“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)

A man performs a split as he practices Kung Fu at Beihai Park in Beijing, China August 20, 2017. (Photo by Reuters/China Stringer Network)

A woman poses with her tattoo during the Shanghai Tattoo Extreme & Body Art Expo 2017 in Shanghai, China September 2, 2017. (Photo by Aly Song/Reuters)

A Hindu pilgrim feeds biscuits to an ox to seek blessing before heading for an annual trip to Sagar Island for the one-day festival of “Makar Sankranti”, in Kolkata, India January 10, 2017. (Photo by Rupak De Chowdhuri/Reuters)

Catholic pilgrim Matilde Madalena de Jesus crawls on a rocky trail carrying a bottle of water on her head during the annual pilgrimage of the dead (Romaria dos Finados), in the city of Juazeiro do Norte, Ceara state, in Brazil October 31, 2016. (Photo by Ueslei Marcelino/Reuters)

“Seagulls by Snuff Puppets causing mischief” stand alongside members of “Smashed: The Nightcap cabaret show” during the opening day press call for Sydney Festival 2024 on January 05, 2024 in Sydney, Australia. (Photo by Don Arnold/WireImage)

Jeffrey Shiau, 35, a volunteer from the crowd, spits water into the mouth of Sam Kaufman, 27, a performer from the Human Fountains, during a reopening party held as coronavirus disease (COVID-19) restrictions are gradually lifted in Los Angeles, California, U.S. June 15, 2021. (Photo by Cheney Orr/Reuters)

A view shows “The Farnese Bridge”, a participatory monumental cardboard installation by French artist Olivier Grossetete, over the Tiber river in front of the Palazzo Farnese, the seat of the French embassy in Italy, during its inauguration in Rome on July 13, 2021. A French Embassy project, the Farnese bridge is the realization of the dream of Cardinal Farnese, who wished to build a bridge over the Tiber to connect Palazzo Farnese to the gardens of the Villa Farnesina. A project, at the time, entrusted to Michelangelo, but that remained unfinished. (Photo by Filippo Monteforte/AFP Photo)