability of Jupiter's icy moon Europa.
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Affiliation(s)
- Arnaud Sanderink
- Laboratoire de Physique et Chimie de l'environnement et de l'Espace, UMR-CNRS 7328, 45071 Orléans, France.,Institute of Geological Sciences, Freie Universität Berlin, 12249 Berlin, Germany
| | - Fabian Klenner
- Institute of Geological Sciences, Freie Universität Berlin, 12249 Berlin, Germany
| | - Illia Zymak
- ELI-Beamlines, 252 41 Dolní Břežany, Czech Republic
| | - Jan Žabka
- J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, 182 00 Prague 8, Czech Republic
| | - Frank Postberg
- Institute of Geological Sciences, Freie Universität Berlin, 12249 Berlin, Germany
| | - Jean-Pierre Lebreton
- Laboratoire de Physique et Chimie de l'environnement et de l'Espace, UMR-CNRS 7328, 45071 Orléans, France
| | - Bertrand Gaubicher
- Laboratoire de Physique et Chimie de l'environnement et de l'Espace, UMR-CNRS 7328, 45071 Orléans, France
| | - Ales Charvat
- Institute of Chemical Technology, University Leipzig, 04103 Leipzig, Germany
| | - Bernd Abel
- Institute of Chemical Technology, University Leipzig, 04103 Leipzig, Germany
| | - Miroslav Polášek
- J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, 182 00 Prague 8, Czech Republic
| | - Barnabé Cherville
- Laboratoire de Physique et Chimie de l'environnement et de l'Espace, UMR-CNRS 7328, 45071 Orléans, France
| | - Laurent Thirkell
- Laboratoire de Physique et Chimie de l'environnement et de l'Espace, UMR-CNRS 7328, 45071 Orléans, France
| | - Christelle Briois
- Laboratoire de Physique et Chimie de l'environnement et de l'Espace, UMR-CNRS 7328, 45071 Orléans, France
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12
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Castillo‐Rogez J, Weiss B, Beddingfield C, Biersteker J, Cartwright R, Goode A, Melwani Daswani M, Neveu M. Compositions and Interior Structures of the Large Moons of Uranus and Implications for Future Spacecraft Observations. JOURNAL OF GEOPHYSICAL RESEARCH. PLANETS 2023; 128:e2022JE007432. [PMID: 37034459 PMCID: PMC10078161 DOI: 10.1029/2022je007432] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 11/29/2022] [Accepted: 12/02/2022] [Indexed: 06/19/2023]
Abstract
The five large moons of Uranus are important targets for future spacecraft missions. To motivate and inform the exploration of these moons, we model their internal evolution, present-day physical structures, and geochemical and geophysical signatures that may be measured by spacecraft. We predict that if the moons preserved liquid until present, it is likely in the form of residual oceans less than 30 km thick in Ariel, Umbriel, and less than 50 km in Titania, and Oberon. The preservation of liquid strongly depends on material properties and, potentially, on dynamical circumstances that are presently unknown. Miranda is unlikely to host liquid at present unless it experienced tidal heating a few tens of million years ago. We find that since the thin residual layers may be hypersaline, their induced magnetic fields could be detectable by future spacecraft-based magnetometers. However, if the ocean is maintained primarily by ammonia, and thus well below the water freezing point, then its electrical conductivity may be too small to be detectable by spacecraft. Lastly, our calculated tidal Love number (k 2) and dissipation factor (Q) are consistent with the Q/k 2 values previously inferred from dynamical evolution models. In particular, we find that the low Q/k 2 estimated for Titania supports the hypothesis that Titania currently holds an ocean.
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Affiliation(s)
| | - Benjamin Weiss
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of Technology (MIT)CambridgeMAUSA
| | - Chloe Beddingfield
- SETI InstituteMountain ViewCAUSA
- NASA Ames Research CenterMountain ViewCAUSA
| | - John Biersteker
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of Technology (MIT)CambridgeMAUSA
| | | | - Allison Goode
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of Technology (MIT)CambridgeMAUSA
| | | | - Marc Neveu
- University of MarylandCollege ParkMDUSA
- NASA Goddard Space Flight CenterGreenbeltMDUSA
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13
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Dannenmann M, Klenner F, Bönigk J, Pavlista M, Napoleoni M, Hillier J, Khawaja N, Olsson-Francis K, Cable ML, Malaska MJ, Abel B, Postberg F. Toward Detecting Biosignatures of DNA, Lipids, and Metabolic Intermediates from Bacteria in Ice Grains Emitted by Enceladus and Europa. ASTROBIOLOGY 2023; 23:60-75. [PMID: 36454287 DOI: 10.1089/ast.2022.0063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The reliable identification of biosignatures is key to the search for life elsewhere. On ocean worlds like Enceladus or Europa, this can be achieved by impact ionization mass spectrometers, such as the SUrface Dust Analyzer (SUDA) on board NASA's upcoming Europa Clipper mission. During spacecraft flybys, these instruments can sample ice grains formed from subsurface water and emitted by these moons. Previous laboratory analog experiments have demonstrated that SUDA-type instruments could identify amino acids, fatty acids, and peptides in ice grains and discriminate between their abiotic and biotic origins. Here, we report experiments simulating impact ionization mass spectra of ice grains containing DNA, lipids, and metabolic intermediates extracted from two bacterial cultures: Escherichia coli and Sphingopyxis alaskensis. Salty Enceladan or Europan ocean waters were simulated using matrices with different NaCl concentrations. Characteristic mass spectral signals, such as DNA nucleobases, are clearly identifiable at part-per-million-level concentrations. Mass spectra of all substances exhibit unambiguous biogenic patterns, which in some cases show significant differences between the two bacterial species. Sensitivity to the biosignatures decreases with increasing matrix salinity. The experimental parameters indicate that future impact ionization mass spectrometers will be most sensitive to the investigated biosignatures for ice grain encounter speeds of 4-6 km/s.
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Affiliation(s)
- Marie Dannenmann
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Fabian Klenner
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Janine Bönigk
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Miriam Pavlista
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Maryse Napoleoni
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Jon Hillier
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Nozair Khawaja
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Karen Olsson-Francis
- AstrobiologyOU, Faculty of Science, Technology, Engineering & Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Morgan L Cable
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Michael J Malaska
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Bernd Abel
- Leibniz-Institute of Surface Engineering (IOM), Leipzig, Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Leipzig University, Leipzig, Germany
| | - Frank Postberg
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
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14
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Mitton S. A Short History of Panspermia from Antiquity Through the Mid-1970s. ASTROBIOLOGY 2022; 22:1379-1391. [PMID: 36475958 DOI: 10.1089/ast.2022.0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Panspermia is the philosophical proposition that the precursors of life are present in space and able to initiate life on reaching a suitable environment (especially the Earth). Only in the past century has the subject advanced from the lowly status of a dreamy hypothesis to a vibrant new science that is testable and observable. This history of panspermia presents the major figures associated with such hypotheses. It examines their motives, methods, and arguments, situated when possible in their historical context and culture rather than their impact on the present. From antiquity to the early modern period (1500-1800), the debates on the plurality of worlds and panspermia overlapped considerably. In the later modern period (1800 to the present), the narrative thread interweaves panspermia with the origin of life and the theory of evolution, and we can see authentic inputs from scientists rather than philosophers. In the interests of concision, I have omitted topics such as the Search for Extraterrestrial Intelligence, the exploration of the solar system by probes and landers, planetary protection (the inverse of panspermia), and the discovery of exoplanets. The historical literature is sometimes confusing: to correct for that, I have personally examined the original sources of every work cited rather than simply accepting the published findings of other scholars at face value.
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Affiliation(s)
- Simon Mitton
- St Edmund's College, University of Cambridge, Cambridge, United Kingdom
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15
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Twing KI, Ward LM, Kane ZK, Sanders A, Price RE, Pendleton HL, Giovannelli D, Brazelton WJ, McGlynn SE. Microbial ecology of a shallow alkaline hydrothermal vent: Strýtan Hydrothermal Field, Eyjafördur, northern Iceland. Front Microbiol 2022; 13:960335. [PMID: 36466646 PMCID: PMC9713835 DOI: 10.3389/fmicb.2022.960335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/05/2022] [Indexed: 10/20/2023] Open
Abstract
Strýtan Hydrothermal Field (SHF) is a submarine system located in Eyjafördur in northern Iceland composed of two main vents: Big Strýtan and Arnarnesstrýtan. The vents are shallow, ranging from 16 to 70 m water depth, and vent high pH (up to 10.2), moderate temperature (T max ∼70°C), anoxic, fresh fluids elevated in dissolved silica, with slightly elevated concentrations of hydrogen and methane. In contrast to other alkaline hydrothermal vents, SHF is unique because it is hosted in basalt and therefore the high pH is not created by serpentinization. While previous studies have assessed the geology and geochemistry of this site, the microbial diversity of SHF has not been explored in detail. Here we present a microbial diversity survey of the actively venting fluids and chimneys from Big Strýtan and Arnarnesstrýtan, using 16S rRNA gene amplicon sequencing. Community members from the vent fluids are mostly aerobic heterotrophic bacteria; however, within the chimneys oxic, low oxygen, and anoxic habitats could be distinguished, where taxa putatively capable of acetogenesis, sulfur-cycling, and hydrogen metabolism were observed. Very few archaea were observed in the samples. The inhabitants of SHF are more similar to terrestrial hot spring samples than other marine sites. It has been hypothesized that life on Earth (and elsewhere in the solar system) could have originated in an alkaline hydrothermal system, however all other studied alkaline submarine hydrothermal systems to date are fueled by serpentinization. SHF adds to our understandings of hydrothermal vents in relationship to microbial diversity, evolution, and possibly the origin of life.
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Affiliation(s)
- Katrina I. Twing
- School of Biological Sciences, The University of Utah, Salt Lake City, UT, United States
- Department of Microbiology, Weber State University, Ogden, UT, United States
| | - L. M. Ward
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Department of Geosciences, Smith College, Northampton, MA, United States
| | - Zachary K. Kane
- Department of Microbiology, Weber State University, Ogden, UT, United States
| | - Alexa Sanders
- Department of Microbiology, Weber State University, Ogden, UT, United States
| | - Roy Edward Price
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, United States
| | - H. Lizethe Pendleton
- School of Biological Sciences, The University of Utah, Salt Lake City, UT, United States
| | - Donato Giovannelli
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Department of Biology, University of Naples “Federico II”, Naples, Italy
| | - William J. Brazelton
- School of Biological Sciences, The University of Utah, Salt Lake City, UT, United States
| | - Shawn E. McGlynn
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Center for Sustainable Resource Science, RIKEN, Saitama, Japan
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16
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Salter TL, Watson JS, Waite JH, Sephton MA. Hydrothermal Processing of Microorganisms: Mass Spectral Signals of Degraded Biosignatures for Life Detection on Icy Moons. ACS EARTH & SPACE CHEMISTRY 2022; 6:2508-2518. [PMID: 36303715 PMCID: PMC9589906 DOI: 10.1021/acsearthspacechem.2c00213] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/30/2022] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
Life detection missions to the outer solar system are concentrating on the icy moons of Jupiter and Saturn and their inferred subsurface oceans. Access to evidence of habitability, and possibly even life, is facilitated by the ejection of subsurface material in plumes and outgassing fissures. Orbiting spacecraft can intersect the plume material or detect past sputtered remnants of outgassed products and analyze the contents using instruments such as mass spectrometers. Hydrothermalism has been proposed for the subsurface environments of icy moons, and the organic remains of any associated life would be expected to suffer some degradation through hydrothermalism, radiolysis, or spacecraft flyby impact fragmentation. Hydrothermalism is treated here for the first time in the context of the Europa Clipper mission. To assess the influence of hydrothermalism on the ability of orbiting mass spectrometers to detect degrading signals of life, we have subjected Earth microorganisms to laboratory hydrothermal processing. The processed microorganism samples were then analyzed using gas chromatography-mass spectrometry (GC-MS), and mass spectra were generated. Certain compound classes, such as carbohydrates and proteins, are significantly altered by hydrothermal processing, resulting in small one-ring and two-ring aromatic compounds such as indoles and phenols. However, lipid fragments, such as fatty acids, retain their fidelity, and their provenance is easily recognized as biological in origin. Our data indicate that mass spectrometry measurements in the plumes of icy moons, using instruments such as the MAss Spectrometer for Planetary Exploration (MASPEX) onboard the upcoming Europa Clipper mission, can reveal the presence of life even after significant degradation by hydrothermal processing has taken place.
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Affiliation(s)
- Tara L. Salter
- Impacts
and Astromaterials Research Centre, Department of Earth Science and
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jonathan S. Watson
- Impacts
and Astromaterials Research Centre, Department of Earth Science and
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - J. Hunter Waite
- Space
Science and Engineering Division, Southwest
Research Institute, San Antonio, Texas 78238, United States
| | - Mark A. Sephton
- Impacts
and Astromaterials Research Centre, Department of Earth Science and
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
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17
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Wong ML, Bartlett S, Chen S, Tierney L. Searching for Life, Mindful of Lyfe's Possibilities. Life (Basel) 2022; 12:783. [PMID: 35743813 PMCID: PMC9225093 DOI: 10.3390/life12060783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 05/03/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
We are embarking on a new age of astrobiology, one in which numerous interplanetary missions and telescopes will be designed, built, and launched with the explicit goal of finding evidence for life beyond Earth. Such a profound aim warrants caution and responsibility when interpreting and disseminating results. Scientists must take care not to overstate (or over-imply) confidence in life detection when evidence is lacking, or only incremental advances have been made. Recently, there has been a call for the community to create standards of evidence for the detection and reporting of biosignatures. In this perspective, we wish to highlight a critical but often understated element to the discussion of biosignatures: Life detection studies are deeply entwined with and rely upon our (often preconceived) notions of what life is, the origins of life, and habitability. Where biosignatures are concerned, these three highly related questions are frequently relegated to a low priority, assumed to be already solved or irrelevant to the question of life detection. Therefore, our aim is to bring to the fore how these other major astrobiological frontiers are central to searching for life elsewhere and encourage astrobiologists to embrace the reality that all of these science questions are interrelated and must be furthered together rather than separately. Finally, in an effort to be more inclusive of life as we do not know it, we propose tentative criteria for a more general and expansive characterization of habitability that we call genesity.
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Affiliation(s)
- Michael L. Wong
- Earth & Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
| | - Stuart Bartlett
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA; (S.B.); (S.C.)
| | - Sihe Chen
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA; (S.B.); (S.C.)
| | - Louisa Tierney
- The Potomac School, Science Engineering & Research Center, McLean, VA 22101, USA;
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18
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Leonard EJ, Howell SM, Mills A, Senske DA, Patthoff DA, Hay HCFC, Pappalardo RT. Finding Order in Chaos: Quantitative Predictors of Chaos Terrain Morphology on Europa. GEOPHYSICAL RESEARCH LETTERS 2022; 49:e2021GL097309. [PMID: 35866056 PMCID: PMC9287068 DOI: 10.1029/2021gl097309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/23/2022] [Accepted: 03/28/2022] [Indexed: 06/15/2023]
Abstract
The mechanisms for chaos terrain formation on Europa have long been a source of debate in the scientific community. There exist numerous theoretical and numerical models for chaos formation, but to date there has been a lack of quantifiable observations that can be used to constrain models and permit comparison to the outputs of these chaos models. Here, we use mapping and statistical analysis to develop a quantitative description of chaos terrain and their observed morphologies. For nine chaos features, we map every block, or region of pre-existing terrain within disrupted matrix. We demonstrate that chaos terrains follow a continuous spectrum of morphologies between two endmembers, platy and knobby. We find that any given chaos terrain's morphology can be quantified by means of the linearized exponential slope of its cumulative block area distribution. This quantitative metric provides a new diagnostic parameter in future studies of chaos terrain formation and comparison.
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Affiliation(s)
- E. J. Leonard
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - S. M. Howell
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - A. Mills
- University of AlabamaTuscaloosaALUSA
| | - D. A. Senske
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | | | - H. C. F. C. Hay
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - R. T. Pappalardo
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
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19
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Modeling Virus and Bacteria Populations in Europa’s Subsurface Ocean. Life (Basel) 2022; 12:life12050620. [PMID: 35629289 PMCID: PMC9147769 DOI: 10.3390/life12050620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/15/2022] [Accepted: 04/18/2022] [Indexed: 12/11/2022] Open
Abstract
The search for life in the universe is often informed by the study of “extreme” environments on Earth, which provide analogs for habitable locations in the Solar System, and whose microbial inhabitants may therefore also serve as analogs for potential life forms in extraterrestrial milieus. Recent work has highlighted the ubiquity and importance of viral entities in terrestrial ecosystems, which calls for a greater understanding of the roles that viruses might play in hypothetical extraterrestrial biomes. While some studies have modeled the dynamics of viral and bacterial populations in icy ocean environments on Earth, previous work has yet to apply these findings to icy ocean worlds such as Jupiter’s moon Europa. It is commonly theorized that hydrothermal vents on Europa could produce the necessary reductants for chemosynthesis to take place on the ocean bottom. In the case that Europa’s ocean is a reductant-limited environment, how might reductants and organic matter reach the sub-ice region to power a more easily accessible ecosystem? Here, we propose a ‘viral elevator,’ a mechanism that functions similarly to the ‘viral shunt’ in Earth’s oceans, which could create and shuttle dissolved organic matter (DOM) to a hypothetical sub-ice biosphere through viral carriers. Current models of Europa’s ocean currents and stratification support the movement of DOM to the sub-ice biosphere. We adapt an existing model for bacterial and viral population dynamics in Earth’s Arctic sea ice to Europa and use parameters from various Arctic-based studies as proxies for Europa’s environment. We find that viral burst size has the most significant effect on the virus-to-bacteria ratio (VBR) and system longevity in closed systems (such as brine pockets within Europa’s icy crust), with higher burst sizes clearly increasing both. When applying our model to an open system with an influx of DOM from the viral elevator, we found that a steady-state system is attainable, with resulting sub-ice biofilms on the order of 0.1 mm thick (global equivalent layer). This has implications for future searches for life on Europa, given that life directly under the ice will be easier to detect and observe than life near the ocean bottom.
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20
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Melwani Daswani M, Vance SD, Mayne MJ, Glein CR. A Metamorphic Origin for Europa's Ocean. GEOPHYSICAL RESEARCH LETTERS 2021; 48:e2021GL094143. [PMID: 35865189 PMCID: PMC9286408 DOI: 10.1029/2021gl094143] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 07/26/2021] [Accepted: 08/04/2021] [Indexed: 05/28/2023]
Abstract
Europa likely contains an iron-rich metal core. For it to have formed, temperatures within Europa reached ≳ 1250 K. Going up to that temperature, accreted chondritic minerals - for example, carbonates and phyllosilicates - would partially devolatilize. Here, we compute the amounts and compositions of exsolved volatiles. We find that volatiles released from the interior would have carried solutes, redox-sensitive species, and could have generated a carbonic ocean in excess of Europa's present-day hydrosphere, and potentially an early CO 2 atmosphere. No late delivery of cometary water was necessary. Contrasting with prior work, CO 2 could be the most abundant solute in the ocean, followed by Ca 2 + , SO 4 2 - , and HCO 3 - . However, gypsum precipitation going from the seafloor to the ice shell decreases the dissolved S/Cl ratio, such that Cl > S at the shallowest depths, consistent with recently inferred endogenous chlorides at Europa's surface. Gypsum would form a 3-10 km thick sedimentary layer at the seafloor.
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Affiliation(s)
| | - Steven D. Vance
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Matthew J. Mayne
- Department of Earth SciencesStellenbosch UniversityStellenboschSouth Africa
| | - Christopher R. Glein
- Space Science and Engineering DivisionSouthwest Research InstituteSan AntonioTXUSA
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21
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Klenner F, Postberg F, Hillier J, Khawaja N, Cable ML, Abel B, Kempf S, Glein CR, Lunine JI, Hodyss R, Reviol R, Stolz F. Discriminating Abiotic and Biotic Fingerprints of Amino Acids and Fatty Acids in Ice Grains Relevant to Ocean Worlds. ASTROBIOLOGY 2020; 20:1168-1184. [PMID: 32493049 DOI: 10.1089/ast.2019.2188] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Identifying and distinguishing between abiotic and biotic signatures of organic molecules such as amino acids and fatty acids is key to the search for life on extraterrestrial ocean worlds. Impact ionization mass spectrometers can potentially achieve this by sampling water ice grains formed from ocean water and ejected by moons such as Enceladus and Europa, thereby exploring the habitability of their subsurface oceans in spacecraft flybys. Here, we extend previous high-sensitivity laser-based analog experiments of biomolecules in pure water to investigate the mass spectra of amino acids and fatty acids at simulated abiotic and biotic relative abundances. To account for the complex background matrix expected to emerge from a salty Enceladean ocean that has been in extensive chemical exchange with a carbonaceous rocky core, other organic and inorganic constituents are added to the biosignature mixtures. We find that both amino acids and fatty acids produce sodiated molecular peaks in salty solutions. Under the soft ionization conditions expected for low-velocity (2-6 km/s) encounters of an orbiting spacecraft with ice grains, the unfragmented molecular spectral signatures of amino acids and fatty acids accurately reflect the original relative abundances of the parent molecules within the source solution, enabling characteristic abiotic and biotic relative abundance patterns to be identified. No critical interferences with other abiotic organic compounds were observed. Detection limits of the investigated biosignatures under Enceladus-like conditions are salinity dependent (decreasing sensitivity with increasing salinity), at the μM or nM level. The survivability and ionization efficiency of large organic molecules during impact ionization appear to be significantly improved when they are protected by a frozen water matrix. We infer from our experimental results that encounter velocities of 4-6 km/s are most appropriate for impact ionization mass spectrometers to detect and discriminate between abiotic and biotic signatures.
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Affiliation(s)
- Fabian Klenner
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
- Institute of Earth Sciences, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Frank Postberg
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
- Institute of Earth Sciences, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Jon Hillier
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Nozair Khawaja
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
- Institute of Earth Sciences, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Morgan L Cable
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Bernd Abel
- Leibniz-Institute of Surface Engineering, Leipzig, Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Universität Leipzig, Leipzig, Germany
| | - Sascha Kempf
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado, USA
| | - Christopher R Glein
- Space Science and Engineering Division, Southwest Research Institute, San Antonio, Texas, USA
| | - Jonathan I Lunine
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- Department of Astronomy and Carl Sagan Institute, Cornell University, Ithaca, New York, USA
| | - Robert Hodyss
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - René Reviol
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
- Institute of Earth Sciences, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Ferdinand Stolz
- Leibniz-Institute of Surface Engineering, Leipzig, Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Universität Leipzig, Leipzig, Germany
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22
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Howell SM, Pappalardo RT. NASA's Europa Clipper-a mission to a potentially habitable ocean world. Nat Commun 2020; 11:1311. [PMID: 32161262 PMCID: PMC7066167 DOI: 10.1038/s41467-020-15160-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 02/21/2020] [Indexed: 12/02/2022] Open
Abstract
Jupiter’s satellite Europa almost certainly hides a global saltwater ocean beneath its icy surface. Chemistry at the ice surface and ocean-rock interface might provide the building blocks for life, and NASA’s Europa Clipper mission will assess Europa’s habitability.
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Affiliation(s)
- Samuel M Howell
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
| | - Robert T Pappalardo
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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23
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Olsson-Francis K, Ramkissoon NK, Macey MC, Pearson VK, Schwenzer SP, Johnson DN. Simulating microbial processes in extraterrestrial, aqueous environments. J Microbiol Methods 2020; 172:105883. [PMID: 32119957 DOI: 10.1016/j.mimet.2020.105883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/28/2020] [Accepted: 02/28/2020] [Indexed: 10/24/2022]
Abstract
Finding evidence of life elsewhere in the Solar System is dependent on understanding biotic processes that could occur within potentially habitable environments. Here, we describe a suite of high-pressure flow-through reactors that have been developed to investigate biotic and abiotic processes within simulated sub-surface martian and icy moon environments.
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Affiliation(s)
- K Olsson-Francis
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
| | - N K Ramkissoon
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | - M C Macey
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | - V K Pearson
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | - S P Schwenzer
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | - D N Johnson
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
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24
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Lang SQ, Brazelton WJ. Habitability of the marine serpentinite subsurface: a case study of the Lost City hydrothermal field. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2020; 378:20180429. [PMID: 31902336 PMCID: PMC7015304 DOI: 10.1098/rsta.2018.0429] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 10/01/2019] [Indexed: 06/10/2023]
Abstract
The Lost City hydrothermal field is a dramatic example of the biological potential of serpentinization. Microbial life is prevalent throughout the Lost City chimneys, powered by the hydrogen gas and organic molecules produced by serpentinization and its associated geochemical reactions. Microbial life in the serpentinite subsurface below the Lost City chimneys, however, is unlikely to be as dense or active. The marine serpentinite subsurface poses serious challenges for microbial activity, including low porosities, the combination of stressors of elevated temperature, high pH and a lack of bioavailable ∑CO2. A better understanding of the biological opportunities and challenges in serpentinizing systems would provide important insights into the total habitable volume of Earth's crust and for the potential of the origin and persistence of life in Earth's subsurface environments. Furthermore, the limitations to life in serpentinizing subsurface environments on Earth have significant implications for the habitability of subsurface environments on ocean worlds such as Europa and Enceladus. Here, we review the requirements and limitations of life in serpentinizing systems, informed by our research at the Lost City and the underwater mountain on which it resides, the Atlantis Massif. This article is part of a discussion meeting issue 'Serpentinite in the Earth System'.
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Affiliation(s)
- Susan Q. Lang
- School of the Earth, Ocean, and Environment, University of South Carolina, Columbia, SC 29208, USA
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25
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Vance SD, Melwani Daswani M. Serpentinite and the search for life beyond Earth. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2020; 378:20180421. [PMID: 31902342 DOI: 10.1098/rsta.2018.0421] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/27/2019] [Indexed: 06/10/2023]
Abstract
Hydrogen from serpentinization is a source of chemical energy for some life forms on Earth. It is a potential fuel for life in the subsurface of Mars and in the icy ocean worlds in the outer solar system. Serpentinization is also implicated in life's origin. Planetary exploration offers a way to investigate such theories by characterizing and ultimately searching for life in geochemical settings that no longer exist on Earth. At present, much of the current context of serpentinization on other worlds relies on inference from modelling and studies on Earth. While there is evidence from orbital spectral imaging and martian meteorites that serpentinization has occurred on Mars, the extent and duration of that activity has not been constrained. Similarly, ongoing serpentinization might explain hydrogen found in the ocean of Saturn's tiny moon Enceladus, but this raises questions about how long such activity has persisted. Titan's hydrocarbon-rich atmosphere may derive from ancient or present-day serpentinization at the bottom of its ocean. In Europa, volcanism or serpentinization may provide hydrogen as a redox couple to oxygen generated at the moon's surface. We assess the potential extent of serpentinization in the solar system's wet and rocky worlds, assuming that microfracturing from thermal expansion anisotropy sets an upper limit on the percolation depth of surface water into the rocky interiors. In this bulk geophysical model, planetary cooling from radiogenic decay implies the infiltration of water to greater depths through time, continuing to the present. The serpentinization of this newly exposed rock is assessed as a significant source of global hydrogen. Comparing the computed hydrogen and surface-generated oxygen delivered to Europa's ocean reveals redox fluxes similar to Earth's. Planned robotic exploration missions to other worlds can aid in understanding the planetary context of serpentinization, testing the predictions herein. This article is part of a discussion meeting issue 'Serpentinite in the Earth System'.
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Affiliation(s)
- S D Vance
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8001, USA
| | - M Melwani Daswani
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8001, USA
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26
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Klenner F, Postberg F, Hillier J, Khawaja N, Reviol R, Stolz F, Cable ML, Abel B, Nölle L. Analog Experiments for the Identification of Trace Biosignatures in Ice Grains from Extraterrestrial Ocean Worlds. ASTROBIOLOGY 2020; 20:179-189. [PMID: 31825243 DOI: 10.1089/ast.2019.2065] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Reliable identification of biosignatures, such as amino acids, fatty acids, and peptides, on extraterrestrial ocean worlds is a key prerequisite for space missions that search for life or its emergence on these worlds. One promising approach is the use of high-performance in situ impact ionization mass spectrometers to sample water ice grains emerging from ocean-bearing moons such as Europa or Enceladus. A predecessor of such detectors, the Cosmic Dust Analyzer on board the Cassini spacecraft, has proven to be very successful in analyzing inorganic and organic ocean constituents and with that characterizing the habitability of Enceladus ocean. However, biosignatures have not been definitively identified in extraterrestrial ocean environments so far. Here, we investigate with an analog experiment the spectral appearance of amino acids, fatty acids, and peptides in water ice grains, together with their detection limits, as applicable to spaceborne mass spectrometers. We employ a laboratory-based laser induced liquid beam ion desorption technique, proven to simulate accurately the impact ionization mass spectra of water ice grains over a wide range of impact speeds. The investigated organics produce characteristic mass spectra, with molecular peaks as well as clearly identifiable, distinctive fragments. We find the detection limits of these key biosignatures to be at the μM or nM level, depending on the molecular species and instrument polarity, and infer that impact ionization mass spectrometers are most sensitive to the molecular peaks of these biosignatures at encounter velocities of 4-6 km/s.
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Affiliation(s)
- Fabian Klenner
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
- Institut für Geowissenschaften, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Frank Postberg
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
- Institut für Geowissenschaften, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Jon Hillier
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
| | - Nozair Khawaja
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
- Institut für Geowissenschaften, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - René Reviol
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
- Institut für Geowissenschaften, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Ferdinand Stolz
- Leibniz-Institut für Oberflächenmodifizierung, Leipzig, Germany
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Leipzig, Germany
| | - Morgan L Cable
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Bernd Abel
- Leibniz-Institut für Oberflächenmodifizierung, Leipzig, Germany
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Leipzig, Germany
| | - Lenz Nölle
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
- Institut für Geowissenschaften, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
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27
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Lam BR, Barge LM, Noell AC, Nealson KH. Detecting Endogenous Microbial Metabolism and Differentiating Between Abiotic and Biotic Signals Observed by Bioelectrochemical Systems in Soils. ASTROBIOLOGY 2020; 20:39-52. [PMID: 31560219 DOI: 10.1089/ast.2018.1892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Unambiguous detection of chemical and physical signatures of microbial life on Mars or other solar system bodies requires differentiation between signals produced by biotic and abiotic processes; instruments aimed at generalized in situ extant life detection would therefore increase the science return of a life-detection mission. Here, we investigate Bioelectrochemical Systems (BES) as a technique to measure microbial metabolism (which produces electrical current and redox changes) and distinguish between potential abiotic and biotic responses in environmental samples. Samples from inhabited niches should contain everything necessary to produce current, that is, catalysts (microorganisms) and fuel (nutrients). BES can also probe for inactive organisms in less energetically rich areas by adding a fuel to drive metabolism. A commercial potting soil and a Mars simulant soil were inoculated in the anodic chamber of microbial fuel cells, and current was monitored over time. Addition of a fuel (electron donor) source was tested for metabolic stimulation of endogenous microbes. Redox reactions between Mars simulant soil and the introduced electron donor (lactate) produced false-positive results, emphasizing the importance of careful interpretation of signals obtained. The addition of lactate to both soils resulted in enhanced biologically produced current, allowing stimulation and detection of dormant microbes. Our results demonstrate that BES provide an approach to detect metabolism in samples without prior knowledge of the organisms present, and that thorough electrochemical analyses and experimental design are necessary to determine if signals are biotic.
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Affiliation(s)
- Bonita R Lam
- Department of Biological Sciences, University of Southern California, Los Angeles, California
| | - Laura M Barge
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Aaron C Noell
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Kenneth H Nealson
- Department of Biological Sciences, University of Southern California, Los Angeles, California
- Department of Earth Sciences, University of Southern California, Los Angeles, California
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28
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Heinz J, Waajen AC, Airo A, Alibrandi A, Schirmack J, Schulze-Makuch D. Bacterial Growth in Chloride and Perchlorate Brines: Halotolerances and Salt Stress Responses of Planococcus halocryophilus. ASTROBIOLOGY 2019; 19:1377-1387. [PMID: 31386567 PMCID: PMC6818489 DOI: 10.1089/ast.2019.2069] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/26/2019] [Indexed: 06/10/2023]
Abstract
Extraterrestrial environments encompass physicochemical conditions and habitats that are unknown on Earth, such as perchlorate-rich brines that can be at least temporarily stable on the martian surface. To better understand the potential for life in these cold briny environments, we determined the maximum salt concentrations suitable for growth (MSCg) of six different chloride and perchlorate salts at 25°C and 4°C for the extremotolerant cold- and salt-adapted bacterial strain Planococcus halocryophilus. Growth was measured through colony-forming unit (CFU) counts, while cellular and colonial phenotypic stress responses were observed through visible light, fluorescence, and scanning electron microscopy. Our data show the following: (1) The tolerance to high salt concentrations can be increased through a stepwise inoculation toward higher concentrations. (2) Ion-specific factors are more relevant for the growth limitation of P. halocryophilus in saline solutions than single physicochemical parameters like ionic strength or water activity. (3) P. halocryophilus shows the highest microbial sodium perchlorate tolerance described so far. However, (4) MSCg values are higher for all chlorides compared to perchlorates. (5) The MSCg for calcium chloride was increased by lowering the temperature from 25°C to 4°C, while sodium- and magnesium-containing salts can be tolerated at 25°C to higher concentrations than at 4°C. (6) Depending on salt type and concentration, P. halocryophilus cells show distinct phenotypic stress responses such as novel types of colony morphology on agar plates and biofilm-like cell clustering, encrustation, and development of intercellular nanofilaments. This study, taken in context with previous work on the survival of extremophiles in Mars-like environments, suggests that high-concentrated perchlorate brines on Mars might not be habitable to any present organism on Earth, but extremophilic microorganisms might be able to evolve thriving in such environments.
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Affiliation(s)
- Jacob Heinz
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
| | - Annemiek C. Waajen
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Alessandro Airo
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
| | - Armando Alibrandi
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
| | - Janosch Schirmack
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
| | - Dirk Schulze-Makuch
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
- School of the Environment, Washington State University, Pullman, Washington, USA
- GFZ German Center for Geoscience, Section Geomicrobiology, Potsdam, Germany
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Department of Experimental Limnology, Stechlin, Germany
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Onstott T, Ehlmann B, Sapers H, Coleman M, Ivarsson M, Marlow J, Neubeck A, Niles P. Paleo-Rock-Hosted Life on Earth and the Search on Mars: A Review and Strategy for Exploration. ASTROBIOLOGY 2019; 19:1230-1262. [PMID: 31237436 PMCID: PMC6786346 DOI: 10.1089/ast.2018.1960] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 04/25/2019] [Indexed: 05/19/2023]
Abstract
Here we review published studies on the abundance and diversity of terrestrial rock-hosted life, the environments it inhabits, the evolution of its metabolisms, and its fossil biomarkers to provide guidance in the search for life on Mars. Key findings are (1) much terrestrial deep subsurface metabolic activity relies on abiotic energy-yielding fluxes and in situ abiotic and biotic recycling of metabolic waste products rather than on buried organic products of photosynthesis; (2) subsurface microbial cell concentrations are highest at interfaces with pronounced chemical redox gradients or permeability variations and do not correlate with bulk host rock organic carbon; (3) metabolic pathways for chemolithoautotrophic microorganisms evolved earlier in Earth's history than those of surface-dwelling phototrophic microorganisms; (4) the emergence of the former occurred at a time when Mars was habitable, whereas the emergence of the latter occurred at a time when the martian surface was not continually habitable; (5) the terrestrial rock record has biomarkers of subsurface life at least back hundreds of millions of years and likely to 3.45 Ga with several examples of excellent preservation in rock types that are quite different from those preserving the photosphere-supported biosphere. These findings suggest that rock-hosted life would have been more likely to emerge and be preserved in a martian context. Consequently, we outline a Mars exploration strategy that targets subsurface life and scales spatially, focusing initially on identifying rocks with evidence for groundwater flow and low-temperature mineralization, then identifying redox and permeability interfaces preserved within rock outcrops, and finally focusing on finding minerals associated with redox reactions and associated traces of carbon and diagnostic chemical and isotopic biosignatures. Using this strategy on Earth yields ancient rock-hosted life, preserved in the fossil record and confirmable via a suite of morphologic, organic, mineralogical, and isotopic fingerprints at micrometer scale. We expect an emphasis on rock-hosted life and this scale-dependent strategy to be crucial in the search for life on Mars.
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Affiliation(s)
- T.C. Onstott
- Department of Geosciences, Princeton University, Princeton, New Jersey, USA
- Address correspondence to: T.C. Onstott, Department of Geosciences, Princeton University,, Princeton, NJ 008544
| | - B.L. Ehlmann
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, California, USA
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- B.L. Ehlmann, Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - H. Sapers
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, California, USA
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
| | - M. Coleman
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- NASA Astrobiology Institute, Pasadena, California, USA
| | - M. Ivarsson
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - J.J. Marlow
- Department of Organismic & Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| | - A. Neubeck
- Department of Earth Sciences, Uppsala University, Uppsala, Sweden
| | - P. Niles
- Astromaterials Research and Exploration Science Division, NASA Johnson Space Center, Houston, Texas, USA
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Georgiou CD, McKay CP, Quinn RC, Kalaitzopoulou E, Papadea P, Skipitari M. The Oxygen Release Instrument: Space Mission Reactive Oxygen Species Measurements for Habitability Characterization, Biosignature Preservation Potential Assessment, and Evaluation of Human Health Hazards. Life (Basel) 2019; 9:E70. [PMID: 31461989 PMCID: PMC6789740 DOI: 10.3390/life9030070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/21/2019] [Accepted: 08/25/2019] [Indexed: 11/17/2022] Open
Abstract
We describe the design of an instrument, the OxR (for Oxygen Release), for the enzymatically specific and non-enzymatic detection and quantification of the reactive oxidant species (ROS), superoxide radicals (O2•-), and peroxides (O22-, e.g., H2O2) on the surface of Mars and Moon. The OxR instrument is designed to characterize planetary habitability, evaluate human health hazards, and identify sites with high biosignature preservation potential. The instrument can also be used for missions to the icy satellites of Saturn's Titan and Enceladus, and Jupiter's Europa. The principle of the OxR instrument is based on the conversion of (i) O2•- to O2 via its enzymatic dismutation (which also releases H2O2), and of (ii) H2O2 (free or released by the hydrolysis of peroxides and by the dismutation of O2•-) to O2 via enzymatic decomposition. At stages i and ii, released O2 is quantitatively detected by an O2 sensor and stoichiometrically converted to moles of O2•- and H2O2. A non-enzymatic alternative approach is also designed. These methods serve as the design basis for the construction of a new small-footprint instrument for specific oxidant detection. The minimum detection limit of the OxR instrument for O2•- and O22- in Mars, Lunar, and Titan regolith, and in Europa and Enceladus ice is projected to be 10 ppb. The methodology of the OxR instrument can be rapidly advanced to flight readiness by leveraging the Phoenix Wet Chemical Laboratory, or microfluidic sample processing technologies.
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Affiliation(s)
| | | | - Richard C Quinn
- SETI Institute, Carl Sagan Center, Mountain View, CA 94043, USA
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Rennó NO, Backhus R, Cooper C, Flatico JM, Fischer E, Greer LC, Krasowski MJ, Kremic T, Martínez GM, Prokop NF, Sweeney D, Vicente-Retortillo A. A Simple Instrument Suite for Characterizing Habitability and Weathering: The Modern Aqueous Habitat Reconnaissance Suite (MAHRS). ASTROBIOLOGY 2019; 19:849-866. [PMID: 30964330 DOI: 10.1089/ast.2018.1945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The shallow subsurface of Mars is extremely interesting as a possible microbial habitat because it becomes temporarily wet, it is shielded from radiation, and mixing by aeolian processes could provide the sources of energy and nutrients necessary for sustaining microbial life in it. The Modern Aqueous Habitat Reconnaissance Suite (MAHRS) was developed primarily to search for potentially habitable environments in the shallow subsurface of Mars and to study weathering, but it can also be used to search for potentially habitable environments in the shallow subsurface of other planetary bodies such as the Icy Worlds. MAHRS includes an instrument developed to measure regolith wetness and search for brine in the shallow subsurface of Mars, where it is most likely to be found. The detection of brine can aid in our understanding not only of habitability but also of geochemistry and aqueous weathering processes. Besides the regolith wetness sensor, MAHRS includes an electric field sensor, an optical microscope, and a radiometer developed to characterize the near-surface environment and study mixing by aeolian processes. MAHRS was designed to aid in the selection of optimum areas for sample collection for return to Earth.
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Affiliation(s)
- N O Rennó
- 1Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan
| | - R Backhus
- 2Space Physics Research Laboratory, University of Michigan, Ann Arbor, Michigan
| | - C Cooper
- 2Space Physics Research Laboratory, University of Michigan, Ann Arbor, Michigan
| | | | - E Fischer
- 1Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan
| | - L C Greer
- 4NASA Glenn Research Center, Cleveland, Ohio
| | | | - T Kremic
- 3Ohio Aerospace Institute, Cleveland, Ohio
| | - G M Martínez
- 1Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan
| | - N F Prokop
- 4NASA Glenn Research Center, Cleveland, Ohio
| | - David Sweeney
- 1Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan
| | - A Vicente-Retortillo
- 1Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan
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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] [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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Vance SD, Barge LM, Cardoso SSS, Cartwright JHE. Self-Assembling Ice Membranes on Europa: Brinicle Properties, Field Examples, and Possible Energetic Systems in Icy Ocean Worlds. ASTROBIOLOGY 2019; 19:685-695. [PMID: 30964322 DOI: 10.1089/ast.2018.1826] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Brinicles are self-assembling tubular ice membrane structures, centimeters to meters in length, found beneath sea ice in the polar regions of Earth. We discuss how the properties of brinicles make them of possible importance for chemistry in cold environments-including that of life's emergence-and we consider their formation in icy ocean worlds. We argue that the non-ice composition of the ice on Europa and Enceladus will vary spatially due to thermodynamic and mechanical properties that serve to separate and fractionate brines and solid materials. The specifics of the composition and dynamics of both the ice and the ocean in these worlds remain poorly constrained. We demonstrate through calculations using FREZCHEM that sulfate likely fractionates out of accreting ice in Europa and Enceladus, and thus that an exogenous origin of sulfate observed on Europa's surface need not preclude additional endogenous sulfate in Europa's ocean. We suggest that, like hydrothermal vents on Earth, brinicles in icy ocean worlds constitute ideal places where ecosystems of organisms might be found.
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Affiliation(s)
- Steven D Vance
- 1 NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Laura M Barge
- 1 NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Silvana S S Cardoso
- 2 Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Julyan H E Cartwright
- 3 Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, Granada, Spain
- 4 Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, Granada, Spain
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35
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Hendrix AR, Hurford TA, Barge LM, Bland MT, Bowman JS, Brinckerhoff W, Buratti BJ, Cable ML, Castillo-Rogez J, Collins GC, Diniega S, German CR, Hayes AG, Hoehler T, Hosseini S, Howett CJ, McEwen AS, Neish CD, Neveu M, Nordheim TA, Patterson GW, Patthoff DA, Phillips C, Rhoden A, Schmidt BE, Singer KN, Soderblom JM, Vance SD. The NASA Roadmap to Ocean Worlds. ASTROBIOLOGY 2019; 19:1-27. [PMID: 30346215 PMCID: PMC6338575 DOI: 10.1089/ast.2018.1955] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 09/21/2018] [Indexed: 05/20/2023]
Abstract
In this article, we summarize the work of the NASA Outer Planets Assessment Group (OPAG) Roadmaps to Ocean Worlds (ROW) group. The aim of this group is to assemble the scientific framework that will guide the exploration of ocean worlds, and to identify and prioritize science objectives for ocean worlds over the next several decades. The overarching goal of an Ocean Worlds exploration program as defined by ROW is to "identify ocean worlds, characterize their oceans, evaluate their habitability, search for life, and ultimately understand any life we find." The ROW team supports the creation of an exploration program that studies the full spectrum of ocean worlds, that is, not just the exploration of known ocean worlds such as Europa but candidate ocean worlds such as Triton as well. The ROW team finds that the confirmed ocean worlds Enceladus, Titan, and Europa are the highest priority bodies to target in the near term to address ROW goals. Triton is the highest priority candidate ocean world to target in the near term. A major finding of this study is that, to map out a coherent Ocean Worlds Program, significant input is required from studies here on Earth; rigorous Research and Analysis studies are called for to enable some future ocean worlds missions to be thoughtfully planned and undertaken. A second finding is that progress needs to be made in the area of collaborations between Earth ocean scientists and extraterrestrial ocean scientists.
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Affiliation(s)
- Amanda R. Hendrix
- Planetary Science Institute, Tucson, Arizona
- Address correspondence to: Amanda R. Hendrix, Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719
| | | | - Laura M. Barge
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Michael T. Bland
- Astrogeology Science Center, U.S. Geological Survey, Flagstaff, Arizona
| | - Jeff S. Bowman
- Scripps Institution of Oceanography, La Jolla, California
| | | | - Bonnie J. Buratti
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Morgan L. Cable
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Julie Castillo-Rogez
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | | | - Serina Diniega
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | | | - Alexander G. Hayes
- Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, New York
| | - Tori Hoehler
- NASA Ames Research Center, Mountain View, California
| | - Sona Hosseini
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | | | - Alfred S. McEwen
- Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona
| | - Catherine D. Neish
- Planetary Science Institute, Tucson, Arizona
- Department of Earth Sciences, The University of Western Ontario, London, Ontario, Canada
| | - Marc Neveu
- NASA HQ/Universities Space Association, Washington, District of Columbia
| | - Tom A. Nordheim
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | | | | | - Cynthia Phillips
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | | | - Britney E. Schmidt
- School of Earth & Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | | | - Jason M. Soderblom
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Steven D. Vance
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
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Gallo ND, Levin LA, Beckwith M, Barry JP. Home sweet suboxic home: remarkable hypoxia tolerance in two demersal fish species in the Gulf of California. Ecology 2018; 100:e02539. [PMID: 30480802 DOI: 10.1002/ecy.2539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/28/2018] [Accepted: 09/10/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Natalya D Gallo
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA.,Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA
| | - Lisa A Levin
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA.,Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA
| | - Maryanne Beckwith
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA
| | - James P Barry
- Monterey Bay Aquarium Research Institute, Moss Landing, California, 95039, USA
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Hanczarek I, Kenna AJ, Lindensmith C, Nadeau J. Performance of Fluorescent Cell-Labeling Dyes under Simulated Europa Mission Radiation Doses. Radiat Res 2018; 190:634. [PMID: 30325265 DOI: 10.1667/rr15187.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We investigated the performance of several commonly used fluorescent dyes after exposure to a simulated Europa mission total ionizing radiation dose of 300 krad (3 kGy) applied using a 60Co source. Dyes irradiated in aqueous solution or as lyophilized powders were evaluated for absorbance and emission spectra, quantum yield, and where appropriate, ability to label cells or nucleic acids. Although some dyes showed significant increase or decrease in quantum yield with the dose, their spectra and cell-labeling properties remained essentially unchanged after irradiation in powder form. Irradiation in aqueous solution led to significantly greater changes, including a large blue shift in the DNA intercalator propidium iodide. These results suggest that many fluorescent probes are appropriate for use in astrobiological missions to Europa, but that SYTO9 and propidium iodide should be used with caution or not mixed with each other, as is commonly done in "Live/Dead" labeling applications.
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Affiliation(s)
- Iulia Hanczarek
- a Department of Physics, Portland State University, Portland, Oregon 97201
| | - Aaron J Kenna
- b Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109
| | - Chris Lindensmith
- b Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109
| | - Jay Nadeau
- a Department of Physics, Portland State University, Portland, Oregon 97201
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38
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A Systematic Way to Life Detection: Combining Field, Lab and Space Research in Low Earth Orbit. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/978-3-319-96175-0_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Creamer JS, Mora MF, Willis PA. Stability of reagents used for chiral amino acid analysis during spaceflight missions in high‐radiation environments. Electrophoresis 2018; 39:2864-2871. [DOI: 10.1002/elps.201800274] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Jessica S. Creamer
- Jet Propulsion LaboratoryCalifornia Institute of Technology Pasadena CA USA
| | - Maria F. Mora
- Jet Propulsion LaboratoryCalifornia Institute of Technology Pasadena CA USA
| | - Peter A. Willis
- Jet Propulsion LaboratoryCalifornia Institute of Technology Pasadena CA USA
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Trivedi CB, Lau GE, Grasby SE, Templeton AS, Spear JR. Low-Temperature Sulfidic-Ice Microbial Communities, Borup Fiord Pass, Canadian High Arctic. Front Microbiol 2018; 9:1622. [PMID: 30087659 PMCID: PMC6066561 DOI: 10.3389/fmicb.2018.01622] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 06/28/2018] [Indexed: 11/30/2022] Open
Abstract
A sulfur-dominated supraglacial spring system found at Borup Fiord Pass (BFP), Ellesmere Island, Nunavut, Canada, is a unique sulfur-on-ice system expressed along the toe of a glacier. BFP has an intermittent flowing, subsurface-derived, glacial spring that creates a large white-yellow icing (aufeis) that extends down-valley. Over field campaigns in 2014, 2016, and 2017, numerous samples were collected and analyzed for both microbial community composition and aqueous geochemistry. Samples were collected from multiple site types: spring discharge fluid, aufeis (spring-derived ice), melt pools with sedimented cryoconite material, and mineral precipitate scrapings, to probe how microbial communities differed between site types in a dynamic freeze/thaw sulfur-rich system. Dissolved sulfate varied between 0.07 and 11.6 mM and was correlated with chloride concentrations, where the fluids were saltiest among spring fluids. The highest sulfate samples exhibited high dissolved sulfide values between 0.22 and 2.25 mM. 16S rRNA gene sequencing from melt pool and aufeis samples from the 2014 campaign were highly abundant in operational taxonomic units (OTUs) closely related to sulfur-oxidizing microorganisms (SOM; Sulfurimonas, Sulfurovum, and Sulfuricurvum). Subsequent sampling 2 weeks later had fewer SOMs and showed an increased abundance of the genus Flavobacterium. Desulfocapsa, an organism that specializes in the disproportionation of inorganic sulfur compounds was also found. Samples from 2016 and 2017 revealed that microorganisms present were highly similar in community composition to 2014 samples, primarily echoed by the continued presence of Flavobacterium sp. Results suggest that while there may be acute events where sulfur cycling organisms dominate, a basal community structure appears to dominate over time and site type. These results further enhance our knowledge of low-temperature sulfur systems on Earth, and help to guide the search for potential life on extraterrestrial worlds, such as Europa, where similar low-temperature sulfur-rich conditions may exist.
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Affiliation(s)
- Christopher B. Trivedi
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, United States
| | - Graham E. Lau
- Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, United States
| | | | - Alexis S. Templeton
- Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, United States
| | - John R. Spear
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, United States
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Jones RM, Goordial JM, Orcutt BN. Low Energy Subsurface Environments as Extraterrestrial Analogs. Front Microbiol 2018; 9:1605. [PMID: 30072971 PMCID: PMC6058055 DOI: 10.3389/fmicb.2018.01605] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/27/2018] [Indexed: 11/13/2022] Open
Abstract
Earth's subsurface is often isolated from phototrophic energy sources and characterized by chemotrophic modes of life. These environments are often oligotrophic and limited in electron donors or electron acceptors, and include continental crust, subseafloor oceanic crust, and marine sediment as well as subglacial lakes and the subsurface of polar desert soils. These low energy subsurface environments are therefore uniquely positioned for examining minimum energetic requirements and adaptations for chemotrophic life. Current targets for astrobiology investigations of extant life are planetary bodies with largely inhospitable surfaces, such as Mars, Europa, and Enceladus. Subsurface environments on Earth thus serve as analogs to explore possibilities of subsurface life on extraterrestrial bodies. The purpose of this review is to provide an overview of subsurface environments as potential analogs, and the features of microbial communities existing in these low energy environments, with particular emphasis on how they inform the study of energetic limits required for life. The thermodynamic energetic calculations presented here suggest that free energy yields of reactions and energy density of some metabolic redox reactions on Mars, Europa, Enceladus, and Titan could be comparable to analog environments in Earth's low energy subsurface habitats.
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Affiliation(s)
| | | | - Beth N. Orcutt
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
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Altair T, de Avellar MGB, Rodrigues F, Galante D. Microbial habitability of Europa sustained by radioactive sources. Sci Rep 2018; 8:260. [PMID: 29321597 PMCID: PMC5762670 DOI: 10.1038/s41598-017-18470-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 12/12/2017] [Indexed: 11/09/2022] Open
Abstract
There is an increasing interest in the icy moons of the Solar System due to their potential habitability and as targets for future exploratory missions, which include astrobiological goals. Several studies have reported new results describing the details of these moons' geological settings; however, there is still a lack of information regarding the deep subsurface environment of the moons. The purpose of this article is to evaluate the microbial habitability of Europa constrained by terrestrial analogue environments and sustained by radioactive energy provided by natural unstable isotopes. The geological scenarios are based on known deep environments on Earth, and the bacterial ecosystem is based on a sulfate-reducing bacterial ecosystem found 2.8 km below the surface in a basin in South Africa. The results show the possibility of maintaining the modeled ecosystem based on the proposed scenarios and provides directions for future models and exploration missions for a more complete evaluation of the habitability of Europa and of icy moons in general.
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Affiliation(s)
- Thiago Altair
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM)., Av. Giuseppe Máximo Scolfaro, 10000, 13083-100, Campinas, SP, Brazil.,Programa de Pós-Graduação em Física Biomolecular, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
| | - Marcio G B de Avellar
- Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo., Rua do Matão, 1226, 05508-090, São Paulo, SP, Brazil.
| | - Fabio Rodrigues
- Departamento de Química Fundamental Instituto de Química, Universidade de São Paulo., Av. Prof. Lineu Prestes, 748, 05508-000, São Paulo, SP, Brazil
| | - Douglas Galante
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM)., Av. Giuseppe Máximo Scolfaro, 10000, 13083-100, Campinas, SP, Brazil.,Programa de Pós-Graduação em Física Biomolecular, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
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Russell MJ, Murray AE, Hand KP. The Possible Emergence of Life and Differentiation of a Shallow Biosphere on Irradiated Icy Worlds: The Example of Europa. ASTROBIOLOGY 2017; 17:1265-1273. [PMID: 29016193 PMCID: PMC5729856 DOI: 10.1089/ast.2016.1600] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 04/28/2017] [Indexed: 05/17/2023]
Abstract
Irradiated ice-covered ocean worlds with rocky mafic mantles may provide the conditions needed to drive the emergence and maintenance of life. Alkaline hydrothermal springs-relieving the geophysical, thermal, and chemical disequilibria between oceans and tidally stressed crusts-could generate inorganic barriers to the otherwise uncontrolled and kinetically disfavored oxidation of hydrothermal hydrogen and methane. Ionic gradients imposed across these inorganic barriers, comprising iron oxyhydroxides and sulfides, could drive the hydrogenation of carbon dioxide and the oxidation of methane through thermodynamically favorable metabolic pathways leading to early life-forms. In such chemostatic environments, fuels may eventually outweigh oxidants. Ice-covered oceans are primarily heated from below, creating convection that could transport putative microbial cells and cellular cooperatives upward to congregate beneath an ice shell, potentially giving rise to a highly focused shallow biosphere. It is here where electron acceptors, ultimately derived from the irradiated surface, could be delivered to such life-forms through exchange with the icy surface. Such zones would act as "electron disposal units" for the biosphere, and occupants might be transferred toward the surface by buoyant diapirs and even entrained into plumes. Key Words: Biofilms-Europa-Extraterrestrial life-Hydrothermal systems. Astrobiology 17, 1265-1273.
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Affiliation(s)
- Michael J. Russell
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Alison E. Murray
- Division of Earth and Ecosystem Sciences, Desert Research Institute, Reno, Nevada
| | - Kevin P. Hand
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
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Russell MJ, Nitschke W. Methane: Fuel or Exhaust at the Emergence of Life? ASTROBIOLOGY 2017; 17:1053-1066. [PMID: 28949766 PMCID: PMC5655419 DOI: 10.1089/ast.2016.1599] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 03/20/2017] [Indexed: 05/28/2023]
Abstract
As many of the methanogens first encountered at hydrothermal vents were thermophilic to hyperthermophilic and comprised one of the lower roots of the evolutionary tree, it has been assumed that methanogenesis was one of the earliest, if not the earliest, pathway to life. It being well known that hydrothermal springs associated with serpentinization also bore abiotic methane, it had been further assumed that emergent biochemistry merely adopted and quickened this supposed serpentinization reaction. Yet, recent hydrothermal experiments simulating serpentinization have failed to generate methane so far, thus casting doubt on this assumption. The idea that the inverse view is worthy of debate, that is, that methanotrophy was the earlier, is stymied by the "fact" that methanotrophy itself has been termed "reverse methanogenesis," so allotting the methanogens the founding pedigree. Thus, attempting to suggest instead that methanogenesis might be termed reverse methanotrophy would require "unlearning"-a challenge to the subconscious! Here we re-examine the "impossibility" of methanotrophy predating methanogenesis as in what we have termed the "denitrifying methanotrophic acetogenic pathway." Advantages offered by such thinking are that methane would not only be a fuel but also a ready source of reduced carbon to combine with formate or carbon monoxide-available in hydrothermal fluids-to generate acetate, a target molecule of the first autotrophs. And the nitrate/nitrite required for the putative oxidation of methane with activated NO would also be a ready source of fixed nitrogen for amination reactions. Theoretical conditions for such a putative pathway would be met in a hydrothermal green rust-bearing exhalative pile and associated chimneys subject to proton and electron counter gradients. This hypothesis could be put to test in a high-pressure hydrothermal reaction chamber in which a cool carbonate/nitrate/nitrite-bearing early acidulous ocean simulant is juxtaposed across a precipitate membrane to an alkaline solution of hydrogen and methane. Key Words: Green rust-Methanotrophy-Nitrate reduction-Emergence of life. Astrobiology 17, 1053-1066.
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Affiliation(s)
- Michael J. Russell
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Wolfgang Nitschke
- CNRS/Aix-Marseille University, BIP UMR 7281, IMM FR 3479, Marseille, France
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45
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Barge LM, White LM. Experimentally Testing Hydrothermal Vent Origin of Life on Enceladus and Other Icy/Ocean Worlds. ASTROBIOLOGY 2017; 17:820-833. [PMID: 28836818 DOI: 10.1089/ast.2016.1633] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We review various laboratory strategies and methods that can be utilized to simulate prebiotic processes and origin of life in hydrothermal vent systems on icy/ocean worlds. Crucial steps that could be simulated in the laboratory include simulations of water-rock chemistry (e.g., serpentinization) to produce hydrothermal fluids, the types of mineral catalysts and energy gradients produced in vent interfaces where hydrothermal fluids interface with the surrounding seawater, and simulations of biologically relevant chemistry in flow-through gradient systems (i.e., far-from-equilibrium experiments). We describe some examples of experimental designs in detail, which are adaptable and could be used to test particular hypotheses about ocean world energetics or mineral/organic chemistry. Enceladus among the ocean worlds provides an ideal test case, since the pressure at the ocean floor is more easily simulated in the lab. Results for Enceladus could be extrapolated with further experiments and modeling to understand other ocean worlds. Key Words: Enceladus-Ocean worlds-Icy worlds-Hydrothermal vent-Iron sulfide-Gradient. Astrobiology 17, 820-833.
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Affiliation(s)
- Laura M Barge
- NASA Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
| | - Lauren M White
- NASA Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
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Alternative Energy: Production of H
2
by Radiolysis of Water in the Rocky Cores of Icy Bodies. ACTA ACUST UNITED AC 2017. [DOI: 10.3847/2041-8213/aa6d56] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Barge LM, Branscomb E, Brucato JR, Cardoso SSS, Cartwright JHE, Danielache SO, Galante D, Kee TP, Miguel Y, Mojzsis S, Robinson KJ, Russell MJ, Simoncini E, Sobron P. Thermodynamics, Disequilibrium, Evolution: Far-From-Equilibrium Geological and Chemical Considerations for Origin-Of-Life Research. ORIGINS LIFE EVOL B 2017; 47:39-56. [PMID: 27271006 DOI: 10.1007/s11084-016-9508-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 04/19/2016] [Indexed: 10/21/2022]
Affiliation(s)
- L M Barge
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91125, USA.
- Icy Worlds Team, NASA Astrobiology Institute, Mountain View, CA, 94043, USA.
| | - E Branscomb
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana-Champaign, Champaign, IL, USA
| | - J R Brucato
- Astrophysical Observatory of Arcetri, Florence, Italy
| | - S S S Cardoso
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge, CB2 3RA, UK
| | - J H E Cartwright
- Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, E-18100 Armilla, Granada, Spain
- Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, E-18071, Granada, Spain
| | - S O Danielache
- Sophia University, Tokyo, Japan
- Earth and Life Science Institute, Tokyo Technical University, Tokyo, Japan
| | - D Galante
- Brazilian Synchrotron Light Laboratory, LNLS / CNPEM, Campinas, Brazil
| | - T P Kee
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Y Miguel
- Observatoire de Côte d'Azur, Nice, France
| | - S Mojzsis
- Department of Geological Sciences, University of Colorado, Boulder, CO, 80309-0399, USA
| | - K J Robinson
- School of Molecular Sciences and School of Earth & Space Exploration, Arizona State University, Tempe, AZ, 85287, USA
| | - M J Russell
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91125, USA
- Icy Worlds Team, NASA Astrobiology Institute, Mountain View, CA, 94043, USA
| | - E Simoncini
- Astrophysical Observatory of Arcetri, Florence, Italy
| | - P Sobron
- Carl Sagan Center, SETI Institute, Mountain View, CA, USA
- Impossible Sensing, St. Louis, MO, USA
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50
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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] [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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