World’s biggest telescope was just ‘born’ in WA’s Murchison region, starting 50-year, billion-dollar mission

Humanity’s biggest telescope, the multibillion-dollar SKA Observatory, was officially “born” in WA’s Murchison this week, beginning a 50-year mission to understand the birth of the universe, among other cosmic mysteries. The SKA-Low radio telescope will eventually consist of more than 131,000 antennas spread across a vast swathe of Wajarri Yamaji country east of Geraldton, forming a twin observatory with a sister facility, SKA-Mid, being constructed in South Africa. On Thursday, the first two completed “stations”, or clusters, of the antenna array were activated, forming a baseline that allows interferometry to be performed, which is critical to the operation of radio telescopes. Almost immediately, a signal from Centaurus A, a galaxy famously active in the radio end of the electromagnetic spectrum, was detected. SKAO director-general Phil Diamond said: “This is the day the SKAO as a scientific facility was born.” SKA-Low lead commissioning scientist George Heald described the reaction to the first signal detection as “pure excitement”. “This moment of finding the first correlated signal is such a key moment in the evolution of the telescope into a scientific instrument, and it was just so exciting to see the signal come through as clearly as it did,” Dr Heald said. “It was actually sort of a surprise. We were doing some testing and not actually expecting to see the signal right away, but it came through quite clearly.” Radio telescopes work differently from their optical cousins, which is why the output of the SKA-Low bears no resemblance to the eye-catching images produced by instruments such as the James Webb Space Telescope. But initial SKA-Low images look every bit as beautiful to the global consortium behind the project, which is headquartered in the UK. “There’s been hundreds of people working on this project for decades, and there’s been thousands of scientists around the world waiting anxiously for SKA to start functioning as an interferometer, and we’ve reached that moment this week,” Dr Heald said. Dr Heald said some colleagues became emotional on seeing the images, but the most common reaction was excitement about the potential of the radio telescope when its full, monumental scale is realised by the end of the decade. “What we really want to do is use the incredible sensitivity of the full telescope to detect the fingerprints of the first stars and galaxies starting to create light near the beginning of the universe,” Dr Heald said. Many more secrets of the cosmos will be revealed by this facility in the Murchison, which is designed to be a world-leading radio telescope for the next five decades.