But it wasn’t until the close of the 1950s that anyone proposed a credible way to look for these distant, hypothetical neighbors. The space age had dawned, and science was anxious to know what lay in wait beyond the confines of our thin, insulating atmosphere. The Russians had, in 1957 and 1958, launched the first three Sputnik satellites into Earth orbit; the United States was poised to launch in 1960 the successful Pioneer 5 interplanetary probe out toward Venus. We were readying machines to travel farther than most of us could imagine, but in the context of the vast reaches of outer space, we would come no closer to unknown planetary systems than if we’d never left Earth at all. Our only strategy was to hope intelligent life had taken root elsewhere and evolved well beyond our technological capabilities—to the point at which they could call us across the empty plains of space. Our challenge was to figure out which phone might be ringing and how exactly to pick it up. And so it was in mid-September of 1959 that two young physicists at Cornell University authored a two-page article in Nature magazine entitled “Searching for Interstellar Communications.” With that, the modern search for extraterrestrial life was born, and life on Earth would never again be the same. Launch the gallery to see how the search began and where it will take us next.
