George Hale's Dream

The Palomar Observatory is part of Palomar Mountain socially, but it sits above the community proper, both literally and figuratively.  Owned and operated by  the California Institute of Technology, a privately endowed educational and research institution located in Pasadena, California, the Palomar Observatory is an institution with a world famous reputation.  The 160 acre Observatory site is a self-contained home for the telescope staff and visiting scientists. It operates year round, weather permitting, and "telescope time," at Palomar is a treasured commodity in the astronomical community. 

The principal telescopes in use at Palomar are the 18-inch Schmidt telescope, the 48-inch Oschin Telescope, the 60-inch reflecting telescope and the mammoth 200-inch Hale Telescope.  The famous 200-inch telescope was named for George Ellery Hale in recognition for his contributions to astronomy, and his dedicated efforts at shepherding the long and difficult process of constructing the Palomar Observatory and the 200-inch telescope itself.

Hale was born in Chicago in 1869 and he died before the great telescope bearing his name was completed.  Hale made his first telescope at the age of 19, inaugurating a lifetime fascination and professional dedication to astronomy.  During his career, he invented the spectroscope and the helioscope, contributing to the concept of the stars as cosmic laboratories.  

The heart of the Hale Telescope is the huge 200-inch mirror that gathers enough light to allow the telescope to look billions of light years into space.  When work began on this mirror, at the Corning Glass Works in New York during the 1930's, no one was even sure that a mirror of this size could be successfully cast.  Special glassmaking techniques and a custom formula for the mirror's pyrex disk were required.  The job was completed in 1934, and, after an eight month cooling period, the 20-ton mirror was transported by rail to Cal Tech for final grinding and polishing prior to its installation at the Palomar Observatory.  These preparations were almost complete when they were interrupted by World War II, and it was not until 1947 that the 200-inch mirror was finally installed in the giant white dome of the Hale Telescope.

For many years the Hale Telescope was the largest optical telescope in the world, and it has racked up some impressive scientific achievements over the years. In 1952, astronomers used the Hale Telescope to view distant galaxies and reveal that our universe was both older and larger that we had believed.  In 1963, the mystery of "radio stars" was solved using the Hale Telescope, and the celestial objects known as quasars were first described by Maarten Schmidt.  Over the years the research value of the Palomar telescopes has been eclipsed somewhat by development of other optical scopes with larger mirrors and, most significantly, the Hubble space telescope.  That said, observing time on the Palomar telescopes is still a precious commodity and they are used for a variety of research studies on every clear night. 

A typical night's observing at Palomar will likely include a variety of research plans. The study of asteroids and comets, so called "near-space" objects plays an increasingly large role at Palomar.  The Shoemaker-Levy comet that crashed spectacularly into Jupiter in 1994 was originally discovered at Palomar using the 18-inch Schmidt.  In another area, the 48-inch Oschin Telescope operates like a huge camera, capturing incredibly detailed images on 14 inch glass plates.  It is currently involved in the creation of an atlas of the entire northern sky that will provide a basic resource for astronomers world wide.

The usefulness of the 200-inch Hale telescope has improved dramatically in recent years through the installation of sophisticated CCD sensors that are hundreds of times more sensitive to the faint light from distant celestial objects than the photographic plates the telescope was originally designed for.  Other sensors and "adaptive optics" are used to detect infrared light allowing researchers to "see" outside the visible spectrum and correct for atmospheric distortions.  These improvements have helped keep the Palomar Observatory an important and valued research tool despite the encroaching light pollution from the city of San Diego spreading along the base of Palomar Mountain


1 Palomar Observatory Info:
Comet Shoemaker - Levy 9:

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