Dark Barn Startrail
Stars appear to rotate above this abandoned barn in 3 hours time. In reality it is the stars that are stationary and the earth that is rotating. In 23 hours and 56 minutes, the stars make one counterclockwise rotation of 360 degrees. This 4 minute difference is what causes the stars to change position from night to night, and the constellations to change from season to season. Earth's northern axis happens to be pointed at Polaris, or the North Star. It hardly moves at all in the course of a night. For thousands of years people have been using Polaris to navigate. It not only tells you which way is north, but it also tells you your latitude. In this case the North Star was 40 degrees above the horizon. Those in the southern hemisphere do not have such a star to guide them.
I found this old barn in Jim Edgar State Park a couple nights ago.
