The Phoenix Lights were a mass UFO sighting which occurred in Phoenix, Arizona, USA and Sonora, Mexico on Thursday, March 13, 1997. Lights of varying descriptions were reported by thousands of people between 19:30 and 22:30 MST, in a space of about 300 miles (480 km) from the Nevada state line, through Phoenix, to the edge of Tucson. There were allegedly two distinct events involved in the incident: a triangular formation of lights seen to pass over the state, and a series of stationary lights seen in the Phoenix area. The U.S. Air Force later identified the second group of lights as flares dropped by A-10 Warthog-aircraft that were on training exercises at the Barry Goldwater Range in southwest Arizona.
Although, many people think that was a cover up. The Governor of Arizona at the time, was one witness to this incident. As governor, he ridiculed the idea of alien origin,
but later he told people that the lights seems “otherworldly”. He admitted he saw
the UFO lights years later. (Via: YouTube / Wiki)