Radio broadcasting began in 1906. The signals betrayed the existence of earth civilization to any advanced ET worlds with the capacity to intercept the signals originating from this planet. The Roswell visitation, I feel, may have been the direct consequence of such interception. That being the case, the Roswell crafts would have originated no more than 41 light years from earth. At this point in time the earth would most likely to have become known to, and visited by, other ET worlds within 104 light years of our solar system. It is also my feeling that the atomic explosions of 1945 taken in conjunction with the radio and television broadcasts would definitely be of interest to any highly developed ET civilization within the 65 light year limits of speed of light signal emanation. Any visiting ET explorers will also no doubt recognize that our species is close to becoming space travelers ourselves. The question then arises: are we perceived as a curiosity or a threat?
And it's also worth noting that the entire case lay dormant for 40 years before it was revived by serious Ufologists like Stan Friedman in the 80s. It was one of those anomalous events that Charles Fort would have called the 'damned.' Don Keyhoe never mentioned it in his UFO expositions in the early 50s. As it turns out all the records of the 509th were mysteriously lost soon after Friedman's research was published. There was and continues to be a tight cover-up in place by the US Gov. What are they covering up? Mogal balloon tests? Crashed V-2 rockets? After 60 years would such cold war nonsense still be worth covering up? The General Twining Memo explains everything in that regard. He concluded in 1947 that we were dealing with ET phenomena and an incipient invasion against which our armed forces had no defense. That was and still is the reason for the cover up.