Cars are parked near Place de la Concorde on March 12, 2014 in Paris, France. Inset: World War I, German airplanes at Place de la Concorde in Paris, wrecked by celebrating crowds on the day of the restoration of Alsace-Lorraine, November 18, 1918. (Photo by Peter Macdiarmid/Getty Images)

“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)

Bella Hadid attends “The Unknown Girl (La Fille Inconnue)” Premiere during the 69th annual Cannes Film Festival at the Palais des Festivals on May 18, 2016 in Cannes, France. (Photo by Alberto Pizzoli/AFP Photo)

A portrait of French WWI soldier Edouard Marius Ivaldi is displayed on a tablet, in this illustration picture, alongside his battlefield grave memorial, a wooden cross with a battlefield helmet in Champagne, eastern France, November 3, 2015. (Photo by Charles Platiau/Reuters)

A model presents a creation by German designer Karl Lagerfeld as part of his Haute Couture Spring Summer 2015 fashion show for French fashion house Chanel in Paris January 27, 2015. (Photo by Gonzalo Fuentes/Reuters)

Members of contemporary circus group perform inside the subway train, amid the energy crisis in Prague, Czech Republic on March 2, 2023. (Photo by David W. Cerny/Reuters)

French actress Pom Klementieff (L), Israeli-American actress Natalie Portman (C) and US actress Tessa Thompson pose on the red carpet on arrival to attend the UK Gala Screening of the film “Thor: Love and Thunder”, at the Odeon Luxe in London on July 5, 2022. (Photo by Daniel Leal/AFP Photo)

French actress Audrey Tautou arriving to the Balmain show as part of Paris Fashion Week Fall/Winter 2020/2021 on February 28, 2020 in Paris, France. (Photo by Meryl Curtat/SIPA Press)