MMT
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MMT can also refer to Methylcyclopentadienyl Manganese Tricarbonyl, an additive for automotive gasoline.
MMT can also refer to Manual muscle testing, a way of evaluating the strength of a specific muscle
The MMT (Multiple Mirror Telescope) is a 6.5-meter telescope located on the summit of Mount Hopkins, in the Santa Rita Mountains in southern Arizona. As originally built, the MMT combined light gathered from telescopes in a common mount. Despite the name, it now has a single primary mirror.
The telescope is operated by the MMT Observatory, a joint venture of the Smithsonian Institution and the University of Arizona located on the grounds of the Whipple Observatory.
The MMT operated between 1979 and 1998 with 6 mirrors, each with a diameter of 1.8 meters, providing the equivalent gathering area of a 4.5-meter telescope, making it the third largest optical telescope in the world at the time of its dedication. It featured ambitious design innovations including its unusual optical design proposed by Aden Meinel[1], a co-rotating building and an altitude-azimuth mount.
With the exception of the Bolshoi Teleskop Azimutalnyi[[2]], all major optical telescopes prior to the MMT used equatorial mounts [3]. The MMT heralded a change in telescope design; all major optical telescopes since the MMT have been built with alt-azimuth mounts. Several technologies pioneered at the MMT contributed to the success of the subsequent generation of large telescopes. These included: high dynamic-range servos for the alt-azimuth mount[4]; highly accurate pointing that eliminated the need for sky charts; co-alignment and co-phasing of multiple telescopes; improvements to optical performance by attention to the thermal environment of the facility; contributions to vacuum coatings deposition, optics cleaning, and maintenance; and early experiments in co-phased adaptive optics.
One of the reasons for its original multiple mirror design was the difficulty of casting large mirrors. One solution to this problem was found by Roger Angel of Steward Observatory, of the University of Arizona, who cast mirrors with a honeycomb structure in the interior of a rotating oven. This made it possible to replace the six mirrors with a single 6.5-meter one. The original building and part of the structure could be reused. The new mirror was cast and polished in the Steward Observatory Mirror Laboratory at the University of Arizona. It was the first 6.5-meter mirror cast at SOML. The new MMT was rededicated on 20 May 2000.[5]
In late 2002, a novel deformable secondary mirror was added to the telescope.[6] While other adaptive optics designs do their corrections with additional mirrors, minimizing the number of warm surfaces in the light path produces better results in infrared wavelengths.
