New York Times Bestseller | Wall Street Journal Bestseller | Publishers Weekly Bestseller | Publishers Marketplace 2020 Buzz Book | Amazon Best Book of the Year | Longlisted for the 2022 PEN/E.O. Wilson Literary Science Writing Award Harvard's top astronomer lays out his controversial theory that our solar system was recently visited by advanced alien technology from a distant star. "Provocative and thrilling ... Loeb asks us to think big and to expect the unexpected."--Alan Lightman, New York Times bestselling author of Einstein's Dreams and Searching for Stars on an Island in Maine In late 2017, scientists at a Hawaiian observatory glimpsed an object soaring through our inner solar system, moving so quickly that it could only have come from another star. Avi Loeb, Harvard's top astronomer, showed it was not an asteroid; it was moving too fast along a strange orbit, and left no trail of gas or debris in its wake. There was only one conceivable explanation: the object was a piece of advanced technology created by a distant alien civilization. In Extraterrestrial, Loeb takes readers inside the thrilling story of the first interstellar visitor to be spotted in our solar system. He outlines his controversial theory and its profound implications: for science, for religion, and for the future of our species and our planet. A mind-bending journey through the furthest reaches of science, space-time, and the human imagination, Extraterrestrial challenges readers to aim for the stars--and to think critically about what's out there, no matter how strange it seems.

Isaac Asimov concludes that we are not alone! Using the most up-to-date astronomical research as the backdrop for speculation, Asimov confronts the possibilities of other-worldly life head-on in Extraterrestrial Civilizations . In what will surely become one of the most provocative books ever written on the possibilities of life elsewhere in the universe, the incomparable Isaac Asimov provides chilling, hopeful, and exciting new insights. Here is astounding speculation about where the next giant step for mankind will take us. . . . Praise for Extraterrestrial Civilizations "[Isaac] Asimov holds our attention as he builds a meticulous case. We are not alone. It's just a matter of time until we know for sure." -- Miami Herald "Intriguing" -- Publishers Weekly

In a unique effort, this book brings together, for the first time, scholarly analyses by eminent researchers of the historical, social, legal, and cultural influences on the young newcomers' lives as well as reports by practitioners in major aid organizations about the concrete work that their organizations have been carrying out.