4. Flares
Military aircraft often drop flares while conducting night training operations (or, in combat areas, as a means of diverting heat-seeking anti-aircraft missiles). These flares, unlike the tiny ones used to mark highway obstacles or for emergency use, are quite large and will burn brightly for up to a half an hour at a time and, when suspended from parachutes, can remain airborne for some time. As such, if dropped in a cluster, they can take on a beaded necklace effect that gives them the impression of either aircraft hovering in formation or, if close enough together, can even appear to be a string of running lights or “portholes”. To a public generally unfamiliar with such ordnance and its characteristics, the effect can be spectacular and even frightening, making flares an especially good candidate to be mistaken for a UFO. This, in fact, may be the explanation behind the mysterious lights that were seen hanging over Phoenix, Arizona in 1997 (which does, in fact, lie near a military training ground where evening bombing exercises are frequently held.)