Abstract

This paper shows why radio signal Blc1 could be from extra-terrestrial life on an exoplanet or exomoon other than the exoplanet Proxima Centauri b, which is the most popular extraterrestrial theory for the origin of the signal. The paper suggests that the signal could be from somewhere else in the Alpha Centauri star system., and argues that this would be a better extra-terrestrial theory.

The radio signal BLC1 was first reported in 2020. The media widely reported that it came from the exoplanet Proxima Centauri b. However, the signal could have come from within a 16 arcminute circle of Proxima Centauri b. This means that it could have come from far beyond Proxima Centauri b, or from anywhere in the vicinity of the star system it is part of, Alpha Centauri. The Alpha Centauri star system iis a triple star system, and id the closest star system to our own. It consists of the Sun-like stars Alpha Centauri A and Alpha Centauri B, which together form the binary star Alpha Centauri AB, as well as the closest star to the Sun, the red dwarf star Proxima Centauri.

Because of their similarities to the Sun in terms of spectral types, star type, age and probable stability of the orbits, it has been suggested that Alpha Centauri A and Alpha Centauri B could hold one of the best possibilities for harbouring extraterrestrial life. In contrast, a paper released in 2020 reported the detection of "a bright, long-duration optical flare accompanied by a series of intense, coherent radio bursts from Proxima Centauri. This suggests that, even if it has a magnetic field, Proxima Centauri b may not be habitable.

The Doppler shift in the signal is the opposite of what would be expected from the Earth's spin, in that the signal increases in frequency rather than decreases. It would, however, be what would be expected from a free-floating transmitter or from a transmitter on an exomoon.

An exoplanet candidate called Candidate 1 was discovered in the habitable zone of Alpha Centauri A in 2021. This exoplanet candidate may have an exomoon which would also be in the habitable zone and may harbour an extraterrestrial civilization. Such an exomoon could be the source of BLC1. This theory would fit well with the fact that the signal is the opposite of what would be expected of a signal from a planet but is what would be expected of a signal from a moon.

It could also be the case that the signal originates from another exoplanet or exomoon orbiting Alpha Centauri A or Alpha Centauri B or the binary star Alpha Centauri AB.

It has been argued that the Copernican Principle would mean that it is extremely unlikely that there would be an exoplanet like Earth and a civilization like our own in the nearest star system to the Sun. I think that the opposite would be true, however; if Earth is not special it would be unsurprising if an exoplanet like Earth and a civilization like our own were to exist in the closest star system to the Sun.

This theory may not be a very good theory and is highly speculative, but I think that it is at least a better theory than the theory that the signal originated on Proxima Centauri b. This is because this theory, unlike the theory that BLC1 originated on Proxima Centauri b, does not have any evidence against it.

I would urge governments to therefore consider funding telescopes that would be sensitive enough to detect exoplanets and exomoons orbiting Apha Centauri A or Alpha Centauri B or both of them.