Lenticular cloud and zebra. (Photo by National Geographic)

A reveller, covered in mud, chats with friends during the Glastonbury Festival at Worthy Farm in Somerset, Britain, June 26, 2015. The outdoor festival runs from 24 to 29 June. (Photo by Dylan Martinez/Reuters)

A child looks at a polar bear swimming under a water in its enclosure on a hot summer day at Prague Zoo, Czech Republic, July 30, 2015. (Photo by David W. Cerny/Reuters)

French National Front party deputy Marion Marechal-Le Pen attends the questions to the government session at the National Assembly in Paris April 14, 2015. (Photo by Charles Platiau/Reuters)

This September 22, 2014 photo, shows a building with street art murals in the Santurce neighborhood in San Juan, Puerto Rico. (Photo by Ricardo Arduengo/AP Photo)

A hot air balloon floats past an almost full rising moon on a warm fall evening near Encinitas, California October 5, 2014. (Photo by Mike Blake/Reuters)

A man braces his umbrella while walking through the snow on February 13, 2014 in New York City. Heavy snow and high winds made for a hard morning commute in the city. (Photo by John Moore/Getty Images)

This plane looks like it's bound for the moon as it shoots across the sky. Photographer Sebastien Lebrigand was impressed he could even see the lights on the jet's wings in this stunning silhouette. (Photo by Sebastien Lebrigand/Solent News)