  In this paper, we present preliminary results on the stability of massless
particles in two and three-planet systems. The results of our study may be used
to address questions concerning the stability of terrestrial planets in these
systems and also the trapping of particles in resonances with the planets. The
possibility of the existence of islands of stability and/or instability at
different regions in multi-body systems and their probable correspondence to
certain resonances are also discussed.
