As groups of almond-eyed aliens troop past or peer in from page edges, Krull sifts through basic facts and official explanations about the mysterious debris found near Roswell, New Mexico, in 1947, and offers rationales for the rumors that have circulated ever since. She deals only tangentially with the entire UFO phenomenon, but does bring in the Cold War, the film E.T., the TV series X-Files, and government conspiracy theories in general. Though the paper and Web resources with which she closes may overwhelm the young or reluctant readers she addresses here, the skeptical but not dismissive tone of the presentation will give her audience a leg up in distinguishing fact from fancy without closing down the possibility of alternative versions of events. (Nonfiction. 8-10)
