Frozen Planet

This extraordinary journey heads across both the Arctic and Antarctic. These polar regions are the greatest and least-known wildernesses of all -- magical ice worlds inhabited by the most bizarre and hardy creatures on earth.

Spring returns to the polar regions, and the sun appears after an absence of five months. Warmth and life return to these magical ice worlds, and the greatest seasonal transformation on the planet is underway.

It's high summer in the polar regions, and the sun never sets. Vast hordes of summer visitors cram a lifetime of drama into one long, magical day -- they must feed, fight and rear their young in this brief window of plenty.

For the animals of the polar regions, autumn means dramatic battles and epic journeys. Time is running out -- the Arctic Ocean is freezing over, and the sea ice is advancing 2.5 miles a day around Antarctica.

There is no greater test for life than winter as temperatures plummet to 70 below and winds reach high speeds. Darkness and ice extend across the polar regions, and only a few remarkable survivors gamble on staying.

The extraordinary riches and wonders of the polar regions that have kept people coming here for thousands of years are revealed. Today, their survival relies on a combination of ancient wisdom and cutting edge science.