A visitor passes behind the sculpture “Puma-Dentist” made with plastic, wax and original heads of a puma and a hind by Austrian artist Deborah Sengl during an exhibition at the art gallery Deschler in Berlin April 15, 2008. (Photo by Fabrizio Bensch/Reuters)

“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)

Kim Kardashian west and Madonna backstage at MDNA SKIN hosts Madonna and Kim Kardashian West for a beauty conversation at YouTube Space LA on March 6, 2018 in Los Angeles, California. (Photo by Kevin Mazur/Getty Images for Madonna's MDNA SKIN)

Reflected in an ornament, a reporter takes a photo of the White House Christmas Tree in the Blue Room during a media preview of the holiday decor at the White House in Washington, U.S., November 29, 2016. (Photo by Kevin Lamarque/Reuters)

A man with blood on his shirt is evacuated from Brussels Airport in Zaventem, Belgium, on Tuesday, March 22, 2016. (Photo by Dirk Waem/Belga/Zuma Press/TNS)

A supporter of the team of Ukraine cheers prior to the Euro 2016 Group C soccer match between Ukraine and Poland at the Velodrome stadium in Marseille, France, Tuesday, June 21, 2016. (Photo by Thanassis Stavrakis/AP Photo)

Some people prepare to catch offerings thrown by Tengger tribe people into the crater of Bromo volcano to in Probolinggo, East Java province, on June 30, 2018, as part of Yadnya Kasada festival which falls on the 14th day of the Kasada month based on the traditional Hindu lunar calendar. (Photo by Juni Kriswanto/AFP Photo)

11-year-old Balinese dancer girl Intan puts on makeup before she performs Mergapati Dance at a village event in Banjar Wangaye Kelod, Denpasar, Bali, Indonesia on November 19, 2017. To preserve traditional dances and culture, Balinese train their children to learn various traditional dances from childhood. (Photo by Mahendra Moonstar/Anadolu Agency/Getty Images)