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New York Times October 7, 2009 established a channel of communication, aimed also Anyone Out There? at us. By GIOVANNI BIGNAMI Look up at the stars and ask yourself: What scares me more? To be alone in the universe, or to know that there’s someone else up there? It’s easy to see that such a channel would probably use radio waves as the most efficient way of transmitting a signal. The two men suggested frequencies for us to listen in on, using the new It’s an age-old question, as valid for you and me as antennas of radio-astronomy, just then coming of it was for Giordano Bruno when he wrote about an age. “infinity of worlds” before being burnt at the stake in 1600. They had no clue as to what to listen for, of course. Prime number sequences? Digits of pi? No use But 50 years ago last month, a letter to the guessing, just trust them. magazine Nature ended the passive, look-up-and ponder attitude by proposing a scientific, experimental approach. We don’t have an answer yet (or you and I would know), but in the process we have come up with quite a tale to tell. The suggestion of the two physicists fired quite a bit of enthusiasm. Almost immediately, Frank Drake, at the newly created National Radio Astronomy Observatory, started Project Ozma, the first radio search for an intelligent signal. Since then, over 100 Giuseppe Cocconi (1914-2008) and Phil Morrison search programs have been carried out, culminating (1915-2005) were both accomplished physicists in the biggest of them all, SETI (Search for when they wrote “Search for Interstellar ExtraTerrestrial Intelligence), still going strong. Communications” (Nature, Sept. 19, 1959). Mr. Cocconi started his life in science doing experiments with the physicist Enrico Fermi and later had a brilliant career at the European Particle Physics Laboratory (CERN) in Geneva. Mr. Morrison, professor at M.I.T., had been a group leader in the Manhattan Project. Their letter to Nature reported the obvious. At the time, they had no evidence of the existence of planets around stars and no clue about life on them, much less on any evolution of technological societies. But if there are intelligent beings somewhere out there, they wrote, they may have All to no avail, of course: not an intelligent peep on any antenna. Does this mean that we are alone in the sky? Not at all. As Francis Bacon wrote, “They are ill discoverers that think there is no land, when they can see nothing but the sea.” SETI itself, and its predecessors, have prompted a small revolution in science, technology and sociology. Over 50 years, our ability to search for radio signals has increased 10,000 times more than the increase in sensitivity enjoyed by all optical astronomy in the 400 years since Galileo. SETI has also been able to survive dramatic funding The only thing we can safely discard is the cuts, notably from NASA, and is now thriving on “directed panspermia” theory of Francis Crick and mostly private support. It does so through the Leslie Orgel. In 1973, the DNA Nobel discoverer extraordinary involvement of the public. and his co-author theorized that “organisms were deliberately transmitted to earth by intelligent The enormous computer power necessary to process beings on another planet.” That would require all the radio signals collected from the sky is now enthusiastically supplied by a network of close to a living matter travelling to us from another star. An million personal computers. Download SETI implausible prospect, we now think. software as your (fascinating) screensaver and you could, one day, be the first to spot an extraterrestrial signal — an irresistible prospect to many. While we are making palpable progress on the emergence of life, we are definitely stuck on assessing the chances of life forms being capable of Meanwhile, astronomy from ground and space has sending radio signals. We still have a sample of just found extra-solar planets. The first was discovered one, our own planet. The visible proof of it, from in 1995 around a nondescript local star. Nearly 400 the outside, is a sphere of radio and TV waves more are now catalogued in one of the greatest expanding in all directions at the speed of light. leaps of astronomical discovery. We have today a good insight into the existence of planets: We know they are the norm, not the exception, around stars. In the century that has elapsed since Guglielmo Marconi started sending radio signals, this sphere must have engulfed the many stars surrounding us With 100 billion stars in our galaxy alone, we have within 100 light years. Of course, it has become ground for optimism about the emergence of life much stronger in recent decades: In Italy, it is somewhere else. affectionately known as the “Berlusconi Bubble.” Data are accumulating on organic materials in outer It is debatable whether TV commercials are really space. Some important building blocks of life, such the message our civilization wants to convey to our as amino acids and sugars, are now routinely found galactic neighbors. What cannot be debated, in meteorites and in extraterrestrial environments. however, is the final sentence of the Cocconi and Recently, NASA brought back some amino acids Morrison letter, urging us to listen for interstellar straight from a comet’s tail. messages: “... success is difficult to estimate, but, if we never search, the chance of success is zero.” Complex organic molecules just randomly present in the stuff our solar system was made from? Panspermia — the theory that life seeds came from outer space — confirmed? Too early to tell. Giovanni F. Bignami, former president of the Italian Space Agency, is professor of astronomy at the Instituto Universitario di Studi Superiori in Pavia, Italy, and the Accademia dei Lincei in Rome.