Dust capture by the Saturnian magnetosphere

We examine the capture of interplanetary dust particles by Saturn using a simple two-dimensional code. The incoming grain's energy may be lost to the magnetosphere due to the grain's finite charging time as it passes through the magnetospheric plasma. We observe a preference for retrograde captures, with an approximately 2 : 1 ratio of retrograde to prograde captures. The computer simulations show that this asymmetry is due to the larger range of values of the Jacobi constant for retrograde orbits.