The Square Kilometre Array radio telescope will become the most sensitive in history. This opens unprecedented opportunities for the search for extraterrestrial intelligence. It will be able to detect not only deliberate signals, but also incidental radio emission that accompanies any technological activity.
Unprecedented Sensitivity
The antennas of the next-generation Square Kilometre Array, or SKA, which is set to become the most sensitive radio telescope in history, are being deployed on two continents at once — in Australia and Africa. The array is currently going through a multi-year phase of construction and commissioning.
The new calculations are striking. Dr. Chenoa Tremblay and her colleagues calculated how sensitive this instrument will be in the search for extraterrestrial technologies. One hour of observations will make it possible to detect emission equivalent to a modern terrestrial mobile network near an exoplanet four light-years away. By comparison, today’s instruments would spend years searching for a signal of the same power, with no guarantee of success.
The enormous sky coverage makes it possible to detect not a narrow beam, but a broad background of emission. This refers to incidental noise, without which no technological activity exists — from mobile communications to radars.
Parallel Data Processing
Obtaining observing time on world-class telescopes is extremely difficult, so SETI teams rarely get direct access to such instruments. Researchers have found a workaround: they plan to use data that SKA will collect for other scientific tasks, such as observations of supernovae or bright radio galaxies.
Radio data can easily be duplicated without harming the primary observations. The team will run its own processing stream, which will not interfere with the array’s main scientific tasks. The results obtained will be cross-checked against large catalogs such as Gaia in order to assess the most promising sources.
The bottleneck remains computing power. Radio receivers collect a colossal amount of data that requires immediate analysis. Because long-term storage is expensive, potentially interesting signals are sometimes discarded too early.
Two Tools Against Earthly Noise
Ground-based radio astronomy is constantly accompanied by interference from terrestrial sources. An aircraft flying over the Australian outback can create a signal that is difficult to distinguish from an interstellar one. The SKA team intends to end this confusion using two main tools.
The first is artificial intelligence algorithms. They will be trained to filter out human radio-frequency interference by studying the subtle differences between terrestrial and hypothetical extraterrestrial signals. The second tool is the method of very-long-baseline radio interferometry. Receivers placed far apart across the surface of the planet help determine the parallax of a source. For terrestrial interference, this shift will be noticeable; for a signal from another planetary system, it will be reduced almost to zero.
As Universe Today reports, the combination of these methods still has to prove its operational effectiveness. Scientists do not guarantee that the array will find an extraterrestrial signal. However, even a negative result in such a large-scale experiment would be a major scientific argument. And if progress only requires copying data and processing it on distributed computing resources, this is truly a no-lose strategy.
