The Universe is an unfathomably large and ancient place. It began with a giant explosion roughly 14 billion years ago (the Big Bang) and has been in a state of expansion ever since. Based on current estimates, there are more than 2 trillion galaxies in the "observable Universe," some with as many as a trillion stars each. Within our galaxy alone, there are between 100 and 400 billion stars and 100 to 160 billion planets. And according to every bit of scientific evidence available, the ingredients for life are everything in abundance. For this reason, scientists can be forgiven for the conjecture that life exists elsewhere in the Universe, and advanced life to boot. Not only is it a foregone conclusion based on science, but there is ample historical precedent for assuming that humanity is not alone. With the birth of modern astronomy in the late-19th and early-20th centuries, scientists sought to address this question head-on by searching for indications of life and civilizations.…