Zenith Telescope Facts

Zenith Telescope Facts
A zenith telescope is a telescope designed to point straight up near or right at the zenith, which is an imaginary point above a specific location on the celestial sphere. Zenith telescopes can be used for determining the precise measurement of star positions. Until the early 1980s zenith telescopes were used to track the position of the north pole of the earth, but the zenith telescope has been replaced by radio astronomical quasar measurements. The classic zenith telescope has a strong alt-azimuth mount, which is a two-axis mount designed to support the zenith with one vertical and one horizontal axis.
Interesting Zenith Telescope Facts:
The word 'zenith' is derived from an Arabic expression that means 'direction of the head' or 'path above the head' but it is believed to have been inaccurately read. The expression was misspelled as 'senit' and eventually became 'zenith' in the 1600s.
Some zenith telescopes use a mirror with a pan filled with liquid mercury and is only able to look directly up. A zenith telescope is a telescope that can only point straight up.
The zenith telescope is able to collect valuable data in regards to galaxy evolution and the structure of the universe.
The University of British Columbia in Canada has a zenith telescope called the Large Zenith Telescope located in the Malcolm Knapp Research Forest, roughly 43 miles from Vancouver. This zenith telescope is one of the largest in the world at 6 meters in diameter. This is one of the world's largest optical telescopes. It was finished construction in 2003.
The Large Zenith Telescope spins once every 8.5 seconds, and contains 28 litres of liquid mercury. The mirror of the zenith telescope collects more light, which is focused to create an image.
The Large Zenith Telescope (LZT) was made from parts that had been used in the three meter diameter telescope from NASA Orbital Debris Observatory.
The objective of the Large Zenith Telescope is to measure "spectral energy distributions and redshifts of over 100,000 galaxies and quasars and to detect distant supernovae".
Telescopes with mercury are much less expensive to make than glass mirror lense telescopes.
The fact that the mirror is made of liquid mercury is the reason why the liquid zenith telescope can only be pointed straight up. If it were tilted the mercury would spill.
Zenith telescope liquid mirrors cost about only 1% of the typical telescope mirror.
Isaac Newton theorized a zenith telescope a long time before the first one was built. He couldn't build a zenith telescope because he couldn't control the rotation speed of the liquid.
The liquid mirror telescope was further developed in 1850 by Ernesto Capocci, but the first working liquid mirror telescope was not successfully built until 1872, by Henry Skey, a New Zealander.
There are many astronomers that want to see liquid mirror telescopes on the moon. With their low cost and ability to collect valuable information, they would provide low-cost research data.
The Monument to the Great Fire of London has a central shaft zenith telescope.

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