'Stacked' Space Station Photos Highlight Star Trails

 
on June 08 2012 5:20 PM
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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