As the world's largest radio telescope nears structural completion, the project's choice of location in rural southeast China has sent out clear signals of its own. The success of the Five-hundred-meter Aperture Spherical Telescope, known as FAST, owes much to the unique geographic conditions offered by the Dawodang depression, a natural karst basin deep in the mountains of the Pingtang County in Guizhou province.
After the project was first proposed in 1994, scientists selected the final location from over 300 potential areas across China. They said Dawodang is the "one and only natural basin in the world," making it the perfect home for the telescope.
"Dawodang is named after local dialect in Guizhou Province. 'Dang' describes a crater, so 'shuidangdang' means a crater full of water. This place got its name because of its landform, a natural basin surrounded by mountains," said Zhong Yi, a graduate student of The National Astronomical Observatories at the Chinese Academy of Sciences.
The Dawodang location provided a highly favorable choice to host the FAST project. The site fitted the 500-meter diameter of the curved telescope perfectly, and required minimal excavation work due to its ready-made natural basin. When it comes to maintenance, the karst terrain's natural drainage system will allow water to flow through the cracks and holes of the mountain, reducing the erosion of the equipment.
From an operational perspective, the five mountains around Dawodang create a relatively isolated environment, allowing the radio telescope to work without electromagnetic wave interference from the outside world.
