“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)

Students pose for a pictures taken by their friends during spring break on the beach in the resort city of Cancun, Mexico, February 27, 2009. (Photo by Israel Leal/AP Photo)

Sports have the ability to transform groups of strangers into a united community. In the celebratory spirit surrounding the 2014 FIFA World Cup, Sony and the World Photography Organisation present UNITED – a contest honouring the passion of football fans around the world. Seven inspirational photographers have been selected by Sony and WPO to capture the atmosphere and celebration of the World Cup across the globe. Photo: France – French fans cheering for their team. (Photo by Anthony Lepinay)

Bottlenose dolphins swim over visitors in water tank at the Hakkeijima Sea Paradise aquarium-amusement park complex in Yokohama, southwest of Tokyo, Tuesday, July 21, 2015. Temperatures in Tokyo's metropolitan area neared around 96 degree Fahrenheit, or 35 degree Celsius, on Tuesday. (Photo by Shuji Kajiyama/AP Photo)

The Chicago Air & Water Show is an annual air show held on the shore of Lake Michigan in Chicago, Illinois. The show has been held each year since 1959 and is Chicago's second most popular festival. In 2005, 2,200,000 watched the Chicago Air and Water Show.

Zoee Heath of New South Wales competes in the womens U18 discus throw during day two of the Australian Junior Athletics Championships at Sydney Olympic Park Athletic Centre on March 11, 2011 in Sydney, Australia.

Coronavirus vaccinated audience members watch Saudi prominent singer Mohammed Abdu as he performs at the newly built Super Dome, in Jiddah, Saudi Arabia, late Thursday, July 8, 2021. The concert is organized by the Saudi General Entertainment Authority after the kingdom lifted coronavirus restrictions on events in May. (Photo by Amr Nabil/AP Photo)

People take home sacrificial animals after purchasing it at a cattle market ahead of the Muslim festival of Eid al-Adha in Karachi on July 19, 2021. (Photo by Asif Hassan/AFP Photo)