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-