“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)

A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

Impala pictured in the Kruger National Park on December 7, 2007 in Mpumalanga, South Africa. (Photo by Warren Little/Getty Images)

German model Alena Gerber poses wearing a full chocolate dress during the presentation of chocolate dresses designed by German bakery group Lambertz on January 21, 2010 in Munich, Germany. (Photo by Alexandra Beier/Getty Images)

Police officers stand near a fishing boat, the Carolina Queen III, as it rests in shallow water just off Rockaway Beach, Thursday, February 25, 2016, in the Queens borough of New York. Authorities say a Coast Guard vessel overturned while assisting the fishing boat that ran aground in an inlet off New York City. (Photo by Frank Franklin II/AP Photo)

Dayane Mello attends the photocall for the television miniseries “The Young Pope” at the 73rd Venice Film Festival in Venice, Italy, September 3, 2016. (Photo by Alessandro Bianchi/Reuters)

A woman holds her veil as she takes part in Huranga, a game played between men and women a day after Holi, at Dauji temple near Mathura, March 3, 2018. (Photo by Adnan Abidi/Reuters)

People wear face masks while participating in the annual Memorial Day Parade on May 25, 2020 in the Staten Island borough of New York City. Dozens of cars and nearly 100 members of the patriotic motorcycle group Rolling Thunder joined the event. This year’s parade was diminished in size and in person-to-person contact due to the coronavirus outbreak. Across the country, events honoring the nation’s veterans have been cancelled or scaled back as America continues to experience high numbers of deaths and new cases of COVID-19. (Photo by Spencer Platt/Getty Images)