A model showcases designs on the catwalk during Beijing Institute of Fashion Technology and Taiwan Shin Chien University Graduates Collection show of China Fashion Week A/W 2011 on March 25, 2011 in Beijing, China. (Photo by Feng Li/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)

Two chimpanzees share a piece of watermelon at Taronga Zoo on December 23, 2010 in Sydney, Australia. (Photo by Rick Stevens/Taronga Zoo via Getty Images)

Models showcase Valentine's Day underwear celebrating the results of a recent survey revealing that men find the lingerie, boxer shorts and vests, the biggest turn on ahead of February 14 Valentine celebrations, at Waterloo on February 2, 2006 in London, England. (Photo by Gareth Cattermole/Getty Images)

A steam traction engine with a broken rear axle in Pall Mall, London. (Photo by Topical Press Agency/Getty Images). November 1923

A model presents a creation made with chocolate by professional designers and pastry chefs during a Chocolate Fashion Show at the Salon Du Chocolat in Beirut, Lebanon November 12, 2015. (Photo by Jamal Saidi/Reuters)

Elephants are paraded in front of the Grand Palace to pay respects to the late Thai King Bhumibol Adulyadej in Bangkok on October 8, 2016. Thailand' s King Bhumibol Adulyadej died at the age of 88 on October 13 after years of ill health, ending a seven- decade reign and leaving the politically divided nation without its key pillar of unity. (Photo by Lillian Suwanrumpha/AFP Photo)

A man carries a figurine of Santa Muerte or The Saint of Death during the first prayer of the New Year in Mexico City, Mexico January 1, 2017. Nuestra Señora de la Santa Muerte is a female deity of Mexican folk religion, venerated primarily in Mexico and the Southwestern United States. (Photo by Carlos Jasso/Reuters)