Those Mysterious UFO's: The Story of Unidentified Flying Objects

For hundreds of years people have seen mysterious lights and flying objects in the heavens. Some of these sightings have been explained as optical illusions or phony pranks. But in many cases, the objects are never identified! What can we believe? Is there life in other worlds? Here are the facts regarding the U.S. Air Force investigations and the many different kinds of UFO's - complete with photographs.