“A small British company with a dream of building a re-usable space plane has won an important endorsement from the European Space Agency (ESA) after completing key tests on its novel engine technology. Reaction Engines Ltd believes its Sabre engine, which would operate like a jet engine in the atmosphere and a rocket in space, could displace rockets for space access and transform air travel by bringing any destination on Earth to no more than four hours away”. – Chris Wickham via Reuters. Photo: Artist's impression of Skylon. (Photo by Reaction Engines Ltd)

“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)

The world heavyweight boxing champion Joe Frazier, before his fight with Joe Bugner. (Photo by Evening Standard/Getty Images). 18th June 1973

In this April 28, 2014 file photo, a woman throws a rock and a bag at police blocking her from getting home in the Huepetuhe district of the Madre de Dios region of Peru. Security forces began destroying illegal gold mining machinery in Peru's southeastern jungle region of Madre de Dios, as authorities began enforcing a ban on illegal mining. (Photo by Rodrigo Abd/AP Photo)

A winter swimmer, wearing a Santa Claus hat to celebrate the upcoming Christmas, reacts as he plays on a frozen lake at a park in Shenyang, Liaoning province, December 22, 2014. The characters on the hat read: “Shenyang Winter Swimming”. (Photo by Reuters/Stringer)

Elvis Presley tribute artist Bruce Stewart (L) of Georgian Bay, Ontario passes Lorenz Francke of Scarborough, Ontario during the four-day Collingwood Elvis Festival in Collingwood, Ontario July 25, 2015. Featuring over 120 Elvis tribute artists, it is the world's largest Elvis festival and last year hosted 30,000 visitors. (Photo by Chris Helgren/Reuters)

Aleksandra Miroslaw, of Poland, competes during the speed portion of the women's sport climbing final at the 2020 Summer Olympics, Friday, August 6, 2021, in Tokyo, Japan. (Photo by Tsuyoshi Ueda/Pool Photo via AP Photo)

Adrienne Yip takes a picture of her Burmese mountain dog named “Walter”, beneath the cherry blossoms in peak bloom at the Tidal Basin with the Washington Monument seen behind, in Washington, DC, USA, 18 March 2024. Peak bloom, as defined when seventy percent of the cherry blossoms are open, is occuring this week. This year's peak bloom, beginning the 17th of March, is tied for the second earliest in history and is seen as a reflection of warming temperatures. (Photo by Michael Reynolds/EPA/EFE/Rex Features/Shutterstock)