A native Brazilian competes in a tora competition, which is a race while carrying a log, during the Indigenous Youth Games of Pataxos nation in Santa Cruz de Cabralia, Bahia state, Brazil, April 18, 2016. (Photo by Roosevelt Cassio/Reuters)

A U.S. Marine kneels beside a Multi-Utility Tactical Transport ( MUTT) during a patrol as part of Rim of the Pacific (RIMPAC) 2016 an exercise held at Camp Pendleton, California United States, July 13, 2016. (Photo by Mike Blake/Reuters)

Crowds look on as the super moon rises behind the Fremantle War Memorial at Monument Hill on November 14, 2016 in Fremantle, Australia. A super moon occurs when a full moon passes closes to earth than usual, with the November 14th moon expected to be closer than it has been in over 70 years. (Photo by Paul Kane/Getty Images)

Humanoid robots compete in a group match of the 20th RoboCup in Leipzig, Germany, June 30, 2016. About 3,500 participants from 45 countries and regions compete in the robot world championship until 04 July. (Photo by Sebastian Willnow/EPA)

A visitor stands in front of a portrait taken by artist Bruce Gilden at the “Masters of Photography” exhibition at the Photokina trade fair in Cologne on September 20, 2016. The fair for the photographic and imaging sector, that is running from September 20 to 25, 2016, presents products from image capture, image processing and storage to image output. Photokina also includes a program of events with congresses, workshops, symposiums and photography exhibitions. (Photo by Patrik Stollarz/AFP Photo)

A competitor tries to swipe away some grease as he slips off the “gostra”, a pole covered in grease, during the celebrations for the religious feast of St Julian, patron of the town of St Julian's, outside Valletta August 30, 2015. In the traditional “gostra”, a game stretching back to the Middle Ages, young men, women and children have to make their way to the top of a pole and try to uproot one of the flags to win prizes. Photo by Darrin Zammit Lupi/Reuters)

Steve Shirts, aka “Strike Pony”, left, gets a hug from Amber Snyder, aka “Ditsy Dots” in Baltimore, MD on July 8, 2016. Both are from Suburban Chicago. BronyCon is the world's largest My Pretty Pony convention. Featuring cosplay and fan events, the annual convention was held at the Baltimore Convention Center. (Photo by Andre Chung/The Washington Post)

A vintage military aircraft is seen parked ahead of the International Air and Space Fair (FIDAE) at the Arturo Merino Benitez international airport in Santiago, Chile March 29, 2016. (Photo by Rodrigo Garrido/Reuters)