World's best stargazing (11/17/2007)

Dr Zhu in Tibet

Space scientists from UNSW and China have built an unmanned observatory destined for what they hope is the world's best place for stargazing in Antarctica.

Dubbed PLATO, the self-powered observatory leaves Sydney in a week's time on an 8,000km land-sea-ice journey destined for "Dome A", the highest point on the Antarctic plateau.

PLATO is expected to beam back pictures two to four times sharper than any previously achieved and to look up to ten times further into deep space than any existing land-based observatory, rivalling the Hubble Space Telescope. The key to the extraordinary quality of the images is the optimal viewing conditions at the site where seven telescopes will be installed by Chinese astrophysicist, Dr Zhu Zhenxi.

The Antarctic plateau is ideal for astronomy because it has clear skies, it doesn't rain, clouds are rare and the air is so still the stars barely twinkle. PLATO will be delivered to Dome A as part of the Polar Research Institute of China (PRIC) that made the first visit to Dome A in January 2005 via overland traverse. The PRIC plans to establish a permanently manned station at Dome A within the next decade.

Dr Zhu earned his place on the expedition team after competing successfully with 20 of China's leading space scientists, which travelled to the high peaks of Tibet to take part in an unusual sporting contest.

Watched over by two doctors, the scientists donned tracksuits and set off running in the very thin, cold air of one of the highest civilizations on earth. The point was not speed, but endurance and recovery. The prize for the two with the most favourable health indicators under high altitude stress was a place in scientific history: they would be joining a mission to install a telescope with the best view of the space ever seen from earth. To take part in this astronomical breakthrough, they would have to travel with PLATO to the harshest environment on the globe, the frozen plateau of Antarctica.

For Dr Zhu, the mission is an astrophysicist's dream. At 33, he attributes his success in the physical tests in Tibet to a love of swimming, his relative youth "and a regime of training beforehand".

PLATO's UNSW project leader, Dr Jon Lawrence says: "The superb viewing conditions on the Antarctic plateau result from extreme cold and dryness, a high percentage of cloud-free time, low dust and aerosol content, and low atmospheric infrared thermal emissions. It is one of the calmest and coldest places on Earth, with temperatures plunging as low as -82 degrees Celsius. There are no penguins, no wildlife - nothing but flat white snow from horizon to horizon. And the lack of turbulence makes it the best place on Earth for stargazing."

The site's ideal viewing conditions mean that a 2m infrared telescope on the Antarctic Plateau could achieve the sensitivity of an 8-metre version elsewhere, and an 8-metre telescope would match a 30-metre $1 billion giant telescope now on the drawing board in the US.

Built to operate autonomously in extreme environmental conditions, PLATO is equipped with a suite of site testing instruments measuring a range of atmospheric parameters - air turbulence, weather conditions, optical, infrared and sub-millimetre sky emissions - to establish whether it is the world's best place to watch the universe.

Powered by up to six diesel engines running on aviation fuel in winter and solar energy in summer, PLATO is housed in a heavily insulated modified shipping container containing a labyrinth of site testing equipment, computers, telescopes and a 30m high instrument tower.

PLATO will recycle mechanical and heat energy to ensure its inactive engines and battery banks stay warm during the year-round sub-zero temperatures. Scientists will communicate with PLATO via a low-bandwidth Iridium satellite network and retrieve the bulk of its site-testing data during annual servicing visits to Dome A.

Scientists from UNSW, PRIC, Caltech and the University of Arizona are contributing to PLATO's instruments as part of the 2007-2008 International Polar Year that will see thousands of scientists from more than 60 nations conducting 200 projects, examining a range of physical, biological and social research topics.

Scientists from UNSW and the Anglo-Australian Observatory are currently working on a detailed design study for a 2m class Antarctic telescope, PILOT, Pathfinder for an International Large Optical Telescope.

Note: This story has been adapted from a news release issued by The University of New South Wales

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