Hemispheric color differences on Saturn's moon Rhea are apparent in this false-color view from NASA's Cassini spacecraft in this March 2, 2010 file photo. (Photo by Reuters/NASA/JPL/SSI)

A young Shiite Muslim child participates in a Muharram procession in Ahmadabad, India, Sunday, October 9, 2016. (Photo by Ajit Solanki/AP Photo)

Participants dance and climb on an art installation as approximately 70,000 people from all over the world gather for the 30th annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. August 31, 2016. (Photo by Jim Urquhart/Reuters)

A horse grazes on railway tracks near the old train station on the the Northeast railroad (Ferrovia do Nordeste) in the city of Missao Velha, Ceara state, northeastern Brazil, October 25, 2016. (Photo by Ueslei Marcelino/Reuters)

Police officers with a sniffer dog check a railway as the Soyuz MS spacecraft for the next International Space Station (ISS) crew of Kate Rubins of the U.S., Anatoly Ivanishin of Russia and Takuya Onishi of Japan is ready to be transported from an assembling hangar to the launchpad ahead of its launch scheduled on July 7, at the Baikonur cosmodrome in Kazakhstan July 4, 2016. (Photo by Shamil Zhumatov/Reuters)

In this Wednesday, July 20, 2016 photo, a child carries kettles through a flooded street with a woman in Tianjin, China. China says dozens of people have died or gone missing since Monday in massive floods across the country's north. (Photo by Chinatopix via AP Photo)

In this June 20, 2015 photo, Niberta Galvez uses the bottom half of his shirt to collect coca leaves in Samugari, Peru. Coca farmers were among the locals who, in 1984, formed citizen militias to help the military beat back Shining Path rebels, reducing them to a small group of fewer than 500 who now are deeply involved in drug trafficking. (Photo by Rodrigo Abd/AP Photo)

A quartet of showgirls in costume sit at an outdoor table and drink from mugs at Disneyland amusement park, Anaheim, California, 1955. (Photo by Loomis Dean/The LIFE Picture Collection/Getty Images)