Avi Loeb’s book Extraterrestrial: The First Signs of Intelligent Life Beyond Earth is still riding high in the book charts, proving that there’s still plenty of interest in life elsewhere in the Solar System. Loeb’s book, however, has proven controversial, not only for its insistence that the interstellar interloper 1I/’Oumuamua is a spacecraft (I explain why it probably isn’t here), but also for its criticism of the scientific community in terms of what Loeb sees as an unwillingness on scientists’ behalf to entertain new ideas and a lack of effort to win funding for SETI.
His claims have drawn a lot of negative reaction from the scientific community, but they have been lapped up by the public and mainstream media. I’d say that it’s up to readers to read Loeb’s book and decide for themselves.
In order to help readers decide, I wanted to highlight some other books about SETI that have inspired me, and although they may not have benefitted from the juggernaut of publicity that Loeb’s book gets, they are equally well deserving of your time and, I would argue, provide a more balanced view of the search for extraterrestrial intelligence.
A book perfect for beginners
A great primer for newcomers to SETI is Wade Roush’s Extraterrestrials (MIT Press Essential Knowledge Series, 2020), not to be confused with Loeb’s Extraterrestrial. This small-format book is an excellent introduction to the subject, with Roush framing the search for extraterrestrial intelligence in the context of the Fermi Paradox. He begins by running through history to show us how people in the past thought of aliens, then describes the beginnings of SETI as a scientific subject in the late 1950s and early 1960s, explores the Drake Equation, discusses technosignatures, and much more. What’s delightful about Roush’s book is that it is a welcoming read for the uninitiated, not getting bogged dow in jargon or making assumptions about readers’ prior knowledge. One of the ways Roush excels in doing this is by relying on analogy to make his point, which makes his book all the more relatable – particularly important when discussing topics of an otherworldly nature.
You can find my more detailed review of Extraterrestrials here.
Where are they?
Speaking of the Fermi Paradox, next up is Stephen Webb’s If the Universe is Teeming With Aliens… Where Is Everybody? 75 Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life (Springer, 2017). Despite the unwieldy title, Webb’s book has proven itself to be perennially popular ever since it was first published in 2002. That first hardback edition ran to just 50 solutions to the Fermi Paradox, but a second edition published in 2017 added an extra 25 possible solutions! Webb introduces Fermi’s famous question (‘where is everybody?’ – it wasn’t described as a paradox until the 1970s by researchers such as Michael Hart) and then runs through every possible solution imaginable. These range from the Zoo hypothesis (where we exist in some kind of cosmic preserve that allows aliens to observe us without us ever noticing) to Rare Earth, with commentary in between on everything from interstellar travel to artificial intelligence. Webb summarises each solution and gives his opinion of how probable he thinks they are. Ultimately, his preferred solution is that we are alone, and that there is no one else out there.
One thing for sure is that Webb’s books is bound to get you thinking, which is the point of any good book. And who knows, maybe you’ll come up with your own solution that no one else has thought of yet!
On the hunt for the Wow! signal
In recent years, Robert Gray has argued that the Fermi Paradox isn’t a paradox at all (I agree with him to an extent – it’s a paradox of our assumptions, not of actual observations) and that discussing it is harmful to attempts to gain funding for SETI (I disagree with him here). But Gray’s original inspiration to become involved in SETI wasn’t the Fermi Paradox, but the famous Wow! signal of 1977. This was a mysterious burst of narrowband radio waves detected by the Big Ear radio telescope in Ohio, for which no convincing explanation has ever been found. Was it aliens? No one knows, but Gray has led the charge, researching the signal and conducting amateur radio searches for it (sometimes even on the big professional telescopes), to no avail. He has written up his adventures chasing the Wow! signal in The Elusive Wow (Palmer Square Press, 2011). Most of the book is dedicated to the signal, the complexities of radio SETI and possible explanations for the signal, while the remainder of the book gives an overview of SETI and its various searches and theories. As the personal journey of one man’s quest to find proof of technological life beyond Earth, The Elusive Wow makes for compelling reading.
Opposing Gray’s viewpoint that Fermi’s Paradox isn’t a paradox at all has been Serbian astronomer Milan Ćirković, and their discourse in the pages of journals such as Astrobiology has been spiky at times. Ćirković has his own book out, called The Great Silence (Oxford University Press, 2018), which discusses how profoundly important the Fermi Paradox might prove to be. Admittedly I have not read his book yet, but I would be remiss if I didn’t mention it, and knowing Ćirković to be an erudite and plain-spoken communicator, I am looking forward to reading his book when I get chance.
The granddaddy of SETI books
You might imagine that the first (or certainly, one of the first) books about modern SETI would seem a bit dated now, but Iosif Shklovskii’s (and Carl Sagan’s) book Intelligent Life in the Universe holds up remarkably well. Originally written and published in the Soviet Union in 1962, it was translated into English, with additional material and dialogue by both Shklovskii and Sagan, in 1966. It covers a remarkably broad scope in surprisingly mature fashion, which isn’t a reflection of the authors by any means but more the fact that the field was still young in the 1960s.
There’s interesting contrast between the two authors based on their respective political and societal backgrounds, coming from nations that were arch enemies of one another. The book showed the power of science to overcome those differences, and although Shklovskii and Sagan were not able to meet during the production of the translated version, exchanging notes, ideas and suggestions by letter, they were finally able to come together in person at the Soviet–American SETI conference at Byurakan Observatory in Armenia in 1971.
Intelligent Life in the Universe doesn’t just focus on radio SETI, which was the main thrust of SETI at the time. There are also discussions about optical SETI too, as well as the potential for habitable planets (remember, this was three decades before any exoplanets were discovered), astrophysics, astrobiology, interstellar probes and the possible consequences of contact. If you can pick up a second-hand copy, then there’s lots of gold to be found in this book.
Celebrating 50 (now 60) years and counting
Searching for Extraterrestrial Intelligence: SETI Past, Present and Future (Springer–Praxis, 2011), edited by SETI veteran Paul Shuch and featuring papers by a host of experts on all aspects of SETI, was published to commemorate the fiftieth anniversary of Frank Drake’s Project Ozma, which many consider to be the beginning of modern SETI. It features essays, articles and technical treatises from 26 experts in the field, including the SETI Institute’s Jill Tarter and Seth Shostak, Jerry Ehman who discovered the Wow! signal, optical-SETI pioneer Stuart Kingsley, Harvard University’s Paul Horowitz, Stephen Webb, METI International’s Doug Vakoch, science fiction authors Stephen Baxter (who kindly wrote the foreword to my book, The Contact Paradox) and David Brin, anthropologist Kathryn Denning and more.
The book is split into three sections: ‘The Spirit of SETI Past’, ‘The Spirit of SETI Present’ and ‘The Spirit of SETI Future’. Among the best chapters are overviews of Project Cyclops and the mystery of the ‘Wow!’ signal; excellent pieces about the SETI League’s Project Argus and how amateurs can create their own network of radio telescopes; a remarkable history of SETI at NASA by John Billingham; controversial (to some) passages by Alexander Zaitsev on messaging extraterrestrial civilisations; cultural aspects on SETI by Shostak, Denning and Brin; and a delightful surprise in the final pages with a lost letter by one of the founding fathers of the field, the late Philip Morrison.
Many of the chapters are quite technical, so this isn’t a book aimed at beginners, but those with a more technical background will find it quite rewarding.
Hopes and fears
Perhaps readers with less technical expertise will get more out of Michael Michaud’s excellent book, Contact With Alien Civilisations (Springer, 2006). Subtitled Our Hopes and Fears About Encountering Extraterrestrials, this comprehensive book approaches the subject from the point of view of discussing the consequences of making contact with an extraterrestrial species. It ranges across the field, from exploring the probability that there’s anybody out there, the possibility of interstellar travel, the Fermi Paradox, and what our reactions to making contact might be, such as how contact would affect religion, whether contact would be dangerous, and what assumptions we are making about hypothetical aliens in terms of their moral and altruistic attitudes. Michaud, a former diplomat, explores these topics from every possible angle, and as a vocal participant in discussions about whether we should be messaging extraterrestrials, he provides a much-needed fair and balanced critique of the issues surrounding contact.
How about an insight into what it’s like to be a SETI scientist by the leading astronomer at California’s SETI Institute? Seth Shostak’s entertaining Confessions of an Alien Hunter (National Geographic, 2009) is worth the price of admission just for his tense description of how the US Congress shut down NASA’s funding of SETI in 1992, and of the exciting night when an anomalous radio signal was briefly thought to be a real alien message, only to turn out to be coming from the Sun-watching spacecraft SOHO, the Solar and Heliospheric Observatory. Informative, insightful and always fun, Shostak’s book gives a rare glimpse into the work of a SETI scientist, and how the detection of a real signal could never be kept a secret, which will no doubt be disappointing to the conspiracy theorists.
A quick mention also for a biography of Shostak’s SETI Institute colleague, Jill Tarter. Although Making Contact (Pegasus, 2017), written by Sarah Scholes, is ostensibly a biography of the First Lady of SETI rather than a technical look at how scientists do SETI, it’s a much-needed insight into the life, struggles and triumphs of a woman astronomer who found success in a male-dominated world, and who has done more for SETI than almost anybody else.
These are all brilliant books that deserve to be read, but it’s certainly not an exhaustive list as I haven’t read everything (I’ve not even read all the books on my bookcase – I’m one of those people who collects books faster than I can read them!). So if I have missed any out that you think deserve to be on the list, let me know in the comments section! And of course there’s my own book, The Contact Paradox: Challenging Our Assumptions in the Search for Extraterrestrial Intelligence, but I’ll leave it up to you, the reader, to decide whether that deserves to be on this list or not.