A cyclist shops for a gift from a roadside open-air vendor during Valentine's Day celebrations amid the COVID-19 pandemic in Kamwokya, Kampala, Uganda on February 14, 2022. (Photo by Miriam Watsemba/Reuters)

Artist Kong Ning wears a wedding dress made from respirators to highlight concerns about air quality and pollution in Beijing, China on December 1, 2015. (Photo by Luo Xiaoguang/Xinhua Press/Corbis)

A participant prepares for the Red Bull Air Race World Championships in Abu Dhabi, United Arab Emirates on February 6, 2017. (Photo by Red Bull Content Pool/SIPA Press/Rex Features/Shutterstock)

U.S. President Donald Trump boards Air Force One to depart for Vietnam from Beijing Airport in Beijing, China on November 10, 2017. (Photo by Jonathan Ernst/Reuters)

A surfer takes some air off a wave while surfing after sunset in Cardiff, California, U.S., January 7, 2020. (Photo by Mike Blake/Reuters)

People look at a collection of vintage cars during the Expo Transporte event at the Francisco de Miranda Air Base in Caracas on December 7, 2025. (Photo by Juan Barreto/AFP 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)

A Royal Air Force search and rescue helicopter prepares to leaves RAF Valley as the search continues for the crew of cargo vessel The Swanland which sank off north Wales on November 27, 2011 in Anglesey, Wales. (Photo by Christopher Furlong/Getty Images)