“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)

A participant falls on vintage skis during a traditional historical ski race in the northern Bohemian town of Smrzovka February 21, 2015. (Photo by David W. Cerny/Reuters)

A farrier attaches a horse shoe still hot from the furnace at The Household Cavalry Mounted Regiment (HCMR) at Hyde Park Barracks on March 28, 2012 in London, England. (Photo by Peter Macdiarmid/Getty Images)

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)

Elena Reid of USA looks on with bloody face due to a cut during the Women's WIBF Flyweight Championship fight between Regina Halmich and Elena Reid at the Boerderlandhalle on December 3, 2005 in Magdeburg, Germany. (Photo by Christian Fischer/Getty Images)

Groupama Sailing Team, skippered by Franck Cammas of France during leg 1 of the Volvo Ocean Race to Cape Town on November 6, 2011. (Photo by Yann Riou/Groupama Sailing Team/Volvo Ocean Race via Getty Images)