The search for extraterrestrial intelligence (SETI) took an intriguing turn in 2019. Researchers studying Proxima Centauri using the Parkes Radio Telescope encountered a radio wave burst that initially seemed like interference.
However, a year later, Yuri Milner’s Breakthrough Listen identified an anomaly in the data. NASA filmmaker and science educator Simon Holland reignited interest in the signal, which is now known as Breakthrough Listen Candidate 1 (BLC-1).
“One Of the Most Intriguing Signals Seen to Date”
The signal presents several fascinating characteristics. Operating at 983 MHz, BLC-1 is a narrowband signal with a narrow electromagnetic spectrum. This stood out from typical radio telescope captures, which Holland describes as “the giant buzz of everything in the Universe.”
Researchers identified a Doppler shift while tracking the signal. Over two hours of observation, the signal’s frequency demonstrated consistent changes, hinting at the possibility of it orbiting a distant star. The researchers speculated that this could be Proxima Centauri, which is approximately 4.2 light-years from Earth.
Breakthrough Listen’s comprehensive investigation involved scanning Proxima Centauri’s star system across a wide range of frequencies. The scan produced four million hits, which the researchers progressively filtered down. After multiple screening processes, they were left with 5,160 technosignature candidates.
Dr Andrew Siemion from Breakthrough Listen describes BLC-1 as “undoubtedly one of the most intriguing signals we’ve seen to date.”
The Potential for a Monumental Scientific Breakthrough
However, skepticism remains. Analysis suggests the signal could originate from local data interference. Researchers have identified that the signal’s frequencies align closely with common clock oscillator frequencies used in digital electronics. This indicates a human technological source rather than an extraterrestrial one.
The analysis isn’t over yet, though. Research into the signal continues. A verified technosignature would represent a monumental scientific breakthrough, aligning with Yuri Milner’s vision of humanity embracing a mission to explore the Universe. He outlines his reasoning for this mission in his short book, Eureka Manifesto (2021).
About Breakthrough Listen
Breakthrough Listen is the world’s biggest research project examining the Universe for advanced life. It makes use of the largest and most advanced telescopes on the planet, searching for technosignatures like BLC-1.
Aside from the Parkes Telescope, these include the Green Bank Telescope, which is the world’s largest steerable radio telescope, and the South African MeerKAT array.
Breakthrough Listen also enjoys partnerships with:
- The Jodrell Bank Observatory, which houses the 76-meter Lovell Telescope
- The Five-Hundred-Meter Aperture Spherical Telescope (FAST)
- Cherenkov telescopes like VERITAS and the Murchison Widefield array
- The Vera Rubin Observatory
- The Sardinia Radio Telescope (SRT)
The initiative is scanning hundreds of nearby stars and casting a net over millions more stars that wait further afield. The entire Milky Way and galaxies beyond are undergoing analysis.
Breakthrough Listen makes the data it collects accessible to scientists all over the world. Making data public allows non-astronomers who have technical expertise in areas like signal processing, big data analytics, and deep learning to draw insights from the information. As Yuri Milner notes in Eureka Manifesto, we should all be able to contribute to a shared knowledge pool if we are to advance our understanding of the Universe.
Moving forward, Breakthrough Listen will continue to examine technosignature candidates. Perhaps, amid the haystack, the researchers will find a needle that reveals a message from an alien species.
Yuri Milner’s Other Projects
Breakthrough Listen is one of the Breakthrough Initiatives that Giving Pledge signatory Yuri Milner co-launched. He is also one of the minds behind the inspiring competition for young people, the Breakthrough Junior Challenge, and the science award that celebrates scientists as heroes, the Breakthrough Prize.