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A witty romp through the cosmos explores the search for alien life

The Aliens Are Coming! The Extraordinary Science Behind Our Search for Life in the Universe

Ben Miller
The Experiment

For many people, there could be no greater scientific discovery than proof of the existence of life on another planet. This year alone, we have seen examples of how even the hint of alien civilization can capture the attention of the media and, by extension, the public. The so-far-inexplicable light curve of the star KIC 8462852 discovered by NASA’s Kepler telescope has conjured speculation about “alien megastructures” orbiting the star. And for a few days in August, the press stirred over a “strong signal” from another star, HD 164595, that scientists thought could be of alien origin. (Subsequent observations and analysis quickly put a damper on initial reports.)

It is the quest for the discovery of alien life that Ben Miller explores in his new book The Aliens are Coming! In just over 300 pages, Miller provides a light-hearted but thorough exploration of the science behind alien life—what it might be like, where and how we might find it—and reflects on whether we could understand or recognize an alien at all.

Miller organizes the book into eight chapters but shifts from topic to topic with abandon. The opening chapter, “Extremophiles,” starts with the entry of Voyager 1 into interstellar space, dives below the Pacific Ocean with the Alvinsubmarine, and ends with the Huygens probe entering the atmosphere of Saturn’s largest moon, Titan. In between, Miller explains Darwinian evolution, managing to reference the television show Twin Peaks, the opening scenes of the movie Contact, and the “Get a Mac” advertising campaign of the late 2000s in the process.

The book continues in a similar vein—each chapter revolves around a theme but happily bounces off into sidebars and explanations. Some topics would have been enhanced with visuals. The third chapter, for example, has a single picture depicting the now defunct “Big Ear” radio telescope at the Ohio State University, which once (and only once) detected an incredibly strong narrowband radio signal from the constellation Sagittarius, but nothing to help the reader understand the science behind the detection of extrasolar planets.

Mazlan Othman, a Malaysian astrophysicist, served as the director of the United Nations Office for Outer Space Affairs from 2010 to 2014.Photo: Tomer Appelbaum

Mazlan Othman, a Malaysian astrophysicist, served as the director of the United Nations Office for Outer Space Affairs from 2010 to 2014.

As promised in the title, the book doesn’t disappoint when it comes to aliens. The Drake equation (a simple way to estimate the number of intelligent civilizations in our galaxy that we may be able to receive signals from), the Search for Extraterrestrial Intelligence (SETI) Institute, and the Fermi paradox (the question of why an older alien civilization hasn’t already colonized the galaxy) all receive excellent discussions. Despite the fact that we have so far failed to detect evidence of alien life, Miller is optimistic: “[I]f our galaxy contains 10,000 communicable civilizations among 200 billion stars, we’d need to search around ten million stars before we found anything. So far we have searched a paltry 10,000.”

Miller is at his best when he tells a straightforward narrative about a particular discovery or presents an original interview. His conversation with Mazlan Othman—the official “ambassador for Earth” of the United Nations Office for Outer Space Affairs—is particularly amusing, for example. “I do my best to try and convince her that I am not a crazy person, that I know my stuff about science, and that, while I think the evidence for UFOs is feeble, I am very interested in the possibility that there is intelligent, communicable life on other planets,” he writes. “And, in doing so, I am fairly sure that I come across as a crazy person.”

The book’s scope is not limited to alien civilizations. The origin of life on Earth is thoroughly discussed, in the context of what alien life could potentially be like and if it’s even likely to exist. Is Earth particularly and luckily well suited to life? Is the universe itself predisposed to life? These are among the interesting questions Miller addresses.

The book suffers later on, as Miller struggles to pack too much and too varied information into the final chapters. I did not expect to find thermodynamic equations in a chapter entitled “Life,” for example, but there they were. The appearance of these and other equations and the frequent use of field-specific jargon might frustrate some readers. Last, there are ample footnotes throughout the book, although no references—only a short (albeit good) “Further Reading” section at the end.

Despite the huge breadth of science—from cosmology to biogenesis—covered, The Aliens are Coming! is a concise work that will appeal to anyone who has ever wondered whether we are alone in the universe.


  1. NOTE: The opinions expressed in this review are the author’s own and do not reflect the views of the Department of Energy or the U.S. government.

About the author

The reviewer is at the Office of Science, U.S. Department of Energy, 1000 Independence Avenue SW, Washington, DC 20585, USA.