HOWARD, DULLIN and HORANYI, 2000. Stablility of halo orbits. Physical Review Letters, 84(15), pp. 3244–3247
We predict new populations of trapped nonequatorial (“halo”) orbits of charged dust grains about an arbitrary axisymmetric planet. Simple equilibrium and stability conditions are derived, revealing dramatic differences between positively and negatively charged grains in prograde or retrograde orbits. Implications for the Cassini mission to Saturn are discussed.