Namib Desert, Namibia (© Valerio Leone/Solent News/REX/Shutterstock)(Bing United States)

Namib Desert, Namibia (© Valerio Leone/Solent News/REX/Shutterstock)(Bing United States)

Jeff Koons' 'Puppy' outside the Guggenheim Museum, Bilbao, Spain (© Martin Child/Aurora Photos)(Bing United States)

Jeff Koons' 'Puppy' outside the Guggenheim Museum, Bilbao, Spain (© Martin Child/Aurora Photos)(Bing United States)

Paratroopers fill the skies over Fort Bragg in North Carolina, for Operation Toy Drop (© Stocktrek Images/SuperStock)(Bing United States)

Paratroopers fill the skies over Fort Bragg in North Carolina, for Operation Toy Drop (© Stocktrek Images/SuperStock)(Bing United States)

A peregrine falcon surveys the concrete canyons of Chicago (© Luke Massey/Minden Pictures)(Bing United States)

A peregrine falcon surveys the concrete canyons of Chicago (© Luke Massey/Minden Pictures)(Bing United States)

Historic fishing warehouses in Trondheim, Norway (© Oscar Dominguez/Tandem Stills + Motion)(Bing United States)

Historic fishing warehouses in Trondheim, Norway (© Oscar Dominguez/Tandem Stills + Motion)(Bing United States)

English oak tree in a cultivated field in Monmouthshire, Wales (© Phil Savoie/Minden Pictures)(Bing United States)

English oak tree in a cultivated field in Monmouthshire, Wales (© Phil Savoie/Minden Pictures)(Bing United States)

Bush hyrax colony in the Mara North Conservancy, Kenya (© Jonathan & Angela Scott/Aurora Photos)(Bing United States)

Bush hyrax colony in the Mara North Conservancy, Kenya (© Jonathan & Angela Scott/Aurora Photos)(Bing United States)

The Maratona dles Dolomites bicycle race in Italy (© Aurora Photos/Alamy)(Bing United States)

The Maratona dles Dolomites bicycle race in Italy (© Aurora Photos/Alamy)(Bing United States)

West Indian manatee mom and baby at Three Sisters Springs, Florida (© James R.D. Scott/Getty Images)(Bing United States)

West Indian manatee mom and baby at Three Sisters Springs, Florida (© James R.D. Scott/Getty Images)(Bing United States)

Greater snow geese at Montezuma National Wildlife Refuge, New York (© Gerrit Vyn/Minden Pictures)(Bing United States)

Greater snow geese at Montezuma National Wildlife Refuge, New York (© Gerrit Vyn/Minden Pictures)(Bing United States)

North Shore of Lake Superior, Minnesota (© Matt Anderson Photography/Getty Images)(Bing United States)

North Shore of Lake Superior, Minnesota (© Matt Anderson Photography/Getty Images)(Bing United States)

‘Kolonihavehus, 2010’ by Tom Fruin, in Brooklyn Bridge Park, Brooklyn, New York (© Daniel Haug/Getty Images)(Bing United States)

‘Kolonihavehus, 2010’ by Tom Fruin, in Brooklyn Bridge Park, Brooklyn, New York (© Daniel Haug/Getty Images)(Bing United States)

Long-tailed widowbird male, Rietvlei Nature Reserve, South Africa (© Richard Du Toit/Getty Images)(Bing United States)

Long-tailed widowbird male, Rietvlei Nature Reserve, South Africa (© Richard Du Toit/Getty Images)(Bing United States)

Celebrating Teacher Appreciation Day (© Johnny Greig/iStock/Getty Images Plus)(Bing United States)

Celebrating Teacher Appreciation Day (© Johnny Greig/iStock/Getty Images Plus)(Bing United States)

Jackson Square in the French Quarter of New Orleans, Louisiana (© Edwin Remsberg/Getty Images)(Bing United States)

Jackson Square in the French Quarter of New Orleans, Louisiana (© Edwin Remsberg/Getty Images)(Bing United States)

A wetland in Västmanland, Sweden (© Hans Strand/Getty Images)(Bing United States)

A wetland in Västmanland, Sweden (© Hans Strand/Getty Images)(Bing United States)

Mariachis, San Miguel de Allende, Guanajuato, Mexico (© Holly Wilmeth/Getty Images)(Bing United States)

Mariachis, San Miguel de Allende, Guanajuato, Mexico (© Holly Wilmeth/Getty Images)(Bing United States)

Filming location for the ´Star Wars´ movies, Chott el Djerid, Tunisia (© age fotostock/Alamy)(Bing United States)

Filming location for the ´Star Wars´ movies, Chott el Djerid, Tunisia (© age fotostock/Alamy)(Bing United States)

Tree decorated with amulets called nazars, Göreme National Park, Cappadocia, Turkey (© taratata/Getty Images)(Bing United States)

Tree decorated with amulets called nazars, Göreme National Park, Cappadocia, Turkey (© taratata/Getty Images)(Bing United States)

European barracuda and bluefish circling a bait ball of Atlantic horse mackerel off the shore of the Formigas Islets, Azores, Portugal (© Jordi Chias/Minden Pictures)(Bing United States)

European barracuda and bluefish circling a bait ball of Atlantic horse mackerel off the shore of the Formigas Islets, Azores, Portugal (© Jordi Chias/Minden Pictures)(Bing United States)

The Sky Over Nine Columns, by artist Heinz Mack, exhibited during the Venice Architecture Biennale, 2014 (© Cahir Davitt/plainpicture)(Bing United States)

The Sky Over Nine Columns, by artist Heinz Mack, exhibited during the Venice Architecture Biennale, 2014 (© Cahir Davitt/plainpicture)(Bing United States)