It's a moment that's been depicted countless times in science fiction -- but what would actually happen when extraterrestrials make contact via a signal picked up on Earth? The moment could come as early as the end of this decade: if aliens receive signals sent by NASA's Deep Space Network (DSN) to the Pioneer 10 satellite in the 70s, for example. When the moment comes, the signal is most likely to be received by large ground-based telescopes such as FAST in China, the Very Large Array (VLA) in New Mexico and the Parkes Telescope in Australia, says former NASA expert Sylvester Kaczmarek. There is no universally agreed rule on how scientists or governments would respond - or on questions such as whether aliens would have rights. But extraterrestrial-focused organisations including the Search for Extraterrestrial Intelligence (SETI) drew up a framework in 2010.

In the fall of 2016, Oliver Buechse, a Green Bay-based strategy consultant, attended a conference in Silicon Valley with a focus on disruption in the financial industry. Interacting with the artificial intelligence and fintech community, Buechse noticed something different about the discussions there. AI, clearly, had already arrived on the West Coast. "All of California was abuzz about AI," Buechse said. "I thought, why aren't we talking about this in Wisconsin?" Wisconsin's apparent tardiness to the conversation concerned Buechse and he left compelled to spread the word. "Then I thought, 'Well, what am I going to do about it now that I know?'" he said. Eliciting fear or optimism, hype or indifference, artificial intelligence can be an elusive concept to pin down. Leading thinkers in the tech industry diverge on the subject. Entrepreneur Elon Musk has made headlines with near-apocalyptic predictions that the race for artificial intelligence will ignite World War III and that AI poses an existential threat to humans. Microsoft co-founder Bill Gates, meanwhile, has dismissed such concerns.