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

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)

A colony of penguins gather with the Bark Europa in the background, on March 05, 2015 in South Georgia Island. An adventurer has documented his 5,000 miles journey aboard a 100-year-old ship, sailing from Argentina to Antarctica to Cape Town. (Photo by Andrew Orr/Barcroft Images)

Getting it done. Felicity, an athlete at an amateur weightlifting competition in a small local gym. (Photo by Clinton Bradbury/Women in Sport Photo Action Awards 2021)

A vendor sells fruits and nuts at the Green Bazaar in Almaty January 23, 2015. Kazakhstan is spending billions of dollars of its reserves to keep devaluation of its currency gradual and reduce inflationary risks of the sort thrown up in Russia by the rouble's slide, analysts and former central bank officials say. Kazakhstan, Central Asia's largest economy, is closely tied to Russia through trade and, like other ex-Soviet states, has been feeling the pain of the crisis which has driven the rouble down 50 percent against the dollar since the start of 2014. (Photo by Shamil Zhumatov/Reuters)

A member of the United Arab Emirates armed forces gestures as the first batch of UAE military personnel returns from Yemen in Abu Dhabi, November 7, 2015. (Photo by Reuters/United Arab Emirates News Agency WAM)