Listening to the Ancient Sky: Australia Builds Its Piece of the World's Largest Radio Telescope

In a remote stretch of the Western Australian outback, something genuinely strange is taking shape. Row upon row of spindly antennas are being planted across the red earth, part of one of the most ambitious scientific projects the world has ever attempted.

A telescope split across two continents

The project is the Square Kilometre Array Observatory, and it is not confined to one place. The telescopes that will make it up are being built across two southern-hemisphere sites, one in South Africa and one in Australia, working as parts of a single instrument.

Australia's contribution has its own name and character. The country is hosting the component known as SKA-Low, designed to capture low-frequency radio waves from the distant universe, a different task from the dishes rising on the African side.

The setting was chosen for its silence. The antennas are being built at the CSIRO Murchison Radio-astronomy Observatory in Western Australia, a site remote enough to shield the delicate equipment from the radio noise of modern life.

A forest of antennas in the outback

The sheer numbers involved are staggering. SKA-Low is planned to include 131,072 antennas, each standing about two metres tall, a vast array spread across the landscape rather than a single towering structure.

Their appearance is as unusual as their number. Each antenna is described as shaped a little like a Christmas tree, and together they form a sprawling metallic forest whose purpose is to listen rather than to be looked at.

The site itself carries a name rooted in Country. It is known as Inyarrimanha Ilgari Bundara, a reminder that this cutting-edge observatory sits on land with a deep human history long predating the science now unfolding there.

Coming to life in stages

A machine this large cannot simply be switched on. It is being assembled in stages, and reporting on the project indicates that by 2026 a phase known as Array Assembly 2 will bring 64 SKA-Low stations online alongside 64 dishes at the sister site.

The end of the year is set to bring a notable threshold. The array is planned to expand to 68 working stations, a point at which it is expected to become the most sensitive low-frequency radio telescope on Earth even while still far from complete.

Even in that partial state its power is remarkable. At that stage the instrument is reported to be capable of mapping and detecting up to 600,000 galaxies within a single field of view, a census of the cosmos on an almost unimaginable scale.

The road to first light

There is still a long way to go before it is finished. Construction has begun and is expected to conclude by 2028, the year in which the observatory is due to begin taking scientific data as a completed instrument.

When that day comes, the payoff could be historic. A telescope this sensitive is built to peer back toward the early universe, and Australia's forest of antennas may help astronomers listen to signals that have been travelling toward us for billions of years.