BBC - Audio slideshow: Noctilucent clouds

Each summer, high in the night skies of the far northern and southern
hemispheres a unique phenonmenon occurs - noctilucent clouds. Little
is known about them, but now an amateur astronomer from north Wales is
trying to predict when they are likely to appear.

Here, John Rowlands, one of four finalists in the BBC's search for the
Amateur Scientist of the Year So You Want To Be A Scientist? - and his
mentor, Professor Nick Mitchell from the University of Bath - take a
closer look at these mysterious silver and blue waves at the edge of
space.

Stunning images at http://www.bbc.co.uk/news/science-environment-10635796