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.

"The world's leading alien hunter" -- New York Times Magazine From acclaimed Harvard astrophysicist and bestselling author of Extraterrestrial comes a mind-expanding new book explaining why becoming an interstellar species is imperative for humanity's survival and detailing a game plan for how we can settle among the stars. In the New York Times bestseller Extraterrestrial, Avi Loeb, the longest serving Chair of Harvard's Astronomy Department, presented a theory that shook the scientific community: our solar system, Loeb claimed, had likely been visited by a piece of advanced alien technology from a distant star. This provocative and persuasive argument opened millions of minds internationally to the vast possibilities of our universe and the existence of intelligent life beyond Earth. But a crucial question remained: now that we are aware of the existence of extraterrestrial life, what do we do next? How do we prepare ourselves for interaction with interstellar extraterrestrial civilization? How can our species become interstellar? Now Loeb tackles these questions in a revelatory, powerful call to arms that reimagines the idea of contact with extraterrestrial civilizations. Dismantling our science-fiction fueled visions of a human and alien life encounter, Interstellar provides a realistic and practical blueprint for how such an interaction might actually occur, resetting our cultural understanding and expectation of what it means to identify an extraterrestrial object. From awe-inspiring searches for extraterrestrial technology, to the heated debate of the existence of Unidentified Aerial Phenomena, Loeb provides a thrilling, front-row view of the monumental progress in science and technology currently preparing us for contact. He also lays out the profound implications of becoming--or not becoming--interstellar; in an urgent, eloquent appeal for more proactive engagement with the world beyond ours, he powerfully contends why we must seek out other life forms, and in the process, choose who and what we are within the universe. Combining cutting edge science, physics, and philosophy, Interstellar revolutionizes the approach to our search for extraterrestrial life and our preparation for its discovery. In this eye-opening, necessary look at our future, Avi Loeb artfully and expertly raises some of the most important questions facing us as humans, and proves, once again, that scientific curiosity is the key to our survival.

"Robert Zubrin is a true engineering genius like the heroic engineers of the past." -- Frederick Turner, American Enterprise Using nuts-and-bolts engineering and a unique grasp of human history, Robert Zubrin takes us to the not-very-distant future, when our global society will branch out into the universe. From the current-day prospect of lunar bases and Mars settlements to the outer reaches of other galaxies, Zubrin delivers the most important and forward-looking work on space and the true possibilities of human exploration since Carl Sagan's Cosmos. Sagan himself said of Zubrin's humans-to-Mars plan, " Bob Zubrin really, nearly alone, changed our thinking on this issue." With Entering Space , he takes us further, into the prospect of human expansion to the outer planets of our own solar system--and beyond.

David Lasser stands as one of the least-known but extraordinary pioneers of spaceflight. In 1930 he founded the American Interplanetary Society (AIAA) -- the same year he wrote this book -- the first book ever written in the English language to address the notion of spaceflight as a serious possibility. The book has not been in print since 1931 and yet it still stands up to scrutiny. The lucid style with which Lasser explains the basic concepts of rocketry make it a delight for anyone to read.