4. The Kecksburg Incident, Pennsylvania, 1965

This incident holds a prominent place among the most talked-about UFO incidents in history, generating almost as much interest among enthusiasts as the Roswell incident. On December 5, 1965, a fireball or meteor-like object smashed into the ground in Kecksburg, Pennsylvania. After state police were called to the scene to investigate, the military was soon alerted and responded to Kecksburg to take control of the situation. While the Air Force dismissed the whole thing as a meteor, other witnesses who reportedly arrived at the scene of the impact before police reported seeing a acorn-shaped object about 12 feet in height. There were also reports that a flat-bed truck was seen leaving the area with an object onboard that was covered with a tarp. Many believed that object was a UFO that was taken away by the military.