Lick Observatory

The Lick Observatory is an astronomical observatory, which is operated by the University of California. It is located at an altitude of 1,300 meters at the summit of Mount Hamilton, near the town of San Jose, California. Name to the observatory is James Lick, an American piano builders and large landowners, from whose estate the building was financed.

On the summit of the Great Lick Refractor 1888 installed, the then largest refracting telescope in the world ( in 1897 by the Yerkes Observatory by 10% exceeded ). In 1969, the first laser-optical distance determination to the Moon ( Lunar Laser Ranging ) was carried out at the observatory.


The Lick Observatory was the first observatory was built on the summit of a mountain. The decisive factor was the location that without light pollution offers excellent observing conditions with 330 clear nights a year and a very quiet air. The summit of Mount Hamilton is above the fog that often forms over the Bay of San Francisco.

Because all building materials had to be brought in for the construction of the observatory by means of horses and mule carts had to be specially built for the terrain a road. Thus, the slope of the road does not exceed 6.5%, it winds in innumerable bends (supposedly 360) to the summit.

The construction of the observatory itself was carried out in the years 1876 to 1887 and it was handed over to the University of California in April, 1888. At its launch on 3 January 1888 in a telescope with 91 cm aperture width was the world's largest working telescope with lenses. In addition to the historical refractor telescopes were further built on the site over time. 1987 also the body of the late James Lick in 1886 and was buried on the grounds. A brass plaque bears the simple inscription: Here lies the body of James Lick.

On August 1, 1969, succeeded to the observatory to perform with a ruby ​​laser, the hitherto most precise distance measurement between the Earth and the Moon. For this purpose, the beam of a laser pulse was focused on the July 20, 1969 placed on the moon by Apollo 11 reflector. The reflected by the reflector light pulses were collected using the 304 -cm telescope. From the times of the laser pulses a precise distance determination could be made.

With the growth of San Jose and the Silicon Valley, light pollution has become a growing problem for the observation of the sky. Therefore, in 1980 a program was launched to reduce the excessive lighting in the surrounding areas, inter alia, the street lighting was switched to low-pressure sodium vapor lamps. These measures led to the Mount Hamilton could be used as astronomical research station.


The following devices are used at the Lick Observatory:

  • C. Donald Shane 304 -inch reflecting telescope
  • Automated Planet Finder 240cm - mirror telescope
  • Carnegie 50 -cm double refractor
  • Anna L. Nickel 1 -m telescope
  • 91 -inch Lick refractor
  • Edward Crossley 90 -inch reflector telescope
  • Katzman Automatic Imaging Telescope ( KAIT ), a 76- cm reflecting telescope for automatic sky shots.
  • Coude reflector telescope 60 cm
  • Tauchmann 50 - cm reflecting telescope
  • 135- mm CCD Comet Camera


James E. Keeler observed here on January 7, 1888 for the first time the Encke division of Saturn's rings. The following celestial bodies were discovered at the Lick Observatory.

Moons of Jupiter

Moons of Jupiter:

  • Amalthea
  • Ananke
  • Elara
  • Himalia
  • Lysithea
  • Sinope


The following exoplanets have been discovered:

  • Triple systems Upsilon Andromedae (together with the Whipple Observatory )
  • 55 Cancri
  • HD38529 (along with the Keck Observatory )
  • HD12661 ( with Keck )
  • GJ876 ( with Keck )
  • Ursa Majoris 47