SOME ASPECTS OF PARTICLES DYNAMICS

Some features of the dynamics of particles affected by drag, in the field of the Sun and planets, are presented here. In particular mean motion and secular resonances are investigated. When dust particles are considered as a whole in the zodiacal cloud, a simple secular theory can explain much of its geometry. Dynamics of particles near an inner planet is mostly dispersive, but an average behavior can be deduced from some analytical and numerical considerations.