Star trails over the Nicholas U. Mayall 4-meter Telescope on Kitt Peak National Observatory near Tucson, Arizona. (Credit: KPNO/NOIRLab/NSF/AURA/P. Marenfeld)
Star trails over the Nicholas U. Mayall 4-meter Telescope on Kitt Peak National Observatory near Tucson, Arizona. (Credit: KPNO/NOIRLab/NSF/AURA/P. Marenfeld)