A young girl navigates her way around Hampton Court maze in the spring sunshine on May 2, 2009 in London, England. The Hampton Court maze is one of the most famous hedge mazes in the world and was planted between 1689 and 1695 by George London and Henry Wise. (Photo by Dan Kitwood/Getty Images)

Egyptian President Hosni Mubarak speaks to the media after talks with German Chancellor Angela Merkel at the Chancellery on April 23, 2008 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

A visitor passes behind the sculpture “Puma-Dentist” made with plastic, wax and original heads of a puma and a hind by Austrian artist Deborah Sengl during an exhibition at the art gallery Deschler in Berlin April 15, 2008. (Photo by Fabrizio Bensch/Reuters)

An Ambassador car, licensed as taxi rolls past other vehicles through a busy road in Kolkata, india, Monday, May 26, 2014. India's oldest car factory has abruptly suspended production of the hulking Ambassador sedan that has a nearly seven-decade history as the car of the Indian elite. (Photo by Bikas Das/AP Photo)

Faces adorn crosses placed in the Garden of Remembrance of some of Britain's armed forces members who have died in Afghanistan in the Garden of Remembrance outside Westminster Abbey at the official opening of the Royal British Legion's Field of Remembrance on November 5, 2009 in London, England. (Photo by Alastair Grant-Pool/Getty Images)

Mazda Motor introduces the company's concept vehicle, Taiki during the press day of the 40th Tokyo Motor Show at Makuhari Messe, on October 24, 2007 in Chiba Prefecture, Japan. (Photo by Koichi Kamoshida/Getty Images)

“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 giant storm cloud can be seen in the sky above swimmers near Mollymook Beach, south of Sydney, March 5, 2014. (Photo by David Gray/Reuters)