China building world’s largest 500-meter radio telescope


China is assembling what has been hailed as the world’s largest radio telescope, state media reported. The 500-meter tool will boast a dish the size of 30 football pitches, overtaking Puerto Rico’s Arecibo Observatory, “only” 305 meters in diameter.

With a perimeter of about 1.6km, it will take up to 40 minutes to walk around the single-aperture spherical telescope, which is called “FAST”. It will be constructed deep in the mountains of the southwestern Guizhou Province, built on a naturally formed bowl-shaped valley, Xinhua reports.

“There are three hills about 500 meters away from one another, creating a valley that is perfect to support the telescope,” Sun Caihong, chief engineer of FAST’s construction, told the news agency.

The construction of the highly sensitive telescope began in March 2011 and is due to be completed next year. On Thursday, technicians already began attaching 4,450 triangular-shaped panels to the telescope’s reflector. To overlook the whole reflector, visitors will reportedly have to climb up to the top of one of the hills. An observation platform is currently said to be under construction.

The chief scientist of the FAST project, a Chinese astronomer Nan Rendong, explained that the bigger the dish is, the more powerful the telescope.

The so-called Karst topography in the surrounding landscape is ideal for draining rainwater underground and protecting the reflector, according to Chinese scientists, adding that the surrounding area is characterized by a certain “radio silence.”

The dish will shift to receive radio signals from different angles.

“Panels can change their positions through connected wires and parallel robots. We can control their position with an accuracy of 1 mm,” Zheng Yuanpeng, chief engineer of the telescope’s panel project, told Xinhua.

It’s hoped that the new telescope will boost Chinese scientists’ capacity to observe outer space.

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