Leucistic Anna's hummingbird in the Australia Garden, UCSC Arboretum, Santa Cruz, California (© yhelfman/Getty Images)

'Vanishing Point' by French street artist JR on the facade of Palazzo Farnese, Rome, Italy (© Fabrizio Troiani/Alamy)

Beech trees and wild anemones, Jutland, Denmark (© Nick Brundle Photography/Getty Images)

Broken Group Islands, Pacific Rim National Park Reserve, Vancouver Island, British Columbia (© Ron Watts/Design Pics/Getty Images)

Red lechwe herd crossing marshy plain of Okavango Delta, Botswana (© Ibrahim Suha Derbent/Getty Images)

The Bahamas photographed from the International Space Station (© NASA)

Himeji Castle, Himeji, Hyōgo Prefecture, Japan (© Julian Elliott Photography/Getty Images)

North American beaver in a pond near Wonder Lake, Denali National Park, Alaska (© Paul Souders/Getty Images)

Total solar eclipse photographed from Madras, Oregon on August 21, 2017 (© NASA/Aubrey Gemignani)

Whistler Mountain in the creekside of Whistler (© Insight Photography/Design Pics/Getty Images)

The RedBall Project art installation, Centraal Station, Antwerp, Belgium (© Brit Worgan/Getty Images)

Union Square in lower Manhattan at twilight, New York (© Sean Pavone/Getty Images)

American black bear cub in spring, Shenandoah National Park, Virginia (© Scott Suriano/Getty Images)

Medieval city walls, Ávila, Spain (© Alberto Loyo/Getty Images)

The Ring of Brodgar, Orkney, Scotland (© Paul Williams - FunkyStock/Getty Images)

Grand Prismatic Spring at sunrise, Yellowstone National Park, Wyoming (© XIN WANG/Getty Images)

Sparks Lane in Cades Cove, Great Smoky Mountains National Park, Tennessee (© Richard Bernabe/Shutterstock)

Green sea turtle, San Diego, California (© Ralph Pace/Minden Pictures)

Library of Trinity College Dublin, Ireland (© Vincent Isore/Getty Images)

White trillium blooming in Ontario, Canada (© Jun Zhang/Getty Images)

Adélie penguins on an iceberg, Antarctica (© Patrick J. Endres/Getty Images)

Villnöß with the Dolomites in the background, South Tyrol, Italy (© Achim Thomae/Getty Images)

El Capitan at sunrise in Guadalupe Mountains National Park, Texas (© Adam Mowery/Tandem Stills + Motion)

Fujian Tulou complex of historical and cultural heritage buildings in Fujian province, China (© Hongjie Han/Getty Images)

Cheetah in morning rain, Ndutu Plains, Ngorongoro Conservation Area, Tanzania (© Paul Souders/Getty Images)