As our ability to observe space improves with ever-progressing technology, we better grasp the farthest reaches of the cosmos and heighten our understanding of the universe in its entirety. Spacecraft exploration of the outermost planets in our solar system—Jupiter, Saturn, Uranus, and Neptune—reveals many features of these seemingly harsh environments and moves us closer to comprehending the origins of our own planet as well as others. This insightful volume examines the characteristics of these remote planets and the paths they illuminate in our quest for celestial knowledge.