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Patty CHL, Ten Kate IL, Buma WJ, van Spanning RJM, Steinbach G, Ariese F, Snik F. Circular Spectropolarimetric Sensing of Vegetation in the Field: Possibilities for the Remote Detection of Extraterrestrial Life. ASTROBIOLOGY 2019; 19:1221-1229. [PMID: 31361507 DOI: 10.1089/ast.2019.2050] [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: 06/10/2023]
Abstract
Homochirality is a generic and unique property of all biochemical life, and the fractional circular polarization of light it induces therefore constitutes a potentially unambiguous biosignature. However, while high-quality circular polarimetric spectra can be easily and quickly obtained in the laboratory, accurate measurements in the field are much more challenging due to large changes in illumination and target movement. In this study, we measured various targets in the field, up to distances of a few kilometers, using the dedicated circular spectropolarimeter TreePol. We show how photosynthetic life can readily be distinguished from abiotic matter. We underline the potential of circular polarization signals as a remotely accessible means to characterize and monitor terrestrial vegetation, for example, for agriculture and forestry. In addition, we discuss the potential of circular polarization for the remote detection of extraterrestrial life.
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Affiliation(s)
- C H Lucas Patty
- Amsterdam Institute for Molecules, Medicine and Systems (AIMMS), VU Amsterdam, Amsterdam, The Netherlands
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
- Biofotonika R&D Ltd., Szeged, Hungary
| | - Inge Loes Ten Kate
- Department of Earth Sciences, Utrecht University, Budapestlaan 4, Utrecht 3584 CD, The Netherlands
| | - Wybren Jan Buma
- HIMS, Photonics group, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Rob J M van Spanning
- Amsterdam Institute for Molecules, Medicine and Systems (AIMMS), VU Amsterdam, Amsterdam, The Netherlands
| | - Gábor Steinbach
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Freek Ariese
- LaserLaB, VU Amsterdam, Amsterdam, The Netherlands
| | - Frans Snik
- Leiden Observatory, Leiden University, Leiden, The Netherlands
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Cataldi G, Brandeker A, Thébault P, Singer K, Ahmed E, de Vries BL, Neubeck A, Olofsson G. Searching for Biosignatures in Exoplanetary Impact Ejecta. ASTROBIOLOGY 2017; 17:721-746. [PMID: 28692303 DOI: 10.1089/ast.2015.1437] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
With the number of confirmed rocky exoplanets increasing steadily, their characterization and the search for exoplanetary biospheres are becoming increasingly urgent issues in astrobiology. To date, most efforts have concentrated on the study of exoplanetary atmospheres. Instead, we aim to investigate the possibility of characterizing an exoplanet (in terms of habitability, geology, presence of life, etc.) by studying material ejected from the surface during an impact event. For a number of impact scenarios, we estimate the escaping mass and assess its subsequent collisional evolution in a circumstellar orbit, assuming a Sun-like host star. We calculate the fractional luminosity of the dust as a function of time after the impact event and study its detectability with current and future instrumentation. We consider the possibility to constrain the dust composition, giving information on the geology or the presence of a biosphere. As examples, we investigate whether calcite, silica, or ejected microorganisms could be detected. For a 20 km diameter impactor, we find that the dust mass escaping the exoplanet is roughly comparable to the zodiacal dust, depending on the exoplanet's size. The collisional evolution is best modeled by considering two independent dust populations, a spalled population consisting of nonmelted ejecta evolving on timescales of millions of years, and dust recondensed from melt or vapor evolving on much shorter timescales. While the presence of dust can potentially be inferred with current telescopes, studying its composition requires advanced instrumentation not yet available. The direct detection of biological matter turns out to be extremely challenging. Despite considerable difficulties (small dust masses, noise such as exozodiacal dust, etc.), studying dusty material ejected from an exoplanetary surface might become an interesting complement to atmospheric studies in the future. Key Words: Biosignatures-Exoplanets-Impacts-Interplanetary dust-Remote sensing. Astrobiology 17, 721-746.
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Affiliation(s)
- Gianni Cataldi
- 1 AlbaNova University Centre, Stockholm University , Department of Astronomy, Stockholm, Sweden
- 2 Stockholm University Astrobiology Centre , Stockholm, Sweden
| | - Alexis Brandeker
- 1 AlbaNova University Centre, Stockholm University , Department of Astronomy, Stockholm, Sweden
- 2 Stockholm University Astrobiology Centre , Stockholm, Sweden
| | - Philippe Thébault
- 3 LESIA-Observatoire de Paris, UPMC Univ. Paris 06, Univ. Paris-Diderot , Paris, France
| | - Kelsi Singer
- 4 Southwest Research Institute , Boulder, Colorado, USA
| | - Engy Ahmed
- 2 Stockholm University Astrobiology Centre , Stockholm, Sweden
- 5 Royal Institute of Technology (KTH) , Science for Life Laboratory, Solna, Sweden
- 6 Stockholm University , Department of Geological Sciences, Stockholm, Sweden
| | - Bernard L de Vries
- 1 AlbaNova University Centre, Stockholm University , Department of Astronomy, Stockholm, Sweden
- 2 Stockholm University Astrobiology Centre , Stockholm, Sweden
- 7 Scientific Support Office, Directorate of Science, European Space Research and Technology Centre (ESA/ESTEC) , Noordwijk, The Netherlands
| | - Anna Neubeck
- 2 Stockholm University Astrobiology Centre , Stockholm, Sweden
- 6 Stockholm University , Department of Geological Sciences, Stockholm, Sweden
| | - Göran Olofsson
- 1 AlbaNova University Centre, Stockholm University , Department of Astronomy, Stockholm, Sweden
- 2 Stockholm University Astrobiology Centre , Stockholm, Sweden
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Horneck G, Walter N, Westall F, Grenfell JL, Martin WF, Gomez F, Leuko S, Lee N, Onofri S, Tsiganis K, Saladino R, Pilat-Lohinger E, Palomba E, Harrison J, Rull F, Muller C, Strazzulla G, Brucato JR, Rettberg P, Capria MT. AstRoMap European Astrobiology Roadmap. ASTROBIOLOGY 2016; 16:201-43. [PMID: 27003862 PMCID: PMC4834528 DOI: 10.1089/ast.2015.1441] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 01/27/2016] [Indexed: 05/07/2023]
Abstract
The European AstRoMap project (supported by the European Commission Seventh Framework Programme) surveyed the state of the art of astrobiology in Europe and beyond and produced the first European roadmap for astrobiology research. In the context of this roadmap, astrobiology is understood as the study of the origin, evolution, and distribution of life in the context of cosmic evolution; this includes habitability in the Solar System and beyond. The AstRoMap Roadmap identifies five research topics, specifies several key scientific objectives for each topic, and suggests ways to achieve all the objectives. The five AstRoMap Research Topics are • Research Topic 1: Origin and Evolution of Planetary Systems • Research Topic 2: Origins of Organic Compounds in Space • Research Topic 3: Rock-Water-Carbon Interactions, Organic Synthesis on Earth, and Steps to Life • Research Topic 4: Life and Habitability • Research Topic 5: Biosignatures as Facilitating Life Detection It is strongly recommended that steps be taken towards the definition and implementation of a European Astrobiology Platform (or Institute) to streamline and optimize the scientific return by using a coordinated infrastructure and funding system.
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Affiliation(s)
- Gerda Horneck
- European Astrobiology Network Association
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Köln, Germany
| | | | - Frances Westall
- Centre National de la Recherche Scientifique–Centre de Biophysique Moléculaire, Orleans, France
| | - John Lee Grenfell
- Institute for Planetary Research, German Aerospace Center (DLR), Berlin, Germany
| | - William F. Martin
- Institute of Molecular Evolution, Heinrich-Heine University of Düsseldorf, Düsseldorf, Germany
| | - Felipe Gomez
- INTA Centre for Astrobiology, Torrejón de Ardoz, Madrid, Spain
| | - Stefan Leuko
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Köln, Germany
| | - Natuschka Lee
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
- Department of Microbiology, Technical University München, München, Germany
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Kleomenis Tsiganis
- Department of Physics, Section of Astrophysics, Astronomy and Mechanics, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Raffaele Saladino
- Department of Agrobiology and Agrochemistry, University of Tuscia, Viterbo, Italy
| | | | - Ernesto Palomba
- INAF–Institute for Space Astrophysics and Planetology, Rome, Italy
| | - Jesse Harrison
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Fernando Rull
- Department of Condensed Matter Physics, Crystallography and Mineralogy, Valladolid University, Valladolid, Spain
| | | | | | | | - Petra Rettberg
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Köln, Germany
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Detection of circular polarization in light scattered from photosynthetic microbes. Proc Natl Acad Sci U S A 2009; 106:7816-21. [PMID: 19416893 DOI: 10.1073/pnas.0810215106] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The identification of a universal biosignature that could be sensed remotely is critical to the prospects for success in the search for life elsewhere in the universe. A candidate universal biosignature is homochirality, which is likely to be a generic property of all biochemical life. Because of the optical activity of chiral molecules, it has been hypothesized that this unique characteristic may provide a suitable remote sensing probe using circular polarization spectroscopy. Here, we report the detection of circular polarization in light scattered by photosynthetic microbes. We show that the circular polarization appears to arise from circular dichroism of the strong electronic transitions of photosynthetic absorption bands. We conclude that circular polarization spectroscopy could provide a powerful remote sensing technique for generic life searches.
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Parnell J, Cullen D, Sims MR, Bowden S, Cockell CS, Court R, Ehrenfreund P, Gaubert F, Grant W, Parro V, Rohmer M, Sephton M, Stan-Lotter H, Steele A, Toporski J, Vago J. Searching for life on Mars: selection of molecular targets for ESA's aurora ExoMars mission. ASTROBIOLOGY 2007; 7:578-604. [PMID: 17723091 DOI: 10.1089/ast.2006.0110] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The European Space Agency's ExoMars mission will seek evidence of organic compounds of biological and non-biological origin at the martian surface. One of the instruments in the Pasteur payload may be a Life Marker Chip that utilizes an immunoassay approach to detect specific organic molecules or classes of molecules. Therefore, it is necessary to define and prioritize specific molecular targets for antibody development. Target compounds have been selected to represent meteoritic input, fossil organic matter, extant (living, recently dead) organic matter, and contamination. Once organic molecules are detected on Mars, further information is likely to derive from the detailed distribution of compounds rather than from single molecular identification. This will include concentration gradients beneath the surface and gradients from generic to specific compounds. The choice of biomarkers is informed by terrestrial biology but is wide ranging, and nonterrestrial biology may be evident from unexpected molecular distributions. One of the most important requirements is to sample where irradiation and oxidation are minimized, either by drilling or by using naturally excavated exposures. Analyzing regolith samples will allow for the search of both extant and fossil biomarkers, but sequential extraction would be required to optimize the analysis of each of these in turn.
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Affiliation(s)
- John Parnell
- Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, United Kingdom.
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Scott JH, O'Brien DM, Emerson D, Sun H, McDonald GD, Salgado A, Fogel ML. An examination of the carbon isotope effects associated with amino acid biosynthesis. ASTROBIOLOGY 2006; 6:867-80. [PMID: 17155886 DOI: 10.1089/ast.2006.6.867] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Stable carbon isotope ratios (delta(13)C) were determined for alanine, proline, phenylalanine, valine, leucine, isoleucine, aspartate (aspartic acid and asparagine), glutamate (glutamic acid and glutamine), lysine, serine, glycine, and threonine from metabolically diverse microorganisms. The microorganisms examined included fermenting bacteria, organotrophic, chemolithotrophic, phototrophic, methylotrophic, methanogenic, acetogenic, acetotrophic, and naturally occurring cryptoendolithic communities from the Dry Valleys of Antarctica. Here we demonstrated that reactions involved in amino acid biosynthesis can be used to distinguish amino acids formed by life from those formed by nonbiological processes. The unique patterns of delta(13)C imprinted by life on amino acids produced a biological bias. We also showed that, by applying discriminant function analysis to the delta(13)C value of a pool of amino acids formed by biological activity, it was possible to identify key aspects of intermediary carbon metabolism in the microbial world. In fact, microorganisms examined in this study could be placed within one of three metabolic groups: (1) heterotrophs that grow by oxidizing compounds containing three or more carbon-to-carbon bonds (fermenters and organotrophs), (2) autotrophs that grow by taking up carbon dioxide (chemolitotrophs and phototrophs), and (3) acetoclastic microbes that grow by assimilation of formaldehyde or acetate (methylotrophs, methanogens, acetogens, and acetotrophs). Furthermore, we demonstrated that cryptoendolithic communities from Antarctica grouped most closely with the autotrophs, which indicates that the dominant metabolic pathways in these communities are likely those utilized for CO(2 )fixation. We propose that this technique can be used to determine the dominant metabolic types in a community and reveal the overall flow of carbon in a complex ecosystem.
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Affiliation(s)
- James H Scott
- Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA.
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