“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)

O Santa Claus of Australia competes in the mens 80–84 years 100 metres heats during day two of the 2009 Sydney World Masters Games at Sydney Olympic Park on October 11, 2009 in Sydney, Australia. (Photo by Mark Nolan/Getty Images)

Taking it all in at Trolltunga, a piece of rock which juts horizontally out of a mountain, 700 metres above lake Ringedalsvatnet in Norway. (Photo by Sam Rogers/GuardianWitness)

Rush-hour in Russia means one thing for this daredevil: train surfing! The 19-year-old daredevil who goes by the name Kobzarro started train surfing aged 15 as a way of escaping an oppressive family life. Here Kobzarro can be seen balanced on top of a train as it speeds through the wintery Russian environment. Kobzarro is so dedicated to train surfing that she rarely gets inside a train. Even in winter she prefers to travel in this less conventional way. It has resulted in a few run ins with the law, but Kobzarro says it has never resulted in anything more serious than a fine, with many police officers even being interested in the train surfing community. (Photo by Caters News Agency)

Olive Ridley turtle hatchlings (Lepidochelys olivacea) sit in baskets and trays at the turtle camp La Gloria, before their release into the ocean in Tomatlan November 15, 2013. Twenty years ago, Mexico's government implemented ecological plans to protect the sea turtles from being hunted for their leather and meat and established conservation areas and a pay system for local residents to protect turtle nests. Millions of baby turtles hatch on the shores in November and December, according to an environmental group. It is estimated that in 2012, there were 20 million newborns. Hatching season is still underway, but officials say they expect there will be even more turtles born this year. (Photo by Alejandro Acosta/Reuters)

Doris Pennman adjusts her umbrella as she walks along Mission Beach on January 8, 2005 in San Diego, Califonia. (Photo by Sandy Huffaker/Getty Images)

David Nickerson, 28, competes dressed as artist Bob Ross, during the ZJ Boarding House Halloween Surf Contest in Santa Monica, California October 26, 2013. (Photo by Lucy Nicholson/Reuters)

India's Central Reserve Police Force personnel take part in a rehearsal for the Republic Day parade on a cold winter morning in New Delhi January 8, 2014. (Photo by Ahmad Masood/Reuters)