Scaling Up the Search with MeerKAT
New work from Breakthrough Listen describes how an automated system at South Africa’s MeerKAT telescope is allowing the search for signs of technology beyond Earth to run alongside other astronomical observations, greatly increasing the amount of sky that can be searched.
Searching for intelligent life beyond Earth presents astronomers with a basic problem. The Universe is enormous, while telescope time is limited.
A comprehensive search for “technosignatures”, signals or other evidence that could reveal technology beyond Earth, therefore requires both sensitive telescopes and efficient ways of using them.
Recent work from Breakthrough Listen describes how this is being done at MeerKAT, an array of 64 radio dishes in South Africa.
Two searches at once
Breakthrough Listen uses a technique known as commensal observing. When MeerKAT points towards the sky for another astronomy project, a dedicated Breakthrough Listen computing system can analyse the incoming data at the same time.
The original observations continue as planned, while Breakthrough Listen searches selected targets within MeerKAT’s field of view for possible technosignatures.
A preprint released in July 2026 describes the system and its performance in detail. Known as BLUSE, for Breakthrough Listen User Supplied Equipment, it receives data from MeerKAT and processes the huge stream of information produced by the telescope.
Since 2022, the system has processed data from coherent beams synthesised on more than 1.2 million individual pointings, including repeat observations.
This figure does not mean that 1.2 million different stars have been searched, since some targets have been observed more than once. It does, however, demonstrate the scale that commensal observing can achieve.
Searching for unusual signals
One possible technosignature is an unusually narrow radio signal. Human technology can produce signals concentrated into frequency ranges much narrower than those usually associated with natural astronomical sources.
Of course, detecting a narrow signal does not mean finding extraterrestrial technology. Radio telescopes encounter large numbers of signals produced by technology here on Earth, including communications systems and satellites. Distinguishing these sources of interference from anything genuinely interesting is a major part of the search.
MeerKAT provides another advantage. Because its 64 dishes work together as an interferometer, Breakthrough Listen can combine their signals to create narrow, sensitive beams directed towards targets within the telescope’s wider field of view.
The new MeerKAT system paper does not report a detection of extraterrestrial technology. Its significance lies in showing how the search can be conducted on a much larger scale without requiring an equivalent amount of dedicated telescope time.
More than a search for technology
The same observations can also produce valuable astronomy.
Recent Breakthrough Listen work towards the centre of the Milky Way, using the Green Bank Telescope, identified an intriguing signal consistent with a possible millisecond pulsar rotating once every 8.19 milliseconds.
The candidate has not yet been confirmed and follow-up observations are continuing. If confirmed, and if it lies sufficiently close to the supermassive black hole at the centre of our Galaxy, such a pulsar could provide astronomers with a valuable way to study gravity in an extreme environment.
This is one example of how the instruments and techniques developed for technosignature searches can contribute to astronomy more broadly.
Building a bigger search
There are hundreds of billions of stars in the Milky Way. We do not know whether technological life exists elsewhere, how common it might be, or what form detectable technology might take.
That means the search needs to cover as much ground as possible.
Commensal observing offers an efficient way to do this. Rather than requiring a telescope to stop its normal programme for every technosignature search, Breakthrough Listen can operate alongside other science.
There has still been no confirmed detection of a technosignature. But every improvement in sensitivity, observing time and sky coverage allows researchers to explore more of the enormous range of possibilities.
At MeerKAT, that search can now continue while one of the world’s leading radio telescopes goes about its everyday scientific work.