Jocelyn - A Soupçon Of Seas (Vol V)

The intensity of celestial sources passing over the fixed field of radio receivers was recorded on strip charts and had to be analyzed by visual inspection. This task fell naturally to the graduate student of the group, Jocelyn Bell. On August 6, 1967, she first noticed a peculiar train of radio signals when the sky at right ascension 19h19min passed through the field of view. What could have caused such a transient periodic signal? The first suspicion was of course interference from some electric equipment, like the ignition of a passing car or a satellite. But to the surprise of Bell the signal appeared again at about the same time of day. After a few months it was obvious that the regular pulses were coming from a celestial source beyond our solar system. Furthermore a recording of the source with sub-second time resolution on November 28, 1967, revealed pulses repeating at a regular period of 1.33 s. At that point - the discovery of the phenomenon was still kept secret - the thought that radio signals from an extraterrestrial civilization had been recorded was seriously considered, under the code "LGM" (little green men). (An excerpt from ‘Gamma-Ray Pulsars’ by Gottfried Kanbach, chapter 6 in ‘The Universe in Gamma Rays’ (2001), edited by Volker Schönfelder)). Listen in...