The mystery of the repetitive radio signals hitting Earth

The Earth’s magnetic field protects it from the continuous interactions coming from deep space, in the form of cosmic rays. This regular bombardment is made up of radio and microwave signals emitted by distant stars, black holes and other celestial bodies. But there is an intergalactic light signal that is puzzling scientists and their measuring instruments.

These are ultra-strong and ultra-bright radio signals, known as rapid radio waves (FRB). They last only a few milliseconds and are believed to originate billions of light-years away. But what is most disconcerting is that its precise source is still unknown.

The new results (announced on January 9 in two articles in the journal Nature, and at the 233rd meeting of the American Astronomical Society in Seattle) show 13 new detections of these FRB signals, Which has increased the known population by 20 percent.

Its origin is an enigma for scientists

The discovery team analyzed observations from the Canada Hydrogen Intensity Mapping Experiment (CHIME), a new advanced radio telescope in the Okanagan Valley in British Columbia.

Radio broadcasts are so intense that CHIME was not even fully operational when it made the new detections. The 13 Frbs were detected over the course of a few weeks in July and August 2018, and the last of its six known flashes was observed in late October.

Frbs are as enigmatic as they are spectacular. The emissions, only a few milliseconds long, release the energy equivalent of 100 years from our Sun.

And, if there are powerful emissions coming from deep space, why are Frbs so mysterious?

Since they were first discovered by astronomers in 2007, only about 60 have been observed. But, now, those numbers are growing fast.

Two sources, still unknown, have been detected from which these cosmic rays come. The first repeater, known as FRB 180814.J0422 + 73, is about 1.5 billion light-years from Earth, astronomers determined. It is twice as close as the other repeater, FRB 121102, which is known to have fired dozens of bursts in recent years.

What is the explanation for these flashes?

Although their provenance is still unknown, scientists believe they can rule out some origins: these repetitive signals flashed from the same spot six times over the course of several months.

According to the authors of the study, this delayed repetition rules out cataclysmic events, such as supernovae, as the probable source of repeated bursts, as explosions of an exploding star would be expected to occur only once.

Astronomers have offered a number of possible explanations for explosions, some of them natural, such as the fusion of neutron stars; nor can it be ruled out that they come from advanced alien civilizations.

But let’s not get excited. The phenomenon most likely has a natural explanation.

In addition, new discoveries by the CHIME team suggest that Frbs are probably much more common than current technology can reflect. In other words, they probably have a natural origin that human technology is simply not yet able to detect.



The CHIME/FRB Collaboration. A second source of repeating fast radio bursts. Nature (2019).
The CHIME/FRB Collaboration. Observations of fast radio bursts at frequencies down to 400 megahertz. Nature (2019).

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