Kevin Kvasnicka (L) and Jesse Gonzales openly carry firearms as they watch U.S. Republican presidential nominee Donald Trump speak on a big screen television along East 4th street during the Republican National Convention in Cleveland, Ohio, U.S., July 21, 2016. (Photo by Adrees Latif/Reuters)
Students from CAS Ballet Theatre School stretch on the sidewalk Saturday, February 20, 2016, in Ann Arbor, Mich. (Photo by Junfu Han/The Ann Arbor News via AP Photo)
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)
“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)