Splitting the world’s biggest telescope between two countries
According to a report in Nature last week, the SKA management board has asked a new scientific panel to determine whether the telescope could be divided between the two proposed sites.
Nature reporter Geoff Brumfiel writes that although politicians in Australia and South Africa oppose any split, John Womersley, head of the SKA board and chief executive of the UK Science and Technology Facilities Council, says a compromise may be one way to resolve the battle.
“I have heard astronomers that I respect say that such a solution is possible,” Womersley told the magazine.
As University World News reported last month, a SKA site advisory committee narrowly opted for a consortium of eight African nations, led by South Africa, over the joint bid by Australia and New Zealand to build the massive telescope.
The article in Nature quotes Professor Heino Falcke, a radio astronomer at Radboud University in Nijmegen in The Netherlands, as saying that the project could be divided by placing the higher-frequency dishes of the SKA on one continent and the lower-frequency antennas on the other.
“Normally when you have a giant dish, you cannot split it, but the SKA has many different components,” Falcke told the magazine.
But other astronomers pointed out that placing different parts of the telescope on different sides of the Earth would push the price of building the instrument even higher, and there would be little scientific advantage to be gained.
Raising the SKA’s huge price tag could possibly cause some in the group of 20 countries that have agreed to spread the estimated US$25 billion cost over 50 years to reconsider their offers.
Should the SKA ever be built, and that is still far from certain, astronomers say that with up to 50 times the sensitivity and 10,000 times the speed of current radio telescopes, it will be the world’s landmark astronomical facility for the first half of the 21st century, driving innovations in antenna technology, signal transmission and processing, and super-computing.
It will enable researchers to tackle outstanding problems in astrophysics, with particular emphasis on five key projects: studying the extreme environments of pulsars and black holes to put Einstein’s theory of gravity and general relativity to the test; understanding how matter, dark matter and dark energy have evolved; investigating the end of the cosmic ‘Dark Ages’, when the first black holes and stars appeared; probing for places where life might have arisen elsewhere in the universe; and examining the origin and evolution of one of the universe’s most enigmatic features – cosmic magnetism.
Under the Australian-New Zealand bid, the antenna dishes would be spread along a 5,000-kilometre spiral stretching from the deserts of Western Australia to the tip of New Zealand's South Island.
The South African site is north of the Losberg mountains and is said to have significant advantages because it is at a higher altitude, and construction costs would be lower.
Following deliberations by the new scientific panel about splitting the telescope, the SKA board is expected to meet again within a month, when it may make a final decision.