Charge exchange collisions between the ions trapped in a planetary magnetosphere and the ambient neutrals are a principal material loss process in evolving planetary systems (Johnson, 2004). Here we show that low energy charge exchange collisions, in which orbiting occurs, can drastically modify the redistribution and loss of materials in evolving planetary disks. Using Saturn as an example, these collisions can account for the fact that water products, produced primarily in the inner magnetosphere, are found to be the dominant ions throughout Saturn's magnetosphere.