Breakthrough Listen uses radio telescopes like the Parkes Telescope in Australia or the Green Bank Observatory in West Virginia. These instruments regularly record what looks like signals from space, but are actually the result of local interference from Earth. In April and May 2019, the team caught something different – a narrow beam of transmission around 980MHz that lasted 30 hours. The signal, called BLC1, seemed to have shifted in such a way that it could have come from a planet orbiting a star.
The team is still preparing work that the scientific community could study, but there are several reasons for excitement here. Proxima Centauri is the star closest to our solar system, and in 2016, researchers announced the discovery of an Earth-like exoplanet orbiting the habitable zone. Later, astronomers spotted another, larger planet further in the solar system. So, theoretically, it is possible that there is life on one of those planets, especially the one in the inhabited zone.
However, it is still too early to begin celebrating the discovery of extraterrestrial life. BLC1 is candidate a signal to be analyzed, and if we are realistic, it is doubtful that intelligent aliens live in the next solar system. The Milky Way galaxy is estimated to have 300 million exoplanets and is nearly 14 billion years old. To find another intelligent species that coexists with us in just a few light years would be utterly unbelievable. If the aforementioned aliens are using radio frequency technology at the same time as us, it is an even greater coincidence.
This is not the first signal that could be interpreted as an artificial origin. The famous “Wow” signal discovered by SETI researchers in 1977 is another example. That one didn’t fail, but BLC1 could be the first serious candidate in decades. If that’s not it, well, there are a lot more stars out there. The only way we will find them is to keep looking.