Extraterrestrial: The First Sign of Intelligent Life Beyond Earth
Extraterrestrial: The First Sign of Intelligent Life Beyond Earth is a popular science book written by American theoretical physicist and Harvard University astronomer Avi Loeb, published by Houghton Mifflin Harcourt on 26 January 2021.
Contents
The book describes the 2017 detection of Oumuamua, the first known interstellar object to pass through the Solar System. Loeb, an astronomer at Harvard University, speculates that the object might be an extraterrestrial artifact, a suggestion considered unlikely by the scientific community collectively. Earlier, Loeb claimed to have demonstrated that the interstellar object was not an asteroid, was moving too fast in a very unusual orbit and left no gas trail or debris in its path to be a comet. Loeb believes, due to the observed acceleration of the object near the Sun, that Oumuamua may be a thin disk that acts as a solar sail.Elizabeth Kolbert of The New Yorker magazine summarized the reasoning used by Avi Loeb about Oumuamua as follows:
Besides Oumuamua, another interstellar object, the comet 2I/Borisov, has been detected passing through the Solar System. Loeb accepts that 2I/Borisov is a natural object but, asserts, against the scientific consensus, that Oumuamua may be artificial.
Reviews
Jeff Foust, editor and publisher of The Space Review, comments that Loeb "fails to close the case that the object must be artificial... Just because something can’t be immediately explained by natural phenomena doesn't mean it’s not natural." Further, "Perhaps Oumuamua will turn out to be the first of many in a new class of interstellar objects with an unusual, but natural, origin. Or, maybe, it will be like the “Wow!” signal, which was never seen again and its source never identified; mysterious, but not necessarily alien". Dennis Overbye, science writer for The New York Times, notes that the book is, "Few of his scientific colleagues agree with him, as Loeb will be the first to tell you in his new book, “Extraterrestrial,” which is part graceful memoir and part plea for keeping an open mind about the possibilities of what is out there in the universe — in particular, life." Reviewing for The New Yorker, Elizabeth Kolbert writes, "It seems a good deal more likely that will be ranked with von Däniken's work than with Galileo's," but concedes "it's thrilling to imagine the possibilities."A followup book, entitled Interstellar: The Search for Extraterrestrial Life and Our Future in the Stars, was published on August 29, 2023.