A man carries an injured woman in a site hit by what activists said were airstrikes carried out by the Russian air force in the rebel-controlled area of Maaret al-Numan town in Idlib province, Syria January 9, 2016. At least 70 people died in what activists said where four vacuum bombs dropped by the Russian air force in the town of Maaret al-Numan; other air strikes where also carried out in the towns of Saraqib, Khan Sheikhoun and Maar Dabseh, in Idlib. (Photo by Khalil Ashawi/Reuters)

A military aircraft flies low through the Mach Loop in west-central Wales on September 25, 2025 during Cobra Warrior 25-2, one of Nato’s largest multinational air exercises. The operation, running across the UK until October 3, brings together air forces from the UK, US, Canada, Italy and Germany for three weeks of high-intensity training in challenging low-level environments. (Photo by Tony Marsh)

“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)

Ariel Almiron and Alumine Deluchi compete in the final round of the Tango World Championship stage category, in Buenos Aires, Argentina, Saturday, September 25, 2021. (Photo by Natacha Pisarenko/AP Photo)

A woman athlete aims an air rifle while competing in a local shooting championship in Yemen's Huthi rebel-held capital Sanaa on January 3, 2023. (Photo by Mohammed Huwais/AFP Photo)

People take part in a traditional mid-summer solstice night celebration (Rasos Festival) at the Open-Air Museum of Lithuania in Rumsiskes, east of Kaunas, Lithuania, on late June 23, 2020. (Photo by Petras Malukas/AFP Photo)

Jesus Taborda and Sabrina Amuchastegui compete in the final round of the Tango World Championship stage category, in Buenos Aires, Argentina, Saturday, September 25, 2021. (Photo by Natacha Pisarenko/AP Photo)