The Astronomy Picture of the Day (APOD) on March 17, 2014, shows warped star trails over Arches National Park, in Utah, USA.
The warping effect occurs because the picture is actually a full 360 degree panorama, horizontally compressed to fit your screen. As the Earth rotates, stars appear to circle both the North Celestial Pole, on the left, and the South Celestial Pole, just below the horizon on the right. While the eye-catching texture of ancient layered sandstone covers the image foreground, twenty-meter tall Delicate Arch is visible on the far right, and the distant arch of our Milky Way Galaxy and its dark dust lanes may be seen near the image center.
Credit: Vincent Brady