BLC1, the Signal from Proxima
A radio telescope pointed at our nearest star picked up a narrow signal that seemed to come from there and nowhere else.
What was reported
On 29 April 2019, the Parkes radio telescope was observing Proxima Centauri, the closest star to the Sun, for Breakthrough Listen, a project that searches for signs of technology elsewhere. Its data held a narrow signal at around 982 MHz that drifted slowly in frequency and seemed to appear only when the telescope pointed at the star.
It was spotted in the data in 2020 and named BLC1, Breakthrough Listen Candidate 1. News of it leaked before the analysis was finished, causing a stir.
Explanations offered
Detailed analysis published in 2021 found that BLC1 was almost certainly interference from human technology on Earth. The team found many similar signals at related frequencies, produced when signals from electronic equipment mix, and the timing that made it look like it came from Proxima was a coincidence. It's now a textbook example of how such signals are checked.
- When
- 29 April 2019
- Where
- Parkes Observatory, New South Wales, Australia
- Witnesses
- Breakthrough Listen astronomers
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.