Sylvia Engdahl is the author of ten science fiction novels, six of which, including the Newbery Honor book Enchantress from the Stars, are YA books also enjoyed by many adults. Although she is best known as an author for Young Adults, her most recent novels, the Hidden Flame duology (Stewards of the Flame and Promise of the Flame) and the Rising Flame duology (Defender of the Flame and Herald of the Flame) are adult science fiction and are not appropriate for middle-school readers. For more information about them, watch the video trailer and visit her website.
She has also written a nonfiction book, The Planet-Girded Suns: The long History of Belief in Exoplanets, of which updated and expanded paperback and ebook editions were published in 2012, and a collection of her essays. Most of the nonfiction books listed under her name were edited, rather than written, by her as a freelance editor of anthologies for high schools.
Engdahl says, "I list only a few of the books I read here. Those that appear are just some of the best ones about subjects I deal with in my novels."