Dark clouds hang over the Great Belt Bridge connecting Nyborg and Halsskov, Denmark, on June 26, 2023. (Photo by Mads Claus Rasmussen/Ritzau Scanpix via AFP Photo)

An old car passes by while dark clouds are seen due to the tropical storm Idalia in Havana, on August 28, 2023. (Photo by Yamil Lage/AFP Photo)

A couple walks across the Francis Scott Key Bridge as the setting sun lights up the clouds in Washington, Friday, October 30, 2020. (Photo by J. David Ake/AP Photo)

A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

“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)

The sky looked on fire this morning, as it made the clouds glow red, just before sunrise at Peterborough Rowing Lake, in Nene Park, UK on January 18, 2017. (Photo by Paul Marriott/Rex Features/Shutterstock)

A giant storm cloud can be seen in the sky above swimmers near Mollymook Beach, south of Sydney, March 5, 2014. (Photo by David Gray/Reuters)

Smoke and ash are visible during the the Shiveluch volcano's eruption on the Kamchatka Peninsula in Russia, Tuesday, April 11, 2023. Shiveluch, one of Russia's most active volcanoes, erupted Tuesday, spewing clouds of ash 20 kilometers into the sky and covering broad areas with ash. (Photo by Alexander Ledyayev via AP Photo)