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What will the next-generation astronomical telescopes be like?

This article focuses on the question of what the next-generation astronomical telescopes will be like, introducing the large aperture of the mosaic mirrors of the world's top-tier astronomical telescopes, the two mainstream models of multiple telescopes working in collaboration and representative devices, and elaborating on the parameter characteristics and development of different types of next-generation astronomical telescopes, including large-aperture mosaic mirrors such as the Thirty Meter Telescope and the European Extremely Large Telescope, multi-mirror collaborative telescopes like the Giant Magellan Telescope, and the LSST telescope, which combines large aperture with wide field of view.

What will the next-generation astronomical telescopes be like?

Today, the world's top telescopes each have their own unique capabilities. Some use mosaic mirror technology with enormous apertures, such as the 10.4-meter-aperture Gran Telescopio Canarias (GTC) located in La Palma, Canary Islands, and the two 10-meter-aperture Keck telescopes in Hawaii. Others, although not as large in aperture, achieve the effect of a giant telescope by collaborating with multiple telescopes. For example, the European Southern Observatory's four 8.2-meter-aperture telescopes and four 1.8-meter-aperture telescopes combine to form an equivalent focusing power equivalent to a 16-meter-aperture telescope, and their resolution is 25 times higher than that of a single telescope.

What will the next generation of telescopes look like? As the successor to mosaic mirror technology, the planned 30-meter telescope (TMT), which is scheduled to be completed in 2020, will have an aperture of 30 meters and be composed of 492 small mirrors. The European Extremely Large Telescope (E-ELT) is planned to be composed of 798 small mirrors, with an aperture of 39.3 meters, equivalent to half a football field. Such a large light-gathering capacity is 15 times that of today's largest optical telescopes. The collaborative mode of multiple telescopes is also developing. For example, the main mirror of the Giant Magellan Telescope (GMT) is planned to be composed of seven 8.4-meter-diameter mirrors, with an equivalent aperture of 21 meters and a resolution equivalent to 24 meters.

After the completion of China's Guo Shoujing Telescope (LAMOST), large-aperture telescopes with wide fields of view are becoming increasingly popular. The LSST telescope currently under construction will be one of the outstanding examples. This telescope, which has an 8.4-meter-aperture main mirror, will also have a 3.5° field of view. It features a unique design with one main mirror and two secondary mirrors, one more than other telescopes. Although the additional secondary mirror reduces the effective aperture of the telescope, it greatly expands the telescope's field of view. The LSST telescope will conduct sky survey and photometry work and will make more new discoveries among the stars.

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