Terahertz Telescope Added to HIghest Observatory

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September 27, 2010



No place on Earth rivals the Antarctic Plateau for stargazing. The air is thin and bone-dry; dust is minimal. As observatories go, the higher the better—and at 4093 meters above sea level, it doesn’t get any higher on the East Antarctic icecap than Dome A.

Last year, Chinese researchers opened Kunlun Station near Dome A. Now they intend to find out if a superior vantage point translates into superior astronomy. At a workshop last month, astronomers unveiled plans to build two major telescopes at Dome A during the Chinese government’s next 5-year plan, to start in 2011.

The 2.5-meter Kunlun Dark Universe Telescope, or KDUST, would survey the optical and near-infrared bands for planets beyond our solar system and plumb the mysteries of dark matter and dark energy.

However, “one instrument would be lonely,” says astronomer Yang Ji, director of Nanjing’s Purple Mountain Observatory, which is developing a companion: a 5-meter terahertz (THz) telescope to observe 200- to 350-micrometer wavelengths.

This “underexplored frequency window" is acutely sensitive to gas clouds—ideal for probing, for example, star and planet formation, says Qizhou Zhang, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and a member of the group that initiated the THz telescope project. Outside experts are impressed.

“It’s a very ambitious and exciting program,” says John Storey, an astronomer at the Univ. of New South Wales (UNSW) in Sydney, Australia.

The Chinese Academy of Sciences has requested 1 billion yuan ($150 million) for the telescopes and support platform—one of several science megafacilities that the country’s powerful National Development and Reform Commission is weighing for the 12th 5-year plan. A decision is expected around year’s end.

The two telescopes would be a major expansion of China’s formidable Antarctic buildup. During the 2007–08 International Polar Year, China erected Kunlun Station, teamed with the United States and others to study the Gamburtsev Mountains—the origin of the East Antarctic ice sheet—and with Australia began testing observing conditions at Dome A. To pave the way for expansion, China last year built an ice runway at Kunlun; until now, all materials and people have been brought in by arduous traverses.

China is not making a leap into the unknown. Antarctic astronomy first made headlines in 1998, when BOOMERANG, a U.S. NSF–sponsored balloon experiment, mapped the cosmic microwave background and found that the universe is fl at. As an encore, a 10-meter telescope at the U.S. Amundsen-Scott South Pole Station brought online in 2007 has begun microwave background studies.

“South Pole shows it is possible to build major astronomical facilities in Antarctica,” says Storey.