The restricted areas northeast of 42J are firing ranges used for, well, whatever the military wants to lob downrange. If the UFO was within those bounds, that might be what you saw. But at Mach 5.5/4,000MSL, it'd have to be extremely heat resistant and pretty small to avoid busting every window in the county. A very good reason to steer clear of restricted areas!
Many many years ago a Cessna Caravan cargo plane disappeared one night near Mobile, AL. When the wreckage was eventually discovered, there was no obvious reason found for the crash but a large paint smudge was on the skin as if there had been a midair impact with... something.