Adult male polar bear (Ursus maritimus) on multi-year ice floes in Franz Josef Land, Russia, Arctic Ocean, Eurasia

Antarctic fur seal bull (Arctocephalus gazella) on South Georgia, Southern Ocean, Polar Regions

Crabeater seals (Lobodon carcinophaga) hauled out on ice floe in Neko Harbor near the Antarctic Peninsula, Antarctica, Polar Regions

Circumpolar star trail with a tree silhouette and a campfire in the background, Emilia Romagna, Italy, Europe

Concentric circumpolar star trail above sand dunes in the Rub al Khali desert, Oman, Middle East

Views of Deception Island, an island in the South Shetland Islands off the Antarctic Peninsula

Gentoo penguins (Pygoscelis papua) in Antarctica

The Leopard seal (Hydrurga leptonyx) is the second largest species of seal in the Antarctic

Lindblad Expeditions guests doing the "polar Plunge" in Port Foster near Whalers Bay inside the caldera on Deception Island, South Shetland Island Group, Antarctica. NO MODEL RELEASES FOR THIS IMAGE.

Adult emperor penguin (Aptenodytes forsteri) on sea ice near Snow Hill Island in the Weddell Sea, Antarctica.

Adult emperor penguin (Aptenodytes forsteri) on sea ice near Snow Hill Island in the Weddell Sea, Antarctica.

Adult female leopard seal (Hydrurga leptonyx) stalking, then killing and eating an adult gentoo penguin in Paradise Bay, Antarctica, Southern Ocean

Adelie penguin (Pygoscelis adeliae) near the Antarctic Peninsula, Antarctica.

A small pod of 8 Type B killer whales (Orcinus nanus) in pack ice near Snow Hill Island Island, Weddell Sea, Antarctica, Southern Ocean

Guests from the Lindblad Expedition ship National Geographic Explorer enjoy a hot asado sandwich prepared by staff at BBQ on an ice floe near Adelaide Island, Antarctica

Curious adult leopard seal (Hydrurga leptonyx) approaches Zodiac near Booth Island, Antarctica, Southern Ocean

Adelie penguin (Pygoscelis adeliae) near the Antarctic Peninsula, Antarctica.

Molting gentoo penguin (Pygoscelis papua) feather detail in Antarctica

Views of the Drake Passage, the body of water between the southern tip of South America at Cape Horn, Chile and the South Shetland Islands of Antarctica

Humpback whale (Megaptera novaeangliae) surfacing near Zodiac near the Antarctic Peninsula, Antarctica, Southern Ocean

Humpback whale (Megaptera novaeangliae) flukes-up dive near the Antarctic Peninsula, Antarctica, Southern Ocean

Adult emperor penguin (Aptenodytes forsteri) on sea ice near Snow Hill Island in the Weddell Sea, Antarctica.

Guests from the Lindblad Expedition ship National Geographic Explorer take the Polar Plunge off ice floe in the Weddell Sea, Antarctica, Southern Ocean

Gentoo penguin (Pygoscelis papua) chicks covered with mud and guano on Cuverville Island, Antarctica, Southern Ocean

Lindblad Expeditions guests doing the "polar Plunge" in Port Foster near Whalers Bay inside the caldera on Deception Island, South Shetland Island Group, Antarctica. NO MODEL RELEASES FOR THIS IMAGE.

Adult emperor penguin (Aptenodytes forsteri) on sea ice near Snow Hill Island in the Weddell Sea, Antarctica.

Kayaking with a leopard seal near Danco Island, Antarctica

Adelie penguin (Pygoscelis adeliae) tobogganing near the Antarctic Peninsula, Antarctica.

Guests from the Lindblad Expedition ship National Geographic Explorer enjoy a hot asado sandwich prepared by staff at BBQ on an ice floe near Adelaide Island, Antarctica

The Leopard seal (Hydrurga leptonyx) is the second largest species of seal in the Antarctic

Lindblad Expeditions guests doing the "polar Plunge" in Port Foster near Whalers Bay inside the caldera on Deception Island, South Shetland Island Group, Antarctica. NO MODEL RELEASES FOR THIS IMAGE.

Adult Antarctic Minke Whale (Balaenoptera bonaerensis), also known as the Southern Minke Whale, breaching near the Antarctic Peninsula

Divers Lisa Trotter and Robert Alexander enter the water with a large, curious, female leopard seal (Hydrurga leptonyx) near Booth Island on the western side of the Antarctic Peninsula, Antarctica

Full moon (plus 1 day) rising over icebergs in the Weddell Sea, Antarctica. MORE INFO This moonrise occurred on January 1, 2010, the night after the blue moon full of December 31, 2009.

Wandering albatross (Diomedea exulans) on the wing in the Drake Passage between the tip of South America and the Antarctic Peninsula, Southern ocean

Full moon (plus 1 day) rising over icebergs in the Weddell Sea, Antarctica. MORE INFO This moonrise occurred on January 1, 2010, the night after the blue moon full of December 31, 2009.

Wandering albatross (Diomedea exulans) on the wing in the Drake Passage between the tip of South America and the Antarctic Peninsula, Southern ocean

Adult emperor penguin (Aptenodytes forsteri) on sea ice near Snow Hill Island in the Weddell Sea, Antarctica.

Adelie penguin (Pygoscelis adeliae) near the Antarctic Peninsula, Antarctica.

Lindblad Expeditions guests on board the National Geographic Explorer with a lone adult emperor penguin (Aptenodytes forsteri) on sea ice, Antarctica

Southern Giant Petrel (Macronectes giganteus) taking flight near the Antarctic Peninsula, Southern Ocean

An adult Brown Skua (Catharacta antarctica) near the Antarctic peninsula in the southern ocean

Lindblad Expeditions guests doing the "polar Plunge" in Port Foster near Whalers Bay inside the caldera on Deception Island, South Shetland Island Group, Antarctica. NO MODEL RELEASES FOR THIS IMAGE.

Adult southern fulmar (Fulmarus glacialoides) on the wing in the Drake passage between the tip of South America and Antarctica. Southern Ocean

A small pod of 8 Type B killer whales (Orcinus nanus) in pack ice near Snow Hill Island Island, Weddell Sea, Antarctica, Southern Ocean

Guests from the Lindblad Expedition ship National Geographic Explorer enjoy a hot asado sandwich prepared by staff at BBQ on an ice floe near Adelaide Island, Antarctica

Red and green algae-covered snow on Petermann Island, Antarctica, Southern Ocean

Adelie penguin (Pygoscelis adeliae) toboggan prints in fresh snow near the Antarctic Peninsula, Antarctica.

The Leopard seal (Hydrurga leptonyx) is the second largest species of seal in the Antarctic

Kayaking with a leopard seal near Danco Island, Antarctica

Guests from the Lindblad Expedition ship National Geographic Explorer take the Polar Plunge off ice floe in the Weddell Sea, Antarctica, Southern Ocean

Researchers from OCEANITES counting penguins from the Lindblad Expedition ship National Geographic Explorer (shown here is )working in Antarctica

Full moon (plus 1 day) rising over icebergs in the Weddell Sea, Antarctica. MORE INFO This moonrise occurred on January 1, 2010, the night after the blue moon full of December 31, 2009.

Adelie penguin (Pygoscelis adeliae) near the Antarctic Peninsula, Antarctica.

Adult male leopard seal (Hydrurga leptonyx) with Lindblad Expeditions guest in Zodiac

Kayaking with a leopard seal near Danco Island, Antarctica

Iceberg detail in and around the Antarctic Peninsula during the summer months, Southern Ocean

The Leopard seal (Hydrurga leptonyx) is the second largest species of seal in the Antarctic

Lindblad Expeditions guests doing the "polar Plunge" in Port Foster near Whalers Bay inside the caldera on Deception Island, South Shetland Island Group, Antarctica. NO MODEL RELEASES FOR THIS IMAGE.

Guests from the Lindblad Expedition ship National Geographic Explorer enjoy a hot asado sandwich prepared by staff at BBQ on an ice floe near Adelaide Island, Antarctica

The Leopard seal (Hydrurga leptonyx) is the second largest species of seal in the Antarctic

Adult emperor penguin (Aptenodytes forsteri) foot print on frsh snow near Snow Hill Island in the Weddell Sea, Antarctica.

Natural history staff from the Lindblad Expedition ship National Geographic Explorer doing various things in and around the Antarctic Peninsula

Curious adult leopard seal (Hydrurga leptonyx) approaches Zodiac near Booth Island, Antarctica, Southern Ocean

Adult macaroni penguin (Eudyptes chrysolophus) in Elsehul Bay on South Georgia, Southern Ocean

Divers Lisa Trotter and Robert Alexander enter the water with a large, curious, female leopard seal (Hydrurga leptonyx) near Booth Island on the western side of the Antarctic Peninsula, Antarctica

National Geographic photographer Flip Nicklin from the Lindblad Expedition ship National Geographic Explorer in Antarctica

Guests from the Lindblad Expedition ship National Geographic Explorer enjoy a hot asado sandwich prepared by staff at BBQ on an ice floe near Adelaide Island, Antarctica

Adult Antarctic Minke Whale (Balaenoptera bonaerensis), also known as the Southern Minke Whale, breaching near the Antarctic Peninsula

Adult emperor penguin (Aptenodytes forsteri) on sea ice near Snow Hill Island in the Weddell Sea, Antarctica.

Lindblad Expeditions guests with a lone adult emperor penguin (Aptenodytes forsteri) on sea ice in the Gullet between Adelaide Island and the Antarctic Peninsula, Antarctica.

Adult female leopard seal (Hydrurga leptonyx) stalking, then killing and eating an adult gentoo penguin in Paradise Bay, Antarctica, Southern Ocean

Lindblad Expeditions guests doing the "polar Plunge" in Port Foster near Whalers Bay inside the caldera on Deception Island, South Shetland Island Group, Antarctica. NO MODEL RELEASES FOR THIS IMAGE.

Captain Oliver Kruess (L) and Expedition Leader Tim Soper (R) from the Lindblad Expedition ship National Geographic Explorer in Antarctica

Lindblad Expeditions guests doing the "polar Plunge" in Port Foster near Whalers Bay inside the caldera on Deception Island, South Shetland Island Group, Antarctica. NO MODEL RELEASES FOR THIS IMAGE.

Wandering albatross (Diomedea exulans) on the wing in the Drake Passage between the tip of South America and the Antarctic Peninsula, Southern ocean

The Leopard seal (Hydrurga leptonyx) is the second largest species of seal in the Antarctic

Iceberg detail in and around the Antarctic Peninsula during the summer months, Southern Ocean

A small pod of 6 to 8 Type B killer whales (Orcinus nanus) in dense first year sea ice south of the Antarctic Circle near Adelaide Island, Gullet, Antarctica, Southern Ocean

Views of the Drake Passage, the body of water between the southern tip of South America at Cape Horn, Chile and the South Shetland Islands of Antarctica

Humpback whales (Megaptera novaeangliae) surfacing near Zodiac near the Antarctic Peninsula, Antarctica, Southern Ocean

Adult female leopard seal (Hydrurga leptonyx) stalking, then killing and eating an adult gentoo penguin in Paradise Bay, Antarctica, Southern Ocean

Humpback whale (Megaptera novaeangliae) spy-hopping near Zodiac near the Antarctic Peninsula, Antarctica, Southern Ocean

Ice held up to the sun near the Antarctic Peninsula during the summer months, Southern Ocean

Humpback whale (Megaptera novaeangliae) surfacing near Zodiac near the Antarctic Peninsula, Antarctica, Southern Ocean

National Geographic photographer Joel Sartore and his wife Kathy kayaking with a leopard seal near Danco Island, Antarctica

Inside the abandoned Antarctic research British Base "W" on Detaille Island, Lallemand Fjord, Loubet Coast, Antarctica

Lindblad Expeditions guests doing the "polar Plunge" in Port Foster near Whalers Bay inside the caldera on Deception Island, South Shetland Island Group, Antarctica. NO MODEL RELEASES FOR THIS IMAGE.

Gentoo penguins (Pygoscelis papua) in Antarctica

Adult emperor penguin (Aptenodytes forsteri) on sea ice near Snow Hill Island in the Weddell Sea, Antarctica.

An adult Brown Skua (Catharacta antarctica) in flight near the Antarctic peninsula in the southern ocean

Full moon (plus 1 day) in the Weddell Sea, Antarctica. MORE INFO This moonrise occurred on January 1, 2010, the night after the blue moon full of December 31, 2009.

The Lindblad Expedition ship National Geographic Explorer operating in and around the Antarctic peninsula in Antarctica

King Penguin (Aptenodytes patagonicus) breeding and nesting colonies on South Georgia Island, Southern Ocean.

Full moon (plus 1 day) rising over icebergs in the Weddell Sea, Antarctica. MORE INFO This moonrise occurred on January 1, 2010, the night after the blue moon full of December 31, 2009.

King Penguin (Aptenodytes patagonicus) breeding and nesting colonies on South Georgia Island, Southern Ocean.

The Leopard seal (Hydrurga leptonyx) is the second largest species of seal in the Antarctic

Adult macaroni penguin (Eudyptes chrysolophus) on Elephant Island, South Shetlands, Antarctica

The Lindblad Expedition ship National Geographic Explorer in Dahlman Bay in late evening light as the waxing moon rises on the west side of the Antarctic Peninsula in Antarctica.

Guests from the Lindblad Expedition ship National Geographic Explorer slide down snow-covered hill in Orne Harbor, Antarctica