SA's Giant Telescope Turns 20 and It's Still Spotting Things Nobody's Seen Before

Photo Credit: Southern African Large Telescope (salt.ac.za)

Africa’s biggest optical telescope, and one of the most powerful on the planet, has officially turned 20.

Northern Cape, South Africa (17 November 2025) – The Southern African Large Telescope (better known as SALT) has spent the last two decades in the Karoo helping scientists make sense of exploding stars, galaxies and some of the faintest objects humans have ever detected.

SALT sits just outside Sutherland in the Northern Cape and can pick up light a billion times too faint to be seen with the naked eye. It’s been behind some of South Africa’s biggest astronomy milestones.

It’s captured the afterglow of colliding neutron stars, helped describe new exoplanets, identified ultra-hot subdwarf stars, and has even characterised a rare ‘Peekaboo Galaxy’ that offers a glimpse into the early universe.

Astronomical stuff.

To celebrate Africa’s Giant Eye on the Sky’s 20th birthday, astronomers, scientists, and dignitaries gathered in the Northern Cape last week. Many of the guests were people closely tied to SALT’s history, including veteran astronomers who helped shape SA’s research capacity long before the first observation was ever captured.

One of them was Prof Patricia Whitelock, who played a massive role in developing the country’s astronomy pipeline. In the early 2000s, she asked an important question. What’s the point of building SALT if South Africa doesn’t have astronomers to use it?

She, alongside the astronomy community, went on to form the National Astrophysics and Space Science Programme, which, for over two decades, has produced many PhD-level South African astronomers.

People like Dr Itumeleng Monageng, who fell in love with astronomy during a solar eclipse in primary school in Johannesburg. Growing up in a township without much exposure to information about astronomy, he didn’t think becoming an astronomer was possible in South Africa.

Then SALT got inaugurated, and as he watched this major facility come to life in the Northern Cape, the dream became real. Now he sits on the SALT Board, part of the committee making important decisions that keep the telescope running.

Then, there are those who are literally behind the wheel of one of the most powerful telescopes in the world. Dr Moses Mogotsi and his team coordinate observations coming in from astronomers across the world who study everything from exploding stars to asteroids moving across our solar system.

In very simple terms, they decide where SALT points.

“We’re sitting at night and someone says ‘hey, there’s something exploding, can you observe it?’ and we can quickly get on it,” he says.

The telescope studies objects that change in milliseconds.

“Imagine light that’s taken 50 years to reach Earth, and SALT can track changes happening in less than a second. Asteroids that move so fast you can watch them shift on screen whilst the stars look frozen. Galaxies, exploding stars, rocks flying near Earth – all in a night’s work,” shares the Department of Science, Technology and Innovation (DSTI).

South African astronomers and scientists at SALT get to stargaze in a way that makes an astronomical impact.

“The nice thing is we get to see things that no one else has ever seen before. Maybe one or two people in the whole world care about that object. That’s a privilege,” shares Mogotsi.

Two decades after its first light, SALT has produced over 600 scientific papers, trained hundreds of students, boosted local economies in Sutherland, and placed South Africa among the stars on a global level.

“SALT has produced over 600 scientific publications, trained generations of astronomers through the Robert Stobie Scholarship and National Astrophysics Space Science Programme, contributed to the groundbreaking detection of gravitational waves, and transformed Sutherland from 2 guesthouses to 74. But beyond the numbers, SALT represents something bigger – a community that welcomed the stars, partnerships built on mutual respect, and young people like Dr Itumeleng Monageng who grew up in townships thinking astronomy wasn’t possible in South Africa, only to become astronomers and SALT Board members. ” shared the DSTI.