It is probably not extraterrestrials. Nevertheless, a radio signal that seems to come from our neighboring star Proxima Centauri is puzzling researchers.
They still exist, the good news – right? Scientists have received a radio signal at the Australian Parkes Observatory, whose origin is unknown so far. The British newspaper “The Guardian” recently reported on this, and a corresponding publication by the researchers is to follow.
The radio signal seems to come from our neighboring star Proxima Centauri.
The radio signal has a frequency of approximately 982 megahertz. It appears to be coming from the direction of Proxima Centauri. Proxima Centauri, in the southern constellation of Centaur, is a red dwarf star and our nearest stellar neighbor. Its distance to Earth is only 4.2 light-years. A slight frequency shift suggests that the source of the signal would match a planet orbiting Proxima Centauri.
In fact, at least one such planet is known to orbit our neighboring star: Proxima Centauri b. This is a rocky planet located in the habitable zone around its star – the zone where there could be liquid water on the planet’s surface.
No natural causes for radio signal found so far
982 megahertz, which is not a frequency typically used by man-made antennas, spacecraft or satellites. Moreover, the frequency shift – the way the signal looks – suggests that it is not coming from Earth, but from space. The direction also fits: the signal seems to come from our neighboring star and not from nowhere. The scientists have not yet been able to find a natural cause, such as an outburst of the star Proxima Centauri or another astrophysical phenomenon.
The most promising track for the search for extraterrestrial life?
So it’s no wonder that the radio signal has been named “BLC1,” for “Breakthrough Listen Candidate 1.” It is the first candidate of the Breakthrough Listen project. This is a project that has been searching for possible signals of extraterrestrial life since 2016, with the help of the Parkes Telescope in Australia, among others. Now, four years later, there is the very first potential signal, BLC1.
The Wow Signal, a Microwave and BLC1
The “potential” should be taken seriously, however, because BLC1 is far from being an indication of extraterrestrial life. A look into history shows quickly how all other mysterious signals from space have fared so far. On the one hand, there is the story with the microwave: For years, the Parkes telescope in Australia – the telescope with which BLC1 was discovered – received mysterious signals for which no one was able to find an explanation. Eventually it turned out that they were caused by the microwave oven in the observatory’s kitchen. By the way, the microwave could be excluded as the cause of BLC1.
Or the Wow signal: This strong radio signal from the direction of the constellation Sagittarius, received in 1977, caused astrophysicist Jerry Ehman to circle it on the printout and decorate it with a “Wow!”. To this day, there is only speculation about its origin.
Waiting for the repeat
As exciting as BLC1 may be, it could be that the case of the Wow signal will be repeated. After all, the problem in 1977 as well as today is that both signals are unique so far. BLC1 was observed over a thirty-hour period back in early 2019, but not since. In science, however, once is not once. Whether BLC1 turns out to be a one-time mystery, a previously unknown spurious signal, or a truly spectacular discovery remains to be seen.