The term "flying saucer" was coined by an unknown wire-service reporter in late June, 1947, when he tried to describe the silvery disc-like objects which many Americans had reported seeing.
The first book ever published about UFOs was "The Book of the Damned" by Charles Fort in 1919. Fort reported on a variety of unexplained phenomena and ridiculed attempts by scientists to explain them.
Previous to its famous Project Blue Book, the U.S. Airforce undertook two other investigations into the subject of public UFO sightings. Code named Sign and Grudge, they ran from 1947-1948 and from 1949-1952 respectively. Some investigators from project Sign believed some UFOs were extraterrestrial.
Unidentified objects come in all shapes and sizes. Many so-called UFO sightings consist of nothing more than lights in the night sky which move in strange ways. Daytime sightings are most often of saucer-shaped disks, but witnesses have also described triangles, spheres, diamonds, or ships shaped like saucers and boomerangs.
About 90 to 95 percent of all UFO reports turn out to be IFOs---identified flying objects. People may fail to recognize ordinary objects, such as clouds or stars, because of unusual atmospheric conditions or out of ignorance. Other times our eyes can literally play tricks on us, causing us to think stars are moving when they are not. This is called autokinesis.
Some people have become sick following a UFO sighting, reporting burns, nausea, and eye irritation. In 1980, a woman named Betty Cash was hospitalized with symptoms resembling radiation sickness after seeing what she claimed was a space ship.
In World War II both Allied and German fighter pilots reported seeing glowing balls of light flying beside their planes. The Allied pilots called them "foo fighters." Both sides believed they were mysterious weapons which had been developed by the enemy.
In 1942 approximately 1,000 unknown objects were seen in the sky over Sweden and Norway by countless numbers of people, nicknamed "ghost rockets." The Swedish government later stated that 80 percent of the ghost rockets had been identified, but the remainder remain unexplained.
From the 1940s, many people who specialize in studying UFO phenomenon have taken a spiritual approach to the subject. Called "saucerians," they believe that we can commune with aliens on a spiritual or psychic level and they contact us because they want to help us.