This photo taken on December 2, 2015 shows a lenticular cloud forming as white streaks from airplanes mark the blue sky, in a rare atmospheric phenomena above the town of Gevgelija on December 2, 2015. Lenticular clouds have been regularly confused for UFOs throughout history due to the their smooth, round or oval lens-shaped structure. (Photo by Armend Nimani/AFP Photo)

A knight parades in the street during the traditional carnival parade in Cologne, western Germany, Monday, February 16, 2015. (Photo by Martin Meissner/AP Photo)

A frozen public bench is seen next to a lake side due to the heavy wind conditions in Geneva February 8, 2015. (Photo by Pierre Albouy/Reuters)

Women take part in Belarus Cup in bodybuilding and fitness in Minsk, October 24, 2015. (Photo by Vasily Fedosenko/Reuters)

Girls enjoy nice weather at a park in front of the Pothonggang Department Store in central Pyongyang October 11, 2015. (Photo by Damir Sagolj/Reuters)

Revellers take part in a zombie parade to celebrate Halloween in Kiev, Ukraine, October 31, 2015. (Photo by Valentyn Ogirenko/Reuters)

A blurred panaroma of Roemerberg historic center is reflected in a soap bubble in Frankfurt am Main, Germany, 09 July 2015. (Photo by Frank Rumpenhorst/EPA)

A fisherman throws his net to catch fish in a lagoon in Batticaloa November 24, 2015. (Photo by Dinuka Liyanawatte/Reuters)