The strands of the F ring disturbed by its closest satellites

Some Voyager images show that the F ring of Saturn is composed of at least four separate, non-intersecting, strands covering about 45 degrees in longitude. According to Murray et al. (Icarus, 129, 1997) this structure is caused by perturbations due to undetected satellites. These strands have nearly aligned pericenters that may precess due to the oblateness of the planet Saturn. Due to the precession the satellites Prometheus and Pandora and the ring particles can experience periodic close encounters. Giuliatti Winter et al. (Planetary and Space Science, 48, 1999) analysed the behavior of these four strands at closest approach with the satellite Prometheus. Their work suggests that Prometheus can induce the ring particles to scatter in the direction of the planet, thus increasing the population of small bodies in this region. Recent work has shown that Prometheus and Pandora at their closest approach can change their position. In this work has been analysed the effects of both satellites in the strands. Each strand can also have a particle of about 3 to 5 km radius in size. Our results show that Pandora, depending on the initial conditions, suffers a considerable perturbation of Prometheus. This effect changes the behavior of the exterior strands.