Long Exposure Photographs Shot from Orbit
petapixel.com
petapixel.com
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I understand why you might see concentric circles in time elapsed photos from the North or South Poles on Earth, but why from space?
(Edit:) About your other question: the middle of the circles is the ISS's orbit pole.
(Edit 2:) OK, I get what you find weird: the fact that stars's circles and land ones don't have exactly the same pole. That's because Earth's rotation.
IIRC, a very low orbit object makes a circle in 90 minutes. I guess IIS is higher so it would orbit in a few hours. In these few hours the traces of land lights result from the composition of orbit and rotation, while the star's one only from the orbit. An angle of, let's say 20% of ISS orbit with equatorial plane would explain the difference.
BTW, I don't think the camera is rotating. Something, maybe an antenna shows in the photo against the star background. The ISS must be rotating in the same period of the orbit, so it always shows the same face to Earth's surface.
The camera would not be rotating with respect to the ISS. But the ISS, as you said, rotates with the same period as its orbit. The camera, being fixed to the ISS, therefore rotates with this same period in the same plane.
So, yes, the camera is rotating; hence, the star circles.
can someone explain how the long exposure shot is taken, where the local light object (bulb) is not overexposed? everything seems to be perfectly exposed.
the only thing i can think of was that this image was constructed from multiple shots taken at different exposures.
“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.”
http://www.flickr.com/photos/nasa_jsc_photo/sets/72157629726...