China Exclusive: China starts building world's largest radio telescope

GUIYANG, Dec. 26 (Chinese media) -- China officially started construction of a

Five-hundred-meter Aperture Spherical Telescope (FAST), the largest in the

world, in a remote southwest region on Friday.

Preparation and research for the project took some 14 years.

The dish-like telescope, as large as 30 football fields, will stand in a

region of typical Karst depressions in Guizhou Province when it's done in 2013.

Karst depressions are usually located in regions plentiful in limestone and

dolomite, where groundwater has enlarged openings to form a subsurface drainage

system.

The facility will greatly improve China's capacity for astronomical

observation, according to the National Astronomical Observatory (NAO), the major

developer of the program.

FAST's main spherical reflector will be composed of 4,600 panels. Its

observation sensitivity will be 10 times more powerful than the 100-m aperture

steerable radio telescope in Germany. Its overall capacity will be 10 times

larger than what is now the world's largest (300 m) Arecibo radio telescope

developed by the United States, according to Nan Rendong, the chief scientist of

the project and an NAO researcher.

The project, costing more than 700 million yuan (102.3 million U.S.

dollars), will allow international astronomers and scientists to discover more

of the secrets of the universe based on cutting-edge technologies, said Zhang

Haiyan, an NAO official in charge of construction.

Scientists have so far observed only 1,760 pulsars, which are strongly

magnetized spinning cores of dead stars. With the help of FAST, they could find

as many as 7,000 to 10,000 within a year, Nan said.

Pulsars have allowed scientists to make several major discoveries, such as

confirmation of the existence of gravitational radiation as predicted by the

theory of general relativity.

FAST could also be a highly sensitive passive radar to monitor satellites

and space debris, which would be greatly helpful for China's ambitious space

program.

The telescope could also help to look for other civilizations by detecting

and studying communication signals in the universe.

Chinese scientists and officials selected Dawodang, Pingtang County as the

site, where a Karst valley will match the shape of the huge bowl-like

astronomical instrument.

The sparsely populated, underdeveloped region will provide a quiet

environment to ensure the electromagnetic waves, the crucial requirement of

operation, are not interrupted by human activities.

Construction of a new residential area about 60 km away also began on

Friday to relocate 12 households. By 2013, when the telescope is to be in

operation, all 61 farmers will move to their new houses in Kedu town, with

farmland allocated by the government.

"The project is beyond my imagination. I'm glad to see that an ordinary old

guy like me could contribute to the country's science program," said Yang

Chaoli, 68.

The project was approved by the National Development and Reform Commission,

the country's top planning body, the Ministry of Science and Technology, the

Chinese Academy of Sciences and its subordinating NAO, Guizhou Province and

other departments.