Humans are still searching for signs of intelligent alien life on other planets - but how would we react towards it if we ever did make contact?
According to many of our cultural touchstones, there's only one thing for it if extraterrestrials ever take a cosmic detour to our planet: heavy artillery fire.
But from the sugary 1980s blockbuster ET the Extra-Terrestrial and the decades of Star Trek episodes to the books of Isaac Asimov and Ursula K Le Guin, science fiction writers have long wrangled with the question: how would we really treat them?