When people think about unidentified flying objects (UFOs), they tend to think of flying discs piloted by gray beings with large heads and enormous eyes. They tend to think that these sightings only started relatively recently and that belief in UFOs is some sort of modern religion brought on, perhaps, by the very justifiable fears of a nuclear age. But a study of the phenomenon quickly reveals that humanity has been seeing UFOs since the beginning of recorded history and perhaps a lot longer than that.

Modern Ufology focuses on mysterious lights on Ceres or tales of alien abduction, but this wasn't always the case, and looking at how the beliefs in the UFO phenomenon have changed or stayed the same can shed light on how culture and belief changes over time. One does not have to believe humans are actually being visited by aliens from another planet to recognize the importance of UFOs in human society. Any widespread belief that endures for centuries is worthy of study, and as always, cases exist that can't be explained away simple superstition.

Most everyone in America is familiar with theories about UFOs, or "flying saucers" as they were often called then, but even this name dates back only to 1947. Before that time, they were called "ghost rockets" or "ghost airplanes" or "ghost airships." Before the age of flight, the flying objects were called various things such as "flying chariots." No matter what terminology is used, every generation has clearly had its own belief that mankind is not alone.

For example, few things in American history are as controversial as the Roswell Crash. The one undeniable fact is that something happened near Roswell, New Mexico in 1947, but beyond that, the facts become unclear as memories and evidence lose their luster over the years. That said, the impact of an unidentified object continues to mystify residents, visitors and the curious, and it has not only put Roswell on the map but has kept it there for thousands of tourists. At the same time, skepticism about the official version of the incident prevails, and a countless number of people continue to believe the American government covered up a crash landing by aliens. As John B. Alexander, Ph. D., a former project manager at the Los Alamos National Laboratory and consultant to the CIA, put it, "Attempting to come to any complete resolution of the incident is a fool's errand, as whatever the truth may have been has become so distorted over time that facts have merged inextricably with fiction."

The various flying saucer sightings got the attention of the governments of the United States and other nations. The world was gripped in a Cold War, and some officials wondered if the UFOs might be experimental craft from some hostile power, most likely the Soviet Union. The American government in particular wanted to investigate the phenomenon to find out if this might be the case, as well as to calm public fears over what was appearing in the skies. Another motivation was to quash all the calls flooding into Air Force bases and police stations. Communications were limited in the mid-20th century, and every wave of sightings clogged up communication lines that might have been needed to defend against more terrestrial security threats.

The first large-scale, official investigation came during the UFO flap of 1947. On December 30, 1947, Major General L. C. Cragie, director of research and development for the United States Air Force, authorized the study of the flying saucer problem. His statement carried the line "by command of the chief of staff." The program was called Project Sign, and it would be the first of three known U.S. government studies of the UFO phenomenon.