Riders negotiate a dune as they compete in the Adult Solo race at the HydroGarden Weston Beach Race in Weston- super- Mare, south west England, on October 9, 2016. Beach racing is an offshoot of enduro and motocross racing. Riders on solo motorcycles and quad bikes compete on a course marked out on a beach, with man- made jumps and sand dunes being constructed to make the course tougher. (Photo by Adrian Dennis/AFP Photo)

A Kashmiri Shiite Muslim flagellates himself during a Muharram procession in Srinagar, Indian controlled Kashmir, Tuesday, October 11, 2016. Muharram is a month of mourning in remembrance of the martyrdom of Imam Hussein, the grandson of Prophet Mohammed. (Photo by Dar Yasin/AP Photo)

The Spanish photographer Xavi Bou digitally combines sequential pictures of birds to create a single image, or chronophotograph, that reveals the shapes of their flight paths against Catalonian skies. His work shows the variety and beauty to be found in the daily activities of the local birds, including spiralling storks, swooping starlings and giddy swifts. Here: European herring gulls at Llobregat Delta. (Photo by Xavi Bou/Rex Features/Shutterstock)

This week's full Moon as photographed from on board the International Space Station by NASA astronaut Jeff Williams on August 19, 2016. Jeff is currently Commander of the Space Station for the Expedition 48 crew. (Photo by Jeff Williams/NASA)

Thailand's King Bhumibol Adulyadej in serious portrait January 01, 1960. Thailand's Royal Palace said on Thursday, October 13, 2016, that Thailand's King Bhumibol Adulyadej, the world's longest-reigning monarch, has died at age 88. (Photo by John Dominis/The LIFE Picture Collection/Getty Images)

A Syrian boy receives treatment at a hospital in the regime-held part of Aleppo on October 13, 2016. Syrian state television said four children were killed by rebel rocket fire on a school in a western regime-held neighbourhood. (Photo by George Ourfalian/AFP Photo)

A Muslim woman gets caned 23 strokes after being caught in close proximity with her boyfriend in Banda Aceh on October 17, 2016. Out of seven couples caught spending time together outside marriage, 13 were caned while one girl was spared after it was discovered that she was pregnant. Indonesia's Aceh province has gained international infamy for its strict Islamic laws. (Photo by Chaideer Mahyuddin/AFP Photo)

Students from St Andrews University are covered in foam as they take part in the traditional “Raisin Weekend” in the Lower College Lawn, at St Andrews in Scotland, Britain October 17, 2016. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. (Photo by Russell Cheyne/Reuters)