The object appeared to be a dimmly illuminated flying wing approximately diamond shaped with squared off wing tips.The object appeared to be a flying wing approximately diamond shaped with squared off wing tips. The relative size spanned the field of view of my thumb held at arms length (wingtip span same as length of thumb, forward to aft span same as width of thumb). The object brightness was approximately the same as average brightness of Pleiades. The dimness of the object prevented me from focusing on it to observe any detail. The sky was dark with closest street lights more than 100 yards away. There was no interfering noise such as traffic or aircraft. It was dead quiet as the object passed directly overhead from East-South-East to West-North-West. The object traversed a straight line at uniform speed and dissappeared out of sight 10 degrees above the horizon within 10 to 15 seconds from the time I first spotted it. I observed the object through approximately 100 angular degrees of the sky. The object moved into my field of view as I was observing Pleiades and thinking to myself about how clear the sky was and how well my vision was working that evening. I would not have noticed it otherwise. At first I thought it was a satellite but it was moving too fast and was too large. I was walking with my wife and when I said "Look at that!" she caught view of it immediately. All her impressions of the object agreed with mine. I cannot say what the alitiude of the object was but if it was at relatively low altitude (1000's of feet) then it was moving fast enough to break the sound barrier and if it was at satellite altitude then it would have to have been several miles wide.((NUFORC Note: Witness is a college-trained professional in a technical field. We suspect that, because of his field, he probably is a very competent observer. PD))