Radio telescopes – the Square Kilometre Array

An international radio telescope powerful enough to pull dual PM backing

By Professor Sergei Gulyaev, Director of the Institute for Radiophysics and Space Research, AUT University

“New Zealand will offer strong support for Australia’s bid to host the world’s largest radio telescope, the Square Kilometre Array (SKA)” – New Zealand Prime Minister Helen Clark

“This is a massive project of global significance and for radio astronomy in our two countries. Once constructed this would be the largest radio telescope in the world, 50 times more powerful than any current radio telescope, a huge contribution to global radio astronomy, a huge contribution to the science in our respective countries, to innovation in our respective countries” – Australian Prime Minister Kevin Rudd

When Prime Ministers Helen Clark and Kevin Rudd sat down to talk about crucial issues for the two countries, aside from the customary discussions on economics, there was one standout topic – the Square Kilometre Array. So what put science, and particularly radio astronomy, so far up the agenda?

The Square Kilometre Array (SKA) – a vast network of dishes that will create the world’s largest radio telescope – is one of four international mega-science projects currently under development. The other three projects of this scale ($3 -10 billion) are the International Space Station (ISS), the Large Hadron Collider (LHC – being built in Switzerland and to be operational by the end of 2008) and the International Thermonuclear Reactor (ITER – construction underway in France in 2008).

The difference between SKA and the other mega-science projects is that this one is likely to be built in Australia and New Zealand. Many countries desperately wanted it – the initial list of competitors for hosting rights was lengthy but it has been pared down to Australia (in partnership with New Zealand) and South Africa (the Republic of South Africa and six neighbouring countries). However the signs are good for our side of the world.

There are plenty of strong incentives to vie for this project – the accompanying international attention and recognition will be great, and this will be matched by huge external funding with all its economic spin-offs. Another pull is the ‘educational factor’ – the boost to science education.

But the biggest attraction is the chance to be involved in the world-changing discoveries that this incredible facility is expected to deliver.

When did the first stars and galaxies form? How did it happen? Did Einstein have the last word on gravity? What is the origin of cosmic magnetism? What is the nature of the dark matter and dark energy? We believe the SKA will be capable of answering these questions, the most intriguing and important in modern science.

If SKA does go ahead with Australia and New Zealand as the hosts, it will have a major impact on this country’s education sector, its economy, its research reputation and the way we are viewed by the world. For now, understanding this project and spreading the excitement about what it can achieve is the best way forward.

The SKA is a radio telescope. It will consist of thousands of dishes working simultaneously as one colossal radio telescope. Clusters of dishes will be distributed over all of Australia and some will jump to New Zealand. To provide joint operation all dishes will be connected via broadband link. The bigger the size of the telescope, the finer the resolution it can achieve on the sky. In the case of the SKA the size of the whole facility will be 3000 km if it is located in South Africa and as big as 6000 km if it is based in Australia and New Zealand. Currently 17 countries are participating in the SKA project and 30 research institutes around the world are involved in this project.

The Square Kilometre Array is not just a 1 km by 1 km parcel on the ground. One square kilometre (or 1 million square metres) is the total collecting area of all SKA dishes – the total area of their metal surfaces directed to the sky. The collecting area determines a very important property of a radio telescope – its sensitivity. SKA will be the champion in sensitivity – it will be capable of “seeing” objects which are 100 times more distant/weaker than any existing radio telescope on Earth is capable of. The 100 times leap in sensitivity is unprecedented in the history of astronomy and space science. (Actually, that is not quite right. A similar revolutionary leap happened when Galileo first used the “spyglass” – the first telescope ever. As a result he made discoveries which revolutionized all natural science. It happened almost 400 years ago. This is why 2009 has been chosen as the International Year of Astronomy.)

But why a radio telescope and not just an ordinary optical telescope?

First, cosmic dust and gas are not transparent to visible light, which makes optical observations of some very important objects (such as the centre of our galaxy, the Milky Way) impossible. Radio waves are able to penetrate gas and dust without any scattering or absorption. Since radio astronomy emerged in 1930s, several great discoveries have been made, such as microwave background radiation (which proves the concept of the Big Bang), quasars (the most powerful objects in the universe), pulsars, cosmic masers, and gigantic molecules in space, etc.

Secondly, recent developments in electronics, broadband and supercomputing have provided a boost to radio astronomy in the form of a technique called VLBI (Very Long Baseline Interferometry) and its real-time option eVLBI. eVLBI allows astronomers to use thousands of dishes simultaneously as one powerful instrument. In the case of the SKA it will require a very high-speed broadband connection (on the level of 1 Terabit/sec) and intensely productive supercomputers (on the level of 1 ExaFlop). This level of speed – both for broadband and supercomputing – is not possible today, but according to Moore’s Law ( which states that the number of transistors on an integrated circuit doubles every year) it will be possible in 10 years’ time. This is what makes the SKA special: we are planning a facility today which will be operational in 2020 and which will use the technical achievements of 2020! This approach will guarantee that the host country will be exposed to the latest and most exciting ICT achievements earlier than any other country.

New Zealand is privileged to be at the centre of such an amazing project and should embrace this opportunity to be part of some of the greatest scientific discoveries of our time. We have made educated guesses about what the SKA will reveal, but we cannot know how many serendipitous discoveries will be made. We can only dream.

Professor Sergei Gulyaev

For more information about SKA visit the official SKA website or see the New Zealand and Australian websites: and


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