It was one of the largest mass sightings in UFO history. In 1997, hundreds of people reported intensely bright balls of light forming a "V" shape in the sky over Nevada and Arizona. Some claimed to see an enormous, slow-moving aircraft. But what's behind the bizarre occurrence later nicknamed the "Phoenix Lights"? Was it an alien armada? A top-secret military exercise? See home video and hear from eyewitnesses who provide a vivid glimpse into what it was like on the ground that eerie night. Join a team of rocket scientists, physicists and engineers as they use the latest in advanced technology to attempt to explain the mysterious sightings.