After a tense few months that has had many in Australia and South Africa anxiously awaiting word on whether their particular site will be chosen to host the world’s largest and most sensitive radio telescope, the Square Kilometer Array (SKA) Organisation has finally made its decision. And it’s good news for both bids – or bad news, if you’re the glass half empty sort - with the organization opting for a dual-site solution that will see the SKA telescope shared between Australia and South Africa.
The joint Australia/New Zealand bid and a South African-led bid were left competing after sites in Argentina and Chile were ruled out in 2006. However, hopes in the Australia/New Zealand camp were dealt a blow earlier this year when it was reported that a confidential report from the SKA Site Advisory Committee favored the South African-led bid. While an official announcement was expected on April 4, 2012, the SKA Organization instead decided to postpone the announcement while a working group was set up to examine the two sites further, along with the option of a dual site solution.
Noting that both sites had their own advantages and disadvantages, and wishing to be inclusive, the SKA Organisation has now revealed it has agreed on a dual-site solution that will allow the project to take advantage of investments already made by the bidding nations. The decision will see two of the three SKA receiver components built in Africa, with the third to be constructed in Australia and New Zealand.
The MeerKAT radio telescope, which is currently under construction in the Northern Cape Province of South Africa and will consist of 64 dishes measuring 13.5 m (44 ft) in diameter, will be used to supplement the SKA Phase I dish array, providing the majority of the collection area for the SKA telescope. The majority of SKA dishes in Phase I will be built in Southern Africa, as will all the dishes and mid frequency aperture arrays for Phase II of the SKA.
Meanwhile, in Australia, SKA dishes will be combined with the 36 dishes of the almost completed Australian SKA Pathfinder (ASKAP) array in Western Australia. All of the low frequency aperture array antennas for Phase I and II will also be built in Australia and New Zealand.
When completed, the SKA will have a total collecting area of approximately one square kilometer (0.38 square miles), with thousands of receptors extending to distances of up to 3,000 km (1,864 miles) from its center. It will also generate astronomical amounts of data – with each dish transmitting around 160 Gigabits of data per second to a central processor – posing some pretty intensive computing demands to be addressed by the DOME project.
Boasting 50 times the sensitivity and 10,000 times the survey speed of the best current-day telescopes, the SKA will extend the range of the observable universe, while addressing questions in the fields of astrophysics, fundamental physics, cosmology and particle astrophysics.
Construction of Phase I of the SKA is due to start in 2016, with initial observations set for 2019 and full operation scheduled by 2024.
Source: SKA Organisation