Well, there are two problems. First of all, Pluto is actually in a very stable orbit. It's not circular, but it's stable, so nothing's messing around with it very much. It's possibly something messed with it sometime in the very distant past, but it's stable now.<br /><br />The second problem is that the black hole at the center of the Milky Way is very very distant. Gravitational attraction decreases proportionally to the inverse square of the distance (the "inverse square rule"), and we're far enough away that it really has no measurable effect on Pluto's orbit. <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>