been listening for signals from ET since 2007.
Seth Shostak/Seti Institute
For the uninitiated, the name “SETI Institute” may conjure up sleek glass buildings, mammoth radio dishes, and creased-brow researchers rushing about waving enigmatic printouts. After all, SETI—the Search for Extraterrestrial Intelligence—is one of the most far-reaching and controversial projects in science. The idea that the universe might contain civilizations other than our own probably helped get Giordano Bruno burned at the stake in 1600. It sparked a famous 19th-century newspaper hoax in which astronomers were said to have found a society of “man-bats” on the moon. It motivated Percival Lowell’s writings about canals on Mars at the turn of the last century, and it inspired Orson Welles’s infamous “War of the Worlds” radio broadcast in 1938, which sent hundreds of thousands of listeners into a panic over a fictional Martian invasion they thought was real.
As the culmination of that grand history, the SETI Institute deserves an equally grand location, but the reality is quite a bit more modest. The institute occupies a single floor in an office park across the street from a residential district in suburban Mountain View, California, not far from a printing company and a shop called Fun House Theatrical Costumes. “This is the biggest such operation in the world,” says Seth Shostak, a senior scientist with the institute, “and there are just 10 or 12 of us here doing SETI. It’s not legions of lab-coated scientists with clipboards. I wish it were.”
At first blush, the organization’s results might seem equally disappointing. This year marks the 50th anniversary of the first modern SETI search: It was in April 1960 that astronomer Frank Drake pointed a radio telescope at the nearby star Tau Ceti and began listening for the telltale ping of an alien communication. Instead he just heard static, and in the half-century since, the silence has been complete.
So is Shostak discouraged by all the dead air? “Heck no,” he says, not missing a beat. Despite five decades of null results and chronic underfunding, he and his colleagues are more upbeat than ever. He ticks off some reasons: Dramatic improvements in technology are speeding up the search. Recent star surveys indicate that planetary systems—very likely including many Earth-like planets—are common throughout the Milky Way and the rest of the universe. And the latest explorations of our own planet demonstrate that life can exist in a much wider range of environments than anyone previously thought.
As a result, many SETI scientists regard the last 50 years as just a learning process. “Imagine,” says Jill Tarter, director of the Center for SETI Research at the SETI Institute and one of the stalwarts in the field, “that you didn’t know whether there were any fish in Earth’s oceans. So you go out and dip a single eight-ounce glass in the water. You might find one. But if the glass came up empty, I don’t think your first response would be ‘There are no fish.’”
SETI searchers have known from the beginning that success would be a long shot. “A discriminating search for signals deserves a considerable effort,” wrote Cornell physicists Giuseppe Cocconi and Philip Morrison in a 1959 Nature paper titled “Searching for Interstellar Communications,” the first formally argued rationale for SETI. “The probability of success is difficult to estimate; but if we never search, the chance of success is zero.” Cocconi and Morrison argued that the best way to communicate across interstellar space would be by radio because it is practical to transmit and receive and can easily pass through Earth’s (and presumably the alien planet’s) atmosphere.
Drake was a young radio astronomer at the time, working at the National Radio Astronomy Observatory in Green Bank, West Virginia. When the Nature paper came out, he was already working on a detector he could use on the observatory’s 85-foot radio dish to search for alien signals. He called that first search Project Ozma, after the princess of Oz from L. Frank Baum’s books. The project failed, but he was not surprised. After all, he had looked at just a handful of stars and radio frequencies, for a whopping two months. Nobody could possibly expect to luck onto an alien broadcast that easily, unless there happened to be technologically advanced civilizations lurking around just about every star.
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