The Large Zenith Telescope ( LZT ) was a 6.0-meter diameter liquid-mirror telescope located in the University of British Columbia 's Malcolm Knapp Research Forest , about 70 km (43 mi) east from Vancouver , British Columbia, Canada (north from Maple Ridge ). It was one of the largest optical telescopes in the world, but still quite inexpensive. The telescope was completed in the spring of 2003 and decommissioned in 2016.
7-430: While a zenith telescope has the disadvantage of not being able to look anywhere but at a small spot straight up, its simplified setup permits the use of a mirror consisting of a smoothly spinning pan filled with liquid mercury . Such a mirror can be made much larger than a conventional mirror, greatly increasing light collecting ability. The LZT is used for transit imaging , meaning that Earth's rotation moves stars along
14-536: A zenith sector employs a strong altazimuth mount , fitted with levelling screws. Extremely sensitive levels are attached and the telescope has an eyepiece fitted with a micrometer . They are used for the measurement of small differences of zenith distance, and used in the determination of astronomic latitude . Other types of zenith telescopes include the Monument to the Great Fire of London , which includes
21-483: A central shaft meant for use as a zenith telescope. High-precision (and fixed building) zenith telescopes were also used until the early 1980s to track Earth's north pole position e.g. Earth's rotation axis position ( polar motion ). Since then radio astronomical quasar measurements ( VLBI ) have also measured Earth's rotation axis several orders of magnitude more accurately than optical tracking. The NASA Orbital Debris Observatory with an aperture of 3 m and
28-538: The LMT had been decommissioned, but gave no time frame in the undated article. Science magazine reported in 2019 that the LMT was decommissioned, but was also silent on the date. The university plans a larger 8-meter liquid-mirror telescope named the Advanced Liquid-Mirror Probe (ALPACA) for astronomical use at an estimated first-light cost of $ 5 million, $ 3 million contingency, $ 10 million for
35-556: The camera, $ 5 million for a spectrograph , and $ 0.3 million operating costs per year. A larger project is planned, called LAMA, with 66 individual 6.15-meter telescopes with a total collecting power equal to a 55-meter telescope, resolving power of a 70-meter scope. Zenith telescope A zenith telescope is a type of telescope that is designed to point straight up at or near the zenith . They are used for precision measurement of star positions, to simplify telescope construction, or both. A classic zenith telescope, also known as
42-411: The sensor, and the latent image in the sensor is moved electronically in step with this movement, so that it is read out at the trailing edge. The telescope made use of parts from the 3-meter diameter NASA Orbital Debris Observatory telescope, which had been using a liquid-mercury mirror for several years. This mirror was a test, built for $ 1 million, but it was not suitable for astronomy because of
49-550: The test site's weather. In 2016 it was noted as the third largest telescope in North America, and for its spinning mercury mirror that cost just 1% of normal mirrors, although it must view upward. According to Atlas Obscura the Large Zenith Telescope was decommissioned in the summer of 2016. All of its liquid mercury was stored for other projects. The website Physics Footnotes also mentioned that
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