Black teardrop ship over western part of centreville areaOne black teardrop-shaped ship approximately 20 feet in length. The nose finished in a slightly dulled point. Backswept wing-like extensions were fixed from the middle of the ship to a foot or so behind. It seemed to shimmer as it moved, exceedingly hard for the eye to follow. Unarmed, silent, no lights, no aircraft nearby (strangely enough), left no trail, no magnetic effects. However, the ship did leave a very slight mental signature almost like a ringing in the ears or a tone just below human hearing. It stayed for two minutes, then left in a rush. As it picked up speed the shimmering stopped(or perhaps intensified?). Either way, it disappeared.