Scientists continue to unravel the mystery of strange radio bursts that were recorded from space in 2021. A repeating source of fast radio flares produced 1,863 flares in 82 hours, with a total observation duration of 91 hours. Scientists believe the signals come from collapsed stars – but some have suggested they might be evidence of extraterrestrial civilisations.
Fast radio bursts have been a mystery to astronomers since they were first discovered 15 years ago in archival data dating back to 2001: an incredibly powerful burst of radio emission that lasts only an instant. Since then, many similar outbreaks have been found. Only a few of them were repetitive – this helped scientists at least track them to host galaxies.
Scientists cannot explain the nature of all FRBs. According to them, none of the objects of the Universe known today is capable of independently generating such strange signals in a natural way. However, the source, which was one and a half billion light years from us and received the designation FRB 20201124A, prompted a theory.
Chinese scientists from the School of Astronomy and Space Science, Nanjing University, led by Professor Fayin Wang, proposed an explanation based on specific data related to the behavior of FRB 20201124A: that the signals are sent by a magnetar.
They have found that the strength of the magnetic field and the density of particles around it fluctuate. But so far, scientists cannot find the reason why the number of outbreaks begins to increase dramatically. There is speculation that this companion may be a hot blue Be-type star, which is often found in companions of neutron stars.
But the FRB 20201124A was found in a galaxy very similar to the Milky Way. There is not much star formation here, so there should not be a stellar boom near the unusual FRB.
FRB 20201124A is not the only FRB source found in a galaxy that is relatively devoid of star formation. The growing number of spikes suggests that there is some important piece of information that scientists are missing. it is not yet known to what extent the idea of a magnetar and a Be star corresponds to other FRBs.
Magnetar or Aliens?
For the first time and purely by chance, astronomer Duncan Lorimer from West Virginia University in Morgantown drew attention to strange outbreaks in 2007.
Five years later, the scientific community recognized that FRBs are not a hardware glitch, not some kind of interference, but real signals. In 2012, astronomers discovered four more, then many more. Signals came from all directions, from different places – very and not very distant. Then sources were discovered that sent radiation in ordered series, either turning on for several days, then turning off. FRBs began to register first in tens, then in hundreds, and now in thousands. The starry sky turned out to be literally filled with bursts of a mysterious nature. In addition to the Chinese, signals are caught by numerous other largest radio telescopes Australian Square Kilometer Array Pathfinder (ASKAP), Very Large Array, European Very Long Baseline Interferometry Network.
Some radio bursts behave, to put it mildly, strangely: they change frequency, starting a “transmission”, increase their power hundreds of times in a split second, send signals in different directions. Some are polarized, others are not. There are sources that “get in touch” only once, and then they seem to disappear, and those that “broadcast” regularly from one place.
All of them have tremendous power. It is enough for the signal to burst through billions of light-years of interstellar space.
Surprisingly, but before the advent of the Chinese hypothesis, many quite serious astronomers, perplexed and unable to figure it out, did not rule out that FRBs are of artificial origin. That is, they are products of the technological activity of some highly developed extraterrestrial civilizations. Once upon a time, the term “alien signals” was even coined for FRB.
For example, astrophysicists at the Harvard-Smithsonian Center for Astrophysics (Harvard-Smithsonian Center for Astrophysics), led by Avi Loeb (Avi Loeb) suggest artificial transmitters the size of our Earth or even more as sources of “fast radio bursts”“. Scientists believe that extraterrestrials move their starships, which are equipped with appropriate receivers, with short and powerful impulses.
After estimating the power of bursts, Loeb hypothesized that it should be enough to move spaceships weighing a million tons – 20 times heavier than the largest terrestrial ocean liner.
If so, the recent FRB activity is alarming. Either the aliens were worried about something, and they moved somewhere en masse, or the Universe became restless for an unknown to us reason.
A few years ago, Michael Hippke from the Institute for Data Analysis in Neukirchen-Vluyn, Germany and John Learned from the University of Hawaii in Manoa got a reason to suspect aliens in the FRB signal phenomenon. They found that fast bursts include high and low frequency radio waves.
All the signals caught by that time were subject to a single pattern – the delay time of low frequencies relative to high frequencies is a multiple of 187.5. What this means is also not yet clear but it looks intriguing.