The BLC1 signal from Proxima Centauri
The account
A radio signal from the star closest to the Sun would be the first transmission from cosmic neighbors.
What investigators found
After detailed analysis, researchers concluded in 2021 that the signal was interference from human equipment here on Earth.
The story
In 2019, the Parkes radio telescope in Australia was observing Proxima Centauri, the star closest to the Sun, for the Breakthrough Listen project when it recorded a very narrow radio signal, the kind nature rarely produces. It was named BLC1, "candidate 1."
The news leaked to the press in December 2020 and became a sensation. Scientists handled the case carefully and, in 2021, published their conclusion: the signal came from interference by electronic devices on Earth. Even so, BLC1 became an example of how the search for extraterrestrial life tests every lead with rigor.