It happened 13 years ago, March 13, 1997. Hundreds if not thousands of people called in to radio and TV stations to report something in the skies over Phoenix.
911 operators were swamped with calls, as well as Sky Harbor and Luke Air Force Base.
That mystery in the sky would eventually be known as the Phoenix Lights, one of the most viewed UFO sightings of all time.
There have been many theories about the Phoenix Lights - aliens, military aircrafts, flares, balloons, inter-dimensional travelers.