1. Brilliant Star Trails Captured from Space
On-Board ISS

2. • Currently on-board the International Space Station, NASA astronaut and
Expedition 31 Flight Engineer Don Pettit, recently uploaded an incredible gallery of
star trails to NASA’s Johnson Space Center .
• Speaking about the star trails that result from taking long exposure images (i.e., a
photo taken with a slow shutter speed), Petit relayed some information about the
photographic techniques used to achieve the images:
• “My star trail images are made by taking a time exposure of about 10 to 15
minutes. However, with modern digital cameras, 30 seconds is about the longest
exposure possible, due to electronic detector noise effectively snowing out the
image. 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.”
• In the amazing gallery below we get a surreal glimpse of Earth as seen from the ISS
as it hurtles around our planet at an average speed of 17,500 mph (28,000 km/h).
Enjoy!
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23. POSTED BY
J.JAYAKRISHNAN