By KATHLEEN CHAYKOWSKI in Pretoria, South Africa and GAUTAM NAIK in London
A consortium of countries chose South Africa and Australia to share a groundbreaking €1.5 billion ($1.87 billion) radio telescope that will be the biggest and most sensitive instrument of its kind.
The telescope, known as the Square Kilometer Array, or SKA, will offer an unprecedented view into the heart of the universe. It is expected to shed light on key cosmological mysteries, from the origin of dark matter and dark energy, and also help in the search for extraterrestrial life. SKA is expected to become fully operational in 2014.
In March, a science panel gave a marginal preference to site the telescope in South Africa, but the final decision partly came down to ensuring long-term funding for the machine. “It’s a global project and we want to retain as broad a support as we can,” said Michiel Van Haarlem, interim director general of the SKA organization. Australia has already spent about 150 million Australian dollars (US$146.4 million) on the project, Mr. Van Haarlem added.
In an announcement Friday following a meeting in the Netherlands, an SKA advisory committee said South Africa, along with eight other Southern African countries included in its bid, will host two-thirds of the total telescope dishes. About 90% of Africa’s dishes will be located at a single site in South Africa’s Northern Cape province. Australia will host the other third of the dishes while its bidding partner, New Zealand, will participate in research, SKA said.
The group of scientists said South Africa offered lower construction costs, less frequency interference and a higher-altitude site. The Australian location provided better site security and the presence of a larger astrophysics research community, the panel concluded.
“We accept the compromise [of dual siting] in the interest of science,” said Lunga Ngqengelele, South Africa’s Minister of the Department of Science and Technology, at a news briefing on Friday.
The SKA has been envisioned as astronomy’s answer to the Large Hadron Collider—a “big science” project that has been years in the planning and involves hundreds of scientists from about 20 countries. Several global technology companies have already signed partnership agreements with SKA, including Siemens, BAE Systems PLC, Cisco Systems Inc and Selex Galileo, a unit of Finmeccanica SpA.
The machine underscores that we are in “a golden age for astronomy,” which has marked by the construction of increasingly-powerful telescopes, said Richard Schilizzi, a professor of radio astronomy at the University of Manchester and former international project director for SKA. “There are a lot of new questions opening up and you need bigger and more sensitive telescopes.”
One of the biggest radio telescopes is near Socorro, New Mexico; another is in Arecibo, Puerto Rico, with a primary disk about 985 feet in diameter. China is now building an even larger telescope with a dish diameter of about 1,640 feet.
SKA will dwarf them all. The South Africa portion, for example, will consist of thousands of receptors linked together across an area spanning 3,000 kilometers (1,864 miles). The total collecting area of all the receptors will be about one square kilometer.
One important scientific mystery that SKA will tackle is dark energy, a hypothesized force that could explain why the universe is expanding at an accelerating pace. In 2011, three U.S.-born researchers shared the Nobel Prize in physics for discovering the acceleration effect.
The SKA telescope will be able to do a large-area survey of the sky and observe the distribution of galaxies in recent times as well as billions of years ago. By comparing the two distributions, “we may be able to tell how the geometry of space has changed under the influence of dark energy,” said Prof. Schilizzi.
Other researchers plan to use the instrument to scan space for complex molecules, the building blocks of life, as well as to look for weak extraterrestrial signals. According to the SKA organization, the telescope will be so sensitive that it could theoretically detect an airport radar on a planet 50 light years away.
SKA will collect a torrent of data, about 10 times the amount that courses through the global Internet. To create an image from the skies, information from each antenna will be combined by a supercomputer with the processing power of 100 million personal computers.