Dozens of contestants attend the “Bring Your Own Big Wheel” Race on Easter Sunday at Potrero Hill in San Francisco, California, United States on April 20, 2025. (Photo by Tayfun Coskun/Anadolu via Getty Images)

“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)

People dressed in underwear run into a store to pick free clothes during a promotional event starting the summer sale at an outlet of the Desigual clothing retailer in Berlin, June 20, 2014. Desigual treated the first 100 customers with a free outfit if they stripped down to their underwear for the first day of the outlet's summer sale. (Photo by Thomas Peter/Reuters)

Dallas Cowboys cheerleader performs during the game against the Detroit Lions at AT&T Stadium in Arlington, Texas on October 13, 2024. (Photo by Kevin Jairaj/USA TODAY Sports via Reuters)

Five-year-old Jeda takes a close look at “Sharnana” by artist Drew McDonald at the Sculpture by The Sea on October 18, 2024 in Sydney, Australia. (Photo by Jessica Hromas/The Guardian)

Sophie Hawkshaw, 9, dressed as a Headless Horseman, participates in a lead rein fancy dress competition for riders under 10 years old at an agricultural show, in Athenry, Ireland on May 25, 2025. (Photo by Clodagh Kilcoyne/Reuters)

An undated handout photo obtained on May 14, 2022, from Khartoum's Marshall Nature Reserve for exotic birds, shows a visitor posing for pictures with some of the protected birds in the capital Khartoum. Tucked away east of Sudan's capital Khartoum, a sanctuary of lush green vegetation has been a haven for dozens of exotic birds from far and wide. (Photo by Khartoum Marshall Nature Reserve/AFP Photo)

Tali Spira of Baltimore, Maryland lets the wind aid in her Flow Art style dance moves (using silk material and fans) at the Tidal Basin in Washington, D.C. on March 25, 2022. She danced amid the backdrop of the cherry blossom trees that were still at their peak. (Photo by Michael S. Williamson/The Washington Post)