ON THE DEFINITION OF THE TERM METEOROID

It is argued that the term 'meteoroid' is best defined as being applic able to any natural solid object moving in space, and having a size be tween 100 mu m and Iom (10(-4)-10(1) m). This definition reflects mode rn-day instrumentation limitations and recognizes the physical constra ints that dictate the production of a meteor in the Earth's atmosphere . Our argument also has implications for the definitions of the terms 'asteroid' (synonym 'minor planet'), 'micrometeorite', and 'interplane tary dust.'