A wrestler from the Nuba Mountains tribe is seen during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. The International Day of the World's Indigenous Peoples is observed on August 9 annually. (Photo by Mohamed Nureldin Abdallah/Reuters)

Daniel Filip, Tech Lead Manager for Google Maps, carries the Trekker, a 15-camera device, while mapping the Inca citadel of Machu Picchu for Google Street View in Cuzco, Peru, August 11, 2015. (Photo by Pilar Olivares/Reuters)

Fr Pierre Pepper (C) warms up before his amateur boxing match in the town of Banagher in County Offaly March 15, 2015. Fr Pepper has spent the last two months training for an amateur boxing match to raise proceeds for charity. (Photo by Cathal McNaughton/Reuters)

People make pictures in a Soviet-era vintage subway car, with a Soviet railways emblem on the side of it, parked in the Partizanskaya subway station in Moscow, Russia, Friday, May 15, 2015. Vintage Soviet-era metro cars were exhibited at the Partizanskaya subway station as part of festivities marking the 80th anniversary of the Moscow subway on Friday. (Photo by Pavel Golovkin/AP Photo)

A meteorite burns up in the atmosphere as seen in this photo taken near of Salgotarjan, 109 kms northeast of Budapest, Hungary, late 21 April 2015. The Moon and Venus can be seen on the left. (Photo by Peter Komka/EPA)

An Andalusian horsewoman waits for the animal to drink water before a classical dressage contest during the Sacab Andalusian Horse Show in Coin, southern Spain, April 12, 2015. (Photo by Jon Nazca/Reuters)

A robot Ecce by the Robot studio is pictured at the world's largest industrial technology fair, the Hannover Messe, in Hanover April 13, 2015. (Photo by Wolfgang Rattay/Reuters)

School girls stand next to a ballot box at a polling station during the municipal elections in Havana April 19, 2015. Cuba held its first local elections since a historic thaw in relations with the United States with an unusual wrinkle in the single-party system: two of the 27,000 candidates openly oppose the government. (Photo by Reuters/Stringer)