Lance Corpral Johnnie Miller of the Household Cavalry rehearses at Floors Castle in preparation for massed Pipe Band day on August 26, 2011 in Kelso, Scotland. The event, being held on August 28, will feature the first Scottish performance of the Household Cavalry's Musical ride in over 10 years. (Photo by Jeff J Mitchell/Getty Images)

A picture taken on October 5, 2018, shows a general view of Migingo island which is densely populated by residents fishing mainly for Nile perch in Lake Victoria, the continent's largest lake, on the border of Uganda and Kenya. More than 500 people live on the island, which is barely 2,000-square-metres. (Photo by Yasuyoshi Chiba/AFP Photo)

A cloud of black smoke billows out the exhaust pipe of John Robertson's diesel dragster as he runs down the track during the 2015 NHRA Kansas Nationals, Friday, May 22, 2015, at Heartland Park in Topeka, Kan. (Photo by Chris Neal/The Topeka Capital-Journal via AP Photo)

A Rohingya refugee woman is helped from a boat as she arrives exhausted on the Bangladesh side of the Naf River at Shah Porir Dwip after fleeing her village in Myanmar, on October 1, 2017 in Cox's Bazar, Bangladesh. (Photo by Kevin Frayer/Getty Images)

Models pose alongside the Kia SP SUV Concept car after its launch at India Auto Show 2018 in Greater Noida, February 7, 2018. The biennial automobile exhibition opens to public Friday and runs till Feb. 14. (Photo by Saumya Khandelwal/Reuters)

“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)

People affected by Hurricane Maria bathe in water piped from a creek in the mountains, in Naranjito, Puerto Rico, Thursday, September 28, 2017. Residents of the area drive to the pipes to bathe because they were left without water supplies by the damage caused by Hurricane Maria. The pipe was set up by a neighbor who ran it from a creek in his property to the side of the road in order to help those left without water. (Photo by Ramon Espinosa/AP Photo)

The Bajau people of Malaysia live their lives completely at sea, living in wooden huts and spending their days fishing. Sailing over crystal clear waters, the Bajau people of Malaysia live their lives almost entirely at sea. Photographer Ng Choo Kia joined the Bajau people on their pirogues, which are long narrow canoes made from single tree trunks, and documented their daily life in a series of pictures. (Photo by Ng Choo Kia/Hotspot Media/SIPA Press)