Three countries have agreed to work together to build the largest radio telescope ever made. South Africa, Australia and New Zealand have decided to pool their resources after making separate bids to run the Square Kilometre Array project.

The name comes from the aim of producing a total collecting area of one million square meters. That’s roughly the same size as 189 NFL pitches, or half the size of Monaco.

The telescope works through combining data from thousands of antennas. Many of these will be clustered at a central location, but some will be spread out up to 3,000 kilometers away.

Because the antennas are tracking waves, they need to be sited in areas with as little interference as possible from TV broadcasting and cellphone relays. Two rival suggestions were put forward, with the central clusters to be based in either Western Australia or the Northern Cape of South Africa.

With both bid teams having begun work on building sites, they agreed to combine their resources. This will increase the complexity and cost of the project (now estimated at 1.5 billion euros (approx US$1.8billion) and may mean good quality results can be achieved more quickly.

The plan now is to base the low-frequency antennas in Australia and the mid-frequency antennas in South Africa. In the latter case, while South Africa will host the central cluster, there will be antennas extending out into seven other African nations.

The SKA will have enough power and sensitivity that it could theoretically detect television signals broadcast on other planets, though it has to be said those working on the project aren’t expecting that to happen!

Instead the main aim is to track the billion nearest galaxies to Earth, as well as imaging hydrogen to build up a three-dimensional picture of what happened between the first appearance of hydrogen and the formation of structures that became the first galaxies. There are also plans to further test Einstein’s theory of general relativity.

(Image shows artist impression, courtesy Swinburne Astronomy Productions for SKA Project Development Office)