On March 13, 1997, something strange was reported moving across the sky from Henderson, Nevada, travelling across the state of Arizona and disappearing into the Sonoran Desert. Hundreds of people reported the event, telling officials what they saw - and their stories are all similar. A V-shaped aircraft with bright lights appeared to be moving across Arizona. But when it reached Phoenix, people got out their cameras and documented what was to become one of the most infamous UFO events in US history. What were the Phoenix Lights?