A tourist poses for a picture with the Sphinx at the Pyramids of Giza in Cairo, Egypt, on October 19, 2011. (Reuters/Jamal Saidi)

“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 demonstrator is detained by police officers during clashes in downtown Barcelona, Spain, Friday, October 30, 2020. Clashes have erupted in a central Barcelona square between anti-riot police and hundreds who had gathered to protest the mandatory closure of bars, restaurants and other businesses in the latest effort to rein in on coronavirus outbreaks. (Photo by Joan Mateu/AP Photo)

Firefighters and emergency personnel climb the stairs during the Melbourne Firefighter Stair Climb at the Crown Metropol Melbourne in Melbourne, Australia, 10 September 2022. The Melbourne Firefighter Stair Climb features firefighters and emergency personnel climbing 28 flights of stairs wearing 25kgs of turnout gear to raise money for mental health. (Photo by Con Chronis/EPA/EFE)

Covered body is seen at the site of missile strike downtown Kyiv, Ukraine, October 10, 2022. Ukrainian officials report that at least eight people were killed and 24 wounded in the Ukrainian capital. (Photo by Valentyn Ogirenko/Reuters)

Singer Dua Lipa poses for photographers upon arrival at the amfAR, Cinema Against AIDS, benefit at the Hotel du Cap-Eden-Roc, during the 72nd international Cannes film festival, in Cap d'Antibes, southern France, Thursday, May 23, 2019. (Photo by Joel C. Ryan/Invision/AP Photo)

A female hippopotamus named “Mali”, which means Jasmine, eats fruits arranged to look like a cake during her 50th birthday celebration at Dusit Zoo in Bangkok, Thailand September 23, 2016. (Photo by Chaiwat Subprasom/Reuters)

A Los Angeles County firefighter puts water a burning house in a wildfire in the Lake View Terrace area of Los Angeles Tuesday, December 5, 2017. Ferocious winds in Southern California have whipped up explosive wildfires, burning a psychiatric hospital and scores of other structures. Tens of thousands of people have been ordered evacuated. (Photo by Chris Carlson/AP Photo)