The Search for Extraterrestrial Intelligence 2024 [Microwave Surfing]

Regular readers of the column will recall my long-standing fascination with the scientific search for extraterrestrial intelligence (SETI). Last year, I wrote about the American astrophysicist Frank Drake (1930–2022), who kickstarted SETI in 1960 with his Project Ozma [2] and whose eponymous Drake equation [3] has been used to estimate the number of observable civilizations in our galaxy. Recently, I browsed through a new crop of books devoted to SETI. They included Interstellar: The Search for Extraterrestrial Life and Our Future in the Stars [1] by the Harvard astronomer Avi Loeb; Alien Earths [4] by Lisa Kaltenegger, the director of the Carl Sagan Institute at Cornell; and The Little Book of Aliens [5] by the physicist Adam Frank of the University of Rochester. Even a cursory perusal of these books makes one thing very clear. Not only are scientists going beyond Drake’s original vision of searching for “radio waves sent forth by other intelligent civilizations” [2], but the current SETI discourse also employs many terms unfamiliar to the wider public. Here are a few of them to bring you up to speed.