Bavarian herdsmen and a herdswoman in traditional dresses drive their beasts on a road during the return of the cattle from the summer pastures in the mountains near Oberstaufen, Germany, Friday, September 9, 2016. (Photo by Matthias Schrader/AP Photo)

Ambience backstage and frontstagen at the Y Project fashion show during the Spring Summer 2024 Collections in Paris, France on October 1 30 2023. (Photo by Jonas Gustavsson for The Washington Post)

A model wears a creation for the Louis Vuitton Spring/Summer 2024 womenswear fashion collection presented Monday, October 2, 2023 in Paris. (Photo by Vianney Le Caer/AP Photo)

“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)

Sharon Stone and Anton Rivas by Thierry Le Gouès for French Revue de Modes #20, Spring/Summer 2012 (Dog Day Afternoon; Photo by Thierry Le Gouès; Styling: Marcell Rocha)

Models present creations for Etam during the 2017 Spring/Summer ready-to-wear collection fashion show, on September 27, 2016 in Paris, France. (Photo by Swan Gallet/WWD/Rex Features/Shutterstock)

Models dance during the presentation of Stella McCartney's Spring-Summer 2017 ready-to-wear fashion collection presented Monday, October 3, 2016 in Paris. (Photo by Francois Mori/AP Photo)

A model wears a creation for Miu Miu's Spring-Summer 2017 ready-to-wear fashion collection presented Wednesday, October 5, 2016 in Paris. (Photo by Francois Mori/AP Photo)