Evidence of UFOs

An unidentified flying object, or UFO, in its most general definition, is any apparent anomaly in the sky (or near or on the ground, but observed hovering, landing, or departing into the sky) that is not readily identifiable as any known object or phenomenon by visual observation and/or use of associated instrumentation such as radar. These anomalies were referred to popularly as "flying saucers" or "flying discs" during the late 1940s and early 1950s.