Book excerpt: Like the adventurer who circled an iceberg to see it on all sides, Mariana Gosnell, former Newsweek reporter and author of Zero Three Bravo, a book about flying a small plane around the United States, explores ice in all its complexity, grandeur, and significance.More brittle than glass, at times stronger than steel, at other times flowing like molasses, ice covers 10 percent of the earth’s land and 7 percent of its oceans. In nature it is found in myriad forms, from the delicate needle ice that crunches underfoot in a winter meadow to the massive, centuries-old ice that forms the world’s glaciers. Scientists theorize that icy comets delivered to Earth the molecules needed to get life started, and ice ages have shaped much of the land as we know it.Here is the whole world of ice, from the freezing of Pleasant Lake in New Hampshire to the breakup of a Vermont river at the onset of spring, from the frozen Antarctic landscape that emperor penguins inhabit to the cold, watery route bowhead whales take between Arctic ice floes. Mariana Gosnell writes about frostbite and about the recently discovered 5,000-year-old body of a man preserved in an Alpine glacier. She discusses the work of scientists who extract cylinders of Greenland ice to study the history of the earth’s climate and try to predict its future. She examines ice in plants, icebergs, icicles, and hail; sea ice and permafrost; ice on Mars and in the rings of Saturn; and several new forms of ice developed in labs. She writes of the many uses humans make of ice, including ice-skating, ice fishing, iceboating, and ice climbing; building ice roads and seeding clouds; making ice castles, ice cubes, and iced desserts. Ice is a sparkling illumination of the natural phenomenon whose ebbs and flows over time have helped form the world we live in. It is a pleasure to read, and important to read—for its natural science and revelations about ice’s influence on our everyday lives, and for what it has to tell us about our environment today and in the future.