Part survey of thrilling new discoveries, part memoir of a restless intellect and part polemical airing of grievances, this curious volume from Harvard astrophysicist Avi Loeb challenges readers--and Loeb's contemporaries in the sciences--to take seriously the likelihood that we are not alone in the universe. Loeb's "first sign" of intelligent life from elsewhere in the cosmos: 'Oumuamua, a peculiar object that skipped into and then out of the solar system in 2017, zipping through so quickly that astronomers charted it for only 11 days. Scientific consensus has labeled 'Oumuamua, the first interstellar object humanity has ever tracked through our solar system, as a comet, despite the many peculiarities of its behavior.
Loeb asks readers to consider a bolder hypothesis: the possibility that 'Oumuamua "must have been designed, built, and launched by an extraterrestrial intelligence." Extraterrestrial finds Loeb testing that claim, explaining how his life and his research has brought him to make it, considering its implications and lamenting the reluctance of many scientists to consider such a possibility at all. He encourages his contemporaries to approach the possibility of extraterrestrial intelligence with the open minds of children, and, perhaps inevitably, he trots out the story of Galileo facing trial for heresy for his break with scientific orthodoxy.
Fortunately, Loeb's infectious sense of wonder breezes away the faint sourness of those passages. Loeb proves adept at illuminating cosmic complexities for a lay audience, especially when it comes to the mysteries of 'Oumuamua. He's just as strong at stirring hopeful awe at his vision of humanity--and possibly other civilizations--launching probes powered by lightsails across the vast emptiness. --Alan Scherstuhl, freelance writer and editor