“Close orbit”: that’s the only negative in all this. Bb aerpaps to be even nearer to its sun than Mercury is to ours, making it highly unlikely anything could survive. Having long fantasised about our neighbour, it will be disappointing if when we eventually manage to pop over it turns out there is no-one in, and never had been. But what if it isn’t all on its own? Close to 100 star systems with more than one world have now been discovered (with many more awaiting confirmation), so it is far from impossible that Alpha Centauri could harbour other planets, perhaps even in the “Goldilocks zone” of habitability. If such a world exists, that will only make the science fiction seem even more prophetic although I wouldn’t hold out too much hope when it comes to the details. Down the decades we’ve had the natives of Alpha Centauri envisaged as pygmy elephants with multiple trunks (Larry Niven and Jerry Pournelle’s Footfall*), six-armed, one-eyed giant green hermaphrodites (the two Dr Who Peladon serials) and robots in disguise (it’s where the Transformers home planet Cybertron originated before it was thrown out of orbit).On the BBC radio science programme I present, we even invited listeners to suggest what this closest-by-far extra-solar planet should be called. Among my favourite suggestions were Heart (for both affectionate and anagrammatic reasons) and Mearth (like Earth, only funnier).