Ideal location for a future world-class telescope according to the Chinese

  

  There are just a modest bunch of locales on the planet that give ideal conditions to cosmic perception of the sky. A group of Chinese researchers guarantee to have discovered an area that could equal the observatories at Mauna Kea in Hawaii and Cerro Paranal in Chile.

      An ideal location for a telescope must meet four conditions: a clear sky far from any light pollution and with as few clouds as possible; stable weather and atmospheric conditions (humidity in the air can interfere with observations in particular); relatively easy access and good connection to infrastructure (such as power supply), and a night sky free of human activity (which could bring dust and vibrations).

    The largest telescopes in the world are thus located at altitude - to have the finest atmosphere possible - and in relatively isolated places. We can cite the large telescope of the Canary Islands, at the Roque de los Muchachos observatory at 2,400 meters above sea level, the Very Large Telescope or VLT, at the top of Cerro Paranal (2,635 meters) in Chile, or the Keck I telescopes and Keck II, installed at the top of Mauna Kea (4,145 meters), in Hawaii, in the middle of the Pacific Ocean.

        However, an entire piece of Asia is as yet without a-list seeing destinations. On August 19, a group of Chinese researchers reported in Nature magazine that they had distinguished an optimal site for the implantation of a monster telescope at the highest point of Saishiteng Mountain, in Qinghai territory in Tibet. "The Tibetan Plateau is the most noteworthy level on Earth, with a normal height of more than 4,000 meters, and along these lines presents ideal perception conditions for cosmology and molecule astronomy," clarifies Licai Deng, individual from the China National Astronomical Observatories (NAOC) and lead creator of the examination.

An arid region and an exceptionally clear sky

        The potential locations are between 4,200 and 4,500 meters above sea level in an area of ​​100,000 square kilometers around the town of Lenghu. “Lenghu is renowned for having exceptionally clear skies day and night,” says Licai Deng. The region, very arid "presents a spectacular landscape similar to that of Mars", describes the researcher.

       The researchers spent three years scrutinizing the dark sky, weather and atmospheric conditions in the region. And according to their findings, Lenghu offers viewing conditions similar to those of the world's most renowned observatories in Chile and Hawaii. "70% of the nights have clear photometric conditions [luminous intensity of the stars], with a median view of 0.75 arc seconds, details the Nature article. The median change in nighttime temperature is only 2.4 ° C, indicating very stable local surface air. Precipitable water vapor is less than two millimeters for 55% of the night." 

        In addition, the Lenghu site is better protected against the effects of human activity than Hawaii or Chile: the city adopted regulations against light pollution in 2017, so the sky should remain very dark in the years to come. future. "There are only a handful of astronomical sites that meet the requirements of very large next-generation facilities," Licai Deng said in the Global Times.

Two large telescopes already planned

    Tsinghua University and the University of Arizona are already working on the construction of a 6.5-meter telescope to be installed at the top of Saishiteng Mountain. The Chinese also plan to install another 12-meter telescope there. Not yet enough to compete with the giant telescopes currently under construction in the world, such as the Magellan telescope and its 24.5 meters in diameter which should enter service in 2023 in Chile, or the future Thirty Meter Telescope (TMT), which will be equipped with a mirror 30 meters in diameter. But thanks to its exceptional conditions, Lenghu intends to constitute the bridgehead of new Chinese ambitions in astronomy and attract international research teams. "Ultimately, there will be a lot of people at the top of Saishiteng Mountain," says Licai Deng.

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