NASA astronaut Don Pettit shot these long exposure photographs from from the International Space Station. Some of these photos show star trails, an aurora, and flashes of lightning on Earth. Here are a few words from Don Pettit about how he creates 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.
Found via PetaPixel