A schoolgirl collects rubbish from Karachi's Clifton beach early morning April 22, 2013, during a cleaning campaign as part of the commemoration of Earth Day. (Photo by Akhtar Soomro/Reuters)

Female North Korean soldiers parade to mark the 60th anniversary of the signing of a truce in the 1950-1953 Korean War at Kim Il-sung Square, in Pyongyang. (Photo by Jason Lee/Reuters)

Northern lights (Aurora borealis) glow brightly over an Inupiaq fish camp along the arctic coast in North Slope, Alaska. (Photo by Steven Kazlowski/Barcroft Media)

Liu Yang, China's first female astronaut, waves during a departure ceremony at Jiuquan Satellite Launch Center, on June 16, 2012. (Photo by Jason Lee/Reuters via The Atlantic)

A woman dressed up as a zombie takes part in a zombie walk in the Gaslamp Quarter during the Comic Con International convention in San Diego, California July 13, 2012. (Photo by Mario Anzuoni/Reuters)

Dancers from the Philadelphia Ballet perform for Pope Francis (R) as he attends the Festival of Families rally in Philadelphia, Pennsylvania September 26, 2015. (Photo by Brian Snyder/Reuters)

Head of the department of the interior architecture at Estonian Academy of Arts Hannes Praks poses for a picture in the wooden megaphone in the forest near Pahni village, Estonia, September 28, 2015. (Photo by Ints Kalnins/Reuters)

The first seal pup to be born this season at a major colony of grey seals on the Farne Islands sits beside its mother on Brownsman Island, England on September 30, 2015. (Photo by Owen Humphreys/PA Images)