Astronomers researching extraterrestrial life have discovered an intriguing radio signal that appears to come from Proxima Centauri, the star closest to our Solar System. At least two planets orbit around that star. One of them is probably rocky and about 17% larger than our Earth.
The Breakthrough Listen team, the research project that seeks to detect extraterrestrial life signs, picked up the signal with the Parkes telescope in Australia last year during a survey in April and May.
So far, all “extraterrestrial” signals could be explained by, for example, a passing satellite or ground-based equipment, but for the time being, the researchers have not yet been able to identify the source of the sound – which was given the name BLC-1.
However, the direction of the radio signal and a change in its frequency are consistent with the movement of a planet. This gives the scientists a little hope that BLC-1 has an extraterrestrial origin, although it is still much more likely that the sound originates from Earth.
The radio signal appears to be coming from Proxima Centauri’s direction, a red dwarf 4.2 light-years from Earth. At least two planets orbit the star: a gas giant and a suspected rocky planet about 17 percent larger than Earth.
The latter planet, named Proxima b, orbits the star in eleven days and is located in the so-called “habitable” zone, where liquid water is possible. However, this does not mean that there is water on Proxima b.
Computer models from NASA also showed that the planet’s atmosphere is likely to be severely affected by the intense radiation and solar flares of Proxima Centauri. In addition, Proxima Centauri and Proxima b have a synchronous rotation, making it permanently day on one side and permanently night on the other side.
Since the first sighting last year, the sound has not been seen again, a scientist involved in the investigation told The Guardian. “It’s the first serious candidate since the ‘Wow!’ Signal,” said the source, who wished to remain anonymous as a further report on the investigation is under development.
The “Wow!” Signal was a narrowband radio signal picked up by a telescope in Ohio in 1977 and got its name from astronomer Jerry Ehman who said “Wow!” next to the data written. To date, no acceptable terrestrial explanation has been found for that radio signal.
Lewis Dartnell, an astrobiologist and professor of science communication at the University of Westminster is skeptical. “The odds that this is not an artificial signal from Proxima Centauri seem overwhelming,” he replied. It, under 400 billion stars, absolutely pushes the boundaries of rationality.