Africa is bidding to host the world’s most powerful radio telescope, the Square Kilometre Array (SKA). When constructed, in 2025, it will have 50 times greater sensitivity than any other radio telescope on Earth. The SKA will probe the edges of our universe, even before the first stars and galaxies that formed after the Big Bang. This telescope will contribute to answering fundamental questions in astronomy, physics and cosmology, including the nature of dark energy and dark matter.
South Africa is leading the African bid and has already legislated to create 12.5 million hectares of protected area – or radio astronomy reserve. This area is also referred to as the Karoo Central Astronomy Advantage Area, offering low levels of radio frequency interference, very little light pollution, basic infrastructure of roads, electricity and communication.
The human story began in Africa and it can also be the place where we find answers to the story of our universe.
Young people interested in astronomy and that might work on this project in future, are destined to become experts in future technologies that will be in high demand around the globe,[/pullquote]
-The Square Kilometre Array (SKA) will be a mega radio telescope, about 100 times more sensitive than the biggest existing radio telescope.
-SKA is a €1.5 billion project, with operating costs of about €100 million a year.
-It will be the first to provide mankind with detailed pictures of the “dark ages” 13.7 billion years back in time.
-This mega telescope will be powerful and sensitive enough to observe radio signals from the immediate aftermath of the Big Bang.
-If there is life somewhere else in the Universe, the SKA will help us find it.
-At least 24 organisations from 12 countries, including Australia, Canada, India, China, France, Germany, Italy, Portugal, Spain, South Africa, Sweden,
the Netherlands, the UK and the USA, are involved.
-The SKA will consist of approximately 4 000 dish-shaped antennae and other hybrid receiving technologies.
-Both South Africa and Australia have suitably remote, radio quiet areas for hosting the SKA and have competing bids to host the SKA.
-If Africa wins the SKA bid, the core of this giant telescope will be constructed in the Karoo region of the Northern Cape Province near to the towns of
Carnarvon and Williston, linked to a computing facility in Cape Town.
-Other countries where stations will be placed include Namibia, Botswana, Mozambique, Mauritius, Madagascar, Kenya and Zambia.
-South Africa is already building the Karoo Array Telescope (MeerKAT) which is a precursor instrument for the SKA, but will in its own right be amongst
the largest and most powerful telescopes in the world.
Why is Africa the best site for the SKA?
Most valuable for science
Low levels of radio frequency interference and certainty of future radio quiet zone.
Significant investment in skilled human resources – bursaries for scientists from across Africa, training for technicians and artisans.
An ideal physical environment (little water vapour, calm stable weather conditions).
Required land, labour and support services available and very affordable.
Core basic infrastructure of roads, electricity and communication already in place .
Ideal geographical location, sky coverage and topography.
Safe and stable area with very few people and no conflicting economic activities.
The astronomical “richness” of the southern skies & strong tradition of astronomy.
Excellent academic infrastructure to support SKA science and technology.
The SKA in Africa
A major component of the SKA telescope will be an extensive array of approximately 3000 antennas. Half of these will be concentrated in a 5 km diameter central region, and the rest will be distributed out to 3 000 km from this central concentration. South Africa’s bid proposes that the core of the telescope be located in an arid area of the Northern Cape Province of the Republic of South Africa, with about three antenna stations in Namibia, four in Botswana and one each in Mozambique, Mauritius, Madagascar, Kenya and Zambia. Each antenna station will consist of about 30 individual antennas.
An important milestone was reached with the “detection of fringes” in a joint very long baseline interferometry (VLBI) observation. For the first time South Africa has completed the experiment without assistance from other countries. The 26m Hartebeesthoek Radio Astronomy Observatory (HartRAO) near Pretoria teamed up with one of the seven 12m dishes currently part of the Karoo Array Telescope (KAT-7) over 900 km away to jointly observe and record data from a distant radio source known as 3C273. The data was then correlated in Cape Town to produce the first ever African fringe detection at its first attempt.
South Africa’s Astronomy Geographic Advantage Act (2007) declares the entire Northern Cape Province, with the exception of the Sol Plaatje Municipality (Kimberley) as an astronomy advantage area. Within that an area of 12.5 million hectares is the main protected area – or radio astronomy reserve – for the SKA. This area is also referred to as the Karoo Central Astronomy Advantage Area.
The SKA will be one of the largest scientific research facilities in the world and will consolidate Southern Africa as a major hub for astronomy in the world. Hosting the SKA would be a major accomplishment for the Astronomy Geographic Advantage Programme (AGAP), an initiative by the South African government to establish a hub of world-class astronomy facilities in Southern Africa. Other major astronomy facilities in the region include the Southern African Large Telescope (SALT) in the Karoo, and the HESS gamma ray telescope in Namibia.
Who is the Barefoot Astronomer?
Try exploring the nature and evolution of the universe, looking 13.7 billion years back in time, unraveling black holes and watching stars being born, tracking galaxies, identifying the nature of dark energy, navigating three-dimensional galactic maps and studying cosmic magnets, while decoding extra-terrestrial signals and finding planets capable of supporting life and then challenge the theory of relativity – all barefoot.
Simon Ratcliffe, an astronomer and a member of the South African SKA bid team, has been part of the MeerKAT project (a precursor to SKA) for several years. His work includes cutting-edge astronomy, including the recent and successful very long baseline interferometry (VBLI) observations. “His astronomical colleagues are doubtful if Ratcliffe owns a pair of shoes other than a set of “plakkies” (flip flops or thongs) – let’s just say that no one has even seen him wearing such items. He has a rather peculiar habit of working barefoot,” says Fanaroff, Director, South Africa SKA Project.
In the next few years, in the build up to the SKA project, Ratcliffe – The Barefoot Astronomer – will not only conduct his science but, more importantly, will also travel extensively promoting the benefits of the SKA project for mankind and South Africa, in particular. He will focus not only on the global scientific community and astronomists generally, but interested members of the general public. He does this in a light-hearted fashion, making use of simple, everyday terminology and, of course, barefoot.
“Young people interested in astronomy and that might work on this project in future, are destined to become experts in future technologies that will be in high demand around the globe,” predicts Ratcliffe.