Since the United States detonated its first atomic bomb at the Trinity test site in 1945, dozens of accounts of UFOs have been logged by military witnesses and government scientists working with America's sensitive nuclear arsenal. Now a new, decades-long study has analyzed over 500 of the best supported UFO cases from the heights of the Cold War and hauntingly concluded: 'This intelligence understands atomics, and they understand atomic weaponry.' UFO reports over America's nuclear arsenal appeared to shift from sites where the bombs were made to missile silos and US air bases as the Cold War arms race grew. That's one of the key findings from the new work, a series of three studies led by a retired US Air Force staff sergeant, Larry Hancock, and a data analyst affiliate with Harvard's UFO-hunting Galileo Project, Ian Porritt. Their qualified, but haunting conclusion: Data from this three decade-long period lends credence to the idea that extraterrestrials, or some other intelligence, has methodically surveilled America's rise to a nuclear power. 'This intelligence understands the developmental cycle. They have some contextual knowledge of what they're looking at and what they're looking for,' Hancock [said]. Among the hundreds of cases included in their analysis was the infamous March 16, 1967 Malmstrom case in which Air Force witnesses reported that ten nuclear missiles were switched off by a UFO, confirmed by a US Strategic Air Command report.