A curious leopard cub toys with a camera at MalaMala Game Reserve in Mpumalanga Province, South Africa. (Photo by Barcroft Media)

North Korean girls in similar bathing suits stand under a shower at the Songdowon International Children's Camp, Tuesday, July 29, 2014, in Wonsan, North Korea. The camp, which has been operating for nearly 30 years, was originally intended mainly to deepen relations with friendly countries in the Communist or non-aligned world. But officials say they are willing to accept youth from anywhere – even the United States. (Photo by Wong Maye-E/AP Photo)

An airplane passes the moon as it makes its approach to Philadelphia International Airport, Sunday, September 7, 2014, in Philadelphia. (Photo by Matt Rourke/AP Photo)

Roped up climbers leave the summit of Breithorn at 4,164 metres (13,661 feet) on the ridge marking the border with Switzerland (left) and Italy in the Alpine resort of Zermatt August 4, 2014. Switzerland will vote on November 30 on an initiative from the group Ecopop which proposes a cap on the number of immigrants. The group says it is motivated by concerns about a lack of living space exerting too much pressure on the land and natural resources, rather than by opposition to foreigners. (Photo by Denis Balibouse/Reuters)

Students brave high winds and rain on Blackpool promenade as Britain prepares for high winds over the next two days on October 20, 2014 in Blackpool, England. (Photo by Christopher Furlong/Getty Images)

It might have been foggy in the Willamette Valley, but Cerridwen Martin was able to revel in a view of the top of the clouds from the summit of Spencer Butte in Eugene, Ore., on Tuesday, December 16, 2014. Martin was joined by Joe Martinson, right, for the 1.1 mile trek. Fog shrouded much of the city for most of the day. (Photo by Andy Nelson/AP Photo/The Register-Guard)

A woman walks in central Rason city, northeast of Pyongyang, August 29, 2011. (Photo by Carlos Barria/Reuters)

Girls ride on a donkey cart with grass for animals on the outside of Nangarhar province, Afghanistan May 19, 2015. (Photo by Reuters/Parwiz)