Star trails and cacti Star trails over cacti Star trails are captured by longexposure photography in this case hours The lines of light are made by the relative movement of the stars through the night sky as the Earth rotates The centre of the concentric trails is the point in the sky directly above the earths Celestial Pole South Pole in the southern hemisphere North Pole in the northern hemisphere The colours of the trails reveal the variety of colours and distances from the Earth of the planets and stars th Feb
