5 minute read
MeerKAT: driving South African excellence in radio astronomy
BY DR FERNANDO CAMILO (SARAO)
The 2018 inauguration of the 64-dish MeerKAT radio telescope, built and operated by the South African Radio Astronomy Observatory (SARAO) in the Northern Cape province, signalled a step-change in radio astronomy.
A now-iconic radio image of the Milky Way’s galactic centre, unveiled at the inauguration, demonstrated not only MeerKAT’s superb scientific capability, but also South Africa’s success in establishing itself as a leader in the field through the planning, design and construction of the facility. A stunning later version of that first MeerKAT image is shown on the right.
The MeerKAT survey that led to the 2018 galactic centre image has also transformed our scientific understanding of that chaotic and energetic region, which contains many phenomena that cannot be found in the more benign regions of the galaxy, such as our own solar neighbourhood.
MeerKAT’s first major discovery, published in Nature in 2019 and shown in the associated figures, was the 1400-light-year radio bubbles spanning the galactic centre – evidence of an explosive event in the heart of our galaxy millions of years ago. As well as new discoveries, MeerKAT gives us a much clearer and more detailed view of previously observed phenomena.
By mid-2025, more than 500 articles containing MeerKAT data have been published in the professional literature. Many of the published findings are groundbreaking, addressing key questions in modern astrophysics. These include the detection of tenuous hydrogen gas, probably falling into far-away galaxies from the posited surrounding ‘cosmic web’ and fuelling their star formation, and the detection of signals likely originating from gravitational waves expected to permeate the Universe, via monitoring the largest sample of pulsars – ultra-stable radio-emitting ‘celestial clocks’ – to the highest precision of any such existing pulsar timing array.
Unsurprisingly, MeerKAT is in great demand. The instrument is available to the worldwide community, and each year up to 200 teams, with leaders from at least 28 countries, submit observing proposals to the National Research Foundation’s South African Radio Astronomy Observatory (SARAO) that built, and now operates, the telescope. The requests typically surpass the available time by a factor of approximately three, and only the most compelling projects are awarded telescope time, selected by independent reviews on the basis of scientific excellence. SARAO has been able to grow the local astronomy community through strategic investments, ensuring significant South African participation on international MeerKAT science projects.
MeerKAT was funded by South Africa’s government through its Department of Science, Technology and Innovation, costing R3.2bn (€156m), with approximately three-quarters of the budget spent in South Africa. This took advantage of the relevant engineering excellence already available in the country, and in turn the project was a catalyst for the growth of companies in the sector. For instance, EMSS Antennas was later awarded a contract by the SKAO to build exquisitely sensitive radio receivers for the international SKA-Mid telescope, into which MeerKAT will be incorporated. As noted by the UK’sRoyal Astronomical Society in its 2023 Group Achievement Award: “The MeerKAT team has supported the development of science and technology in Africa and stress-tested technology for the Square Kilometre Array (SKA).” The excellence and flexibility of the MeerKAT design also encouraged and enabled investments by collaborators based in Australia, Germany, UK, USA, and Italy that have in turn made the telescope even more capable.
A key outcome of this investment has been SARAO’s capability to design and develop advanced technologies, resulting in products such as low-cost S3 cloud storage, peta-scale tape library storage, Earth observation data infrastructure, energy-efficient ruggedised compute solution, a self-contained fibre-based continuously operating cable measuring and time transfer reference system, and a sampler-packetiser for direct signal digitisation up to 6.4 GHz with 3 GHz bandwidth. As a result, SARAO has been awarded multiple contracts to deliver key astronomy sub-systems.
MeerKAT’s wider impact has been significant. An independent socio-economic study found that, over 10 years, approximately 23,000 job opportunities have been created, directly and indirectly, through radio astronomy investments linked to MeerKAT.
SARAO has also awarded close to 1,700 grants and bursaries in radio astronomy and related engineering disciplines, including technical and artisan training.
