“With wit and brio, Frank separates current nonsense about aliens from the serious and fascinating search for extraterrestrial life.” —Carlo Rovelli, New York Times bestselling author of Seven Brief Lessons on Physics From astrophysicist Adam Frank, a little book on the biggest questions in our search for extraterrestrial life and the field of astrobiology, questions we stand ready to answer. Everyone is curious about life in the Universe, UFOs and whether ET is out there. Over the course of his thirty-year career as an astrophysicist, Adam Frank has consistently been asked about the possibility of intelligent life in the universe. Are aliens real? Where are they? Why haven’t we found them? What happens if we do? We’ve long been led to believe that astronomers spend every night on the search for extraterrestrial intelligence (SETI), but the truth is we have barely started looking. Not until now have we even known where to look or how. In The Little Book of Aliens, Frank, a leading researcher in the field, takes us on a journey to all that we know about the possibility of life outside planet Earth and shows us the cutting-edge science that has brought us to this unique moment in human history: the one where we go find out for ourselves. In this small book with big stakes, Frank gives us a rundown of everything we need to know, from the scientific origins of the search for intelligent life, the Fermi Paradox, the discovery of exoplanets, the Kardashev Scale, the James Webb Telescope, as well as UAPs and their conspiracy theories. Drawing from his own work and that of other scientists studying the possibility of alien civilizations, he brings together the latest scientific thinking, data, ideas, and discoveries to equip us with the critical facts as we stand at what may be the last moment in human history where we still believe we are all alone. This book is about everything we do—and do not—know about life, intelligent or otherwise beyond Earth. In language that is engaging, entertaining and fun, The Little Book of Aliens provides a comprehensive first look at how close we are to finding out if others actually exist—and if they do, what they might be like. Humankind is on the precipice of finding its neighbors. What comes next? No person is better suited to answer that question—and lead the search—than Adam Frank.  This essential guide separates scientific fact from science fiction to answer the biggest questions in cosmology: The Great Silence: Explore the Fermi Paradox and the Drake Equation—the essential frameworks scientists use to ask: if the universe is so vast, where is everybody? - UFOs vs. UAPs: Get a sober, scientific perspective on the videos and government reports that have captured our imagination. What are they, and what aren’t they? - The Exoplanet Revolution: Learn how the discovery of billions of planets orbiting other stars has completely transformed the search for life, giving us a map of where to look. - Technosignatures & Biosignatures: Discover the cutting-edge methods scientists are developing to find signs of alien life—both microbial and technological—by studying distant planetary atmospheres. “This wonderful book unravels the tangled ball of humanity’s thinking about aliens, and tells the whole story with high humor and immense clarity. Adam Frank helpfully explains what scientists are doing now to explore the galaxy remotely in search of answers to this fascinating mystery.  Read this and you’ll know as much as anyone does on the topic— it’s as clear as a map, as clear as Drake’s Equation.”   - Kim Stanley Robinson, author of The Ministry for the Future and the Mars trilogy "From the details of the origins of life on Earth, to the physics (and hypothetical future physics) of interstellar travel, The Little Book of Aliens is a comprehensive exploration of the seemingly limitless potential of intelligent life, human and beyond. Frank’s book is science writing at its best, revealing the awe-inspiring capacity of science to help us understand, and navigate, the universe.” - Annaka Harris, New York Times bestselling author of Conscious: A Brief Guide to the Fundamental Mystery of the Mind “Aliens and UFOs have held perennial fascination for us all. Now, Adam Frank gives us an entertaining romp through our quickly changing attitudes to these topics. In just the last decade, biologists have achieved genuine insights into life’s origin, and astronomers have discovered thousands of ‘exoplanets’ orbiting distant stars. At last, we understand what to look for and where, and Adam Frank has written it down for us.”  - Martin Rees, Astronomer Royal and author of From Here to Infinity and On the Future “After years of dreaming about exploring the cosmos for signs of intelligent life, [Frank] and other scientists are on the threshold of a new era of unprecedented discovery in the field of astrobiology…. The book brims with fascinating facts and speculations….Frank advises we look for a