Boys walk home for lunch from school in the village of Kogelo, west of Kenya's capital Nairobi, July 16, 2015. U.S. President Barack Obama visits Kenya and Ethiopia later this month. His ancestral home of Kogelo is home to Sarah Hussein Obama, his step-grandmother. The Kenyan village, burial place of Obama's father, features an open-pit goldmine, a pork butcher's, a school named after their most famous son and outdoor market stalls. Villagers get around by motorbike taxi or on foot while a donkey-cart transports water. Children, some of them named Obama in honour of the President, walk to and from school together. (Photo by Thomas Mukoya/Reuters)

A man covered in motor oil, poses for a picture next to a girl dress a traditional clothes during a festivities in honor of Santo Domingo de Guzman in Managua, Nicaragua, Saturday, August 1, 2015. Some of the faithful coat their bodies in a black motor oil, red paint and wear traditional clothes as a promise for a prayer or miracle they believe was performed or answered by Managua's patron saint, Santo Domingo de Guzman. (Photo by Esteban Felix/AP Photo)

A man dressed as Hindu Lord Shiva looks into the mirror as he gets ready to take part in a religious procession on the eve of Janmashtami festival in Amritsar, India, September 4, 2015. The festival, which marks the birth anniversary of Lord Krishna, will be celebrated across India on Saturday. (Photo by Munish Sharma/Reuters)

Gabriella Papadakis and Guillaume Cizeron of France perform during the ice dance skating event at the ISU Grand Prix of Figure Skating final in Barcelona December 13, 2014. (Photo by Albert Gea/Reuters)

Sgt. William Olas Bee, a U.S. Marine from the 24th Marine Expeditionary Unit, has a close call after Taliban fighters opened fire near Garmsir in Helmand Province of Afghanistan, May 18, 2008. (Photo by Goran Tomasevic/Reuters)

A lunar eclipse appears behind a gargoyle atop the old red Dallas County Courthouse early Wednesday morning, October 8, 2014. The moon appears orange or red, the result of sunlight scattering off Earth's atmosphere. This is known as the blood moon. (Photo by Tom Fox/AP Photo/The Dallas Morning News)

Italian police officers carry away a FEMEN activist during a protest in St. Peter's Square at the Vatican, Friday, November 14, 2014. Members of the Ukrainian feminist group Femen staged a protest against the upcoming visit of Pope Francis at the European Parliament and Council. (Photo by AP Photo)

“Thunderstruck”. Summer stom. A super cell formed off the coast of New Zealand, intensified and swept across Christchurch and North Canterbury, February 23, 2014. Photo location: Christchurch, New Zealand. (Photo and caption by David Hardy/National Geographic Photo Contest)