UFOs and Extraterrestrial Life

An unidentified flying object (UFO) is any aerial phenomenon that cannot immediately be identified or explained. Most UFOs are identified or investigated as conventional objects or phenomena. The term is widely used for claimed observations of extraterrestrial spacecraft-aircraft, and was coined as an anacronym by Project Blue Book project head Edward J. Ruppelt. Many UFOs are described as being flying saucers, as is shown in the image to the right.