Clouds and aurora in rare night sky double for sky gazer
21 August 2013 Last updated at 17:22 BST
An amateur astronomer in the north of Scotland has captured a rare form of cloud and the northern lights on film at the same time.
Rolling noctilucent - "night-shining" clouds - are rare enough themselves, but while Maciej Winiarczyk was filming them in the skies above Caithness, the aurora borealis also put on a vivid display.
He spoke to the BBC about night filming the two phenomena.