SA bids for Square Kilometre Array
6 May 2005
South Africa has embarked on an ambitious bid to host what will be one of the biggest scientific instruments in the world, the Square Kilometre Array (SKA) - a future generation international radio telescope that will enable astronomers to probe the early evolution of our galaxy.
If South Africa were to win the bid, it would bring a massive injection of expertise and economic activity to the Northern Cape, with benefits for the local aluminium, computer, communications, electronics, and steel industries.
South Africa faces competition from Australia, China and the US to host the SKA. A final decision is expected in 2006, while construction on the SKA will probably start in about 2013 and be completed by 2019.
Construction of 'mini-SKA' under way
In the meantime, South Africa has begun contruction on a new Pathfinder Telescope in the Karoo, with technology that will parallel that of the SKA.
Construction
on this smaller version of the SKA is expected to be complete in 2008/9, and will entail cooperation with some of the other countries involved in the SKA bid to ensure efficient technology transfer.
The SKA project will cost about US$1-billion, and according to Arts, Culture, Science and Technology Minister Ben Ngubane, could generate as much as R500-million in foreign investment for South Africa.
South Africa's bid to host the SKA was submitted in May to an international panel of experts who will select the host country based on a comprehensive set of criteria.
Southern hemisphere 'has the edge'
The South African SKA has identified three sites in the Northern Cape, all three boasting radio interference-free zones of 150 kilometres, which far exceeds the requirement of 100 kilometre radio interference-free areas.
They are in the Kalahari (north of Upington), in the Karoo (north of Carnarvon), and in Namaqualand (east of
Springbok).
It's thought that Australia offers the stiffest competition, although South Africa's bid is likely to be the cheapest. Counting in Australia's favour is a well-established astronomy base and a larger geographical area in which to extend the SKA.
Professor Justin Jonas, a radio astronomer based at Rhodes University, and a member of the South African bid steering committee, says southern hemisphere nations have an advantage over their northern hemisphere competitors.
"The southern hemisphere is a winner, because we see more of the sky than the northern hemisphere", says Jonas. "We are also in the same longitude as Europe, which means we see the same night sky, and can easily link up with facilities there."
Some of the most important reasons why the Northern Cape is ideal include the "radio quietness" of the area (minimum radio interference from cellphone and radio networks), low population density and suitable topography.
In addition to the
location of the three identified sites, South Africa has the capabilities and track record to host, support and contribute to the science that will be generated by largest radio telescope ever to be built.
Radio signals from the past
The core element of the SKA should be in the centre of a radio interference-free region 100 kilometres in diameter. This is because radio emissions from the early universe - which the SKA will seek to capture - are in the range of a few hundred megaHertz, a frequency band now crowded on earth with TV and cellular telephone transmissions.
To pick up these radio emissions - literally, radio signals from the past - the SKA will have a receiving surface of one million square metres, 100 times larger than the current biggest surface.
The huge receiving surface will consist of many small antennae, divided into a core element and a periphery. The peripheral antennas could be between 1 000 and 10 000 kilometres
away from the core element, making the SKA an intercontinental system.
The signals received by all these antennae will be combined to form one single, big picture. The result will be an instrument capable of probing the secrets of the very early universe, just after it began about 14 billion years ago - so science tells us - with the "Big Bang".
Cutting-edge astronomy projects
"The southern African region has become a premier destination for cutting-edge astronomy projects as a result of decisions taken by governments in the region", says Dr Rob Adam, director-general in the Department of Science and Technology and chairperson of the South African project steering committee.
"South Africa clearly has the history, experience and expertise in constructing, hosting and cooperating in major astronomical and space science projects to make the SKA a success."
Comments Dr Khotso Mokhele, president of the National Research
Foundation, the lead agency in the SKA project: "We already have the Southern African Large Telescope (SALT) at Sutherland in the Northern Cape that will be the largest telescope in the southern hemisphere, while in neighbouring Namibia there is the High Energy Stereoscopic System (HESS) gamma ray observatory that will be the largest of its kind in the world.
"We see the location of global astronomy infrastructure in our region as a way of promoting high-technology investment and of ensuring that local scientists are able to participate in world-class science at limited cost."
SouthAfrica.info reporter
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