In 1939 the Manhattan Project was born. The most secret project ever run by the US Government to that time, so secret that the employees that worked there did not know what they were working on. It resulted in the first atomic bomb.
In 1942, 56,000 acres surrounding the Oak Ridge area of Tennessee, a very sleepy town in the foothills of the Great Smokey Mountains, was acquired by the government. It would be the location of materials development, to include the refinement of uranium-238 into fissionable uranium-235 as part of the project. To this day it continues to be used as a laboratory in the development of nuclear weapons and maintains its secrecy, though, in those days no one outside of that area knew it even existed.
In the early 1950’s something strange was being seen in the skies above the town. By July of 1950 there had been enough activity in the area that a Vanderbilt professor would try to correlate UFO activity with radiation readings. By October, the Army and FBI were taking notice. There had been visual sightings by lab personnel, along with radar hits at Knoxville airport. Several times interceptors were launched to check out the bogies, however, they never saw anything. There were enough incidents that a call to citizens went out in the local newspaper on October 12th. For the first time, The Atomic Energy Commission wanted information on the flying saucers. An article by Robert Allen asked people to contact the AEC and fill out a questionnaire if they had seen anything strange in the skies, especially if it was near one of the AEC facilities. It was the beginning of the cold war and paranoia was growing. The red scare was in full force; Senator Joe McCarthy was on the loose in Washington accusing everyone of being a communist, and the FBI had their hands full checking the backgrounds of anyone seeing one of these things. They could never find anything; in fact they could find no explanations at all.
The Air Force got involved in November. Air Materiel Command, in the form of Project Grudge, precursor to Blue Book, was given the task of analyzing the Oak Ridge data. Project Grudge was not UFO friendly and as a result, sent a letter up the chain stating that the radar cases were likely the result of temperature inversions and faulty equipment. It also explained the visual sightings as weather balloons, aircraft and the like. The Army and AEC were not pleased. They had a meeting at Oak Ridge to discuss the situation, attended by a Tennessee Senator. It was agreed that they would set up additional radar equipment and disperse radiation detector throughout the area. Maybe they could explain the radar hits as the result of high radiation levels. What came of these tests we do not know? As time passed the sightings became less frequent and the hullabaloo died down. Although sightings were still occurring into 1951 and beyond, the Army and AEC never came up with a answer, as far as we know. The Air Force explanations were flimsy at best.
The sightings at Oak Ridge stand out because of the quality of witness testimony (lab personnel whose backgrounds had been thoroughly vetted), and because these incursions were also picked up on radar. If you take the eyewitnesses at their word ( and why not, their careers were at stake), then the strange activity in the skies over Oak Ridge is some of the most convincing on record of something very unusual taking place.