As our planet revolves around the Sun, it inspires the creatures that inhabit it to amazing feats of courage and ingenuity as they embark on an epic adventure across land, sea or air.
Earth tracks these journeys through the story of four heroic animals as they undertake their incredible passage from the harsh terrains of the north to the more temperate climates of the south.
Each challenge and each successive triumph marks a celebration of animal spirit and determination - a tribute to the incredible determination of life on our planet.
Shot over five years by the Planet Earth film crew, this 90-minute adventure sets these rites of passage against a spectacular background of glaciers, mountains, deserts and oceans, captured for the first time on film with breath-taking clarity.
Earth will be released on our screens from summer 2007.