There has been a good deal of work on the crossover between SF and children’s literature—the YA market, after all, is an important one for the genre (Farah Mendelsohn’s exhaustive The Intergalactic Playground is a key research resource here, of course). I’ll confine myself here to noting briefly only picture books for the pre-reading child; but even so I’m only scratching the surface of a very large body of often extraordinary, wonderful texts.
Anyone with children knows that there is a strong non-realist component to many of the best illustrated tales for young readers. This shouldn’t surprise us when we recall the fairy-tale provenance of much of this discourse, and accordingly we might expect picture books to have more in common with Fantasy than SF. For instance, the lunar element in James Thurber and Louis Slobodkin’s touching Many Moons (1943) is only the object of imaginative yearning by the princess protagonist. Conceivably, we might want to argue that ‘Dr Seuss’ (Theodor Seuss Geisel) can be claimed for SF: after all, he created a distinctive and alien-looking world, and some of his books seem to parse sf tropes—Horton Hears A Who! (1954) is a Voltairean or Swift-like fable of the interaction of differently scaled worlds, and The Butter Battle Book (1984) tells of an arms-race between two nations who disagree (in another nod to Swift) over which way to butter their toast, and whose ordnance develops from slingshots to giant battle-robots and flying machines. But it feels somehow wrong to apply the descriptor ‘science fiction’ to Seuss, whose beauty and symbolic eloquence is much more enchanting than estranging. And it is Fantasy, not SF, that informs such masterpieces of the form as Maurice Sendak’s great monster fable Where The Wild Things Are (1963) or Raymond Briggs’ magical The Snowman (1978).
That said, the 1950s and 1960s did see a distinctively science fictional variety of picture book achieve widespread and in some cases lasting success. In the 1950s Scots writer Ruthven Todd and US illustrator Paul Galdone produced a series of engaging Space Cat books, in which the eponymous feline gets his own spacesuit and explores the solar system (Space Cat ; Space Cat Visits Venus ; Space Cat Meets Mars ; Space Cat and the Kittens ). This series was popular enough for an unauthorized parody, Space Cat on Mushrooms, to be produced in the 1960s. Czech writer and illustrator Miroslav Sasek enjoyed lasting success with This is Cape Canaveral (1963; reissued as This is Cape Kennedy ; currently in print as This is the Way to the Moon ), an absorbing account of the early Apollo program. Gertrude Moore (mother of astronomer Patrick Moore) produced a whimsically imaginative account of various alien lifeforms in Mrs Moore in Space (1974). US writer Eric Carle, most famous for The Very Hungry Caterpillar (1969), also wrote a charming lunar adventure Papa, Please Get The Moon For Me (1986). UK artist David McKee created the character ‘Mr Benn’ (a man who assumes various identities by visiting a magical dressing-up shop) for BBC TV in 1971, and later wrote various books starring the character, amongst them the splendid Mr Benn: Spaceman (1993). Dan Yaccarino’s Zoom! Zoom! Zoom! I’m Off To The Moon! (1997), though elementary, has great verve.
In these sorts of books, the conventions of sf are treated more for comic than suspenseful or conceptual-extrapolative effect; the focus is almost always on readerly recognition and earthly interest, as is appropriate for a very young audience. UK author Jeanne Willis has written a series of books from the point of view of alien professor ‘Dr. Xargle’ (beginning with Dr Xargle’s Book of Earth Hounds  and Dr Xargle’s Book of Earthlets ) that provide amusing perspectives on mundane foibles. Mort Drucker (most famous as the artist for MAD magazine) and Arthur Yorinks collaborated on the brightly funny xenovegetation invasion story Tomatoes From Mars (1999). On occasion sometimes such stories can be more meditative, as with Pat Schories’ Jack and the Night Visitors (2006) a wordless picture book of a small boy encountering a UFO. But by and large, fun is the watchword where younger readers are concerned (there are some adult writers of the genre who could, perhaps, usefully take this lesson on board). One contemporary sf classic for younger readers is Simon Bartram’s immensely fun Man on the Moon (2002): Bob is an astronaut who works by day as the moon’s janitor, keeping it clean for tourists and playing inadvertent hide-and-seek with aliens, rendered via detailed, painterly illustrations. Robots are also perennially popular with very young children; and of the great many picture books about them, Bob Staake’s cleanly angular Hello, Robots! (2004) and Heather Brown’s The Robot Book (2010) are particularly to be recommended.