To Sua Ocean Trench on the south coast of Upolu Island in Samoa (© Chris McLennan/Alamy)

Harp seal sleeping at Jones Beach, Long Island, New York (© Vicki Jauron, Babylon and Beyond Photography/Getty Images)

Skyline of Prague, Czech Republic (© benkrut/Getty Images)

Coastguard cottages and Seven Sisters cliffs outside Eastbourne, East Sussex (© Paul Daniels/Alamy Stock Photo)

Borrego Badlands in Anza-Borrego Desert State Park, California, USA (© Tom Hogan/plainpicture)

Ptarmigan (lagopus muta) in snow, Scotland (© David Chapman/Alamy Stock Photo)

The village of Riquewihr in Haut-Rhin, Alsace, France (© Walter Bibikow/eStock Photo)

Nazaré Lighthouse at Forte de São, Nazaré, Portugal (© Richard A Lock/Getty Images)

American bison in Yellowstone National Park, Wyoming, USA (© Steve Gettle/Minden Pictures)

Rice laid out to dry in Dhamrai, Dhaka, Bangladesh (© Amazing Aerial Agency/Offset by Shutterstock)

Ski touring in the High Tauern mountain range near Bad Gastein, Austria (© RooM the Agency/Alamy)

Porcupine hangs on a willow tree branch, Alaska, USA (© Design Pics/Danita Delimont)

Mount Fanjing in south-west China (© zhuxiaophotography/Shutterstock)

Northern Lights over a stranded boat in Tasiilaq, Greenland (© Shane P. White/Minden Pictures)

The road leading to Sa Calobra, Majorca (© Tolo Balaguer/agefotostock)

Sorting chilli peppers at a farm in Bogra, Bangladesh (© Amazing Aerial Agency/Offset/Shutterstock)

Rydal Water in the Lake District, Cumbria (© Tranquillian1/iStock/Getty Images Plus)

Kochelsee and Heimgarten Mountain in Bavaria, Germany (© Reinhard Schmid/eStock Photo)

Saint Elias Mountains and Kaskawulsh Glacier in Kluane National Park and Reserve, Yukon, Canada (© Design Pics Inc/Alamy)

Adélie penguin in Graham Passage, Antarctic Peninsula, Antarctica (© Nick Garbutt/Minden Pictures)

Snow buntings flock during a snowstorm in New York, USA (© Marie Read/Minden Pictures)

Martinique, Lesser Antilles, Caribbean Sea (© Airpano LLC/Amazing Aerial Agency)

Meoto Iwa (Wedded Rocks) off the coast of Ise, Mie Prefecture, Honshu, Japan (© Marco Gaiotti/plainpicture)

Lower Manhattan in New York City, USA (© New York On Air/Offset/Shutterstock)

Museum Of Moon Installation Launches The Burns & Beyond Festival, Edinburgh. (© Jeff J Mitchell/Staff/Getty Images Entertainment)

Mehrangarh Fort in Jodhpur, Rajasthan, India (© Jayakumar/Shutterstock)

Plate-billed mountain toucan in Bellavista Cloud Forest Reserve, Ecuador (© Tui De Roy/Minden Pictures)

Short-eared owl hunting at dusk in Worlaby Carrs, Lincolnshire (© Ben Hall/Minden Pictures)

The Lick Observatory on Mount Hamilton, near San Jose, California, USA (© Jeffrey Lewis/Tandem Stills + Motion)

Halo around the sun in the Ore Mountains, Saxony, Germany (© Martin Ruegner/Getty Images)

Workers in an incense field in the Huyện Ứng Hòa district of Hanoi, Vietnam (© Azim Khan Ronnie/Amazing Aerial Agency)