If one is using a telescope to view the heavens, or one takes a long exposure picture of the stars, it quickly becomes apparent that the stars appear to move. What really is happening is that the earth is rotating. In the northern hemisphere where 90% of the earth's human population lives, if you photograph Polaris (the north star) all of the sky appears to be rotating around it.
Virtually all articles on photographing star trails begin with the exhortation that to do it successfully one must be in a very dark location. In an urban environment with a lot of air pollution and light pollution the results will not be as good as desired.
I experienced this last night. El Paso, Texas and Juarez, Mexico are geographically one city of almost 2 million people. About 75% of these folks live in Mexico, where the air pollution laws are much less stringent than they are in America. So El Paso is not in any way the correct location.
Well, it was worth a try. The dog and I both enjoyed being out in the back yard in the middle of the night. This picture is a 20 minute exposure. My longest try was a 2 hour exposure. The light pollution was terrible, but even so if you click on this picture to enlarge it you can “sort of” see that the stars seem to be circling around Polaris.
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