A scientist aboard the International Space Station took extraordinary photos of the starscape from aboard the vessel, using a special technique that highlights their movement.

Expedition 31 Flight Engineer Don Pettit used long exposures in conjunction with digital editing to achieve the star-trail effect.

Given that some of the shots required nearly 15 minutes of exposure, Pettit needed the software to overcome the limitations of his camera.

[W]ith modern digital cameras, 30 seconds is about the longest exposure possible, due to electronic detector noise effectively snowing out the image, Pettit explained.

To achieve the longer exposures, I do what many amateur astronomers do. I take multiple 30-second exposures, then 'stack' them using imaging software, thus producing the longer exposure.

The gallery was posted via the Johnson Space Center's Flickr account.

ISS Star trail photos
Expedition 31 Flight Engineer Don Pettit used long-exposures in conjunction with digital editing to achieve the star trail effect. NASA
ISS Star trail photos
Expedition 31 Flight Engineer Don Pettit used long-exposures in conjunction with digital editing to achieve the star trail effect. NASA
ISS Star trail photos
Expedition 31 Flight Engineer Don Pettit used long-exposures in conjunction with digital editing to achieve the star trail effect. NASA
ISS Star trail photos
Expedition 31 Flight Engineer Don Pettit used long-exposures in conjunction with digital editing to achieve the star trail effect. NASA
ISS Star trail photos
Expedition 31 Flight Engineer Don Pettit used long-exposures in conjunction with digital editing to achieve the star trail effect. NASA
ISS Star trail photos
Expedition 31 Flight Engineer Don Pettit used long-exposures in conjunction with digital editing to achieve the star trail effect. NASA
ISS Star trail photos
Expedition 31 Flight Engineer Don Pettit used long-exposures in conjunction with digital editing to achieve the star trail effect. NASA
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