“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)

Visitors were able to pick their own flowers on this sunflower trail at Gloagburn Farm near Perth, in Scotland on September 13, 2021. Crawford Niven, a farmer, said he was inspired to make the trail, which is made up of nearly 200,000 plants, after seeing similar ones in America and Australia. (Photo by South West News Service)

The stunning coastline of South Wales in UK on July 12, 2025 was once again turned into a wild and wonderful natural playground as Love Trails Festival powered by Garmin welcomed around 5,000 people to the Gower Peninsula for a long weekend of music, trail running, adventure, movement and community. (Photo by Giulia Spadafora)

In this photograph taken on June 28, 2015, a hiker in Hong Kong takes a picture of the city from a walking trail. The southern Chinese territory is crisscrossed by more than 180 miles of designated hiking trails. (Photo by Alex Ogle/AFP Photo)

A man crosses a mud-covered trail carrying his wife on his back at a flooded Han River park in Seoul, South Korea, August 4, 2020. (Photo by Kim Hong-Ji/Reuters)

A squirrel fights for its life in the bill of a great blue heron at the Mission Trails Regional Park in California in the second decade of April 2025. (Phoot by Decker Nomura/Solent News & Photo Agency)

The provincial highest chimney collapses as it is demolished by explosives in Shenyang, Liaoning province, April 28, 2014. The 150-metre-high chimney used to be part of a local heating factory, according to local media. (Photo by Sheng Li/Reuters)

Young artists perform at the presentation of clowns in a hall of the Arts Palace during the first clown festival in Belarus in Bobruisk, some 150 km from Minsk, Belarus, 01 April 2018. About 60 clowns from Belarus and Russia gathered to entertain spectators. For 1 day Bobruisk became a capital of Jokes and Humour. Theaters of clownery, mime-theaters, individual performers of humorous genre, stilts and hospital clowns performed on a stage of the Palace of Arts. (Photo by Tatyana Zenkovich/EPA/EFE)