In this Tuesday, February 11, 2014, photo, a trained monkey, that makes a living for her Pakistani owner by performing to a crowd in public and private places, sits held by a leash, in Rawalpindi, Pakistan. For Pakistanis who raise and train the monkeys they are an important source of income in an impoverished country, and they form a strong bond with the animals. The monkeys are usually captured in the wild when they are babies and then trained. A trained monkey can fetch 20,000 to 30,000 rupees ($190 to $285). (Photo by Muhammed Muheisen/Associated Press)

New York Police Department tactical police officers stand guard near the New York Stock Exchange on September 9, 2011 in New York City. Officials are stepping up security in New York and Washington D.C. a day after U.S. officials received a credible but unconfirmed terror threat to utilize car bombs on bridges or tunnels in New York or Washington. (Photo by Justin Sullivan/Getty Images)

A zoo employee carries three-month-old female giant panda cub, born to mother Liang Liang and father Xing Xing, on display to the public for the first time at the national zoo in Kuala Lumpur, Malaysia, November 17, 2015. (Photo by Olivia Harris/Reuters)

Actress Marilyn Monroe poses for a portrait in a bathing suit and high heels with a bottle of Coca-Cola in a glass on a table behind her in circa 1953. (Photo by Michael Ochs Archives/Getty Images)

Contrasted against the white flowers in a cotton field, a brown bear is out for a ramble just after midnight in the second decade of July 2023 in Kainuu, Finland, where the sun does not fully set for more than 70 days in the summer months. (Photo by Jane Jeffrey/Animal News Agency)

Commandos of the “Underwater Defence” (SAS), the special operation unit of the Turkish Navy take part in a military training in Istanbul, Turkiye on June 13, 2022. (Photo by Ali Atmaca/Anadolu Agency via Getty Images)

In this image released on November 08, American singer Madison Beer poses at the MTV EMA's 2020 on October 30, 2020 in Los Angeles, California. The MTV EMA's aired on November 08, 2020. (Photo by Rich Fury/Getty Images for MTV)

“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)