This 50 minute exposure facing North was taken just outside of Acadia National park in Maine. The trails are produced from the earth's rotation, and this photo shows that we rotate around Polaris, the North Star, and all other stars will make concentric circles.
Star Trails over Death Valley
This photo was a 50 minute exposure taken below sea level in Death Valley National Park facing West. This orientation makes the star trails longer for the same exposure, and the concentric circles are less obvious so it gives the mirage shooting stars. The anomalous straight line on the left side of the image is a plane that flew through during the exposure.
Milky Way Galaxy
That cloudy, atherial presence in the left of the image is the stars of our own galaxy shining in the night sky.
While this may appear as if it was taken during the day, it's actually a 45 minute exposure of the cornfield behind my house on a moonlit night. The moon provides enough light to bring out the colors that we can't see, plus the stars moved over that period of time to cause the streaks in the background.