A visitor holds up her toy bunny to the aquarium glass in front of Aurora the Russian polar bear at the Sao Paulo Aquarium in Sao Paulo, Brazil, Thursday, April 16, 2015. (Photo by Andre Penner/AP Photo)

A giant storm cloud can be seen in the sky above swimmers near Mollymook Beach, south of Sydney, March 5, 2014. (Photo by David Gray/Reuters)

Russian pop art photographer Sergey Chilikov captures a nation liberated from the social oppression of late-era Soviet rule – at parties, in the streets, and bouncing high. His exhibition, Photoprovocations, will be at Photo London, 19-22 May. Here: Yoshkar-Ola, Matrosova Street (1995). (Photo by Sergey Chilikov)

A competitor loses his shoe during the annual race on high heels during Gay Pride celebrations in the quarter of Chueca in Madrid, Spain, June 30, 2016. (Photo by Susana Vera/Reuters)

Somali security officers gather at the scene of a car bomb attack at the base for the African Union forces in Mogadishu, Somalia, 26 July 2016. Media reports say at least 10 people, including the security guards at the base which is located at Mogadishu's airport, have been killed after two car bombs exploded at the base. Somalia's Islamist militant group al-Shabab has claimed responsibility for the latest attack. (Photo by Said Yusuf Warsame/EPA)

Farmer Franz Schaller rides on an ox called Napoleon during a traditional ox race in the southern Bavarian village of Muensing near Lake Starnberg, Germany August 28, 2016. (Photo by Michaela Rehle/Reuters)

These are the dunes of the Namib Desert, taken by Korea's Kompstat-2 satellite. The blue and white area is the dried riverbed of the Tsauchab river. (Photo by The European Space Agency)

A man photographs Anila Quayyum Agha's “Intersections” art work on the first day of ArtPrize at the Grand Rapids Art Museum in Grand Rapids, Mich. on Wednesday, September 24, 2014. (Photo by Emily Rose Bennett/AP Photo/The Grand Rapids Press)