A plane's vapour trail isn't usually much to look at.
Not the case with this rainbow-coloured vapour trail, which was spotted streaming from a Qatar Airways aircraft flying 30,000ft above Brisbane.
The Boeing 777 jet was flying from its home base of Doha, Qatar, to Auckland in New Zealand when its contrails caught the late winter light.
Photographer Michael Marston captured the rainbow trail for his site ePixel Aerospace. He called the sight “one of the most spectacular rainbow contrails” he had ever seen.
The trail is an aerodynamic contrail – short for condensation trail – as opposed to the more common jet contrails that are formed of exhaust fumes.
Aerodynamic contrails occur when a plane lowers the air pressure as it flies, in turn lowering the air temperature and causing condensation to form on the wings. This condensation then trails behind as the plane continues forward.
In certain humid conditions, the drop in temperature and pressure is such that the droplets of condensation will freeze at varying sizes.
When the sunlight shines through these different sized droplets, it will refract at different wavelengths, hence the variety of colours that can be seen.
