THE SQUARE KILOMETRE ARRAY | SKA
FACTS & FIGURES
Did you know?
- The data collected by the SKA in a single day would take nearly two million years to playback on an ipod.
- The SKA central computer will have the processing power of about one Hundred million PCs.
- The SKA will use enough optical fibre to wrap twice around the Earth!
- The dishes of the SKA will produce 10 times the global internet traffic.
- The aperture arrays in the SKA could produce more than 100 times the global internet traffic.
- The SKA will generate enough raw data to fill 15 million 64 GB iPods every day!
- · The SKA super computer will perform 1018 operations per second – equivalent to the number of stars in three million Milky Way galaxies – in order to process all the data that the SKA will produce.
- The SKA will be so sensitive that it will be able to detect an airport radar on a planet 50 light years away.
- The SKA will contain thousands of antennas with a combined collecting area of about one square kilometre (that’s 1,000,000 square metres!).
Questions and answers about MeerKAT and the SKA
What is the SKA?
The Square Kilometre Array (SKA) will be a mega radio telescope, about 100 times more sensitive than the biggest existing radio telescope. The SKA will consist of approximately 4 000 dish-shaped antennae and other hybrid receiving technologies. It will have a core of several hundred antennae and outlying stations of 30 – 40 antennae spiralling out of the core. These stations will be spread over a vast area – up to 3 000 km. The combined collecting area of all these antennae will add up to one square kilometre (= one million square metres).
What will the SKA do?
This mega telescope will be powerful and sensitive enough to observe radio signals from the immediate aftermath of the Big Bang. It will search for Earth-like planets and potential life elsewhere in the universe, test theories of gravity and examine the mystery of dark energy. A prime objective of the SKA is to probe the so-called “dark ages”, when the early universe was in a gaseous form before stars and galaxies were formed. Scientists are optimistic that the SKA will allow many new discoveries about how the universe was formed and what it is made of.
How will the SKA work?
The SKA will detect electromagnetic radiation (radio waves) and cosmic rays emitted by extremely distant celestial objects (such as stars and galaxies). Because electromagnetic radiation travels at a fixed speed of about 300 000 km per second, very distant objects are observed as they were in the distant past. This will allow astronomers to “look back in time” to observe the early stages of the evolution of the universe.
Where will the SKA be built?
The SKA must be built in a remote area, as far away as possible from man-made radio interference which is caused by sources such as cellular masts, radio broadcasts and air traffic navigation signals. Both South Africa and Australia have suitably remote, radio quiet areas for hosting the SKA. The international radio astronomy community must decide on the optimal site by 2011. They will base their decision on detailed studies of the advantages and disadvantages of both sites, in terms of scientific requirements and comparative costs.
If South 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. However, the SKA is so huge that outlying stations will be spread over several African countries, including Namibia, Botswana, Mozambique, Zambia, Mauritius, Madagascar, Kenya and Ghana.
Who will build and pay for the SKA and how much will it cost?
SKA is a €1.5 billion project, with operating costs of about €100 million a year. 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. Europe is expected to fund 40% of the project, with a comparable amount from the USA. The balance will be funded by the other countries involved in the project.
When will the SKA be operational?
The SKA will be built in phases. It is expected that construction will start in 2012, with significant collecting area in place by 2015 and the full array completed by 2021. South Africa and Australia are building “pathfinder” telescopes to develop and test the technology and science for the SKA. These are both due for completion in 2012 and will be extremely powerful, new generation radio telescopes.
South Africa’s bid to host the SKA
Southern Africa has become a hub of activities in the field of astronomy and related technologies. We have the infrastructure and expertise in place to make the SKA project a success. Winning the SKA bid will be a major step forward for the government’s Astronomy Geographical Advantage Programme (AGAP), building on the Southern African Large Telescope (SALT), the Hartebeesthoek Radio Astronomy Observatory (HartRAO) and the HESS gamma ray telescope in Namibia. The Karoo Array Telescope (known as MeerKAT) is being built on the site proposed for the SKA. South Africa’s new Astronomy Geographic Advantage Act ensures the future of radio astronomy in South Africa by protecting an area of about 12.5 million hectares around the proposed SKA core area against future radio frequency interference.
The SKA project will have substantial long term benefits for South Africa and Africa, corroborating our position as a hub for technological investment, creating local job opportunities, investment in human capital and directly increasing the uptake of science amongst young people.
Why the Northern Cape?
The Northern Cape is an ideal location for hosting the SKA. Because the area is remote and has very few people, it is radio quiet (in other words, it has very low levels of radio frequency interference). In addition to its ideal geographical location, sky coverage and topography, the basic infrastructure of roads, electricity and communication are in place. The land, labour and services required by the project are available and affordable and the Karoo is a safe and stable area with no conflicting economic activities. Finally, South Africa offers the astronomical “richness” of the southern skies and a strong tradition of astronomy.
More about MeerKAT
South Africa is building a premier mid-frequency radio telescope, The Karoo Array Telescope (known as MeerKAT), at the site proposed for the SKA. MeerKAT serves as a “pathfinder” for the cutting-edge technologies of the SKA. Phase one of MeerKAT – the construction of the first seven dishes (called KAT-7) – is under way on the site in the Karoo. The team plans to have the first KAT-7 dish on site by mid April 2009 and all seven dishes on site by December 2009. MeerKAT will eventually consist of up to 80 dishes, each 12 m in diameter. The telescope should be fully operational by 2012.
People skills to power SKA and MeerKAT
One of the major reasons for the support of the South African SKA project by government is that it can attract young people into science and engineering. The SKA South Africa Project, including the building of MeerKAT, is one of the biggest science and engineering projects currently in progress in South Africa and presents a variety of very exciting technological and scientific challenges and opportunities. It requires skills across a wide range of engineering disciplines, such as digital signal processing, radio frequency engineering, antenna design and software development.
The South African SKA Project is supported by a targeted “Youth into Science and Engineering Programme”. The programme offers comprehensive bursaries to students in engineering, mathematics, physics and astronomy at undergraduate and postgraduate level. Students who receive bursaries also benefit from regular workshops and student conferences where they interact with the world’s leading astronomers. To date more than 80 postgraduate students from South Africa and the rest of the African continent and 36 undergraduate students are studying or have studied with SKA bursaries and are on their way to being a part of South Africa’s exciting future in radio astronomy.
The MeerKAT array, currently taking shape in South Africa’s Karoo region, is a world-class radio telescope designed to do ground-breaking science. It will be the largest and most sensitive radio telescope in the southern hemisphere until the Square Kilometre Array (SKA) is completed around 2024. Via MeerKAT, South Africa is playing a key role in design and technology developments for the SKA.
Close to 100 young scientists and engineers are working on the MeerKAT project. Based at the engineering office in Cape Town, and at universities and technology companies across South Africa and Africa, these researchers interact closely with SKA teams around the world. In collaboration with South African industry and universities, and collaborating with global institutions, the South African team has developed technologies and systems for the MeerKAT telescope, including innovative composite telescope dishes and cutting-edge signal processing hardware and algorithms.
|The KAT-7 precursor array has been constructed and is being used as an engineering and science prototype.|
KAT-7 (seven-dish MeerKAT precursor array)
|The seven-dish MeerKAT precursor array, KAT-7, is the world’s first radio telescope array consisting of composite antenna structures.|
South Africa is currently building the Karoo Array Telescope, or MeerKAT, a mid-frequency ‘pathfinder’ or demonstrator radio telescope, alongside the proposed SKA core site.
The first seven dishes of the local precursor instrument – known as KAT-7 – were completed by December 2010 and are now being commissioned.
It is the world’s first radio telescope with dishes made of fibre glass. KAT-7 is an engineering prototype for the 64-dish MeerKAT, but the world’s scientists see it as a useful instrument in its own right, and they are keen to switch it on for doing science as soon as possible.
KAT-7 has already delivered images of the Centaurus A, a galaxy 14-million light years away.
The commissioning of KAT-7 is led by
Dr Debra Shepherd, currently on secondment to the SKA South Africa Project from the National Radio Astronomy Observatory in the USA.