Star Patterns
Star patterns almost never change. The same stars that make up the Big Dipper on one night will make up the Big Dipper every night you may see it. And the Dipper’s pattern will always have the same proportions--meaning that if you see the Dipper once, you’ll be able to recognize its shape again and again. However, the Dipper’s orientation may change, depending on what time of night you see it. Sometimes, the Dipper’s bowl points up, like it’s ready to scoop up some stars. Other times, the bowl appears upside down, like it’s spilling them out. Why do you think the dipper’s orientation changes through the night? Remember that the Dipper’s movement through the sky follows a regular pattern.
Most stars and constellations appear to move through the sky, just like the Sun and Moon. Most stars also rise and set each night, just as the Sun rises and sets each day. They seem to move slowly through the sky, turning in a slow circle. Normally, stars move so slowly they seem to be standing still while you watch them. But if you track the positions of stars throughout the night for a few hours, you can notice the difference.
Time lapse videos cut out time between each shot. Hours of footage is cut down to just a few minutes. That's why the stars seem to move much faster in the video. Time lapse photos show the paths each star makes through the night.