People carry portraits of relatives who fought in World War II, during the Immortal Regiment march in Bishkek, Kyrgyzstan, Monday, May, 9, 2022, marking the 77th anniversary of the end of World War II. (Photo by Vladimir Voronin/AP Photo)

A Star Wars fan in an R2-D2 costume poses for a photo outside the venue during a fan convention called the Star Wars Celebration in Chiba, near Tokyo, Friday, April 18, 2025. (Photo by Hiro Komae/AP Photo)

A dog takes a dip in the river Elbe on February 6, 2012 in Hamburg, Germany.The current cold front that has claimed over 200 lives in eastern Europe makes its way west. (Photo by Stuart Franklin/Getty Images)

A Thorneycroft motor van as used during World War I. (Photo by Topical Press Agency/Getty Images). August 1914

Tourists photograph a red dear stag visiting a car park near Glen Coe on December 1, 2017 in Glen Coe,Scotland. On the first day of the meteorological calendar, the UK was experiencing slightly warmer temperatures today with weather forecasters indicating that the recent cold spell is almost over. Yesterday's snow across eastern parts of England is expected to melt away over the course Friday as temperatures start to rise. (Photo by Jeff J. Mitchell/Getty Images)

A man bundled up for the cold weather carries a dog in his jacket while walking along the waterfront in New Westminster, British Columbia, Tuesday, December 28, 2021. Environment Canada has issued an arctic outflow warning for Metro Vancouver and the south coast with well below normal temperatures forecast for the region. (Photo by Darryl Dyck/The Canadian Press via AP Photo)

Australian World War Two veterans place crosses and flags at graves before attending the French-British ceremony at the British War cemetery in Bayeux, June 6, 2014. REUTERS/Leon Neal/Pool

“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)