Introduction
Astronomical observatory in California
ObservatoryLick ObservatoryThe James Lick telescope, housed in the South (large) Dome of main buildingAlternative nameslick Named afterJames Lick OrganizationUniversity of California Observatory code 662 Locationnear San Jose, CaliforniaCoordinates37°20′28″N 121°38′35″W / 37.3411°N 121.6431°W / 37.3411; -121.6431Altitude1,283 m (4,209 ft) Websiteucolick.org/main/ TelescopesLick Observatory Main BuildingAnna L. Nickel telescopeAutomated Planet FinderC. Donald Shane TelescopeCarnegie telescopeCoudé Auxiliary TelescopeCrossley telescopeJames Lick telescopeKatzman Automatic Imaging TelescopeTauchmann telescope Location of Lick Observatory  Related media on Commons[edit on Wikidata]
The Lick Observatory is an astronomical observatory owned and operated by the University of California. It is on the summit of Mount Hamilton, in the Diablo Range just east of San Jose, California, United States. The observatory is managed by the University of California Observatories, with headquarters on the University of California, Santa Cruz campus, where its scientific staff moved in the mid-1960s. It is named after James Lick, who donated the funds for its construction.
The first new moon of Jupiter to be identified since the time of Galileo, Amalthea, the planet's fifth moon, was discovered at this observatory in 1892.
Early history
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Lick Observatory is the world's first permanently occupied mountain-top observatory.
The observatory, in a Classical Revival style structure, was constructed between 1876 and 1887, from a bequest from James Lick of $700,000, equivalent to $25,100,000 in 2025.
Lick, originally a carpenter and piano maker, had arrived from Peru in San Francisco, California, in late 1847; after accruing significant wealth he began making various donations in 1873. In his last deed he chose the site atop Mount Hamilton, and was buried there in 1887 under the future site of the telescope, with a brass tablet bearing the inscription, "Here lies the body of James Lick".
Layout of Lick Observatory. The dome housing the 91-centimeter (36-inch) Great Lick refractor telescope is on the right.
Lick Observatory in 1900
Lick additionally negotiated that Santa Clara County construct a "first-class road" to the summit, completed in 1876. Lick chose John Wright of San Francisco's Wright & Sanders firm of architects to design both the Observatory and the Astronomer's House. All of the construction materials had to be brought to the site by horse and mule-drawn wagons, which could not negotiate a steep grade. To keep the grade below 6.5%, the road had to take a very winding and sinuous path, which the modern-day road (California State Route 130) still follows. The road from Smith Creek to the summit makes 367 complete turns, in a distance of seven miles. The road is closed when there is snow.
The first telescope installed at the observatory was a 12-inch (300-millimeter) refractor made by Alvan Clark. Astronomer Edward Emerson Barnard used the telescope to make "exquisite photographs of comets and nebulae", according to D. J. Warner of Warner & Swasey Company.
The Great Lick 91-centimeter (36-inch) refractor, in an 1889 engraving
In 1880, a 36-inch (91-centimeter) lens was commissioned to Alvan Clark & Sons, for $51,000 (equivalent to $1,700,000 in 2025). Manufacturing of the lens took until 1885 and it was delivered to the observatory on December 29, 1886. Warner & Swasey Company designed and built the telescope mounting. The telescope, built with this lens, became the world's largest refracting telescope from when it saw first light on January 3, 1888, until the construction of Yerkes Observatory in 1897.
Under the University of California[edit]
In May 1888, the observatory was turned over to the Regents of the University of California, and it became the first permanently occupied mountain-top observatory in the world. Edward S. Holden was the first director. The location provided excellent viewing performance because of lack of ambient light and pollution; additionally, the night air at the top of Mt. Hamilton is extremely calm. Often a layer of low coastal clouds invades the valley below, especially on nights from late spring to midsummer, a phenomenon known in California as the June Gloom. On nights when the observatory remains above that layer, light pollution can be greatly reduced.[citation needed]
E. E. Barnard used the telescope in 1892 to discover a fifth moon of Jupiter, Amalthea. This was the first addition to Jupiter's known moons since Galileo Galilei observed the planet through his parchment tube and spectacle lens. The telescope provided spectra for W. W. Campbell's work on the radial velocities of stars.
In 1905 (Jan. 5 and Feb. 27), Charles Dillon Perrine discovered the sixth and seventh moons of Jupiter (Elara and Himalia) on photographs taken with the 36-inch Crossley reflecting telescope which he had recently rebuilt.
On August 7, 1921, an unusually bright mysterious astronomical object was seen from the observatory only about three degrees from the Sun, where recent analysis in 2016 concluded that this is highly likely a comet.
In 1928, Donald C. Shane studied carbon stars, and was able to distinguish them into spectral classes R0–R9 and N0–N7 (on this scale N7 is the reddest and R0 the bluest). This was an expansion of Annie Jump Cannon of Harvard's work on carbon stars that had divided them into R and N types. The N stars have more cyanogen and the R stars have more carbon.
On May 21, 1939, during a nighttime fog that engulfed the summit, a U.S. Army Air Force Northrop A-17 two-seater attack plane crashed into the main building. Because a scientific meeting was being held elsewhere, the only staff member present was Nicholas U. Mayall. Nothing caught fire and the two individuals in the building were unharmed.
The pilot of the plane, Lt. Richard F. Lorenz, and passenger Private W. E. Scott were killed instantly. The telephone line was broken by the crash, so no help could be called for at first. Eventually help arrived together with numerous reporters and photographers, who kept arriving almost all night long. Evidence of their numbers could be seen the next day by the litter of flash bulbs carpeting the parking lot.
The press widely covered the accident and many reports emphasized the luck in not losing a large cabinet of spectrograms that was knocked over by the crash coming through an astronomer's office window. There was no damage to the telescope dome.
In 1950, the California State Legislature appropriated funds for a 120-inch (300-centimeter) reflecting telescope, which was completed in 1959. The observatory additionally has a 24-inch (61-centimeter) Cassegrain reflector dedicated to photoelectric measurements of star brightness, and received a pair of 20-inch (51-centimeter) astrographs from the Carnegie Corporation of New York.
