“I have no clue if there are aliens out there,” concedes Douglas Vakoch, director of METI International, an organization committed to contacting extraterrestrial intelligence. But he is certain that ...

On a hot November day in the tropical forest of Arecibo, Puerto Rico, amongst the croaking of coquís, the message went out. Warbling audio crackled over loudspeakers—the audible result of the work of ...