Astrobiology

I Organic Material in Space and Habitable Zones.- 1 From Molecular Clouds to the Origin of Life.- 1.1 The Search for Large Organic Molecules in Dense Clouds.- 1.1.1 The Search for Amino Acids in the Interstellar Medium.- 1.1.2 Organic Molecules in our Galactic Center.- 1.2 Molecules in Protoplanetary Disks.- 1.3 Diffuse Interstellar Clouds.- 1.4 The Evolution of Organic Molecules During Solar System Formation.- 1.4.1 Comets.- 1.4.2 Meteorites.- 1.5 Implications for the Origin of Life on Earth.- 1.6 Conclusions.- 1.7 References.- 2 The Diversity of Extrasolar Planets Around Solar-Type Stars.- 2.1 Detections: Milestones and Recent Announcements.- 2.2 Very Recent ELODIE and CORALIE Detections.- 2.3 Observed Properties of Extrasolar Planets.- 2.4 Hot Jupiters.- 2.4.1 Hot Jupiters: Direct Detections.- 2.5 The Mass Function of Substellar Companions.- 2.6 Orbital Element Distributions: Traces of Planet Formation.- 2.6.1 The Distribution of Periods.- 2.6.2 The Distribution of Eccentricities.- 2.7 Metal Enrichment of Stars Bearing Planets.- 2.8 Summary and Future Perspectives.- 2.9 References.- 3 Habitable Zones in Extrasolar Planetary Systems.- 3.1 Models for Calculating the HZ in the Solar System.- 3.2 HZ Around Other Main Sequence Stars.- 3.3 Conclusions.- 3.4 References.- 4 Viable Transfer of Microorganisms in the Solar System and Beyond.- 4.1 Scenario of Interplanetary Transfer of Life Within the Solar System.- 4.2 Survival of the Escape Process.- 4.3 Survival of the Interplanetary Transfer Phase.- 4.3.1 Space Environment of Interest.- 4.3.2 Approaches to Studying the Biological Effects ofSpace.- 4.3.3 Biological Effects of the Vacuum of Space.- 4.3.4 Biological Effects of Galactic Cosmic Radiation.- 4.3.5 Biological Effects of Extraterrestrial Solar UV Radiation.- 4.3.6 Bacterial Survival During Long-Term Dormancy.- 4.3.7 Combined Effects of the Complex Matrix of Space Parameters.- 4.4 Survival of the Landing Process.- 4.5 Conclusions: On the Likelihood of Interplanetary Transfer of Life as a Mode of Distribution of Life Throughout the Solar System.- 4.6 Outlook: On the Likelihood of Transport of Viable Microorganisms Between Solar Systems.- 4.7 References.- II Water and Life.- 5 Water, the Spring of Life.- 5.1 Water as a Diffusion Milieu.- 5.2 Water as a Selective Solvent.- 5.3 Water as a Clay Producer.- 5.4 Water Structures the Biopolymers.- 5.5 Water as a Driving Power for Chemistry.- 5.6 Water as a Heat Dissipator.- 5.7 Life Without Water: The Case for Titan.- 5.8 Conclusion.- 5.9 References.- 6 Geomorphological Record of Water-Related Erosion on Mars.- 6.1 Outflow Channels.- 6.2 Valley Networks.- 6.3 Periglacial and Permafrost Landforms.- 6.3.1 Debris Flow and Terrain Softening.- 6.3.2 Ground Ice.- 6.3.3 Rampart Craters.- 6.3.4 Polygons.- 6.3.5 Thermokarst.- 6.4 Glacial Landforms.- 6.4.1 Eskers and Moraines.- 6.5 Volcano Ice Interactions.- 6.6 Chronology of Martian Erosional Processes.- 6.7 Standing Water.- 6.8 Origin of Martian Surface Erosion and Implications for the Palaeoclimate.- 6.9 References.- 7 Europa's Crust and Ocean: How Tides Create a Potentially Habitable Physical Setting.- 7.1 Tidally Driven Geology and Geophysics.- 7.1.1 Tidal Heating.- 7.1.2 Tidally Driven Rotation.- 7.1.3 Tidal Stress on the Ice Crust.- 7.1.4 Chaotic Terrain.- 7.2 A Habitable Setting.- 7.3 References.- 8 Permafrost Model of Extraterrestrial Habitat.- 8.1 The Importance of Permafrost.- 8.2 Parameters of Permafrost Microbial Habitat.- 8.2.1 Temperature.- 8.2.2 Iciness and Unfrozen Water.- 8.2.3 Ice and Permafrost as a Habitat.- 8.2.4 Gases and Supercooled Water.- 8.2.5 Age and Radiation.- 8.3 Biodiversity in Permafrost.- 8.4 How Long the Life Might Be Preserved.- 8.5 The Perspectives for Future Studies.- 8.6 References.- 9 Microbial Life in Terrestrial Permafrost: Methanogenesis and Nitrification in Gelisols as Potentials for Exobiological Processes.- 9.1 Permafrost Soils and Active Layer.- 9.2 Microbial Life under Extreme Conditions.- 9.3 Microbial Key Processes.- 9.3.1 Methanogenesis.- 9.3.2 Nitrification.- 9.4 Methods for Analogue Studies of Microbial Processes in Terrestrial and Extraterrestrial Habitats.- 9.4.1 Methanogenic and Nitrifying Populations.- 9.4.2 In situ Activity.- 9.4.3 Isotopic Analysis: Carbon Fractionation via Microbial Processes in Permafrost.- 9.4.4 Simulation Experiments.- 9.5 Conclusion and Future Perspectives.- 9.6 References.- 10 Life in Cold Lakes.- 10.1 Source of Samples and DNA Analyses.- 10.2 The Rich Diversity of Bacteria and Archaea.- I 0.3 Conclusions.- 10.4 References.- 11 Hyperthermophilic Microorganisms.- 11.1 Biotopes of Hyperthermophiles.- 11.1.1 Terrestrial Biotopes.- 11.1.2 Marine Biotopes.- 11.2 Phylogeny of Hyperthermophiles.- 11.3 Taxonomy of Hyperthermophiles.- 11.4 Strategies of Life and Environmental Adaptations of Hyperthermophiles.- 11.4.1 General Metabolic Potentialities.- 11.4.2 Physiological Properties.- 11.5 Conclusions: Hyperthermophiles in the History of Life.- 11.6 References.- 12 Halophilic Microorganisms.- 12.1 Adaptation to Saline Environments.- 12.1.1 Salt-in-Cytoplasm Mechanism.- 12.1.2 Organic Osmolyte Mechanism.- 12.2 Saline Terrestrial Environments and Their Inhabitants.- 12.2.1 Distribution and Dating of Ancient Salt Sediments.- 12.2.2 Subterranean Halophilic Microorganisms and Their Relation to Surface Halophiles.- 12.2.3 Uncultivated Phylotypes.- 12.2.4 Distribution, Origin and Dispersal of Haloarchaea.- 12.2.5 Long-Term Survival.- 12.3 Relevance to Astrobiology.- 12.4 References.- III Electromagnetic Fields, Radiation and Life.- 13 Martian Atmospheric Evolution: Implications of an Ancient Intrinsic Magnetic Field.- 13.1 Nonthermal Atmospheric Escape Processes.- 13.1.1 Charge Exchange and Dissociative Recombination.- 13.1.2 Atmospheric Sputtering.- 13.1.3 Solar-Wind Interaction Processes.- 13.1.4 Ionospheric Bubbles.- 13.2 The Early Dense Martian Atmosphere.- 13.2.1 The Quest for Water.- 13.3 The Intrinsic Martian Magnetic Field.- 13.3.1 The Ancient Martian Magnetosphere: Constraints for Atmospheric Escape.- 13.4 Shielding of Hypothetical Primitive Martian Life Forms from Energetic Cosmic Particles and Radiation.- 13.4.1 Cosmic Ray Particle Fluxes on the Surface of Ancient Mars.- 13.5 Conclusions.- 13.6 References.- 14 The Ultraviolet Radiation Environment of Earth and Mars: Past and Present.- 14.1 UV Radiation on Early Earth.- 14.1.1 UV Radiation During the Archean.- 14.1.2 Biological Effects of High UV Radiation Flux.- 14.1.3 Beneficial Effects of High UV Radiation on Archean Earth?.- 14.2 The Ultraviolet History of Mars and Venus: An Exercise in Comparative Evolutionary Photobiology.- 14.3 Conclusions.- 14.4 References.- 15 Ultraviolet Radiation in Planetary Atmospheres and Biological Implications.- 15.1 Solar UV Radiation.- 15.2 Biological Effects of Solar UV Radiation.- 15.3 Biological UV Dosimetry.- 15.4 Experimental Determination of the Biological Effectiveness of Extraterrestrial Solar UV Radiation.- 15.5 Experimental Determination of the Photobiological Effects of Different Ozone Concentrations.- 15.6 Conclusions.- 15.7 References.- 16 Environmental UV Radiation: Biological Strategies for Protection and Avoidance.- 16.1 Effects of UVR and Responses in Terrestrial Ecosystems.- 16.2 Techniques for Studying Microbes and Pigments in situ.- 16.2.1 Epifluorescence Microscopy.- 16.2.2 Raman Spectroscopy of Pigments and Other Compounds in situ.- 16.3 Screening Strategies.- 16.4 Quenching Strategies.- 16.5 Escape and A voidance Strategies (Shade Adaptation).- 16.5.1 Epilithic Lichens.- 16.5.2 Endolithic Communities.- 16.5.3 Stromatolites.- 16.6 Strategies for Extreme UV on Early Earth and Mars.- 16.7 Panspermia and UV Avoidance.- 16.8 Diagnosis of Key Pigments on Earth and Mars.- 16.9 References.- 17 Life under Conditions of Ionizing Radiation.- 17.1 Space Radiation Environments.- 17.1.1 Galactic Cosmic Radiation (GCR).- 17.1.2 Solar Particle Radiation (SPR).- 17.1.3 Radiation Belts in Planetary Magnetic Fields.- 17.1.4 Modulation by Planetary Magnetic Fields, Atmospheres and Surfaces.- 17.2 Radiation Environments on Planets and Other Celestial Bodies.- 17.2.1 Earth.- 17.2.2 Mars.- 17.2.3 Jupiter's Moon Europa.- 17.3 Measures of Ionizing Radiation.- 17.3.1 Physical Measures.- 17.3.2 Biologically Weighted Measures.- 17.4 Interaction of Radiation with Biological Material.- 17.4.1 Radiation Chemistry of Water.- 17.4.2 DNA Damage and Cellular Repair Pathways.- 17.5 Cellular Radiation Responses.- 17.5.1 Radiation Sensitivity of Organisms.- 17.5.2 Mutation Induction.- 17.5.3 Factors Influencing Cellular Radiation Effects.- 17.6 The Chances of Life Surviving Space Radiation Conditions.- 17.6.1 Interplanetary Transfer of Life.- 17.6.2 Putative Habitats on Other Planets.- 17. 7 References.- IV Gravity and Life.- 18 Graviperception and Graviresponse at the Cellular Level.- 18.1 Protists.- 18.1.1 Perception of Varied Acceleration.- 18.1.2 Models of Graviperception.- 18.1.3 Energy Considerations.- 18.104 Gravisensory Channels.- 18.2 Mammalian Cells.- 18.2.1 Gravity Effects and Consequences.- 18.3 Conclusions.- 18.4 References.- 19 Gravistimulated Effects in Plants.- 19.1 Graviperception as the Primary Gravity-Sensing Mechanism.- 19.1.1 Graviperception in Unicellular Plants.- 19.1.2 Graviperception in Multicellular Plants.- 19.2 The Gravity Signal Transduction Pathway.- 19.3 The Graviresponse: The Curvature of Organs.- 19.3.1 Graviresponses in Unicellular Plants or Plant Systems.- 19.3.2 Graviresponses in Multicellular Plants.- 19.4 References.- 20 Gravitational Zoology: How Animals Use and Cope with Gravity.- 20.1 Gravity as a Factor of Physical Restriction: A Brief History of Evolutionary Challenges To Surmount It.- 20.2 Gravity as a Cue for Orientation and Postural Control.- 20.2.1 Graviperception in Unicellular Animals.- 20.2.2 Graviperception in Multicellular Animals.- 20.3 Behavior and Differentiation of Animals at Altered Gravity.- 20.3.1 Invertebrates.- 20.3.2 Vertebrates.- 20.4 Conclusion.- 20.5 References.- V Complexity and Life.- 21 Scaling Phenomena and the Emergence of Complexity in Astrobiology.- 21.1 Astrobiology as the Realm of Emergence, Hierarchies and Scaling.- 21.2 Implications of Power Law Behavior.- 21.3 Exponents and Their Meaning.- 21.4 Where and How Have Power Laws Been Used?.- 21.5 Examples of Power Laws: From Cosmology to Biology.- 21.5.1 Examples from Cosmology and Astrophysics.- 21.5.2 Examples from Planetology.- 21.5.3 Examples from Biochemistry.- 21.5.4 Examples from Biology.- 21.6 Conclusions.- 21.7 References.- 22 Molecular Self-Assembly and the Origin of Life.- 22.1 Key Questions for the Emergence of Life.- 22.2 Directed Molecular Self-Assembly.- 22.3 Direct Microscopic Verification of Self-Assembled DNA Bases on Mineral Template Surfaces.- 22.4 Genetically Based Supramolecular Architectures from Self-Assembled DNA Bases Coding for Amino Acids.- 22.5 Conclusion.- 22.6 References.- 23 Search for Morphological and Biogeochemical Vestiges of Fossil Life in Extraterrestrial Settings: Utility of Terrestrial Evidence.- 23.1 Paleontological Evidence.- 23.1.1 Microbialites.- 23.1.2 Cellular Microfossils.- 23.2 Biogeochemical Evidence.- 23.2.1 Sedimentary Organic Carbon as a Recorder of Former Life Processes.- 23.2.2 13C/12C in Sedimentary Organic Matter: Index of Autotrophic Carbon Fixation.- 23.3 Conclusions and Outlook.- 23.4 References.- VI Forthcoming Space Missions Relevant for Astrobiology.- 24 Space Activities in Exo-Astrobiology.- 24.1 Astrobiological Potential of Space Astronomy Missions.- 24.l.l Infrared Spectroscopy of Cosmic Dust and Organics.- 24.1.2 The New Generation Space Telescope (NGST).- 24.1.3 Exoplanets from Space: GAIA, COROT, EDDINGTON, KEPLER and DARWIN.- 24.1.4 Global Life Signatures on Earth?.- 24.2 Astrobiological Potential of Planetary Missions.- 24.2.1 CASSINI-HUYGENS.- 24.2.2 STARDUST.- 24.2.3 ROSETTA.- 24.2.4 MARS-EXPRESS and Future Mars Missions.- 24.2.5 Europa Missions.- 24.2.6 Moon, Mercury, Formation of Planets and the Early Frustration of Life.- 24.2.7 Space Exposure Experiments.- 24.3 Conclusion: Roadmap for Astrobiology and Long-Term Space Exploration.- 24.3.1 Experimenting for Life in the Universe.- 24.3.2 Expanding Life in the Solar System.- List of Contributors.