People have been spotting strange things in the sky for centuries. In the 1950s, these aerial enigmas received an official label courtesy of the Air Force: UFOs. The United States had a vested interest in tracking unidentified flying objects at the height of the Cold War in the 1950s and '60s. They took them so seriously that they invited average citizens to report their sightings. But while the government was looking out for secret Soviet aircraft, most UFO witnesses had aliens in mind.
According to History, Project Blue Book operated from 1952 to 1969, making it the country's longest-running official investigation into UFOs. If you saw something in the sky you didn't recognize during this period, the Air Force wanted to know about it. They provided questionnaires for witnesses to detail their experiences. There were sections for recording where you saw the UFO, when you saw it, and what it was doing when you spotted it.
After describing the sighting in words, you were expected to sketch a picture of it. The form read: “Draw a picture that will show the shape of the object or objects. Label and include in your sketch any details of the object that you saw such as wings, protrusions, etc., and especially exhaust trails or vapor trails. Place an arrow beside the drawing to show the direction the object was moving.”
Project Blue Book hadn't made much progress after collecting years worth of data, and people were starting to notice. The University of Colorado UFO Project released a report in 1968 arguing that the Air Force's UFO inquiry was a waste of time and resources. The Air Force officially shuttered the project by 1970.
Civilians can no longer file UFO reports with the government, and that's probably for the best. So-called UFO sightings are more common than ever in the age of drones and SpaceX launches. Here are more objects that have been mistaken for UFOs.