People run in panic after a coalition airstrike hit Islamic State fighters positions in Tahrir neighbourhood of Mosul, Iraq, November 17, 2016. (Photo by Goran Tomasevic/Reuters)

A dachshund portraying a racehorse, trots down Duval Street in Key West, Florida, December 31, 2014. About 175 dachshunds and other dogs participated in the event that preludes four warm-weather takeoffs on New York City's Times Square ball drop. (Photo by Steve Panariello/Reuters/Florida Keys News Bureau)

“Contrails (short for “condensation trails”) or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines. As the hot exhaust gases cool in the surrounding air they may precipitate a cloud of microscopic water droplets or, if the air is cold enough, tiny ice crystals”. – Wikipedia

Photo: An airplane leaves a vapor trail as it flies in front of he moon on January 17, 2007 above Hanover, Germany. (Photo by Alexander Hassenstein/Getty Images)

With the entry of Poland into the European Union in 2004, Warsaw is currently experiencing the biggest economic boom of its history. The opening match of UEFA Euro 2012 is scheduled to take place in Warsaw. (Photo by: ryarwood; Source: Flickr)

Poznań is now Poland's fifth largest city. It is sometimes claimed to be the first capital of the kingdom of Poland. Poznań has many historic buildings and sights. The European Football Championship will take place in Poznan 2012.

Photo by: tiseb ; Source: Flickr

In modern Russia there are no free elections, therefore the political elite is almost constant.

Photo: Valentina Matvienko, Mayor of St. Petersburg, attends the St. Petersburg International Economic Forum (SPIEF) on June 17, 2011 in St. Petersburg, Russia. Global business leaders have gathered in Russia for the three-day conference. (Photo by Alexander Aleshkin/Epsilon/Getty Images)

Disabled dogs outfitted with wheelchairs walk at an animal rescue center on July 12, 2008 in Chengdu of Sichuan Province, China. The center has adopted over 100 stray dogs and cats from quake-struck areas. Those who were hurt or disabled are outfitted with a cart to help support they're body and make them mobile. (Photo by China Photos/Getty Images)

Lucie Clayton instructs pupils in the art of correct posture by balancing a glass and book on their heads at her finishing school in Old Cavendish Street, London. (Photo by William Vanderson/Fox Photos/Getty Images). 25th November 1936