Are we alone in the universe? The scientific hunt for extraterrestrial intelligence is now well into its fifth decade, and we still haven’t discovered any cosmic company. Could all this mean that finding biology beyond Earth, even if it exists, is a project for the ages – one that might take centuries or longer?

New approaches and new technology for detecting sentient beings elsewhere suggest that there is good reason to expect that we could uncover evidence of sophisticated civilizations – the type of aliens we see in the movies and on TV – within a few decades. But why now, and what sort of evidence can we expect? And how will that affect humanity?

Also, if we do find E.T., what would be the societal impact of learning that something, or someone, is out there?