Nasa's Greatest Hits

Nasa has released a compilation of the best of its time-lapse photography from space - accompanied by a suitable theme tune.
To the haunting sounds of Walking In The Air, written by Howard Blake for the film The Snowman, the four-minute tape zooms over the earth's surface from the International Space Station, shot by the Expedition 30 crew who boarded in November.

The breathtaking footage captured enchanting light displays and vivid weather systems across the globe in the last five months.Heavenly: Comet Lovejoy captured on camera from the ISS when it tore across the sky in November

Switched on: The images, including this of Central Europe to the Middle East, were shot by Expedition 30 since they set up home in the International Space Station last November

Along with transmitting breathtaking imagery back to earth, the ISS conducts scientific research, answering the many unknowns about our universe.
The station's purpose is to be a laboratory and observatory while acting as a staging base for possible future missions to the Moon, Mars and asteroids.
Time-lapse photography is a technique whereby the frequency at which the frames are captured is much lower than that at which they are played back.