The winner of every major science fiction award, Kim Stanley Robinson is a novelist who looks ahead with optimism even while acknowledging the steep challenges facing our planet and species: a clear-eyed realist who has not forgotten how to dream. His new novel offers his most audacious dream yet. At the heart of a brilliant narrative that stretches from Renaissance Italy to the moons of Jupiter is one man, the father of modern science: Galileo Galilei.To the inhabitants of the Jovian moons, Galileo is a revered figure whose actions will influence the subsequent history of the human race. From the summit of their distant future, a charismatic renegade named Ganymede travels to the past to bring Galileo forward in an attempt to alter history and ensure the ascendancy of science over religion.