If aliens somehow manage to tap into our internet then I wonder what they’ll make of the Vulcan Language Institute. Its website proclaims, ‘In addition to language lessons and many pages with specialized terminology, we have information on noted Vulcans, Vulcan history etc.’ The planet is, of course, the fictional home of Star Trek’s Mr Spock, but fans have been developing the language since 1980 and it now has a vocabulary of 12,000 words.

Levenson’s book is about a fictional planet, but not Spock’s, whose pop-culture universe sadly doesn’t get a look-in. In the 19th century there was believed to be a planet inside the orbit of Mercury, and because it was so close to the Sun and presumably very hot, it was named