Flags outside the UN's Palace of Nations in Geneva, Switzerland (© Mustafa Yalcin/Anadolu Agency/Getty Images)

Rainbow eucalyptus trees along the Hana Highway, Maui (© GlowingEarth/Getty Images Plus)

'Field of Light at Sensorio,' by Bruce Munro, Paso Robles, California (© George Rose/Getty Images)

Sperm whale mother and albino baby swimming off the coast of Portugal (© Flip Nicklin/Minden Pictures)

Burrowing parrots in Las Lajas, Argentina (© Cagan Hakki Sekercioglu/Getty Images)

Ceiling of the Tomb of the Unknown Australian Soldier, Australian War Memorial, Canberra (© David Wall/DanitaDelimont.com)

Moons of Jupiter - Io, Europa, Ganymede, and Callisto (© Branko Šimunek/Alamy)

Seiffen im Erzgebirge, Sachsen, Deutschland (© Reinhard Schmid/Huber/eStock Photo)

Beach in the evening light at Whisky Bay, Wilsons Promontory National Park, Victoria (© Michael Breitung/Huber/eStock Photo)

排列在通往大圣院石径上的小罗汉雕像，日本宫岛 (© Malcolm Fairman/Alamy)

Trakai Island Castle Museum in Trakai, Lithuania (© Andrius Aleksandravicius/Alamy)

Aerial view of Boudhanath stupa in Kathmandu, Nepal (© Maksim Semin/Shutterstock)

Male muskoxen near Prudhoe Bay in Alaska (© Oliver Smart/Alamy)

Aerial view of Boudhanath stupa in Kathmandu, Nepal (© Maksim Semin/Shutterstock)

瓦尔加迪纳的日落，意大利南蒂罗尔多洛米蒂山脉 (© Marco Capellari/Getty Images)

A Brandt's cormorant hunts for a meal in a school of Pacific mackerel beneath an oil rig off the coast of Los Angeles, California (© Alex Mustard/Minden Pictures)

Zebras and wildebeests in the Serengeti National Park in Tanzania (© Raffi Maghdessian/Cavan Images)

Backcountry adventurer Alex Peterson speed riding on the south side of Mount Hood, Oregon (© Richard Hallman/DEEPOL by plainpicture)

Walruses near Kvitøya in the Svalbard archipelago, Norway (© Ole Jorgen Liodden/Minden Pictures)

Eurasian red squirrel in the Cairngorms, Scottish Highlands, Scotland (© Images from BarbAnna/Getty Images)

Northern lights near Whitehorse in Yukon, Canada (© Design Pics/Danita Delimont)

The Taj Mahal for India's Republic Day (© Michele Falzone/plainpicture)

Sunlit ridges against volcanic scree on Eyjafjallajökull, a volcano in Iceland (© Erlend Haarberg/Minden Pictures)

The Chinese New Year celebration in Xi'an, China (© Aleksandar Plavevski/Shutterstock)

Sydney Opera House Australia Day celebration in 2018 (© Michal Ziarno/Shutterstock)

View of New York City from the International Space Station (© NASA Photo/Alamy)

｢クルエーン国立公園・保護区｣カナダ, ユーコン準州 (© Robert Postma/Plainpicture)

Semuc Champey nature park in Guatemala (© Joel Sharpe/Getty Images)

Aerial view of car crossing over the frozen surface of Lake Baikal, Russia (© Amazing Aerial Agency/Offset)

Painted bollards by Jan Mitchell along the Geelong waterfront precinct (© Rachel Lewis/Lonely Planet Images/Getty Images Plus)

A reddish egret hunts in Fort De Soto Park, Florida (© Brian Lasenby/Getty Images)