In this Thursday, August 17, 2017 photo, a troupe charges and fires their rifles during Tabourida, a traditional horse riding show also known as Fantasia, in Mansouria, near Casablanca, Morocco. Thousands gathered recently in Mansouria, a small town south of the capital Rabat, to attend one of the oldest festivals in Morocco. Nineteen horse troupes came from different parts of the kingdom to celebrate a three-day event that blends courage, skill and tradition. (Photo by Mosa'ab Elshamy/AP Photo)

This February 7, 2018, photo shows João Lousada, a flight controller for the International Space Station, wearing an experimental space suit during a simulation of a future Mars mission in the Dhofar desert of southern Oman. The desolate desert in southern Oman resembles Mars so much that more than 200 scientists from 25 nations organized by the Austrian Space Forum are using it for the next four weeks to field-test technology for a manned mission to Mars. (Photo by Sam McNeil/AP Photo)

In this February 20, 2018 photo, fair vendor Noelia Flores holds up a black backdrop behind a small statue of an “Ekeko”, the god of prosperity, for a portrait at her booth during the annual Alasita Fair in La Paz, Bolivia. Every year, thousands of Bolivians head to the feast of Alasitas that is held in his honor to buy miniature cars, houses and toy dollar bills symbolizing their dreams of prosperity. (Photo by Juan Karita/AP Photo)

In this November 3, 2015 file photo, Afghan Taliban fighters listen to Mullah Mohammed Rasool, the newly-elected leader of a breakaway faction of the Taliban, in Farah province, Afghanistan. Despite US President Donald Trump’s pronouncement that there would be no talks with the Taliban following a series of deadly attacks in Kabul, officials say talks continue, but neither side trusts the other and neither believes the other negotiates independently. (Photo by AP Photo/Stringer)

In this August 3, 2015, photo, residents make their way through floodwaters in Minbu, Magway division, in Myanmar. The Ministry of Social Welfare, Relief and Resettlement said that more than 200,000 people are affected in 11 of the country's 14 states and divisions by flooding. In addition to damage to houses and farmland, infrastructure has been very badly hit, with roads and rail lines cut in many places and telecommunication links broken. (Photo by Hkun Lat/AP Photo)

In this May 14, 2016 photo, children wearing their school backpacks climb on a cliff using a bamboo ladder on their way home from school in Zhaojue county, southwest China's Sichuan province. A village in China's mountainous west where schoolchildren must climb an 800-meter (2,625-foot)-high bamboo ladder secured to a sheer cliff face may get a set of steel stairs to improve it's safety. (Photo by Chinatopix via AP Photo)

In this January 31, 2014 file photo released by the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA), shows residents of the besieged Palestinian camp of Yarmouk, queuing to receive food supplies, in Damascus, Syria. That year, the U.N. was able to deliver food to about five percent of people in besieged areas including Yarmouk, while today estimates show the organization is reaching less than one percent. (Photo by UNRWA via AP Photo)

This April 9, 2016 photo provided by Bertrand Piccard via Global Newsroom shows Piccard taking a selfie on board Solar Impulse 2 during a test flight over the Pacific Ocean. The solar-powered airplane on an around-the-world journey had traveled 80 percent of the way from Hawaii to California by Saturday, April 23. The aircraft's destination on this leg of the journey is Mountain View, Calif., at the southern end of San Francisco Bay. (Photo by Bertrand Piccard/Global Newsroom via AP Photo)