WHAT’S THE STORY?

THE first signatures have just been made on an international treaty that will lead to the construction of the world’s largest radio telescope, the Square Kilometre Array – or SKA for short. Funded by 13 nations from around the world, and headquartered at Jodrell Bank, part of the University of Manchester, the SKA is expected to cost €1.7 billion for construction and 10 years of operation. In its first phase, the SKA production group will deploy 130,000 antennas in Australia and add 133 dishes to the 64 of the MeerKAT array, a precursor to SKA that opened last year in South Africa.

In Australia, the SKA low-frequency telescope will comprise 512 stations in a large core and three spiral arms creating a maximum baseline of 65km. Each of the stations will contain around 250 individual antennas in the first phase. Yesterday Italy became the second country after the Netherlands to ratify the SKA Observatory Convention, the treaty which establishes the intergovernmental organisation that will build and operate the SKA telescopes. Australia, the UK, and at least nine other countries will soon sign the Convention, with only the US appearing to have pulled out for reasons that are not certain.

WHY IS SKA A POSSIBLE GAME CHANGER IN THE WAY WE VIEW THE COSMOS?

BECAUSE of its sheer scale. Radio telescopes linked to computers produce the best images of deep space and the SKA will be 50 times more sensitive than existing arrays, promising scientists the ability to “look” further out in space and further back in time.

The SKA will eventually consist of thousands of radio telescope dishes scattered across South Africa and a million stick-like antennas in Western Australia. They are being based in the Southern Hemisphere because there is less interference with signals and a better view of our galaxy, the Milky Way. The more “collecting area” you have, the quicker you can survey the heavens. If all goes to plan, the SKA will carry out surveys 10,000 times faster than existing radio telescopes.

Originally dreamed up in the 1990s, the SKA gets its name from the fact that all of the array will represent a square kilometre of collecting area – a huge increase on current dishes and arrays.

With the actual construction on the two sites scheduled to start next January, we could be seeing results from the telescope within five or six years after that.

It will produce so much raw data that at present there is no machine or system that could handle it. There could be more data traffic than the entire internet which is why the Chinese Academy of Sciences’s Shanghai Astronomical Observatory has had a team of researchers working on a centre that will manipulate data initially processed in Australia and South Africa and then analyse it in cooperation with scientists worldwide.

WHO’S ALL INVOLVED?

ITALY led the multilateral negotiations on the text of the Convention, which was signed in Rome last year by seven countries: Australia, China, Italy, the Netherlands, Portugal, South Africa and the United Kingdom.

The convention will enter into force once five signatories, including the three hosts Australia, South Africa and the UK, have ratified the text.

A £1 million supercomputer called Oblivion has opened in Evora in Portugal in the last few days just to process the initial plans. Around 100 organisations across about 20 countries are participating in the design and development of the SKA. The US is developing its own Very Large Array and the likelihood is that both projects will link up in the future.

WHAT WILL THE SKA DO?

THE projects already lined up for the SKA include observations of pulsars and dark holes to test Albert Einstein’s theory of general relativity.

According to the project website the SKA “will investigate the nature of gravity and challenge the theory of general relativity”.

“Pulsars, the collapsed spinning cores of dead stars, will be monitored to search for gravitational waves – ripples in the fabric of space-time. The SKA will also use pulsars to test general relativity in extreme conditions, for example, close to black holes.”

All experiments to try and disprove Einstein have so far failed. It may well be that his theory will finally be proven totally correct by the SKA.

For many cosmologists and astrophysicists, the really exciting plans are for the SKA to investigate galaxies at the observable edge of the Universe. Here may be found the answers being sought about dark matter, gravity and the primordial Universe.

Of course the question we all want answered is whether there’s anybody out there, and yes the SKA will have a role in the search for extra-terrestrial intelligence.

NOTHING TO DO WITH MADNESS AND THE SPECIALS?

SADLY, it’s all about science, but On My Radio by The Selecter may be their theme tune.