August 15, 1977: the night before Elvis Presley died, at 11:16 p.m. an Ohio radio telescope -a rectangular structure, larger than three football feilds- called the Big Ear recorded a single pulse of radiation that seemed to come from somewhere in the constellation of Sagittarius at the 1420 MHz hydrogen line, the vibration frequency of hydrogen, the most common molecule in the universe -exactly the signal ET-hunters had been instructed to look out for. The signal was so strong that it pushed the Big Ear's recording device off the chart.
Three nights later, on August 18, astronomer Jerry Ehmansat at his kitchen table flipping through a thick computer-generated printout displaying a cryptic stream of blank spaces and black digits falling into regularly spaced columns. As Ehman looked carefully through this forest of information, he zoomed in on a an odd column that read, from top to bottom: “6EQUJ5.”
Ehman circled this group of alpha/numeric characters, and to the left, in the margin, wrote “Wow!” This small section of paper with its imperfectly printed characters, together with Ehman’s emphatic note, "represent what some people think remains the best evidence of a signal from the cosmic depths that was of artificial, purposeful, and intelligent origin," according to Caleb Scharf, director of the multidisciplinary Columbia Astrobiology Center at Columbia University.