The Five-hundred-meter Aperture Spherical Telescope (FAST), located in China, is currently the world’s largest and most sophisticated radio observatory. While its primary purpose is to conduct large-scale neutral hydrogen surveys (the most common element in the Universe), study pulsars, and detect Fast Radio Bursts (FRBs), scientists have planned to use the array in the Search for Extraterrestrial Intelligence (SETI). Integral to this field of study is the search for technosignatures, signs of technological activity that indicate the presence of an advanced civilization.
While many potential technosignatures have been proposed since the first surveys began in the 1960s, radio transmissions are still considered the most likely and remain the most studied. In a recent survey, an international team of SETI researchers conducted a targeted search of 33 exoplanet systems using a new method they call the “MBCM blind search mode.” While the team detected two “special signals” using this mode, they dismissed the idea that they were transmissions from an advanced species. Nevertheless, their survey demonstrated the effectiveness of this new blind mode and could lead to plausible candidate signals in the future.
Fast Radio Bursts (FRBs) are among the most mysterious astronomical phenomena facing astronomers today. While hundreds of bursts have been detected since the first-ever recorded detection of an FRB in 2007 – the Lorimer Burst – astronomers are still unsure what causes them. Even more mysterious, some have occasionally been found to be repeating in nature, which has fueled speculation that they may not be natural in origin (i.e., possible alien transmissions?). Astronomers are naturally very excited whenever a repeating FRB is found, as it gives them the chance to examine them closer.
In a recent survey, an international team of scientists used three major telescopes worldwide to study a repeating FRB (known as FRB 190520) that was first observed in 2019. According to their observations, this particular FRB is not just a repeating source from a compact object but a persistent one that emits low-level bursts of radio waves between larger ones. These findings raise new questions about the nature of these mysterious objects and how they can be used as tools to probe the space between stars and galaxies.