English: A riot of star trails dominate this striking image from Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF’s NOIRLab. Trails such as these are created when astrophotographers take long exposure images; they reveal the passage of the stars across the sky as the Earth rotates.The long exposure time of this photograph has also captured trails with a more down-to-earth origin! A nighttime staff member wearing a headlamp crossed the telescope platform while this photo was being taken. The long wavy streak threading between the telescopes was created by the regular bobbing of the passerby’s head as they walked, and the broader trail below it is the light they used to find their way.