Book Five of Johannes Kepler's great masterpiece on planetary motion is presented with an introduction by the ultimate authority on this topic, noted physicist and bestselling author Stephen Hawking. Modifying Copernicus's sun-centered model of the universe, Kepler's 1619 work went on to establish laws of planetary motion, forming the basis for Newton's discoveries some 60 years later. As part of our On the Shoulders of Giants series, this translation of the original edition of Kepler's monumental essay includes an insightful biography and a highly accessible summary putting into context the significance of Harmony of the World.