Observing the Universe
Square Kilometre Array
It would be an overstatement to suggest that Australians went crazy with enthusiasm when their country was named as a host of the Square Kilometre Array (SKA). Nevertheless, to be a central plank of the project to build and operate the most accurate telescope ever contemplated is something of an honour and the general public, following closely behind industry, is gradually catching on to its importance and the opportunities it presents, both economically and in terms of Australia’s reputation as a high-tech global player.
SKA? This is planned to be the world’s largest and most sensitive radio telescope. Thousands of linked radio wave receptors will be located in Australia and in Southern Africa. Combining the signals from the antennas in each region will create a telescope with a collecting area equivalent to a dish with an area of about one square kilometre.
The SKA is intended to address fundamental unanswered questions about the universe, including how the first stars and galaxies formed after the Big Bang, how galaxies have evolved since then, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth.
This global science and engineering project is led by the SKA Organisation, a not-for-profit company with its headquarters at Jodrell Bank Observatory, near Manchester, UK. However, the southern hemisphere is where the real work is to be carried out: an array of dish receptors will extend into eight African countries from a central core region in the Karoo desert of South Africa. A further array of mid frequency aperture arrays will also be built in the Karoo. A smaller array of dish receptors and an array of low frequency aperture arrays will be located in the Murchison Radio-astronomy Observatory in Western Australia.
Part of the project is already up and running in the form of ASKAP, the Australian Square Kilometre Array Pathfinder. This array of 36 antennas, each 12 metres in diameter, working together as a single instrument is located in the remote Mid West region of Western Australia, an area ideal for a new radio observatory since the population density is very low and hence there is a lack of man-made radio signals that would otherwise interfere with weak astronomical signals.
ASKAP is pioneering and testing revolutionary new technologies in areas of electrical engineering, digital systems, computing and signal transport. It was developed by CSIRO, with input from leading scientists and engineers from the Netherlands, Canada, the USA, and a number of Australian universities.
We managed to catch up with Brian Boyle, leader of the Australian side of the SKA project, to ask him what this intriguing prospect means for both science and Australia. “It represents a great example of a major international co-operation being hosted within Australia,” he said. “Overall it will continue to retain Australia’s world-class astronomical capability, which we have had for more than 50 years, and it ensures a seat at the global table for Australian scientists.” Not least, there is a lot of good solid industrial work to be done to actually build the array and all its connective tissues.
By the time the SKA begins its investigations, hopefully in 2020, it will be so sensitive that it will be able to detect an airport radar on a planet 50 light years away (which may or may not shed light on why your flight to Perth is delayed). Its central computer will have the processing power of about one hundred million PCs. Impressive, but Brian sounds what serves as a warning: “The technology does not yet exist to build it at the cost we need to build it at, so it will take a while yet for the scientists and the engineers to work together to ensure that the computational power in particular required for the SKA will be deliverable at the cost we need.” In its first decade (2016-2025) the cost for SKA Phase 1 construction will amount to around EUR650million ($940 million), with a second construction phase, requiring further investment, to be completed in the latter half of the next decade.
It’s a sign of the times that budgets are not unlimited, even with such an array (if you’ll pardon the term) of nations involved in the SKA. This is very much leading edge stuff with some of the world’s top scientists; Brian himself was a member of a recent Nobel Prize-winning team of physicists.
He points to the importance of this high-flying team being able to collaborate with the ‘real world’ of business. Governments have covered the EUR120 million ($178 million) for the design phase and “despite extraordinarily challenging economic times, from Australia’s perspective we are also having other organisations and industry also providing resources because they believe this is a good use of their money.” It helps build knowledge in some vital technologies that will return value to the participating industries (Brian reminds that the search for black holes, ‘pure’ physics as ever was, eventually led to the patents for wi-fi technology). For the Australian authorities, the project provides a stimulus for young people to find or maintain an interest in science and motivates them to study it at a high level.
ASKAP’s home, the CSIRO-run Murchison Radio-astronomy Observatory, is where the SKA telescope infrastructure in Australia is to be centred. In SKA phase 1, this infrastructure will consist of a low-frequency aperture array of 50 array stations, each with 10,000 individual antennas, and a 96-dish survey telescope incorporating the existing 36 dishes of ASKAP. Handling the volumes of data of the phases of SKA are part of the challenge; its dishes will produce up to 10 times the current global internet traffic.
Also housed at this site is the Murchison Widefield Array (MWA), another Australian-run SKA pre-cursor telescope. This array will be used to inform the design of the SKA low Frequency Array – an important part of the SKA. The MWA is a joint project between an international consortium of universities to build a low-frequency radio array operating in the frequency range 80–300 MHz. Its main scientific goals are to detect neutral atomic Hydrogen emission from the cosmological Epoch of Reionization (EoR), to study the sun, the heliosphere, the Earth’s ionosphere, and to study radio transient phenomena.
Brian pronounces himself very pleased with the way Australian industry has taken up the cudgels on the SKA project. “The interaction we have had so far with industry has been excellent,” he says. “They have been very patient with the long gestation period of SKA and have been very active advocates for the telescope and its hosting in Australia. But I would like to reassure some of the SMEs in Australia that although SKA is a big global project, they should not be afraid to jump in. There are a lot of specialist areas where SMEs can play an incredibly important and valuable role and up-skill themselves.”
He adds that from a quiet start, the project has begun to catch the imagination of the public too. “Our research shows more than 30 per cent of Australia’s population are aware of the SKA; now it’s up to us to ensure they know what it is and give them a sense of pride that Australia is co-hosting the telescope.” A recent art competition to depict key scientific aspects of the project attracted more than 2,300 entries.
SKA is an exercise in theoretical physics and Brian freely acknowledges the project leaders know only a few of the questions to be raised, let alone any of the answers. That is what makes it a challenge, and renders the project exciting for all participants. This is not a project to specifically find the answer to ‘dark matter’ or ‘dark energy’ – but it would of course be fun if discoveries of that magnitude could be made.