For the first time, scientists have detected a radio signal from outer space that repeats at regular intervals. The discovery was made by researchers studying data from the radio telescope used by the Canadian Hydrogen Intensity Mapping Experiment (CHIME)
The series of “fast radio bursts” – short pulses of radio waves that come from across the universe – were detected about once an hour for four days and then stopped, only to start up again 12 days later.
This cycle repeated every 16.35 days for more than a year, according to a new paper about the research. The researchers observed its cycle for a total of 409 days and believed that it could be tied to the emitting object being locked in an orbit which lasts 16 days.
Its origin was located within a medium-sized spiral galaxy about 500 million light-years away, making it the closest FRB discovered to date. Fast radio bursts last only a few milliseconds, which makes it challenging to determine where they have come from accurately.
“The discovery of a 16.35-day periodicity in a repeating FRB source is an important clue to the nature of this object,” the scientists said in the paper.
However, they say that considering that FRBs are enormously powerful bursts of electromagnetic energy, they could be from a neutron star – although if this were the case, the star would be expected to wobble, and not display the same kind of smooth cycle.
The repeating pattern, reports Science X Network, “suggests the source could be a celestial body of some kind orbiting around a star or another body. In such a scenario, the signals would cease when the other body obstructs them.”
“But that still does not explain how a celestial body could be sending out such signals regularly,” Science X said. “Another possibility is that stellar winds might be alternately boosting or blocking signals from a body behind them. Or it could be that the source is a celestial body that is rotating.”
In 2017, Professor Avid Loeb, from the Harvard-Smithsonian Centre for Astrophysics in the US, proposed that FRBs could be leakage from planet-sized alien transmitters.
He said that rather than being designed for communication, they would more likely be used to propel giant space ships powered by light sails, which would bounce the beams off a massive reflective sheet to provide forward thrust.
This isn’t the first SETI story Loeb has waded into. In 2018, for instance, he suggested that the interstellar object ‘Oumuama might be an alien probe.
As of now, there is no evidence supporting the hypothesis that FRBs are connected to alien civilizations.