Naturally, as technological advances and the creation of flying aircraft became realities, the sighting of UFOs increased, as did the interest in potential contact with aliens. While incidents like the one at Roswell led to conspiracies and a craze among those who insisted the government was hiding proof of extraterrestrials' existence, governments across the world were actually secretly studying UFO sightings by the mid-20th century.

By the end of the 1950s, the Cold War was ramping up, but so were scientists' efforts to collaborate on the search for signs of extraterrestrial life, particularly through radio. Proceeding under the forthright moniker of Search for Extraterrestrial Intelligence, the broadly defined mission of organized searches was to "explore, understand, and explain the origin and nature in the universe and the evolution of intelligence." Among its fellow organizations, SETI was unquestionably the most highly interdisciplinary, bringing together elements of cosmology, planetology, atmospheric science, the study of evolution, evolutionary biology, psychology, technology, and sociology. In the more than 60 years since, the efforts of countless scientists, astronomers, and even amateur observers have produced both interesting and controversial results, and the work has led to further speculation surrounding the nature of extraterrestrial life and why scientists have thus far not established definitive results of alien contact.

SETI: The History and Legacy of the Search for Extraterrestrial Life examines the origins of the searches, the SETI Program, and what the work has produced.