Rare sky phenomena caught on film
21 August 2013 Last updated at 15:13 BST
Macieji Winiarczyk, a member of Caithness Astronomy Group, has captured rare images of a night sky lit up by noctilucent clouds and the aurora borealis.
Formed on the edge of space, noctilucent clouds appear as wispy, luminous, silvery-blue clouds, often with a wavy pattern. The clouds and the aurora, also known as Northern Lights, are rarely seen at the same time.
Mr Winiarczyk took his photographs from Caithness earlier this month and has used them to create time lapse footage. Nasa has featured the time lapse on its website.