Picture Books
While readers of all ages can enjoy picture books, they have special appeal to children ages six and under. Space stories in picture books tend to feature colorful and goofy aliens who are invariably friendly. Some of the aliens live on earth while other pictures books let kids go exploring in space ships. Some examples of this genre include Ted Arnold's "Green Wilma," Jon Scieszka's "Robot Zot!," Patrick O'Brien's "You are the First Kid on Mars," Theresa Heine's "Star Seeker: A Journey to Outer Space," Caroline Castle's "Teatime in Space" and Doug Cushman's "Space Cat."
Chapter Books or Easy Readers
Many books target beginning readers. These books are simple enough that early readers can gain confidence and tend to have high appeal subjects. Most space books for this age group focus on the humorous, and like the picture books, contain many brightly colored illustrations. Many of these books are in chapter format, with short chapters. Books for this age group tend to be around 100 pages or less. Examples of space books in this genre include Mike Gorman's "Alien Expedition," Jane Yolen's "Commander Toad in Space," Jonathan Etra's "Aliens for Breakfast," Daniel Pinkwater's "Fat Men from Space," James Kochalka's "Pinky and Stinky" and Bruce Coville's "Space Brat."
Young Adult Novels
Young adult novels, also known as juvenile fiction, targets the independent reader. Often there is little to distinguish these books from their adult counterparts except that the protagonists are usually of teen age or younger and there is typically less sex, violence and vulgar language than there is in adult books. Some examples of space books in this genre range from classics to pulp novels to newer fiction. They include Orson Scott Card's "Ender's Game" and the rest of the series set in that universe, Madeline L'Engle's "A Wrinkle in Time," James Patterson's "Daniel X: Alien Hunter," Stephen Hawking's "George's Secret Key to the Universe," Philip Reeve's "Larklight," Katherine Applegate's "Mayflower Project" and Sylvia Waugh's "Space Race."
Adult Books Appropriate for Children
Many so-called adult novels are also appropriate for children, especially pre-teens and teens. It is important to vet adult science fiction novels carefully as many of them, especially the early ones in the genre, are heavy on sexual content, often exploring different forms of sexuality as humans interact with aliens. Use your judgment about the maturity of your child and how much she is able to handle. Some examples of adult novels set in space or involving space travel that may appeal to the younger set include such classics as Arthur Clarke's "2001," Isaac Asimov's Foundation series and the "I, Robot" series," H.G. Wells' "The Time Machine," Douglas Adams' "Hitchhikers Guide to the Galaxy," and Frank Herbert's Dune series.
Books Based on Movies or Television
Another way to introduce children to space stories is by hooking them in through some of their favorite television shows or movies. While few of the books in this genre represent great literature, they do provide solid entertainment. Nearly every movie has a novelization, most of which are better read after the movie. Major space operas also have series of books that have been written to fill in "gaps" in the shows. Star Wars has hundreds of books as does every incarnation of Star Trek. Shows such as Battlestar Galactica and Babylon 5 also have novels that accompany the series.