Origin and Early Evolution of Comet Nuclei

Cover Page......Page 1
Title Page......Page 2
ISBN 0387775153......Page 3
Contents (with page links)......Page 4
Foreword......Page 6
Introduction......Page 10
Life as a Self-Sustaining System......Page 11
Life and the RNA World......Page 12
Complexity and the Nature of Life......Page 13
Conclusions......Page 14
References......Page 15
Introduction......Page 16
Terrestrial Planets and Giant Planets......Page 18
The Reflected Solar Spectrum......Page 20
The Thermal Spectrum......Page 21
The Reflected Spectrum......Page 23
The Thermal Spectrum......Page 24
Elemental and Isotopic Abundance Ratios......Page 25
The External Oxygen Source......Page 26
References......Page 27
Introduction......Page 30
Carbon in Carbonaceous Chondrites......Page 31
Amino Acids......Page 32
Nucleobases......Page 34
Sugar-Related Compounds......Page 35
Macromolecular Materials......Page 36
Implications for Future In Situ Analytical Instruments......Page 37
Urey......Page 38
References......Page 39
Introduction......Page 42
Titan, an Earth-like Planetary Body......Page 43
A Complex Organic Chemistry......Page 45
Conclusions......Page 50
References......Page 52
Introduction......Page 54
Mars, Europa, and Enceladus......Page 55
Life as Lego......Page 57
References......Page 59
Introduction......Page 60
Biogenicity of Ancient Stromatolites......Page 61
Stromatolite Morphology and Facies Association......Page 66
Columnar stromatolites......Page 68
Coniform stromatolites......Page 69
Domal stromatolitic bioherms with circular base and with laterally linked internal laminae, forming pseudo-columnar structures......Page 72
Elongated domal lithoherms, with columnar to laterally linked pseudo-columnar structure......Page 74
Stratiform stromatolites, of even, bed parallel internal laminae......Page 77
Conclusions......Page 78
References......Page 80
Introduction......Page 86
Chemical Signatures......Page 87
Microbial Growth Structures (Including Kerogen and Carbonate Deposits)......Page 88
What then Is Important for Our Alien Planet Exploration Team?......Page 90
Global Biogenic Structures and Processes......Page 96
References......Page 97
Introduction......Page 100
Morphological Biosignatures......Page 101
Identifying Morphological Biosignatures in Early Terrestrial Rocks......Page 102
Morphological Biosignatures from the Early-Mid Archaean......Page 104
The 3.430 Ga Strelley Pool Chert Stromatolites......Page 108
The 3.333 Ga-old Josefsdal Chert Microbial Mat......Page 111
The 3.446 Ga-old Kitty's Gap Chert......Page 112
Microbial corrosion on the rinds of 3.22-3.48 Ga-old pillow lavas from Barberton......Page 114
Conclusions and Perspectives for the Search for Martian Life......Page 115
References......Page 116
Darwin's Coral of Life......Page 120
Pedigrees and Species Trees......Page 122
Most Recent Common Ancestors in Gene and Species Trees......Page 123
Prokaryotic Evolution and the Trees of Life......Page 124
The Bacterial Radiation......Page 125
The Ribosomal RNA Based Tree of Life......Page 127
Ribosomal RNA and Horizontal Gene Transfer......Page 128
Approach #1: Surrogate Methods......Page 129
Approach #3: Phylogenetic Incongruence......Page 130
Types of Transferred Genes......Page 131
Horizontal Gene Transfer and Genetic Life Rafts......Page 132
Concluding Remarks......Page 133
References......Page 134
Abstract......Page 138
Introduction and Operating Principles......Page 139
Enantiomeric Excess......Page 141
Diastereoisomeric Preference......Page 142
Repeating Constitutional Sub-Units or Atomic Ratios......Page 143
Uneven Distribution Patterns or Clusters (e.g. C-Number, Concentration, delta13C) of Structurally Related Compounds......Page 146
Prebiotic Syntheses......Page 147
Organic Chemistry of Carbonaceous Meteorites......Page 148
Chirality of Amino Acids in the Murchison Meteorite......Page 150
Isotopic Compositions of C, H and N in Meteoritic Organic Matter......Page 151
Reduction Processes and the Preservation of Organic Matter......Page 153
Oxidation as a Secondary Alteration Process of Sedimentary Organic Matter......Page 154
Bulk Analysis of Oxidized Sedimentary Organic Matter......Page 155
Oxidation of Sedimentary Organic Matter: Simulation Experiments......Page 156
The Effects of Thermal Cracking and Ionising Radiation......Page 157
Chemical and Pyrolytic Degradation of Macromolecular Organic Matter......Page 158
Strategies to Strengthen Criteria Technologically......Page 159
References......Page 160
Introduction......Page 166
Lipid Membrane Formation and Functions......Page 167
Membrane Fluidity and Adaptations to Extreme Environments......Page 168
Lipid Taxonomic Specificity......Page 169
Modern Lipids as Analogues for Early Earth and Extraterrestrial Life......Page 171
Diagenesis......Page 172
Molecular Fossils as Records of Life......Page 173
Adulteration of Authentic Records......Page 174
Approaches to Establishing the Provenance of Molecular Fossils......Page 175
PCA Variables and Constraints......Page 176
PCA Results for Molecular Fossil Provenance......Page 177
Syngenicity Test......Page 180
Environmental and Ecological Signatures Revealed by PCA......Page 181
Geochemical Signatures......Page 183
Implications for Life-Detection on Early Earth and Elsewhere......Page 184
References......Page 185
Introduction......Page 192
Homochirality and Life......Page 193
Symmetry and Chirality......Page 196
Inversion Symmetry: Parity, Time Reversal and Charge Conjugation......Page 197
True and False Chirality......Page 198
Symmetry Violation......Page 199
Truly Chiral Influences......Page 201
Falsely Chiral Influences......Page 203
Key Remaining Questions......Page 204
References......Page 205
Introduction......Page 208
Notations......Page 209
Origin of the Semi-Classical Mass-Dependent Isotope Effect......Page 211
Post-Archean Terrestrial Sulphide and Sulphate......Page 213
Archean Sulphur MIF and the Early Earth's Atmosphere......Page 214
Hydrothermal Processes......Page 215
Biological Enzymatic Processes and Kinetic Complexity......Page 217
Atmospheric Processes and Mass-Independent Isotope Effects......Page 219
The Late Archean (2.7 to 2.5 Ga) Sulphur Isotope Records......Page 220
Microbial Sulphate Reduction at 3.47 Ga?......Page 221
Application to Search for Life on Mars......Page 222
References......Page 223
Introduction......Page 226
Assumption 1: Biologic Processes Cause Isotopic Fractionation......Page 228
Assumption 2: Abiologic Processes Do not Produce Significant Isotope Fractionation......Page 229
Assumption 3: Carbon Reservoirs Remained Constant Over Time......Page 231
Assumption 5: The Isotopic Signature Is Syngenetic and Indigenous......Page 232
Implications for Mars......Page 233
The Possible Use of Other Stable Isotopes as a Biomarker on Mars......Page 234
Conclusions......Page 235
References......Page 236
Gas-Exchange (GeX) Experiment......Page 238
Pyrolytic Release (PR) Experiment......Page 239
Labeled Release (LR) Experiment......Page 240
Gas Chromatography / Mass Spectrometer (GCMS) Experiment......Page 241
Lessons Learned from Viking Life-Detection Experiments......Page 242
Soil Chemistry......Page 244
Ecological Considerations......Page 245
Conclusions......Page 246
References......Page 247
Introduction......Page 250
Subsurface Filamentous Fabrics (SFF): A Fossil Record of Subsurface Biosphere(s)?......Page 251
Macroscopic characteristics of SFF:......Page 252
Microscopic characteristics of SFF:......Page 253
Detection of morphofossils, including SFF, on planetary missions......Page 254
3D textures in open space:......Page 255
Completely cemented 3D textures:......Page 256
References......Page 258
Introduction......Page 260
Overview of MSL Science Objectives......Page 261
The Search for Organics in the Atmosphere of Mars......Page 262
The Search for Organics in Solid Phase Martian Materials......Page 263
Distinguishing Sources of Martian Organics......Page 264
Methane on Mars......Page 265
Mars Science Laboratory Planned Capabilities......Page 266
Pyrolysis......Page 267
Solvent Extraction and Derivatization......Page 269
Mars Analog Studies......Page 270
References......Page 272
Abstract......Page 274
Introduction......Page 275
The Urey Instrument Experiments......Page 276
Organic Compound Detection and Characterization......Page 277
Establish Surface and Subsurface Oxidation Mechanisms and Rates......Page 278
Instrumentation Overview......Page 279
References......Page 283
Introduction......Page 286
Raman Scattering......Page 288
Instrument......Page 289
Laser System and Laser Wavelength......Page 292
Raman Optical Head and Rayleigh Filters......Page 293
Spectrometer and Detector (Spectral Sensor)......Page 294
References......Page 296
Abstract......Page 298
Introduction......Page 299
Preservation of Biomarker under Martian Conditions......Page 300
Antibodies......Page 303
Terrestrial Analogues for Biomarker and Antigen Selection for Life Detection......Page 305
Immunoassays with Antibody Microarrays......Page 307
Immunoassays with Organic Solvents......Page 310
Antibody Microarray-Based Instrumentation for in situ Analysis in Astrobiology......Page 311
Conclusion......Page 312
References......Page 314
Introduction......Page 318
The Evolution of the Milky Way Disk......Page 319
On the Probability of Having Stars with Earth-Like Planets......Page 320
On the Probability of Life Surviving Supernova Explosions......Page 322
A GHZ as Large as the Whole Galaxy?......Page 325
References......Page 327
Introduction......Page 328
Basics on Earthshine Spectroscopy and Vegetation Red Edge Signal......Page 331
Review of Results......Page 332
What Did We Learn from ES Observations?......Page 333
Implications for Life Detection on Extrasolar Planets: Perspective and Open Questions......Page 335
References......Page 337
Introduction to Habstars......Page 340
Description of a Habstar......Page 341
Uncertainties Abound......Page 342
Target Selection for TPF-C......Page 343
Spectral Characterization of Exo-Earths......Page 346
References......Page 347
Introduction......Page 350
Densities of Transiting Exoplanets......Page 351
Secondary Eclipse Photometry and Spectroscopy......Page 352
Transit Transmission Spectroscopy......Page 354
Atmosphere Phase Curves......Page 355
Model Atmospheres......Page 356
References......Page 358
Introduction......Page 360
Formulation of the Problem and High Level Scientific Requirements......Page 362
Comparative Planetology......Page 363
Methods and the Need to Go to Space......Page 364
MOST-The First Step......Page 367
CoRoT-The First True Exo-Planetary Mission......Page 368
The Role of Herschel in the Search for Other Earth's......Page 369
SIM-Planet Quest......Page 370
Darwin and the Terrestrial Planet Finder(s)-Other Worlds with Life as We Know It......Page 371
Further Future-Mission Accomplished?......Page 373
References......Page 374
"Strategies of Life Detection'': Summary and Outlook......Page 376
The Search for Organic Compounds on Mars......Page 377
Exploration of the Outer Solar System......Page 378
Molecular and Isotopic Biosignatures......Page 379
Morphologic Biosignatures......Page 381
In-situ Instrumentation......Page 383
References......Page 384
Space Science Series of ISSI......Page 386