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 Symposium on the Global Effects of Environmental Pollution has performed an important task; it has helped to determine the world-wide impact of certain types of local pollution and has uncovered certain unsuspected effects that might hold dan gerous implications for the future. This Symposium should help to make the world aware of a crisis that is becoming more ominous and that involves the developing as well as the developed countries - the crisis of the human environment. The causes of this crisis are not difficult to discern. There has been an unprecedented increase in the world's population, an ever-increasing rate of urbanization, and in many countries, a continuous process of industrialization. Essentially, advancing technology has made it possible for a minority of mankind to achieve affluence and holds out hope for improving the well-being of the great majority. But, because it has not been integrated into the natural environment, this very technology - in industry, in agriculture or in transport - is having many undesir able and potentially catastrophic consequences. Our air, our water and our soil are in grave danger. Many species of animal and plant life have become extinct or are facing extinction. The loss to mankind is grave and even the future oflife on earth may be in danger. The challenge is to find ways of repairing the harm already done and to prevent further harm.