1967: The year we thought we made contact

What would happen if scientists suddenly stumbled upon a message from outer space? There's not actually a formal plan. No international body has ever decided whether we reply or not, and, if so, how we do it and what we say. But in 1967, we did get a dry run at a close encounter and, in the process, worked out a system of how confirm and report an alien communication that's still used today. Technology review has the story.