The first manned flight was in 1903. Even as this new technology began to dominate the skies, widespread reports of unknown flying objects didn't really occur until the 1940s.

1941: Foo Fighters of WWII

UFOs were seen in the skies by Allied pilots during World War II and "foo fighter" was the name given to these objects. One crew described seeing "eight to ten bright orange lights off the left wing … flying through the air at high speed."

1942: The Battle of Los Angeles

The U.S. Army fired 1,400 machine gun and anti-aircraft shells at an object hovering above Los Angeles, California. The object appeared to be unaffected by the ammunition and the event lasted several hours. No debris was found, but an explanation was given — the excitement was due to a meteorological balloon and heightened nerves brought about by World War II. » Read more

1947: The Kenneth Arnold Sighting

The term "flying saucer" was coined in June 1947 when Kenneth Arnold described an incident in which he saw nine mysterious objects and said, "they flew like a saucer would if you skipped it across the water." He was flying his plane near Mount Rainier in Washington state at the time and estimated that the objects were traveling at least 1,200 miles per hour. This event attracted nationwide coverage by the press and many other unusual reports of flying objects came about as a result. » Read more

1947: The Roswell Incident

On July 8, 1947, the local newspaper in Roswell, New Mexico ran the headline, "RAAF Captures Flying Saucer on Ranch in Roswell Region." This became known as the Roswell Incident, perhaps the most famous UFO event to date. Roswell is a complicated UFO story that involved multiple corrections by the U.S. Military and suffers from the passage of time. Interestingly, Roswell isn't the only UFO crash that has been reported. » Read more