由於離心率的緣故，土星的F環和其中一個牧羊犬衛星，普羅米修斯會在每個軌道周期相互接近。在普羅米修斯接近F環的過程中，會在F環盤面上產生出糾結且分段的構造，且由於重力散射，F環中的粒子也會撞擊到普羅米修斯的表面。我們利用限制性橢圓三體運動來研究F環的粒子受到普羅米修斯的影響的運動，來了解重力擾動與在洛希極限附近的質量損失(增加)。;Because of their eccentricities, the narrow F ring of Saturn and one of the shepherding moons, Prometheus, can intercept each other′s orbit. This process would lead to the formation of kinky and segmented structures along the F ring when Prometheus penetrate into the F ring. Besides gravitational scattering, collisional impact at the surface of Prometheus by the F ring particle could also occur. The numerical method in the elliptic restricted three-body problem is used to simulate the orbital motion of the F ring particles under the influence of Prometheus with a view to understand the related dynamical perturbation and mass loss (or accretion) effect in the vicinity of the Roche limit.
