China opens its ear to sounds of the universe
Updated: 2012-10-28 23:56
By Xu Junqian in Shanghai (China Daily)
A radio telescope the size of eight basketball courts, was unveiled at Shanghai Astronomical Observatory on Sunday.
The "ear" officially named the Shanghai 65-meter Radio Telescope, is able to "hear" faint signals from 10 billion light years away.
The ear is the largest of its kind in Asia, and the fourth largest in the world, only bested by radio telescopes in the United States, Italy and Germany. It will be used in the third stage of China's moon observation project next year.
"While an optical telescope operates by gathering and focusing light from the visible part of an electromagnetic spectrum, a radio telescope uses radio frequencies to collect data," said Du Biao, the telescope's chief designer, in an interview with China National Radio on Sunday.
If an optical telescope functions as a pair of sharp eyes peering into the deep universe, a radio is a very high-functioning ear, and is used to receive weak electromagnetic signals from very remote astronomical objects.
The new telescope stands more than 70 meters high and weighs 2,650 tons. It took three years and 10 months to construct and is assembled with 1,008 panels, each smoother than a mirror, and can move 15 millimeters.
"By enlarging the diameter from 25 meters (the typical size of a single antenna of a radio telescope) to 65, the sensitivity of the telescope can be improved by eight times. And that means we can go from below 8 GHZ to 46 in terms of frequency spectrum," Du said.
According to Science and Technology Daily, the new radio telescope will play a pivotal role, together with another three radio telescopes in China, in helping determine the orbit of Chang'e-3, China's third unmanned lunar probe, expected to take off in 2013.
The telescope began full operation at its opening ceremony on Sunday, but it will take another two years of testing, approximately until the end of 2014, for the telescope to reach its intended accuracy, according to Du.
Sunday also marked the 140-year anniversary of the Shanghai Astronomical Observatory, which is affiliated with the Chinese Academy of Sciences, the co-funder of the project.
Globally, the construction of the world's biggest and most sensitive radio telescope, the Square Kilometer Array project, started in May in both South Africa and Australia. SKA project organizers decided that the two nations would share the project.
Like an optical telescope, the location of a radio telescope has to be far away from civilization or centers of human activity where TV and radio signals will greatly interfere with the electromagnetic activity of the telescope.
The 1.5-billion-euro ($1.94 billion) SKA project is expected to be fully operational by 2024, and once completed, the array, connecting 3,000 separate radio dishes, will "have 50 times the sensitivity and 10,000 times the survey speed of the best current-day telescopes", according to SKA officials.
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