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Comets And The Origin Of Life.

The idea that comets may be connected with the origin of life on Earth was considered heresy a few decades ago, with scientists shying away from this possibility as if from a medieval superstition. However the case that comets may have contributed at least the complex organic building blocks of life...

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Detalles Bibliográficos
Clasificación:Libro Electrónico
Formato: Electrónico eBook
Idioma:Inglés
Publicado: World Scientific 2009.
Temas:
Acceso en línea:Texto completo
Tabla de Contenidos:
  • Cover13;
  • Contents
  • Preface
  • 1. Overview
  • 1.1 Introduction
  • 1.2 Cometary Panspermia
  • 1.3 History of Panspermia
  • 1.4 The Ultraviolet Problem
  • 1.5 Resilience of Bacteria
  • 1.6 Extremophiles
  • 1.7 The Discovery of Organics in Cosmic Dust
  • 1.8 Comets
  • 1.9 The Origin of Life
  • 1.10 Modern Advances
  • 1.11 Protoplanetary Nebulae and Extra-solar Planetary Systems
  • 1.12 Habitable Zone
  • 2. Cosmic Dust and Life
  • 2.1 Introduction
  • 2.2 Constraints on Composition
  • 2.3 Extinction by Spherical Particles
  • 2.4 The Interstellar Extinction and Bacterial Dust
  • 2.5 Infrared Evidence
  • 2.6 Comet Dust and Biomaterial
  • 2.7 The Identification of PAH and Biological Aromatics
  • 2.8 Other Spectral Features
  • 2.9 Fluorescence
  • 2.10 The Origin of Organic Molecules in Space
  • 2.11 Direct Analysis of Comet Dust
  • 2.12 Capture of Comet Dust in the Stratosphere
  • 3. The Origin of Comets
  • 3.1 The Galactic Disc
  • 3.2 The Formation of Stars
  • 3.3 Planet Formation
  • 3.4 The Formation of Comets
  • 3.4.1 The structure of the comet population
  • 3.4.2 Comet chemistry
  • 3.4.3 Cometary origin inferred
  • 3.4.4 Other ideas about comet origins
  • 4. Comets in the Galactic Environment
  • 4.1 The Mechanism of Lithopanspermia
  • 4.1.1 Transferring boulders between planetary systems
  • 4.1.2 Erosion of ejected boulders
  • 4.2 The Formation Sites of Comets
  • 4.2.1 Origin in the planetary region
  • 4.2.2 Origin in molecular clouds
  • 4.2.3 Exocomets
  • 4.3 The Suns Orbit in the Galaxy
  • 4.3.1 The effect of the vertical Galactic tide
  • 4.3.2 Flux modulation due to the Suns vertical motion
  • 4.3.3 Perturbations by molecular clouds
  • 4.3.4 The effect on Oort cloud comets
  • 4.4 The Impact Cratering Record
  • 4.4.1 Impact melts in large craters
  • 4.4.2 Galactic periodicity
  • 5. Dark Comets: A Link to Panspermia
  • 5.1 A Mass Balance Problem
  • 5.1.1 Disintegration to dust
  • 5.1.2 Dark comets
  • 5.1.3 Super-dark comets
  • 5.2 The Impact Hazard and the Panspermia Connection
  • 6. Expulsion of Microbes from the Solar System
  • 6.1 Introduction
  • 6.2 Expectations from Impact Cratering Mechanisms
  • 6.3 Mechanisms for Ejection and Fragmentation of Boulders
  • 6.4 946;-Meteoroids
  • 6.5 Protective Shielding in Small 946;-Meteoroids
  • 6.6 Carbonisation of the Surface Layers of Grains
  • 6.7 Radiation Pressure Effects
  • 6.7.1 Ratio of radiation pressure to gravity
  • 6.7.2 Results and dynamical considerations
  • 6.8 Surviving the Hazards of Galactic Cosmic Rays
  • 6.9 How Comets Distribute Life
  • 6.10 Dispersal of Life by Impacts
  • 7. Liquid Water in Comets
  • 7.1 Introduction
  • 7.2 Primordial Melting
  • 7.3 Evidence of Present-day Melting
  • 7.4 Results from Deep Impact
  • 7.5 Frozen Lake Surfaces
  • 7.6 Microbial Fossils in Carbonaceous Meteorites
  • 8. Origin of Life
  • 8.1 Preamble183
  • 8.2 Cometary Interiors as Incubators of Early Life
  • 8.3 Comparison with a Terrestrial Origin of Life
  • 9. Expanding Horizons of Life
  • Bibliography
  • Index.