Pope Francis greets the crowd from his popemobile in downtown Rio de Janeiro. Pope Francis touched down in Rio de Janeiro on Monday, starting his first foreign trip as pontiff and a weeklong series of events expected to attract more than a million people to a gathering of young faithful in Brazil, home to the world's largest Roman Catholic population. (Photo by Ueslei Marcelino/Reuters)

Young man making the O.K. sign. (Photo by George Marks/Retrofile/Getty Images). Circa 1950s

A pilot inflates his balloon before the 37th International Hot Air Balloon Week in Chateau-d'Oex, January 24, 2015. According to the organizers, over 80 balloons from 20 countries are participating in the ballooning event in the Swiss mountain resort. (Photo by Pierre Albouy/Reuters)

“Born in 1965 at Tokyo, living at Tokyo. Starting shooting since 2008. 2011: 1x Photo Awards Honorable Mention (Street). 2012: Black and White Spider Awards 2nd Place (Portrait), Honorable Mention (Fashion); PX3 Gold Awards (Press); Israel Harvanism Street Contest 1st Place. 2013: Urban Picnic Street Contest Top30 Finalist; PX3 3rd Place (Portrait), Gold (Portrait - Personality), Gold (Press - People/Personality); Photolux + PhotoVogue Photo Contest 1st Place. 2014: Sony World Photography Awards Commended (Smile Category)”. – Tatsuo Suzuki. Photo: “Spring”. (Photo by Tatsuo Suzuki)

Daniel Fox inside the Mendenhall Glacier, in September 2014, in Juneau, Alaska. Driving in an open-roofed jeep is no longer the fashionable way to see wildlife – as this adventurer shows. A keen wildlife photographer has circled islands in the south of Alaska, the United States, in a kayak to see spectacular scenery and animals. Daniel Fox, 40, from San Francisco spent three months travelling around the islands by kayak, meeting sea lions and brown bears along the way. (Photo by Daniel Fox/Barcroft Media)

Children react as they celebrate Guy Fawkes day in Soweto, South Africa, on November 5, 2014. (Photo by Siphiwe Sibeko/Reuters)