Palomar Observatory, << PAL uh mahr, >> is an astronomical observatory in southwestern California, about 45 miles (72 kilometers) northeast of downtown San Diego. It stands atop Palomar Mountain, 5,597 feet (1,706 meters) above sea level. The observatory is best known for the Hale Telescope, one of the world’s largest optical telescopes. (An optical telescope collects and focuses visible light given off, or reflected, by celestial objects [see Telescope ].) The Hale Telescope was named for American astronomer George Ellery Hale, who planned its construction (see Hale, George Ellery ).
In 1963, astronomers using the Hale Telescope first identified quasars, extremely bright objects in the center of some distant galaxies (see Quasar ). Energy from quasars takes billions of years to reach Earth. For this reason, the study of quasars can provide information about early stages of the universe.
The Hale Telescope is a reflecting telescope (one that collects and focuses light with a concave mirror). Its mirror is 200 inches (508 centimeters) in diameter. This telescope can also be equipped with detectors for observation and photography with infrared rays (heat rays). One major use of these detectors is the study of stars in the process of formation. Palomar also has a reflecting telescope with a 60-inch (152-centimeter) mirror.
In addition, the observatory has two Schmidt telescopes. These telescopes are instruments with both a large mirror and a large lens. The bigger of the two telescopes, called the Oschin Telescope, has a 72-inch (183-centimeter) mirror and a 48-inch (122-centimeter) lens. This telescope, built to map the sky and locate celestial bodies for detailed study with the Hale Telescope, can photograph an area of the sky about 200 times as large as the area that the Hale Telescope can map. However, the Hale Telescope provides images with greater detail.
During the 1950’s, astronomers used the Oschin Telescope to map millions of stars and galaxies. This survey revealed the distant sources of light that later were discovered to be quasars. From 1985 to 2000, astronomers conducted a second survey, using more sensitive photographic plates. In 2007, engineers enhanced the Hale Telescope’s adaptive optics system, which corrects for blurring caused by Earth’s atmosphere. Some of the new images rivaled those of the Hubble Space Telescope. The Palomar Observatory began operations in 1948. It is owned by the California Institute of Technology.
