South Africa To Host World’s Largest Telescope

South Africa’s bleakest semi-desert area, the Karoo region, is enjoying an unexpected spell in the limelight. It has been selected as the site of the country’s largest solar park, it has billions of cubic metres of gas and now, it will be home to the world’s largest and most sophisticated telescope – the Square Kilometre […]


South Africa’s bleakest semi-desert area, the Karoo region, is enjoying an unexpected spell in the limelight. It has been selected as the site of the country’s largest solar park, it has billions of cubic metres of gas and now, it will be home to the world’s largest and most sophisticated telescope – the Square Kilometre Array.

South Africa’s semi-desert  wilderness, stretching from the southwest to the Botswana and Namibia borders, is a forlorn and lonely bleakness of scorching summers and sub-zero winters. It is sparsely populated, favoured by snakes and scorpions with attitude and often deadly bite.

More recently, however, it has become a potential magnet for hundreds of billions of dollars in foreign investment.

The reasons are disparate and interesting and together they will thrust the region deeply into the 21st century, and could make it very wealthy.

The region, especially the northern tracts, enjoyed a glittering debut a couple of centuries ago with the discovery of diamonds there, but once the rush petered out and mines and pans ran dry of their sparkling harvest, the spiders and snakes resumed their sovereignty. But that’s all about to change yet again, and this time for more reasons than one.

The shiny stones have been replaced by glittering objects of the celestial kind; down below the hot sands gas in its billions of cubic metres lies waiting to be tapped while the sun, cursed by mineworkers and goatherds alike for its harsh and relentless radiance, is now a blessing for its solar life-giving radiation.

African Business has been tracking the goings-on in the Northern Cape Province and the Karoo region and has kept readers abreast of economic developments there including the advent of the world’s biggest solar park set to generate 5m solar kilowatt hours in the not too distant future.

The Karoo region holds a subterranean bonanza of literally billions of cubic metres of gas that might or might not be exploited, depending on how the battle between the Greens and the petroleum companies pans out.

And now, as something completely different, the driest and most desolate expanse in the area will be home to South Africa’s share of the Square Kilometre Array (SKA) a project of astronomical proportions that will attract billions of dollars in construction investment and yield a wealth of scientific knowledge about the universe.

For nearly a decade, scientists at the SKA Site Advisory Committee (SSAC)  have been trying to decide whether to locate the SKA in South Africa or in Australasia. Both sites, barren with clear, interference-free skies, are imminently suitable, and each had its admirers and detractors. In the end, the decision was an immense compromise: 70% would be constructed in Africa with 30% in Australia and New Zealand.

Why so cumbersome an arrangement? The answer seems to be that, inevitably, politics got in the way of a smooth and sensible process, and we ended up with a camel. But more about that later.

Radio as telescope

The important thing was that the SKA process could move forward after wheel-spinning for eight years. In that time the SKA scientific community had been arguing over where to site the home of a square kilometre of radio telescopes that together would constitute one hyper-powerful instrument that would see more deeply and more clearly into space than anything that has gone before. Its mission: to probe the universe to try and understand its origins.

Notes Dr Kelvin Klemm, a nuclear physicist based in Pretoria, “The rule of thumb is that the wider  a telescope is, the further it can see. It would be impossible to build a telescope of 1km² as one single unit so it is being built as an array of smaller telescopes all operating together as one.”

Klem also explains how ‘radio’ becomes ‘telescope’. “This telescope does not ‘see’ using light in the conventional understanding of a telescope. SKA will be a radio telescope. Such a telescope monitors radio waves rather than light, and astronomers can generate accurate pictures built up from radio waves.”

Such radio waves have been travelling through space since the birth of the universe, so a snapshot of these waves will be a picture created at the beginning of time.

“Major astronomical events, such as exploding stars, do not just emit light; they emit energy covering the whole electromagnetic spectrum including radio waves, X-rays and gamma rays,” says Klemm. “Radio waves travel much farther, with fewer disturbances, than does light. So to see back to the beginning of time, it is best to use radio waves.”

Klemm also expounds on how the SKA will improve our chances of finding extraterrestrial life “out there”.

“SKA will be so sensitive that if there are alien beings living on another planet orbiting a nearby star we will be able to detect their TV broadcasts,” he says.

“So, are we spending $3bn to eavesdrop on Mars TV?” is the inevitable question.   

“Well, it would be exciting if we did find aliens but that is not the purpose of SKA,” says Klemm. “It will be used to probe deep space to unravel more mysteries of the universe. We know that galaxies in the universe are flying away from each other at a great rate, but we don’t know why. SKA will be able to measure these motions so accurately that it will add to knowledge, leading to the solution of the mystery.”

So why will the SKA, conceived as one comprehensive entity to be sited either in Australia or South Africa, be split up and located disparately around the globe?

According to South Africa’s science and technology department the decision to split the construction of the world’s most powerful radio telescope between Africa and Australasia is a “political compromise”.

It said in a statement that the move was clearly a political one “and not the outcome of a technical and scientific review”. It was, however, a compromise South Africa would accept “in the interest of science”.

South Africa’s main site will be outside Carnarvon in the Karoo, while Australia’s core site will be the Mileura station, about 100km west of Meekathara in western Australia.

Satellite dishes for the project will stretch across south and east Africa located in Botswana, Ghana, Kenya, Madagascar, Mauritius, Mozambique, Namibia and Zambia.

In order to be inclusive, however, the SKA Organisation agreed to constructing one of the three SKA receiver components in Australia. Two will be constructed in South Africa. The SKA project is a global scientific enterprise to build one of the largest scientific instruments ever envisaged.

It is being designed to answer fundamental questions in physics, astronomy and cosmology in order for us to understand the origin and workings of the universe better, and to reveal new and unexpected phenomena that will enthral and challenge us.

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