SETI : The Dream of a New Era

Carl Sagan’s words convey how the detection of an extraterrestrial form of intelligence would not just be a new discovery, it would be the beginning of a new era. Fortytwo years ago when Philip Morrison and Giuseppe Cocconi, two physicists at MIT, published the famous paper “Searching for Interstellar Communications”, they gave birth to the idea of starting a Search for ExtraTerrestrial Intelligence, commonly known as SETI (2). Their proposal was to use radiotelescopes to search for signals coming from an extraterrestrial civilization, and they immediately found support from the scientific community. Only one year later a young astronomer, Frank Drake, started Project Ozma, the first radio search for signals using a simple antenna pointed at two nearby Sunlike stars (3). Frank Drake was also the greatest contributor in laying down the theoretical motivations to support SETI. His work can be summarized by the well-known Drake’s equation: N = R*fp*ne*fl*fi*fc*L . This equation gives an estimate of the number N of communicative civilizations present in our galaxy. Each parameter denotes the probability that a necessary condition for the existence of an extraterrestrial civilization occurs. Technological developments allow and will allow us to give a good estimate of the first param-