Listening for Aliens

In the movie Contact, heroine Ellie Arroway (played by actress Jody Foster) first detects the signal of alien intelligence from the star Vega over a set of headphones. This is a concession to Hollywood stereotypes. In modern SETI the search is done by computer, monitoring many stars and many wavelength channels at once. Only if the computers detect certain patterns in the radio signal do they alert their human masters for a further look. For example, Project Phoenix scans 28 million channels simultaneously. They don't have that many headphones, so they have to use computers!