Rectangular object traveling at a high rate of speed, south to north, dimly illuminated, visible for approx. 5 secondsBeing an amateur astronomer I try to be outside as much as possible during the summer months. On this star lit night I just happened to be looking straight up. This object was traveling at a high rate of speed in a south to north direction. It was dimly illuminated and emitted no sound. It happened so quickly I didn't have a chance to use my binoculars. Due to the size of the object I would guess its altitude would be approximately 4 to 5 thousand feet. My location is in the northeast corridor for commercial aircraft coming into Lambert International Airport in St. Louis. So I am familiar with aircraft. I am also located appromimately 10 miles north of Scott Air Force Base, IL.