Frozen Planet: King penguins on blubber beach

Frozen Planet: Deep in to the polar bear's den

Field Producer Jason Roberts and Cameraman Mark Smith crawl into a polar bear's den in the Arctic. Nervous that the bear will return, they bravely take a tour of the den, lined with icy polar bear hairs and scratched with claw marks.

Frozen Planet: Musk Ox Save Calf from Wolves

Arctic wolves attack a musk ox calf on Canada's Ellesmere Island, but the herd rushes to its defense. When threatened, musk oxen will form a defensive circle around the calves, the sick and the elderly.

Frozen Planet: Killer Whales "Wave Wash" Seal

A pod of orcas, or killer whales, cooperate to wash a Weddell seal off an ice floe. This sequence, filmed for Frozen Planet, marks the first complete filming of killer whale "wave washing" behavior.

Frozen Planet: Gray Wolves Chase Down Bison

A pack of northern gray wolves harass and then attack a herd of wood bison. This is the first time wolves have been filmed hunting bison, both from the ground and from the air.

Frozen Planet: Caterpillar Survives Frozen Death

The Arctic's woolly bear caterpillar freezes solid every winter, the natural antifreeze in its body keeping it from dying. It takes 14 years before it has eaten enough to become a moth.

Frozen Planet: Woolly Bear Caterpillar

Frozen Planet producer Vanessa Berlowitz takes you behind the scenes of one of only four scenes in the series that were shot under controlled conditions.

Frozen Planet: Awkward Sea Lion Chases Penguin

A group of Gentoo penguins needs to go fishing but a Southern sea lion stands between them and their meals.

Frozen Planet: Living With Criminal Penguins

The most extreme shoot on the Frozen Planet series? Hands down, the Adelie penguin shoot: a grueling 4-month exercise in isolation and endurance. The two filmmakers nearly lost their minds, but came back with brilliant footage.

Frozen Planet: Wolves of Winter

Go behind the scenes of Frozen Planet and witness a wolf and bison in a life or death battle.

Frozen Planet: Surrounded by Fur Seals

A cameraman discusses the arrival of Antarctic fur seals to a breeding colony. The males have set up territory and the females have arrived to give birth to their pups. The males battle along the edges of their territories, creating a dangerous situation.

Earth: Prescribed Fires Help Prairies

In southern Arkansas, Nature Conservancy officials set 80 acres of prairie ablaze. Jorge Ribas walks through fire to find out why they do it.

Frozen Planet: Penguins Launch Like Rockets

After three months feeding at sea, the female penguins return to their colony to eager mates.