Mankind's mythologies have been ransacked so thoroughly that the need to identify each orbiting rock has resulted in such curiosities as Zappafrank, Lennon, Mc Cartney and even Bagehot.

Every planet, asteroid, moon, mountain and crater has its name.

Those who study the solar system fall into the former camp.

Those who study other planetary systems have been more restrained.

Planets orbiting stars beyond the sun are labelled merely with the name of the star and a suffix letter.

Even if planets and moons were found round Alpha Centauri, as envisaged by the writers of “Avatar”, they would not get glorious monikers like Polyphemus and Pandora.

They would just be letters—and lower-case ones, to boot. Though the nominative diarrhoea of the solar system may have gone a little far, a well-chosen name is both picturesque and memorable.