According to Engineering News, the Square Kilometre Array Observatory (SKAO) has announced the successful first interferometry test of its SKA-Mid telescope in South Africa. The test involved two of the seven dishes currently assembled, which were pointed at a radio galaxy located 2.6-billion light years from Earth. The successful combination of their data, known as achieving “first fringes,” proves the core systems are working together. SKAO director-general Professor Philip Diamond called it the first true test showing the telescope is “alive as a scientific instrument.” The next milestone is to produce the first image from a four-dish array within the next few months. When complete, the SKA-Mid array will consist of 197 dishes, integrating South Africa’s existing MeerKAT telescope.
Why this milestone matters
Look, building a single, massive radio dish that’s kilometers wide is basically impossible from an engineering standpoint. So astronomers use a clever trick: interferometry. By having multiple, separate dishes observe the same target and then mathematically combining their signals, you can simulate a telescope as large as the distance between them. That’s what “first fringes” means—it’s the proof that this incredibly complex synchronization and data combination actually works. Without this, you just have a bunch of individual dishes. With it, you have the foundation of a single, revolutionary instrument. It’s a huge technical and software challenge, and they’ve just proven they can do it.
The long road ahead
Here’s the thing to keep in mind: this test used just two dishes. The finished SKA-Mid will have 197. The project’s Senior Project Manager, Ben Lewis, is already targeting an image from four dishes soon. But scaling from a proof-of-concept with two dishes to a fully operational array of nearly 200 is a monumental task. Every new dish added increases the complexity of the network exponentially. They have to maintain perfect timing, manage a flood of data, and keep everything in sync. It’s a slow, gradual build-out. For context, the SKA’s low-frequency counterpart in Australia, SKA-Low, produced its first image last year using 1,024 antennas—which is still less than 1% of its planned final size. These projects operate on a timescale of decades, not years.
A new era for radio astronomy
So what does this mean for science? Once fully built, the SKA will be the most sensitive radio telescope on Earth, capable of seeing the faintest signals from the earliest epochs of the universe. It will map cosmic hydrogen, hunt for gravitational waves, and search for signs of life. This first test is a critical, confidence-building step for the international teams involved. It tells the engineers and scientists that their designs are sound and that the path forward is clear. For a project of this ambition, you need these early wins. They prove the vision is achievable, which is crucial for maintaining funding and global collaboration over the many years of construction still to come. It’s a small step for two dishes, but a giant leap for the future of how we see the cosmos.
