The last decade of this century has seen a renewed interest in the dynamics and physics of the small bodies of the Solar System, Asteroids, Comets and Meteors. New observational evidences such as the discovery of the Edgeworth-Kuiper belt, refined numerical tools such as the symplectic integrators, analytical tools such as semi-numerical perturbation algorithms and in general a better understanding of the dynamics of Hamiltonian systems, all these factors have converged to make possible and worthwhile the study, over very long time spans, of these "minor" objects. Also the public, the media and even some political assell}blies have become aware that these "minor" objects of our planetary environnement could become deadly weapons. Apparently they did have a role in Earth history and a role more ominous than "predicting" defeat (or victory, why not?) to batches of credulous rulers. Remembering what may have happened to the dinosaurs but keeping all the discretion necessary to avoid creating irrational scares, it may not be unwise or irrelevant to improve our knowledge of the physics and dynamics of these objects and to study in particular their interactions with our planet.

Every year Earth is bombarded with about 40,000 tons of extraterrestrial material. This includes microscopic cosmic dust particles shed by comets and asteroids in outer space, meteorites, as well as large comets and asteroids that have led to catastrophic events in the geologic past. Originally considered only a curiosity, extraterrestrial matter found on Earth provides the only samples we have from comets, asteroids and other planets. Only recently mankind has started to actively collect extraterrestrial matter in space (Apollo program, Stardust mission) rather than to wait for its delivery to Earth. Still, most of our knowledge of the origin and evolution of our solar system is based on careful studies of meteorites, cosmic dust, and traces of large impact events in the geologic record such as the mass extinction that terminated the Cretaceous Period and led to the extinction of the dinosaurs. This book summarizes our current knowledge of the properties, origin, orbital evolution and accretion mechanism of extraterrestrial matter accreted on Earth and sheds light on accretion processes and fluxes in the geologic past. The chapters in the first part of the book are arranged in order to follow extraterrestrial matter from its origin in space, its orbital evolution on its way to Earth, its interaction with the Earth magnetosphere and atmosphere to its more or less violent collision with the Earth's surface. In the second part of the book several chapters deal with the present?day flux of cosmic dust and meteorites to Earth. Finally, several chapters deal with the reconstruction of the accretion history of extraterrestrial matter on Earth, starting with the most recent geologic past and ending with the very early, violent accretion period shortly after the formation of Earth, Moon and other solid planets in our solar system.

With the bulk of asteroids floating in space between the orbits of Mars and Jupiter, astronomers puzzle over where these rocks came from. Are they the remnants of a planet? Excess not used in the formation of the Solar System? Nothing more than random bits of debris? The location of the belt makes for a quasi-barrier separating the inner from the outer planets. Perhaps asteroids were meant to discourage human space exploration. NASA has sent missions to explore the asteroid belt and the rocks themselves, and those missions have yielded some interesting observations on the composition of the asteroids but no definitive answer as to their origin. Earth-based tools such as telescopes and satellites also contribute to asteroid research but cannot plumb the depths behind these varied chunks of flotsam. Presented in this book is a list of carefully chosen abstracts and citations of relevant literature about asteroids and the research into them. Prior to this listing, though, comes an overview of the nature of the asteroids and what we know now about them and what we hope to discover in the future. lifeless but mysterious rocks inhabiting the solar system. To conclude, easy access is provided through author, title, and subject indexes.

This unique and encyclopedic reference work describes the evolution of the physics of modern shock wave and detonation from the earlier and classical percussion. The history of this complex process is first reviewed in a general survey. Subsequently, the subject is treated in more detail and the book is richly illustrated in the form of a picture gallery. This book is ideal for everyone professionally interested in shock wave phenomena.

Minor bodies in the Solar System, though representing only a small fraction of the mass in the Solar System, may well play a fundamental role in terrestrial evolution. This book contains investigations of the dynamics and physics of comets, asteroids and meteor streams, and the rather controversial topic of periodic phenomena in the Solar System as signified by geological records, together with several associated developments in celestial dynamics. All these problems are interwoven. This book makes a contribution towards unravelling the nature of the interactions between the Earth and its celestial environment.

In 1993, the U.S. Department of Defense declassified information dealing with frequent explosions in the upper atmosphere caused by meteoric impact. It is estimated that impacts have occurred of a magnitude equivalent to the atomic bomb detonated at Hiroshima. Not all such space voyagers meet their end in the atmosphere, however; huge craters attest to the bombardment of earth over millions of years, and a major impact may have resulted in the extinction of dinosaurs. An impact in Siberia near the beginning of this century proves that such events are not confined to geologic time. Hazards Due to Comets and Asteroids marks a significant step in the attempt to come to grips with the threats posed by such phenomena. It brings together more than one hundred scientists from around the world, who draw on observational and theoretical research to focus on the technical problems related to all aspects of dealing with these hazards: searching for and identifying hazardous comets and asteroids; describing their statistics and characteristics; intercepting and altering the orbits of dangerous objects; and applying existent technologies—rocket boosters, rendezvous and soft-landing techniques, instrumentation—to such missions. The book considers defensive options for diverting or disrupting an approaching body, including solar sails, kinetic-energy impacts, nuclear explosives, robotic mass drivers, and various propulsion systems. A cataclysmic impact posing a threat to life on Earth is a possibility that tomorrow's technology is capable of averting. This book examines in depth the reality of the threat and proposes practical measures that can be initiated now should we ever need to deal with it.