Medical personnel jump in the COVID-19 unit at the CHR Centre Hospitalier Regional de la Citadelle Hospital, during the coronavirus disease (COVID-19) outbreak, in Liege, Belgium, April 22, 2020. (Photo by Yves Herman/Reuters)

Greyhounds resume racing behind closed doors on June 01, 2020 in Perry Barr, England. Greyhound racing across England is returning as restrictions on sporting events are relaxed during the coronavirus pandemic. (Photo by Clive Mason/Getty Images)

This photo taken on November 7, 2021 shows a panda falling from a platform as it plays in its enclosure after snowfall in Xian in China's northern Shaanxi province. (Photo by AFP Photo/China Stringer Network)

The towers of Russky Bridge are seen over the fog covered Vladivostok, Russia on May 26, 2020. The so-called “fog season” on the Pacific coast and in the south of Russia's Primorye Territory lasts from April till September. (Photo by Yuri Smityuk/TASS)

Five year-old Fatima plays as women weave a carpet in a home workshop in Peshawar, Pakistan, January 13, 2022. (Photo by Fayaz Aziz/Reuters)

“Kids of Sapa”. Four little beautiful Hmong girls from Lao Chai Village, near Sapa, Vietnam. (Photo and caption by Felipe Hanower/National Geographic Traveler Photo Contest)

MAKS (Russian: МАКС, Russian: Международный авиационно-космический салон, International Aviation and Space Salon) is The International Air Show took place near Moscow, Russia on Zhukovskiy LII air field on 16-21 August 2011.

“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)