Jodie Foster’s astronomer in the 1997 film Contact was based on a real scientist: Dr. Jill Tarter, who spent 35 years turning the search for extraterrestrial intelligence from a career-ending fringe pursuit into a rigorous discipline. This episode follows her from beach walks with her father in the 1950s, through Cornell where she was the only woman in a graduating class of 300 engineering students, to Berkeley where her 1975 dissertation coined the term brown dwarf for objects that never ignite fusion.

Her entry into SETI came through an obsolete PDP-8S computer nobody else could program and the Cyclops Report, which proposed phased arrays of antennas and the quiet water hole frequency band between hydrogen and hydroxyl. We cover the SERENDIP project that piggybacked on other astronomers’ observations, the 1993 congressional defunding, the pivot to privately funded Project Phoenix, the HabCat catalog she built with Margaret Turnbull to filter 100,000 stars down to 17,000 candidates, and her debate with Stephen Hawking over whether advanced civilizations would be predators or explorers.

• How a junk computer and a NASA-Stanford summer study pulled Tarter into the search for alien signals
• Why the water hole between 1420 and 1662 megahertz was chosen as the cosmic town square for listening
• The age, stability, and metallicity filters used to build the catalog of habitable stellar systems
• Tarter’s ocean-glass analogy for why decades of silence are not evidence of absence
• Her argument that any species capable of interstellar travel must have outgrown its destructive tendencies