This is a splendid book and a major achievement in the study of Mars. It’s also much more than a book about mapping, as the subtitle suggests. Although Oliver Morton pays due homage to generations of patient sky watchers, the real story of mapping Mars began in July 1965, when the Mariner 4 fly-by gave us a score of grainy black- and-white images. The missions that followed, with orbiters, landers and more fly-bys, provided more coverage at ever higher resolution. As scientists gradually stitched the images together to generate a pole-to-pole mosaic, the complex cratered surface of this world emerged.