Karoo SKA takes giant leap into a distant past
IT is going to take decades to reach its full capacity, but the Square Kilometre Array telescope is already overtaking its own technological advances in a gruelling game of scientific catand-mouse.
Once a week, a charter plane flies in from Johannesburg and Cape Town to the remote region of the Northern Cape, bringing with it whichever local and international brilliant minds are needed at that moment.
Their collective expertise will be used to create a device so powerful it will one day be able to demystify the Big Bang.
Until then, engineers, scientists and other experts are improving the technology, even as different components are being built. The design of the dishes has improved during the past few years, the computing hardware used for digital signal processing is already into its next generation, and the telescopes are now operated remotely from 700km away.
When done, the collective surface area of all dishes combined will make up a square kilometre and will have cost SECRETS OF THE STARS: Visitors take a walk among some of the dishes that make up the Square Kilometre Array in the Northern Cape around à650- million.
André Walker, a senior radiofrequency technician, drives into the wilderness every day from nearby Carnarvon and sees the landscape slowly changing. He walks among KAT-7, a collection of seven dishes that were completed by December 2010 at a cost of R140- million and which marked the first phase of the project. They are still in use, their large, curved faces looming over the thirsty vegetation below.
KAT stands for Karoo Array Telescope, and the region was chosen for its purity. With nobody living there, it is free of radio-frequency interference from cellphones and other devices that would disturb the signals. The landscape itself is quintessential Karoo — a flawless blue sky stretched over hectares of flat, rough shrubbery. But now KAT-7 has etched itself against the skyline.
“Scientists are still getting useful data out of it. Instead of scrapping it, we want to retrofit it to become part of MeerKAT,” he said.
KAT-7 was the pilot project, whereas MeerKAT, which will comprise 64 dishes, is the next phase of the project. It in turn will act as the precursor to SKA, which will ultimately comprise around 3 000 dishes.
MeerKAT is already under way, but the design of the dishes marks yet another breakthrough.
It is hoped that this innovation will become a candidate for a Nobel prize.
Pieter Snyman, SKA’s stakeholder manager, said the advances made at SKA would change the world’s perception of how everything started.
“Right now, 95% of our universe is a complete mystery. We can describe some of its properties, but we don’t know what it is. It would take 100 million light years to travel from one end of the Milky Way to the other, and the Milky Way is just a drop in the ocean of billions of galaxies.”
But, he said, SKA would be “100 times more sensitive than any other instrument in the world”, and would enable us to read signals that are only reaching us billions of years later.
“The technology enables us to look back in time because it enables us to receive signals from events that happened far back. We are then able to analyse those signals from so long ago.”
This includes signs of the Big Bang, which happened 13.8 billion years ago, he said.