A huge amount of extraterrestrial matter enters the Earth's atmosphere every year and eventually settles on the ground. The two main sources of this matter are cosmic dust and meteoroid streams. Meteorites form only a very small fraction of the total mass that is captured by the Earth's atmosphere. Most of the matter is in the form of very fine dust particles. Because of the temperatures reached during entry, a large proportion of these particles evaporate at high altitudes, giving rise to radar signatures, and to the visual phenomenon of shooting stars. This book integrates astronomical observations and theories with geophysical studies, presenting a comprehensive overview of the extraterrestrial matter that falls to Earth from space. Meteoroids are the main topic of the book, although cosmic dust, interplanetary matter and meteorites are also discussed. This work will be of great value to researchers involved in the study of meteor phenomena.