More and more high-altitude vapour trails appear in the skies, as the flight density of commercial aviation increases. They follow the jet straight and narrow, but then degrade into fuzzy formations, blending as one with the clouds and into our subconscious. We almost do not notice them any more. The following photos show, however, that even the common engine's exhaust contrail can be worth a second glance.
Contrail, or "Vapor Trail", forming at high altitudes. Contrails generated by engine exhaust are, of course, linked with pollution, but the visible white streams in the sky made from plane's "wing-tip vortices" are essentially ice crystals and pure condensation trails. "Being composed of water, the are not, in and of themselves, air pollution."(wiki)
(images credit: Laurent Malbecq)
USAF F-15 Eagle Fighters Intercept Two Soviet MiG-29 Fighters:
(image credit: Staff Sgt. Kevin L. Bishop, USAF)
(image credit: Strange Vehicles)
"Fly me to the Moon"
(image credit: Barry McGrath)
...or out of the Sun
Some shooting (or launching decoys) also produces interesting trails:
The amazing cloud "downwash effect" from a passing jet plane:
(image credit: Strange Vehicles.com)
(image credit: Daniel Koury)
(images credit: Checksix-forums)
Breaking the Sound Barrier: Transonic Cloud Effects
Going over the sound barrier produces one of the most amazing condensation effects - so called "Prandtl-Glauert Condensation Clouds", formed by the rapid cooling of the air. You have to be really quick with your camera "trigger" to capture it, as it only occurs at the sonic barrier. This page has many photographs and videos of this phenomena.
F/A-18F Super Hornet streaks past the aircraft carrier U.S.S. Kitty Hawk in the Philippine Sea:
(U.S. Navy photo by Petty Officer 3rd Class Jonathan Chandler)
Skilled pilots can actually control where this cloud appears:
"It is possible to work the plane's throttle to move the shock wave forward or aft." (source)
(U.S. Navy photo by Ensign John Gay)
F-14 completes a super-sonic flyby:
(U.S. Navy photo by Communication Specialist 3rd Class Jarod Hodge)
Rainbow on the Clouds
Perhaps the most sublime is the rainbow/shadow combination, forming on the vapor and clouds around a passing jet.
image credit: Jeff Well, Airliners.net