Investigation of the interplanetary dust cloud is characterized by contributions from quite different methods and fields, such as research on zodiacal light, meteors, micrometeoroids, asteroids, and comets. Since the earth's environment and interplanetary space became accessible to space vehicles these interrelations are clearly evident and extremely useful. Space measurements by micrometeoroid detectors, for example, provide individual and eventually detailed information on impact events, which however are limited in number and therefore restricted in statistical significance. On the other...