A scene from “Unfinished Business”

We've encoded our stories in radio waves and beamed them into space . . . for over 70 years. [And since] 1960, we've been listening for extraterrestrial radio signals without hearing so much as a tolling bell. . . . For all we know, we may have just missed an alien signal. [Or perhaps a civilization] even slightly more advanced than ours may have already moved on to some other mode of communication.