An astronomer at work inside the Solar Vacuum Telescope at Kitt Peak National Observatory, Arizona. The telescope has a 75-foot (22.9-metre) high tower. Two flat mirrors at the top of the tower reflect the Sun's image down through an evacuated tube to the 24-inch (0.6m) diameter image-forming mirror at the foot of the tower. The use of a vacuum tube prevents the Sun's image from being distorted by hot air within the tower. The telescope has been in operation since 1973.
Model release not available. Property release not required.