Neptune is the eighth and most distant planet from the Sun, an ice giant known for its deep blue color, supersonic winds, and frigid temperatures, with a solid core, icy mantle (water, ammonia, methane), and hydrogen/helium atmosphere. Discovered through math, it has long seasons, faint rings, and moons like Triton, taking nearly 165 Earth years to orbit the Sun, and only visited once by Voyager 2.