Brown bear in the Brooks River, Katmai National Park, Alaska, USA (© littleting/Pradthana Jarusriboonchai/Getty Images)

Mural of Gandhi by Eduardo Kobra, Churchgate Railway Station, Mumbai (© Kunal Patil/Hindustan Times via Getty Images)

Montage of images of Jupiter and its volcanic moon Io (© NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Goddard Space Flight Center)

Emperor penguin adults and chicks at the Snow Hill Island rookery, Antarctica (© Martin Ruegner/Getty Images)

Blanket octopus in Palm Beach, Florida, USA (© Steven Kovacs/Minden Pictures)

Restormel城堡上空的秋雾，英国康沃尔 (© Robert Harding/Alamy)

Akash Ganga, the 14-member skydiving team of the Indian Air Force in action (© Shaukat Ahmed/Pacific Press/Alamy Live News)

Roaring Fork in Great Smoky Mountains National Park, Tennessee (© Bernie Kasper/Getty Images)

Aerial view of American flamingos flying over Los Roques Archipelago National Park, Venezuela (© Cristian Lourenco/Getty Images)

Geghard Monastery, Armenia (© traumlichtfabrik/Getty Images)

Poenari Castle on Mount Cetatea, Făgăraș Mountains, Romania (© porojnicu/Getty Images)

Red fox in the Netherlands (© Wim Weenink/Minden Pictures)

Dragonfly fossil, about 150 million years old, in Solnhofen, Bavaria, Germany (© Ingo Arndt/Minden Pictures)

Dragonfly fossil, about 150 million years old, in Solnhofen, Bavaria, Germany (© Ingo Arndt/Minden Pictures)

View of a tractor and trailers of cabbage in a field in Sankt Pölten, Austria (© Stephan Zirwes/Getty Images)

Malabar grey hornbill feeding on a fig tree at Dandeli, Karnataka (© AmitRane1975/iStock/Getty Images Plus)

Pisgah National Forest near Brevard, North Carolina (© Adam Jones/Danita Delimont)

The Mati Si (Horse's Hoof Temple) and grottoes of Mati Si Scenic Area, Gansu province, China (© Ana Flašker/Alamy)

Bare trees and autumn ferns in Beaver Lake Nature Center, New York, USA (© Chris Murray/Alamy)

Bare trees and autumn ferns in Beaver Lake Nature Center, New York (© Chris Murray/Alamy)

Starlings flock over Lauwersmeer National Park, Netherlands (© Frans Lemmens/Alamy)

Starlings flock over Lauwersmeer National Park, Netherlands (© Frans Lemmens/Alamy)

New York City skyline with United Nations headquarters (© Sean Pavone/Alamy)

Masks for the Dussehra festival (© Piergiorgio Sclarandis/Sime/eStock Photo)

Corfe Castle, Dorset, England (© Ross Hoddinott/Minden Pictures)

Cambron Covered Bridge in Green Mountain Park, near Huntsville, Alabama, United States (© Jens Lambert/Shutterstock)

Grotesques of native Ecuadorian seabirds on the Basílica del Voto Nacional in Quito, Ecuador (© Henri Leduc/Getty Images)

Mazezilla corn maze at Klingel's Farm in Pennsylvania, USA (© Alex Potemkin/Getty Images)

Blakiston's fish owl in Hokkaido, Japan (© Martin Bailey/Offset by Shutterstock)

Dark Hedges in County Antrim, Northern Ireland (© VanderWolf Images/Shutterstock)

River running through Cheran Gorges, Alps, Savoie, France (© Jean-Philippe Delobelle/Minden)