Possibly, but the solar wind ought to have even more of an affect on an atmosphere. A moon within its parent's magnetosphere would be protected from the worst of the solar wind, but counter-intuitively, Titan is only sometimes within Saturn's magnetosphere.<br /><br />Of course, another possibility for Titan's atmosphere is that it may be continuously replenished from within, but I'm not sure how; it's pretty dense.<br /><br />BTW, Ganymede does have a very thin atmosphere (probably roughly comparable to that of our moon, which is so thin it can easily be considered a vacuum; it's considerably thinner than the Earth's atmosphere at the ISS's altitude!), which may be produced by the continual bombardment of the moon by the solar wind. It is constantly being lost, however. Io has a more significant atmosphere, constantly replenished by Io's volcanoes, but it, too, is continually being lost to space. Io's constantly shedding atmosphere is trapped into the Io torus around Jupiter, and may actually be responsible for renewing at least some of the material in Jupiter's faint ring system. Europa also has an incredibly thin atmosphere. These atmospheres are quite unlike that of Titan, however. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>