“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 women rides a motor bike on a street covered with volcanic ash from an eruption of Mount Kelud, in Solo, Indonesia, Friday, February 14, 2014. A major volcanic eruption in Indonesia blasted clouds of ash and debris 18 kilometers (12 miles) into the air on Friday, forcing authorities to close six airports, cancel flights elsewhere in Southeast Asia and evacuate more than 100,000 people from the mountain. (Photo by Hafidz Novalsyah/AP Photo)

A young boy walks to his school bus on a foggy day in Dubai on March 14, 2024. (Photo by Chris Whiteoak/The National)

A Pakistani farmer guides his bulls as he competes in a traditional bull race in Khunda village in the northwestern district of Attock, some 80 kilometers from Islamabad on January 3, 2015. Tens of thousands of people gather whenever there is a bull race held in Pakistan which are usually the highlight of festivals organized in rural areas of the Asian country, and attract lots of spectators due to their thrilling nature. The traditional competition attracts landlords and farmers from all around the province where the race is held, and they all bring their fastest and strongest bulls in hopes of gaining a reputation. (Photo by Aamir Qureshi/AFP Photo)

A reflection of the Alps mountain “Nordkette” is seen in the ski googles of Anders Bardal of Norway during the training round of the FIS Ski Jumping World Cup event at the 60th Four Hills ski jumping tournament at Bergisel on January 3, 2012 in Innsbruck, Austria. (Photo by Alexander Hassenstein/Bongarts/Getty Images)

LAPD chopper flies in a foregraund of the Super Moon in Los Angeles, California on May 05, 2012. Tonight's moon is set to appear 14 percent larger and 30 percent brighter from our perspective on Earth. The Supermoon lines up much closely with perigee – the moon's closest point to Earth. The 2012 May full moon falls some six minutes after perigee, the moon's closest point to Earth for this month. At perigee, the moon lies only 221,802 miles (356,955 kilometers ) away. Later this month, on May 19, the moon will swing out to apogee – its farthest point for the month – at 252,555 miles (406,448 kilometers) distant. (Photo by AFP/File, Joe Klamar)

People stand along Aviation Blvd. as the space shuttle Endeavour lands at LAX in Los Angeles. (Photo by Wally Skalij/Los Angeles Times/MCT)

Michael O’Neill won a prize in animal portraits with fry of a peacock bass hovering around their mother for protection against predators in South Florida. (Photo by Michael Patrick O'Neill/2016 National Geographic Nature Photographer of the Year)