action adventure aliencontact criticism elfes elves etc extraterrestrialbeings fiction greekpoetry guerrespatiale hardsciencefiction hellenistic human-alienencounters imaginaryplaces imaginarywarsandbattles interplanetaryvoyages lieuximaginaires lifeonotherplanets magic nouvelles princes quests(expeditions) quête rencontresaveclesextraterrestres romans sciencefiction spacecolonies spaceopera spacewarfare survival textgenese textkritik textual vieextraterrestre voyagesinterplanétaires