I’m not the biggest fan of the Astronomy Picture of the Day (APOD), but today’s post is pretty kewl. What you see above is a time-lapse image of the sky (well, actually, 477 30-second exposures taken over a period of 4.3 hours) that reveals the apparent motion of the stars that results from Earth’s rotation. I’ve never seen a wide-angle image that shows the celestial equator crossing directly across the image: thus, the star trails in the upper left and lower right appear to arc in different directions. Neato.
The image was taken (and is copyrighted) by Koen van Gorp.