When I first began planning this book, I believed that we would eventually find clear signs of life beyond our solar system, and suspected that contact with other cosmic civilizations was just a matter of time, for they were probably common throughout our galaxy. I believed that humans had a future, a destiny, beyond the Earth, and that our discoveries of other habitable or inhabited worlds would galvanize society to strive to voyage to the stars. I no longer hold these beliefs as foregone conclusions. My optimism for humanity’s long-term prospects has dimmed.
I now believe that while life may be widespread in the universe, creatures like us are probably uncommon, and technological societies are vanishingly rare, making the likelihood of contact remote at best. I am less confident than I once was that we will find unequivocal signs of life in other planetary systems within my lifetime. I believe that, when seen in the fullness of planetary time, our modern era will prove to have been the fulcrum about which the future of life turned for, at minimum, our entire solar system. I believe that we humans are probably the most fortunate species to have ever arisen on Earth, and that those of us now alive are profoundly privileged to live in what can objectively be considered a very special time.