On January 13, 1976, the largest optical telescope in the southern hemisphere was placed in full-time operation at Cerro Tololo Inter- American Observatory, 480 km north of Santiago, Chile. The new instrument will give astronomers their best look yet at objects such as the Magellanic clouds.
The telescope, located near the town of La Serena, is housed in a 41- m-high building with a 450-ton dome that rotates on 32 sets of wheels. The instrument is 14 m long. Its movable portion weighs 270 tons and is so delicately balanced that it can be moved by hand by one person. The mirrors are made of Cer-Vit, an optical material insensitive to temperature changes. The 13.5-ton main mirror measures 4 m in diameter and 61 cm in thickness. The secondary mirror is 1.3 m in diameter.