I was in charge of it until late in 1953. During this time members of my staff and I traveled close to half a million miles. We investigated dozens of UFO reports, and read and analyzed several thousand more. These included every report ever received by the Air Force.

For the size of the task involved Project Blue Book was always understaffed, even though I did have ten people on my regular staff plus many paid consultants representing every field of science. All of us on Project Blue Book had Top Secret security clearances so that security was no block in our investigations. Behind this organization was a reporting network made up of every Air Force base intelligence officer and every Air Force radar station in the world, and the Air Defense Command's Ground Observer Corps. This reporting net sent Project Blue Book reports on every conceivable type of UFO, by every conceivable type of person.

What did these people actually see when they reported that they had observed a UFO? Putting aside truly unidentifiable flying objects for the present, this question has several answers.

In many instances it has been positively proved that people have reported balloons, airplanes, stars, and many other common objects as UFO's. The people who make such reports don't recognize these common objects because something in their surroundings temporarily assumes an unfamiliar appearance.

Unusual lighting conditions are a common cause of such illusions. A balloon will glow like a "ball of fire" just at sunset. Or an airplane that is not visible to the naked eye suddenly starts to reflect the sun's rays and appears to be a "silver ball." Pilots in F- 94 jet interceptors chase Venus in the daytime and fight with balloons at night, and people in Los Angeles see weird lights.

On October 8, 1954, many Los Angeles newspapers and newscasters carried an item about a group of flying saucers, bright lights, flying in a V formation. The lights had been seen from many locations over Southern California. Pilots saw them while bringing their airplanes into Los Angeles International Airport, Air Force pilots flying out of Long Beach saw them, two CBS reporters in Hollywood gave an eyewitness account, and countless people called police and civil defense officials. All of them excitedly reported lights they could not identify. The next day the Air Force identified the UFO's; they were Air Force airplanes, KC-97 aerial tankers, refueling B-47 jet bombers in flight. The reason for the weird effect that startled so many Southern Californians was that when the refueling is taking place a floodlight on the bottom of the tanker airplane lights up the bomber that is being refueled. The airplanes were flying high, and slowly, so no sound was heard; only the bright floodlights could be seen. Since most people, even other pilots, have never seen a night aerial refueling operation and could not identify the odd lights they saw, the lights became UFO's.

In other instances common everyday objects look like UFO's because of some odd quirk in the human mind. A star or planet that has been in the sky every day of the observer's life suddenly "takes off at high speed on a highly erratic flight path." Or a vapor trail from a high-flying jet—seen a hundred times before by the observer—becomes a flying saucer.

Some psychologists explain such aberrations as being akin to the crowd behavior mechanism at work in the "bobby-sox craze." Teen-agers don't know why they squeal and swoon when their current fetish sways and croons. Yet everybody else is squealing, so they squeal too. Maybe that great comedian, Jimmy Durante, has the answer: "Everybody wants to get into the act." I am convinced that a certain percentage of UFO reports come from people who see flying saucers because others report seeing them.

But this "will to see" may have deeper roots, almost religious implications, for some people. Consciously or unconsciously, they want UFO's to be real and to come from outer space. These individuals, frightened perhaps by threats of atomic destruction, or lesser fears—who knows what—act as if nothing that men can do can save the earth. Instead, they seek salvation from outer space, on the forlorn premise that flying saucer men, by their very existence, are wiser and more advanced than we. Such people may reason that a race of men capable of interplanetary travel have lived well into, or through, an atomic age. They have survived and they can tell us their secret of survival. Maybe the threat of an atomic war unified their planet and allowed them to divert their war effort to one of social and technical advancement. To such people a searchlight on a cloud or a bright star is an interplanetary spaceship.

If all the UFO reports that the Air Force has received in the past eight years could be put in this "psychological quirk" category, Project Blue Book would never have been organized. It is another class of reports that causes the Air Force to remain interested in UFO's. This class of reports are called "Unknowns."

In determining the identity of a UFO, the project based its method of operation on a well-known psychological premise. This premise is that to get a reaction from one of the senses there must be a stimulus. If you think you see a UFO you must have seen something. Pure hallucinations are extremely rare.

For anything flying in the air the stimulus could be anything that is normally seen in the air. Balloons, airplanes, and astronomical bodies are the commoner stimuli. Birds and insects are common also, but usually are seen at such close range that they are nearly always recognized. Infrequently observed things, such as sundogs, mirages, huge fireballs, and a host of other unusual flying objects, are also known stimuli.

On Project Blue Book our problem was to identify these stimuli. We had methods for checking the location, at any time, of every balloon launched anywhere in the United States. To a certain degree the same was true for airplanes. The UFO observer's estimate of where the object was located in the sky helped us to identify astronomical bodies. Huge files of UFO characteristics, along with up-to-the- minute weather data, and advice from specialists, permitted us to identify such things as sun-dogs, paper caught in updrafts, huge meteors, etc.

This determination of the stimuli that triggered UFO sightings, while not an insurmountable task, was a long, tedious process. The identification of known objects was routine, and caused no excitement. The excitement and serious interest occurred when we received UFO reports in which the observer was reliable and the stimuli could not be identified. These were the reports that challenged the project and caused me to spend hours briefing top U.S. officials. These were the reports that we called "Unknowns."

Of the several thousand UFO reports that the Air Force has received since 1947, some 15 to 20 per cent fall into this category called unknown. This means that the observer was not affected by any determinable psychological quirks and that after exhaustive investigation the object that was reported could not be identified. To be classed as an unknown, a UFO report also had to be "good," meaning that it had to come from a competent observer and had to contain a reasonable amount of data.

Reports are often seen in the newspapers that say: "Mrs. Henry Jones, of 5464 South Elm, said that 10:00A.M. she was shaking her dust mop out of the bedroom window when she saw a flying saucer"; or "Henry Armstrong was driving between Grundy Center and Rienbeck last night when he saw a light. Henry thinks it was a flying saucer." This is not a good UFO report.

This type of UFO report, if it was received by Project Blue Book, was stamped "Insufficient Data for Evaluation" and dropped into the dead file, where it became a mere