Many times all of us could hear from mass media that an asteroid approached and swept past the Earth. Such an asteroid or comet will inevitably strike the planet some day. This volume considers hazards due to collisions with cosmic objects, particularly in light of recent investigations of impacts by the authors. Each chapter written by an expert contains an overview of an aspect and new findings in the field. The main hazardous effects cratering, shock, aerial and seismic waves, fires, ejection of dust and soot, tsunami are described and numerically estimated. Numerical simulations of...