Charlie Summers / Stars in the southern hemisphere from the Kalahari Desert. The star in the middle of the rotation is the Southern Poler (Sigma octantis) It is one degree off true south. Southern Africa

Jorma Luhta / Aurora borealis colours in night sky, northern Finland, March

Jorma Luhta / Cross country skier and aurora borealis colours in night sky, northern Finland, winter

Jorma Luhta / Moving belt of aurora borealis colours in night sky. Lapland, northern Finland, winter

Jorma Luhta / Aurora borealis colours in midnight sky, northern Finland, April

Jorma Luhta / Aurora borealis corona colours in night sky, Lapland, northern Finland, winter

Jorma Luhta / Aurora borealis colours in night sky showing corona, northern Finland, winter

Jorma Luhta / Aurora borealis bow prior to storm. Northern Finland, winter 2002

Jorma Luhta / Aurora borealis bow indicating approaching borealis storm. Northern Finland, winter 2002

Jorma Luhta / Aurora borealis storm colours in night sky, northern Finland, winter

Jorma Luhta / Aurora borealis storm colours in night sky, northern Finland, February 2002, winter

Jorma Luhta / Aurora borealis colours in night sky, northern Finland, winter

Jorma Luhta / Aurora borealis colours in night sky over lake, northern Finland

Jorma Luhta / Aurora borealis colours in night sky over lake, northern Finland (nr Arctic circle), October 2002. Auroras also occur in the southern hemisphere where they are know as Aurora australis.

Jorma Luhta / Aurora borealis colours in night sky over lake, northern Finland, October 2002

Jorma Luhta / Aurora borealis colours in night sky, northern Finland, winter

Jorma Luhta / Aurora borealis lights in night sky and full moon. Northern Finland, January, winter 2002

Jorma Luhta / Person watching Aurora borealis colours in night sky, northern Finland, winter

Jorma Luhta / Aurora borealis colours, moon and Jupiter in night sky, northern Finland, winter 2002

Jorma Luhta / Aurora borealis bow in moonlit night sky, northern Finland, January, winter 2002

Jorma Luhta / Green aurora borealis colours in night sky, Lapland, northern Finland, winter. Greeen is the most commonly seen colour in Auroras.

Jorma Luhta / Aurora borealis storm showing blue corona in night sky, northern Finland.

Jorma Luhta / Aurora borealis colours in night sky, northern Finland, September 2001. Red corona at beginning of storm

Marie Read / Wilson's Phalaropes (Phalaropus tricolor) flock flying over tufa formations at Mono Lake in late summer, with reflection, California, USA. July 2013. Mono Lake is an important staging site for sho...

Marie Read / Wilson's Phalaropes (Phalaropus tricolor) large flock on the shore at Mono Lake in late summer, California, USA. July. Mono Lake is an important staging site (stopover site) for migrating shorebir...

Adrian Davies / Starfish fungus (Aseroe rubra) at its only known site in the Northern Hemisphere, Surrey, UK. September 2017.

Adrian Davies / Starfish fungus (Aseroe rubra) emerging from the egg stage in its only known site in the Northern Hemisphere, Surrey, UK. September 2017.

Adrian Davies / Starfish fungus (Aseroe rubra) at its only known site in the Northern Hemisphere, Surrey, UK. September 2017.

Adrian Davies / Starfish fungus (Aseroe rubra) at its only know site in the northern hemisphere, Surrey, UK. September 2017.

Michel Roggo / Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere ,New Zealand February 2013 . Photographed for The Freshwater Project

Michel Roggo / Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, New Zealand February 2013 . Photographed for The Freshwater Project

Michel Roggo / Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, New Zealand February 2013 . Photographed for The Freshwater Project

Michel Roggo / Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, New Zealand February 2013 . Photographed for The Freshwater Project

Michel Roggo / Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, New Zealand February 2013 . Photographed for The Freshwater Project

Michel Roggo / Forest around Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere ,New Zealand February 2013 . Photographed for The Freshwater Project

Michel Roggo / Dawn scene in Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere.New Zealand February 2013 . Photographed for The Freshwater Project

Michel Roggo / Forest around Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, New Zealand February 2013 . Photographed for The Freshwater Project

Michel Roggo / Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, New Zealand February 2013 . Photographed for The Freshwater Project

Heidi & Hans-Juergen Koch / Wolf (Canis lupus), native to Northern Hemisphere

Tony Wu / North Pacific hemisphere humpback whale calf (Megaptera novaeangliae kuzira) breaching on a sunny day in the calm waters of Chatham Strait, Alaska, USA, July.

Adrian Davies / Starfish fungus (Aseroe rubra) growing at its only known site in the northern hemisphere. Surrey, UK, October.

Adrian Davies / Starfish fungus (Aseroe rubra) growing at its only known site in the northern hemisphere. Surrey, UK, October.

Adrian Davies / Starfish fungus (Aseroe rubra) growing at its only known site in the northern hemisphere. Surrey, UK, October.

Roger Powell / Wolverine (Gulo gulo) in long grass, Animal Park, Hann-Munden, Lower Saxony, Germany. Captive, occurs throughout the boreal zone of the northern hemisphere.

Nature Picture Library / Whale meat for sale in a supermarket. The label on the top right with the blue whale tail indicates that this meat is from the southern hemisphere research whaling. As such, it is probably minke whale...

Tony Wu / Southern hemisphere humpback whales (Megaptera novaeangliae australis) two engaged in tail slapping together, female on left, male on right, the pair was travelling north in winter, South Africa.

Edwin Giesbers / Golden eagle (Aquila chrysaetos) portrait, captive, occurs in the Northern hemisphere.

Edwin Giesbers / Golden eagle (Aquila chrysaetos) portrait, captive, occurs in the Northern hemisphere.

Edwin Giesbers / Golden eagle (Aquila chrysaetos) portrait, captive, occurs in the Northern hemisphere.

David Kjaer / Long-eared owl (Asio Otus) flying. Captive, native to the Northern Hemisphere.

David Kjaer / Long-eared owl (Asio Otus) perched. Captive, native to the Northern Hemisphere.

David Kjaer / Long-eared owl (Asio Otus) flying. Captive, native to the Northern Hemisphere.

David Kjaer / Long-eared owl (Asio Otus) flying. Captive, native to the Northern Hemisphere.

David Kjaer / Long-eared owl (Asio Otus) perched. Captive, native to the Northern Hemisphere.

John Waters / Professional bird handler and trainer Rose Buck holding adult female Goshawk (Accipiter gentilis) Somerset, UK, February 2014. Captive, occurs throughout much of the Northern Hemisphere.

John Waters / Rose and Lloyd Buck, professional bird handlers and trainers, holding adult female Goshawk (Accipiter gentilis) Somerset, UK, January 2013. Captive, occurs throughout much of the Northern Hemisphere.

John Waters / Rose and Lloyd Buck, professional bird handlers and trainers, holding adult female Goshawk (Accipiter gentilis) Somerset, UK, January 2013. Captive, occurs throughout much of the Northern Hemisphere.

Michel Roggo / Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, this spring is of high cultural and spiritual significance for the local Maori, New Zealand, February 2013. Taken for the Fr...

Michel Roggo / Aquatic plants in Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, this spring is of high cultural and spiritual significance for the local Maori, New Zealand, February 2013...

Michel Roggo / Underwater view of Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, this spring is of high cultural and spiritual significance for the local Maori, New Zealand, February 201...

Michel Roggo / Underwater view of Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, this spring is of high cultural and spiritual significance for the local Maori, New Zealand, February 201...

Michel Roggo / Underwater view of Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, this spring is of high cultural and spiritual significance for the local Maori, New Zealand, February 201...

Michel Roggo / Te Waikoropupu spring, largest coldwater spring in the Southern Hemisphere, at full moon, taken with long exposure. This spring is of high cultural and spiritual significance for the local Maori, New...

Bryan and Cherry Alexander / Street scene in Verkhoyansk, the coldest town in the Northern Hemisphere. Yakutia, Siberia, Russia, 1999.

Bryan and Cherry Alexander / Winter street scene in Verkhoyansk, the coldest town in the Northern Hemisphere. Yakutia, Siberia, Russia, 1999.

David Kjaer / Long-tailed Duck (Clangula hyemalis) on water in summer plumage, native to Northern Hemisphere. Captive.

David Kjaer / Pair of Long-tailed Ducks (Clangula hyemalis) on water, native to Northern Hemisphere. Captive.

David Kjaer / Long-tailed Duck (Clangula hyemalis) native to Northern Hemisphere. Captive.

David Kjaer / Common / Black Scoter (Melanitta nigra) male 'captive' native to coastal waters of Northern Hemisphere and occasionally lakes.

David Kjaer / Common / Black Scoter (Melanitta nigra) male and female 'captive' native to coastal waters of Northern Hemisphere and occasionally lakes.

David Kjaer / Red-breasted merganser (Mergus serrator) captive, female, from Northern Hemisphere

David Kjaer / Goosander (Mergus merganser) male, captive, from the Northern Hemisphere

David Kjaer / Red-breasted merganser (Mergus serrator) captive, male, from Northern Hemisphere

David Kjaer / Greater Scaup (Aythya marila) female, native to the Northern Hemisphere

David Kjaer / Greater Scaup (Aythya marila) drake or male, native to the Northern Hemisphere

David Kjaer / Long-eared Owl (Asio Otus) captive, UK, from the Northern Hemisphere

David Kjaer / Long-eared Owl (Asio Otus) captive, UK, from the Northern Hemisphere

David Kjaer / Long-eared Owl (Asio Otus) captive, UK, from the Northern Hemisphere

David Kjaer / Goldeneye (Bucephala islandica) male, Captive, from the Northern Hemisphere

David Kjaer / Long-eared Owl (Asio Otus) captive, UK, from the Northern Hemisphere

David Kjaer / Long-eared Owl (Asio Otus) (C) Native to the Northern Hemisphere

David Kjaer / Long-eared Owl (Asio Otus) captive, UK, from the Northern Hemisphere

David Kjaer / Goldeneye (Bucephala islandica) female, Captive, from the Northern Hemisphere

David Kjaer / Long-eared Owl (Asio Otus) captive, UK, from the Northern Hemisphere

David Kjaer / Long-eared Owl (Asio Otus) (C) sitting on post Native to the Northern Hemisphere

Nature Production / The Milky Way in the Southern Hemisphere, Australia

Jorma Luhta / Aurora borealis colours in Spring sky, never completely dark. Lapland, northern Finland. Dead trees stay standing many years in cold climate.

Jorma Luhta / Aurora borealis colours in night sky showing corona, northern Finland, winter 2002

Jorma Luhta / Aurora borealis colours in night sky, northern Finland, winter 2002

Jorma Luhta / Aurora borealis corona in night sky, northern Finland, 2002

Jorma Luhta / Aurora borealis colours in night sky, northern Finland, Autumn

Jorma Luhta / Aurora borealis colours in night sky, northern Finland, Autumn 2002

Jorma Luhta / Aurora borealis colours in night sky, Naatasuo-wilderness, Pudasjarvi, northern Finland, Autumn

Jorma Luhta / Aurora borealis colours in night sky reflected in lake, northern Finland, Autumn. 2002

Jorma Luhta / Aurora borealis colours in night sky, Spruce forest, northern Finland, winter

Jorma Luhta / Aurora borealis colours in night sky above camp tent, Lapland, northern Finland, winter