“Catch of the Decade”. Can you guess what happened next? Photo location: Katmai National Park, Alaska, USA. (Photo and caption by Aaron Baggenstos/National Geographic Photo Contest)

These beautiful shots may look like works of modern art – but they are actually close-ups of chemical reactions. The works were snapped with the help of a group of scientists from the University of Science and Technology of China (USTC) in Anhui, China. Here: Zinc reacting with lead nitrate in a soft gel to form lead crystals. (Photo by Yan Liang/Caters News)

Actress/Singer Victoria Justice arrives at the 2012 Teen Choice Awards at Gibson Amphitheatre on July 22, 2012 in Universal City, California. (Photo by Jeffrey Mayer)

Dancers attend a photocall for the new “The One – Grand Show” at Friedrichstadt-Palast in Berlin, Germany September 28, 2016. The show, which features costumes by French fashion designer Jean Paul Gaultier, premieres on 06 October. (Photo by Hannibal Hanschke/Reuters)

A woman poses for a picture as bunches of paprika hang on the walls of her house to dry in the village of Donja Lakosnica, Serbia October 6, 2016. Donja Lokosnica is the Serbian “capital of paprika”, since almost all of the 1300 inhabitants are involved in growing paprika. As autumn approaches, the whole village turns red, because of many threads of dried peppers, that hang around Lokosnica, waiting for their winter use. Each of these paprika threads is handmade, still dried according to traditional techniques, assisted solely by the sun and fresh air. (Photo by Marko Djurica/Reuters)

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)

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)