A look at the role comets may have played in the origins and evolution of life, particularly in light of recent investigations of Halleys comet, new insights into organic synthesis in meteorites and comets, and new results of numerical simulations of cometary orbits and impacts on Earth. This is a comprehensive review of current research, accessible to graduate students and others new to the field. Each chapter was prepared by an expert in the field, and carefully revised by the editors for uniformity in style and presentation.

Since several decades, comets have been considered as key witnesses of solar system formation. Their nature has been explored using the modern arsenal of Earth- and space-based observations, and they hold a central place as dynamical arbiters of the planetary system in the new paradigm of solar system evolution known as the Nice Model. Thus, they have the potential to test the various ideas, using the detailed data recently gathered by the ESA/Rosetta mission. This requires an understanding of their origin and evolution, which form the subject of the present book. All the relevant issues are covered, describing both the background and the current frontiers of research.

Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.