5. Meteoroid Populations and Orbits

Abstract

Statistical studies of the photographic data on atmospheric trajectories and orbits of meteors (from 10-4 g to hundreds of tons) point to 5 groups of bodies with different structure and composition. The following classification is proposed: Fireball group I = exceptional cases of so-called “asteroidal” bodies among Super-Schmidt (SS) and small-camera (SC) meteors 5 ordinary chondrites. Fireball group II = group A among SS and SC = carbonaceous chondrites. Group B among SS and SC = dense cometary materials with small perihelion distances (not distinguishable among fireballs). Fireball group IIIa = group C among SS and SC = regular cometary material. Fireball group IIIB = group D (above C) of SS and SC = Draconid-shower type of cometary material. Statistics of the orbits for separate groups is considered and characteristic orbits are given.