First Contact: An Alien Encounter BBC2, 9pm

In the past 20 years, technology has improved our ability to explore the universe, leading to the possibility that we could soon discover evidence of extraterrestrial life. This programme imagines what would happen if we did find aliens, mixing interviews with leading scientists and thinkers, including Dr Jill Tarter, with fictionalised news, podcasts and media reports. ★★★★★