Calling All Aliens

Part I takes the audience into the labs where the SETI community works, including the new Allen Telescope Array at Hat Creek, North-East of San Francisco - an array of 350 dishes, each 6 meters across. The cast of characters includes Frank Drake himself and Jill Tarter, the woman scientist who inspired the radio-astronomer played by Jodie Foster in "Contact".

Part II shows us that not everyone is eager to make contact. Author David Brin thinks it is dangerous to try to communicate to a life form that we have no real knowledge of. He fears ET will come to annihilate the human race. "I'm not claiming that there are a million deadly horrible probes out there," says Brin. "But there is no proof that there are not."