African telescopes are driving frontier space discoveries

A record-breaking cosmic signal detected by South Africa’s MeerKAT telescope is signalling a deeper shift in where frontier astronomy is happening.

Astronomers at the University of Pretoria recently observed the most distant hydroxyl megamaser ever detected using MeerKAT. The system, HATLAS J142935.3–002836, lies more than eight billion light-years away and emits an extraordinarily powerful radio signal, known as a “cosmic laser.”

According to the South African Radio Astronomy Observatory, the signal is “so luminous it warrants classification as a gigamaser, a rare cosmic phenomenon” produced when radio waves are amplified by hydroxyl molecules in gas-rich merging galaxies.

Hydroxyl megamasers form under extreme conditions, typically when galaxies collide, and massive gas reservoirs trigger intense star formation. They also feed supermassive black holes, making these signals powerful probes of early-universe dynamics.

MeerKAT detected the signal thanks to a rare cosmic alignment. A foreground galaxy acted as a gravitational lens, magnifying the radio waves and allowing the telescope to capture them despite the vast distance.

“This system is truly extraordinary,” said Dr. Thato Manamela, SARAO-funded postdoctoral researcher at the University of Pretoria and lead author of the study. “We are seeing the radio equivalent of a laser halfway across the universe. Not only that, during its journey to Earth, the radio waves are further amplified by a perfectly aligned, yet unrelated foreground galaxy. This galaxy acts as a lens because its mass curves local space-time, enabling a wonderfully serendipitous discovery.”

According to the discovery team, the observation offers scientists a direct view of the universe when it was less than half its current age. It also demonstrates MeerKAT’s extraordinary sensitivity and underscores that Africa-hosted instruments can make frontier science discoveries.

“This is just the beginning,” Manamela said. “We don’t want to find just one system, we want to find hundreds to thousands.”

MeerKAT radiotelescope, a 64-dish radio telescope located in South Africa’s Karoo, was built as a precursor to the Square Kilometre Array Observatory, testing technologies and scientific workflows that will scale to the much larger array now under construction.

The array supports deep imaging, spectral-line surveys, pulsar timing, and high-cadence transient detection, making it one of the most capable radio astronomy instruments on the planet.

The gigamaser detection is not an isolated event. African observatories are now increasingly producing discoveries that are reshaping understanding of the universe and positioning the continent as a driver of frontier astronomical research.

In previous years, MeerKAT has revealed enormous radio structures and contributed to global pulsar timing campaigns. It has also participated in very long baseline interferometry networks, linking with telescopes worldwide to produce high-resolution images of distant cosmic sources, demonstrating the role of African facilities in global science collaboration.

MeerKAT’s integration into global transient-detection networks enables rapid follow-up of time-sensitive phenomena, such as fast radio bursts and supernovae. Researchers have already used the array to localise repeating fast radio bursts and explore other aspects of the time-domain universe, showing that African-led facilities can contribute to the most dynamic frontiers of astrophysics.

South Africa’s Southern African Large Telescope, the largest single optical telescope in the southern hemisphere, has been in full science operations since 2011 near Sutherland in the Northern Cape. It combines a large collecting area with flexible spectrographs capable of rapid follow-up of transient sources.

SALT is now preparing to provide spectroscopic follow-up for discoveries from the Vera C. Rubin Observatory, whose Legacy Survey of Space and Time will repeatedly scan the southern sky for millions of transient events.

The telescope can quickly classify and measure the distance or physical properties of these events, exploding stars, neutron star mergers, and flaring black holes, making it a high-impact partner for Rubin’s time-domain programme.

According to project scientists, this integration establishes African telescopes as essential nodes in global time-domain astronomy networks.

The trend is pan-African. The Ghana Radio Astronomy Observatory, converted from a 32-metre satellite dish into a scientific radio telescope, has begun producing observations, including spectral-line detections of methanol masers and successful pulsar timing. It is also linked with global observatories through Very Long Baseline Interferometry, which allows widely separated telescopes to operate as a single instrument with extremely high precision.

Ghana’s facility now serves as West Africa’s first operational node in the African VLBI Network, a continent-wide initiative spanning Kenya, Zambia, Botswana, Namibia, and Madagascar, enhancing Africa’s ability to contribute to precision radio astronomy.

These projects reflect decades of investment in infrastructure and human capital, beginning to yield scientific results and career pathways for local researchers. According to SARAO, its human capital development programme has trained hundreds of African engineers, astronomers, and data scientists, many of whom are now leading frontier research projects.

Partnerships with international institutions are reinforcing the growth of scientific skills across the continent.

In September 2024, the Square Kilometre Array Observatory signed memoranda of understanding with SARAO and the African Astronomical Society to collaborate on human capital development programmes that provide training for students and scientists across Africa.

SKAO Director-General Prof. Philip Diamond said “these partnerships aim to broaden opportunities in STEM fields and foster the next generation of African researchers.”

Smaller initiatives are also expanding participation. Kenyan universities, Namibian institutes, and other countries are deploying low-cost radio arrays and educational observatories that provide hands-on training while generating usable astronomical data.