But one airline passenger appears to have captured the impossible by taking a shot that looks as if it’s taken over a rainbow.Flying through, or above a rainbow, isn’t possible because it is optical trick caused by light reflected and refracted in water droplets - but the effect these images create are still stunning.The three shots were taken by Melissa Rensen, 51, as she flew over the Caribbean Sea.But Ms Rensen, from London in Ontario, Canada said she didn’t realise she’d captured the kaleidoscope of colours until she viewed the images later in the day.Ms Rensen was travelling from North America to Hounduras and spotted an interesting cloud formation below.‘I was passing time on our long flight and looked out the window to see hundreds of these little cotton-like clouds,’ explained Ms Rensen.‘I noticed how shadows were cast on the Caribbean Sea and thought it was such a beautiful scene I had to snap some shots.‘When I saw the "rainbow" in the shot I was stunned - I'd never experienced anything like it and I doubt I ever will again.‘Having not seen the rainbow with my naked eye, it wasn't until I reviewed the images later that I saw [it].’‘At first I thought maybe it was caused by jet fuel vapour, or perhaps from the polarised window on the plane, but then another photographer friend of mine pointed out that the [colours] were beneath the clouds.‘All my uncertainty faded and I knew I'd captured something special.’A rainbow forms when light is reflected and refracted in water droplets in the sky, or in other liquids or surfaces.They appear in the sky as multi-coloured arcs, and are caused when sunlight hits water droplets in a section of sky directly opposite the sun.In one of Ms Rensen’s images, the sun is seen behind the wing of the plane, opposite where the colours appear.Rainbows can be full circles, too, but people typically only seen them as arcs.Because they are formed by droplets above the ground, centred on a line from the sun to the viewer’s eye, they are only visible from a distance.This means it is not possible to ‘fly through’ a rainbow.Photography expert Gary Bown from Portsmouth University told MailOnline that Ms Rensen’s images were not a rainbow, and were caused by the polarisation of the airplane’s window.The light from the sky illuminates the landscape and travels through the window, at which point it is partially polarised.The extent of polarisation depends on the angle from the sun, and is greatest at 90°.Airplane windows additionally have at least one layer of thick plastic, explained Atmosphere Optics.(dailymail.co.uk)Bakudaily.Az