“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)

Elaborately dressed monks costumed as wrathful guardian spirits perform ceremonial dances during the Tenchi Festival on May 25, 2014 in Lo Manthang, Nepal. The Tenchi Festival takes place annually in Lo Manthang, the capital of Upper Mustang and the former Tibetan Kingdom of Lo. Each spring, monks perform ceremonies, rites, and dances during the Tenchi Festival to dispel evils and demons from the former kingdom. (Photo by Taylor Weidman/Getty Images)

Women dance in costume during the West Indian Day Parade in Brooklyn, New York September 7, 2015. The parade, which takes place annually, celebrates Caribbean culture and history. (Photo by Andrew Kelly/Reuters)

Show hosts Anna Faris (L) and Allison Janney dance on stage during the 2015 People's Choice Awards in Los Angeles, California January 7, 2015. (Photo by Mario Anzuoni/Reuters)

Demonstrators perform a dance in front of riot policemen during a march called by students to request changes in the education system in Santiago, Chile September 5, 2017. (Photo by Ivan Alvarado/Reuters)

An ultra-Orthodox Jewish bride takes part in the “mitzva tantz”, the custom in which relatives dance in front of the bride after her wedding ceremony, in Netanya, Israel, early March 16, 2016. (Photo by Baz Ratner/Reuters)

Angel Hall, 22, (C) and Bri Artis, 21, (R) dance in a silent disco on the fourth and final day of the Firefly Music Festival in Dover, Delaware on June 17, 2018. (Photo by Mark Makela/Reuters)

People perform Chinese Lion dance in Chinatown during the Chinese Lunar New Year in Lima, Peru on February 5, 2019. (Photo by Guadalupe Pardo/Reuters)