An airplane crosses a nearly full-moon on its way to Los Angeles International Airport near Whittier, Calif., Thursday, December 24, 2015. Not since 1977 has a full moon dawned in the skies on Christmas. (Photo by Nick Ut/AP Photo)

A man sleeps between tombstones in front of his single-room home on a hot night in the Cairo Necropolis, Egypt, October 13, 2015. In the sprawling Cairo Necropolis, known as the City of the Dead, life and death are side by side. Amid a housing crisis in Egypt, and with the population of greater Cairo estimated at about 20 million, people count themselves lucky to have a place to call home in the graveyards that date back hundreds of years. (Photo by Asmaa Waguih/Reuters)

Peruvian shamans holding a poster of Russia's President Vladimir Putin perform a ritual of predictions for the new year at Morro Solar hill in Chorrillos, Lima, Peru, December 29, 2015. The ritual is an end-of-the-year tradition and the shamans called for world peace and wished good luck for the upcoming elections in Peru and the U.S. (Photo by Mariana Bazo/Reuters)

Public Space series, 2015. This series by Morteza Niknahad and Behnam Zakeri tends toward cinema, taking an almost cartoonish view of modern life in Iran. This work was inspired by the social life of dolphins. (Photo by Morteza Niknahad and Behnam Zakeri/The Guardian)

A flock of starlings is seen as they perform their traditional dance fly before landing to sleep during the sunset near the southern Arab Israeli city of Rahat, in the northern Israeli Negev desert, on February 2, 2015. (Photo by Menahem Kahana/AFP Photo)

(L-R) Leigh-Anne Pinnock, Jesy Nelson, Perrie Edwards and Jade Thirlwall of Little Mix attend the KISS FM Haunted House Party at SSE Arena on October 29, 2015 in London, England. (Photo by Dave J. Hogan/Dave J. Hogan/Getty Images)

A photo made avialable on 05 August 2015 shows an Indian woman collecting drinking water from a water pump in the submerged village of Sreerampur, some 150 kilometers north of Calcutta, India, on 04 August 2015. At least 215 people have died in floods and a landslide following monsoon rains in India over the past week, 83 deaths were reported from the western state of Gujarat and 69 from eastern West Bengal. The worst-affected states were West Bengal, Gujarat and Rajasthan, the Home Ministry said. (Photo by Piyal Adhikary/EPA)

Then U.S. Army First Lieutenant Kirsten Griest (C) and fellow soldiers participate in combatives training during the Ranger Course on Fort Benning, Georgia, in this handout photograph taken on April 20, 2015 and obtained on August 20, 2015. When Griest and another woman completed the daunting U.S. Army Ranger school this week they helped end questions about whether women can serve as combat leaders, as the Pentagon is poised to open new roles, including elite Navy SEALs, to women in coming months. The feat by Griest and First Lieutenant Shaye Haver followed a re-evaluation of the role of women after their frontline involvement in Iraq and Afghanistan and the end of a rule barring them from combat roles in 2013. (Photo by Spc. Nikayla Shodeen/Reuters/U.S. Army)