Blog

Focussing on a patch of sky covering roughly the same area as 100 full moons, the Square Kilometre Array (SKA) radio telescope in Western Australia has captured the bright glow of dozens of galaxies as they looked billions of years in the past.

The scattering of around 85 dots might not be as colourful as Hubble’s stunning snapshots, nor as complex as the James Webb Space Telescope’s detailed photographs, but for radio astronomers the picture’s crystal-clear definition is far beyond their wildest expectations.

Combined with its sister SKA-Mid facility in South Africa, SKA-Low in Wajarri Yamaji Country some 600 kilometres north of Perth represents what will one day be the biggest telescope of its kind. Their antennas are designed to catch waves of energy from the radio part of the spectrum to provide a unique look of ancient galaxies in ‘colours’ beyond the reach of other telescopes.

When construction is finished, a total of 131,000 antennas will work together to map the distant Universe. So far just 1,024 of the devices have been built. But already they’re working exactly as scientists had hoped.

“The bright galaxies we can see in this image are just the tip of the iceberg,” says the SKA-Low Lead Commissioning Scientist George Heald.

“With the full telescope we will have the sensitivity to reveal the faintest and most distant galaxies, back to the early Universe when the first stars and galaxies started to form. This is technically difficult work and the first step to unlocking the awesome science that will be possible.” 

George hopes the SKA will be sensitive enough to put 600,000 galaxies on a map of the sky, giving scientists clues on the Universe’s entire structure. Looking back, those 85 tiny dots in the SKA-Low’s first ever image will feel a long way away.