LONG-TERM DYNAMICAL EVOLUTION OF THE BRIGHTEST BOLIDES

We have integrated backwards in time the orbits of 17 very bright boli des - including four associated with meteorite finds - over a time spa n of 1 Myr or more. The results show dynamical mechanisms and evolutio nary patterns fairly similar to those recently found for near-Earth as teroids, including frequent solar collisions, the widespread influence of secular resonances, some cases of comet-like hyperbolic ejections by Jupiter, and others of ''slow-track'' evolution driven by random en counters with the inner planets. This suggests that the sources for km -sized NEAs and metre-sized meteoroids are probably the same, and that the two types of bodies just sample different parts of the size distr ibution of a population of interplanetary objects with common dynamica l features. The results of our integrations appear also consistent wit h the idea that ordinary chondrites come from the inner part of the ma in asteroid belt.