Apollo 11 astronaut Aldrin welcomes young people to his crew for a journey "to build the first city on Mars," while related passages fill in information about the planet and the challenges of colonizing it. Aldrin wrote the book with Dyson, a science writer, physicist, and one-time NASA flight controller. The text includes first-person narrative passages directed at the reader ("It will be our job to build the first city on Mars"), as well as fact-packed informational sections. Brightening almost every page of this colorful book are photos, NASA images of space objects, and digital pictures (sometimes incorporating photo elements) of imagined scenes that occasionally look stilted. A number of hands-on activities are included, with small-print directions and modest photos as illustrations. The book's text and the visuals sometimes strike a tone intended for younger kids, while at other times they seem to target an older audience. Aldrin's name will draw readers among space-exploration fans, including the many who see Mars as the next frontier.