London Mayor Boris Johnson takes part in a tug of war with members of the armed services to launch the London Poppy Day, outside City Hall, in London, October 27, 2015. London Poppy Day is a street collection event to raise money for serving and retired members of the armed services and their families. (Photo by Stefan Wermuth/Reuters)

Members of the Russian Red Army Choir perform at Water Front Theatre in Beirut September 13, 2014. (Photo by Jamal Saidi/Reuters)

Pro-government supporters attend a rally of members of the education sector in Caracas, Venezuela June 14, 2016. (Photo by Ivan Alvarado/Reuters)

“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)

An LGBTQ member prepares before a streamed performance of “Pride at Home”, at the National Theatre in Caracas, Venezuela, Saturday, July 4, 2020. To celebrate 20 years of gay pride in Venezuela, LGBTQ members organized a presentation of different artistic shows via live streaming amid the new coronavirus pandemic. (Photo by Matias Delacroix/AP Photo)

Wolfgang (L), member of World War One historical association “Darstellungsgruppe Suddeutsches Militar 1870-1918” (DSM 18), from Munich, Germany, and Florent, member of French association “Le Poilu de la Marne”, dressed in vintage army uniforms, visit the Bezonvaux bunker in the national forest of Verdun, eastern France, March 29, 2014. Members of French and German historical associations, who gather annually, together visited the battlefield of Verdun in France, the site of a bloody World War One battle that dragged on for around 10 months in 1916, claiming hundreds of thousands of lives and destroying many villages. (Photo by Charles Platiau/Reuters)

A girl sticks out her tongue during snowfalls on a street in Hefei, Anhui province February 13, 2014. (Photo by Reuters/Stringer)

An internally displaced Afghan girl plays near their shelter at a refugee camp in Kabul January 13, 2015. (Photo by Omar Sobhani/Reuters)