NASA astronaut and Expedition 31 Flight Engineer Don Pettit, who is currently on-board the International Space Station, spends his free time capturing long exposure images of star trails. That’s right, what you see above is Earth as seen from the ISS as it hurtles around our planet at an average speed of 17,500mph. Continue reading for more.
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.