SCIENCE: by Joe PoprzecznyNews Weekly
WA bid to host $2 billion radio telescope
, February 17, 2007
Western Australia could be home to the world's most important radio telescope, up to 100 times more sensitive than any other one currently operating, reports Joe Poprzeczny.
the SKA concept
There could also be valuable spin-offs for Australia, with up to $400 million worth of local infrastructure being required.A pastoral station near Western Australia's outback mining town of Meekatharra has emerged as a strong contender to become the focal point of a $2 billion radio telescope designed to observe the formation of the early universe and galaxy evolution.
Mileura station, which is 100km west of Meekatharra and 400km south-east of Carnarvon, has been listed as a possible site for the huge new-generation radio telescope known as the Square Kilometer Array (SKA).
The reason for its unusual three-pronged name is because the planned facility will have an array of up to 1,000 receiver dishes dispersed across several thousand square kilometres with a combined one square kilometre of low-frequency signal-collection area.
Mileura is one of two finalists now being assessed by a specialist international scientific panel as the venue for the deep-space astronomical facility. The other contender, also in the southern hemisphere, is Karoo, in South Africa's northern Cape region.
Mileura means "to see a long way" in the Aboriginal dialect of the Meekatharra region.
Australia's SKA project director, Professor Brian Boyle of the CSIRO Australia Telescope National Facility, said the Mileura-Karoo contest represented another milestone for the SKA project which was launched in 1994, three years after the concept of observing deep space had been devised.
This followed years of conjecture and theorising by astronomers who dream of peering deep into time and space at gamma-ray bursts, extra-solar planets, evolving galaxies, dark matter and hopefully even to the Big Bang, believed to be the origin of the universe.
The decision on which site will house the SKA's core array of dishes and monitoring equipment will be made either in 2008 or 2009. Construction will begin in 2010. Thereafter will follow a phased-in construction phase culminating in a fully operational SKA in 2020.
However, initial deep space observing will begin in 2015.
"The Mileura site also has excellent sky coverage, a stable ionosphere and low precipitable water vapour," according to the latest Australian SKA Planning Office's newsletter.
Mileura and Karoo were deemed as the quietest, with Mileura regarded as promising because of its low-frequency radio silence. One reason for this attribute is because the closest major urban centre is Perth, 620km away.
Late last year, the WA Government undertook to establish a $7 million Radio Astronomy Park (RAP) near Meekatharra, to help ensure Mileura becomes the venue for the world's pre-eminent planned radio astronomical facility.
Some of the 1,000 individual radio antennae, called "stations", will be steerable satellite dishes, while others will be spherical radio lenses, or electronically-steered flat sheets to look out at different segments of the universe.
The SKA project, although collectively a single huge radio telescope, and made up of 1,000 small collection stations, will together form one "big picture".
Though spread over more than 3000km, half the SKA's antennae network will be situated in a central or core zone covering about 5km-by-5km. Another quarter of the collecting area will be within a diameter of 150km of the core zone, with the remainder situated out to 3000km or more from Mileura.
Up to 10 antennae can be built in already designated locations, with two each in South Australia, NSW, Northern Territory and Queensland, and one each in Victoria and Tasmania.
Four possible antennae sites have been earmarked for positioning in New Zealand — two each in the north and south islands — meaning the SKA's maximum west-east baseline could span up to 5500km of the lower southern hemisphere.
The SKA's size and spread over WA's radio-quiet outback will make it up to 100 times more sensitive than any currently operating radio telescope. It will, in fact, be so sensitive that it could detect radio and television broadcasts on the nearest stars.Radio sources
Technologies being developed at Mileura and overseas promise to advance understanding of the behaviour and impact of solar storms, by measuring the thousands of bright radio sources which change as they pass through the ejected plasma.
The SKA's central project planning group is headquartered in the Netherlands.
The $2 billion price tag for the highly sensitive astronomical facility will be primarily outlayed on custom-built antennae, microwave receivers, digital processors and complex software.
Nothing like the SKA has ever been attempted before by the international astronomical community. Participating countries include Australia, Canada, the United States, India, Japan, China, France, the United Kingdom, Germany, Argentina, Brazil, Russia, Poland, Sweden, South Africa, New Zealand and the Netherlands.
Over 30 institutes in 15 countries have so far participated in the SKA's planning and assessment phases.
Dr Peter Quinn of the European Southern Observatory in Garching, Germany, said the SKA would focus on two areas separated by time and distance — the epoch of re-ionisation, which refers to a period about 400,000 years after the Big Bang's creation of the cosmos 15 billion years ago, and space weather generated by the sun.
Although Perth will emerge as a major astronomical centre if Mileura is chosen, the SKA project has so far involved scientists from the CSIRO Australia Telescope National Facility; the University of Sydney SKA Project; the Swinburne University of Technology SKA Simulation and Radio Interferometry Group; and SEARFE (Students Exploring Australia's Radio Frequency Environment).
Regardless of which site is selected, the SKA will be the world's most important telescope and promises to penetrate back to the first stars and galaxies after the Big Bang.
Although software and hardware inputs into the SKA will come from each of the 17 partners involved in the project, there will be added spin-offs for Australia, with up to $400 million worth of local infrastructure being required. This will include outback road construction, remote power-generating units, radio-dish station foundations, security fencing and the laying down of thousands of kilometres of fibre-optic cabling.— Joe Poprzeczny.