People often ask how to photograph star trails, so here’s a useful guide from DIY Photography.
What you saw was star trails. The streaks were light left behind on the sensor or film from the star as it traveled across the sky in front of an open camera shutter. In fact, it only seems that way. What actually being recorded are stationary stars and the rotation of the earth that makes them spin. Kinda like you were standing on a vinyl record while it is playing. (yes, vinyl record, it is a form of ancient iPod).
For me, the images seem to have a certain magic or mystery about them. You must have heard a photographer talking about capturing that perfect moment in time. Well for capturing star trails you will need to capture the perfect hour or two in time. For such amazing looking images the technique to capture them is really quite simple.