Tourists ice skate at night on the Eiffel Tower's skating rink in Paris December 9, 2014. The skating rink, located on the first level of the Eiffel Tower, opens to the public as part of the Christmas holiday season. (Photo by Charles Platiau/Reuters)

Aerobatic pilot Sean D. Tucker flies in the two-seat Oracle Extra airplane over downtown Chicago skyline, Wednesday, June 8, 2016. Tucker will perform before the start of of the America's Cup World Series racing on Saturday and Sunday. (Photo by Kiichiro Sato/AP Photo)

A migrant carries his belongings as he arrives at the Beijing railway station to catch a train in Beijing, Friday, February 13, 2015. (Photo by Andy Wong/AP Photo)

Film actress Audrey Hepburn (1929–1993) on a film set with her pet poodle, circa 1960. (Photo by Hulton Archive/Getty Images)

A boy flies his kite in a cemetery in the Vila Operaria Favela of Rio de Janeiro, Brazil, July 9, 2016. (Photo by Nacho Doce/Reuters)

A mahout removes the prosthetic from Motala, age 50, at the Friends of the Asian Elephant (FAE) elephant hospital in the Mae Yao National Reserve August 29, 2011 Lampang,Thailand. Motala lost a foot many years back after stepping on a land mine and now is on her third prosthetic, as they need to be changed according to the weight of the elephant. (Photo by Paula Bronstein/Getty Images)

More than 400 people stripped off and ran into freezing waters to celebrate the autumn equinox – and raise money for charity at Druridge Bay, Britain, September 25, 2016. It was the largest turnout the North East Skinny Dip has ever seen in its five-year history, and it was also the first time it has ever rained on the morning of the event. Revellers gathered from 5.30am on Sunday at Druridge Bay, in Northumberland, before baring all in the North Sea. (Photo by David Charlton Photography)

A Bengal cat is seen during the Mediterranean Winner 2016 cat show in Rome, Italy, April 3, 2016. (Photo by Max Rossi/Reuters)