This sequence of images shows simulated views of the night sky from Chicago, Illinois. The frames show the view from Earth at midnight, once a week over a year.
The stars that are visible each week change through the year because Earth is revolving around the sun—the animation is a time-lapse movie that shows one year, viewed from the dark side of Earth. Stars appear to move to the west through the year as our planet moves toward the east in its orbit around the sun.
Click the image to see the animation. Use the movie controls to see the constellations that are visible in summer, fall, winter, and spring.