SETI, or the Search for Extraterrestrial Intelligence, has a new director in Gerry Harp, who took over the post last May from famed signal hunter Jill Tarter. In a recent interview, Harp explained how he and his team use the 42 radio telescopes of the Allen Telescope Array to search a wide swath of the heavens for signs of intelligent life elsewhere in the Universe. Since the project’s inception, its team of scientists have looked primarily for a narrowband signal just 1 Hz wide, reasoning that alien civilizations would send a narrow signal because it travels faster than wide signals. Today, however, the reasoning has changed and astronomers, believing that aliens would send an encoded message, are searching for wider signals.
What’s the Big Idea?
The 42 telescopes SETI currently uses are just part of the 350 originally planned, but securing funding has been a problem for the group. There is light on the horizon, however, in the form of the Square Kilometre Array (SKA), a large collection of radio dishes that’s set to be constructed in Australia and South Africa. Even if all 350 dishes were to be built, their combined power would still be less than 1% of the SKA. “When SETI becomes more complete,” said Harp, “when we have more complete information about what sorts of signals are arriving from stars in the galaxy, we are going to start making statements of the probability of there being intelligent life in the galaxy.”