April 25, 2024

The Radio Signal From Proxima Centauri Came From Earth After All

Turns out we were hearing ourselves! Earth can be a loud location when listening to stars.
Called “blc1” (Breakthrough Listen Candidate 1), the signal appeared to originate from the direction of Proxima Centauri, the closest neighbouring star to the Sun. Now that the analysis is total, research study reveals blc1 is in fact “RFI”– radio frequency disturbance– and not an interstellar signal.
While its not aliens– or “Proxima Centaurians” as lead author on the signal analysis Dr. Sofia Sheikh whimsically refers to them– new methods for carrying out radio-based SETI (Search for Extraterrestrial Intelligence) have actually been developed by evaluating blc1; further developing our ability to identify future potential ET signals from our own world.
Simulation of Proxima Centauri b, Rocky World in the Proxima Centauri System– SpaceEngine by author

A Needle in a Hay Stack

BLC1– Breakthrough Listens First “Signal of Interest”– with Dr. Sofia Sheikh
From April 29th to May 4th of 2019, the Murriyang telescope targeted ProxCen (Proxima Centauri) to keep an eye on solar flare activity. ProxCen is a red dwarf star located 4.2 light years from Earth.
The software filters signals with specific patterns that may show something of interest. After filtering 4 MILLION detection “hits”, one really peculiar signal remained necessitating further scrutiny.
Narrowband (technological) signal strikes found in variety of the Muriyang telescope. Kept in mind are the registered cellular, satellite, and broadband internet transmitters which can be eliminated instantly as Earth-based signals. c. Smith et al 2021 Figure 2
Some can be eliminated straight away as Earth-based signals such as cell-phones and internet transmissions at known frequencies. Another inform is whether the signal still appears when the telescope is pointed “off-source”. If the signal stays when the telescope is moved away from the target, the source of the signal is more most likely from Earth and not from the target.
The signals are then looked for “drift.” Wander is the modification in a signals frequency in time. Since it is orbiting around a remote star, the hope is that this change in frequency is caused by the source of the signal moving relative to Earth– for example. Its motion develops a Doppler result similar to the modification in pitch of a passing ambulance. This filtering. One signal stayed– a signal likewise so narrow in frequency, it couldnt be produced by any known natural phenomenon. A prospect! Blc1! * Cue X-Files whistle. *.
A “Waterfall Plot” that shows the existence of blc1. The vertical access is the detection with time from leading to bottom. Circled around in purple is the identified signal. Circled around in yellow are the gaps where the telescope was pointed and off-source to calibration sources. The slope of the signal line is the signals drift gradually which could show a signal source in relative motion to Earth. c. Smith et al 2021 Figure 4.
Who Said That?
” For me, its the enormity of the challenge that draws me to SETI as a research study field. In addition, due to the fact that theres a lot research still to do in SETI, it allows me to be creative in my work and juggle numerous tasks at a time, which I actually enjoy!”- Dr. Sofia Sheikh.
Is blc1 Proxima Centaurians !? Dr. Sofia Sheikh, lead writer on the recently released signal analysis, wanted to find out.
As a special discovery, blc1 required new approach for screening which was established by Sheikh and her team. The first tests dismiss the most local of possibilities– the Murriyang facility itself. Diagnostics of the telescope on the days of recording were evaluated. The team also validated the scope didnt simply identify local RFI from the surrounding complex. Was blc1 seen just when the telescope dish was pointed at a building corresponding with ProxCens direction? Reobservations of ProxCen were likewise made which yielded no signal.
The signal could still be from Earth however in motion relative to the telescope- originating from a car, satellite, or plane. Neither did the drift match what would be anticipated if the signal were moving relative to Earth within the ProxCen system itself.
What else could trigger the drift if not a moving object? Wander can likewise be developed by an electronic device created to alter frequency like tuning a knob on a dial. To the telescope, such a gadget may appear to be moving even while fixed to the Earths surface area.
A tasting of the RFI set that blc1 ultimately belongs too. The drift slope shape is similar across all these signals that appeared on-source as well as off-source suggesting they are all part of a set of RFI most likely belonging to a single source or created by the interference of different sources. c. Sheikh et al 2021.
As a last action in the analysis, the group revisited the data to see if other signals similar to blc1 might be discovered. 60 signals, across a series of frequencies and all with incredibly comparable drift to blc1, were found in the information. Each signal appeared to the telescope at the same time as blc1. Why were these signals at first filtered out? Due to the fact that they appeared off-target therefore were identified to be RFI. Blc1s resemblance to these other signals shows it is most likely among a set of signals that are all RFI. And, as a result of the way these signals blended and connected, blc1 appeared localized in area towards ProxCen although it wasnt. Furthermore, the spacing in frequency between the signals is in multiples of 2Mhz, a common spacing created by recognized Earth-technology– a clock oscillator. So, since blc1 so carefully matches this set of signals, and the set can be recognized as RFI, blc1 itself can also be ruled out as RFI. No calls from ET …( yet).
Listening to the Future.
” As Freeman Dyson once said “Every look for alien civilizations should be prepared to offer fascinating results even when no aliens are found.” Our “fascinating outcomes” are frequently innovative astronomy in their own right!”- Dr. Sofia Sheikh.
The actual source of blc1, and its companion set of RFI, has yet to be figured out. While not aliens, working to verify the signal helps us much better detect aliens in the future. No signal has actually ever been ruled out as RFI by comparing it to other RFI before. Because no signal like blc1 had actually ever been seen prior to, thats! This whole procedure was the outcome of the most sensitive search of ET radio signals ever conducted on a single target star. The outcomes also demonstrate that software tools like turboSETI were doing their job. The software application discovered that 1 in 4 million signal that MIGHT be extraterrestrial triggering the flurry of analysis.

2 Confirmed Planets at Proxima Centauri– Video by Fraser Cain of Universe Today.
Breakthrough Listen is expanding operation to consist of MeerKAT, a telescope variety in South Africa that can observe targets with Murriyang all at once. The benefit of simultaneous observation is that a true interstellar signal will reveal up in both telescopes while RFI would be special to one– a technique utilized by some past SETI efforts such as Project Phoenix.
Offered the systems proximity to Earth, it stays a target of interest for future observation. We might likewise just GO to Proxima Centauri to find out! Another part of the Breakthrough effort is Breakthrough Starshot, a future mission to send a mini probe all the method to our neighbouring star.
Until then, we keep listening to the stars.
” It would be extremely, really cool if life, technology, and even intelligence were features of our galaxy more broadly, and not just restricted to our “pale blue dot” of Earth. However well just have to see what the data holds in the future!”– Dr. Sofia Sheikh.
Function Image: The 3 telescopes at CSIROs Murriyang Observatory. The primary meal is 64 meters large and among the biggest moving meals worldwide. Credit: Red Empire Media/CSIRO.

More to Explore.
Advancement Initiatives Press Release.
BLC1– Breakthrough Listens First “Signal of Interest” (berkeley.edu) Press Summary.
BLC1– Breakthrough Listens very first “Signal of Interest”– YouTube.
Dr. Sofia Sheikh on Twitter (@SETI_Sheikh).
A radio technosignature search towards Proxima Centauri resulting in a signal-of-interest (Open Access Research Paper led by Shane Smith).
Analysis of the Breakthrough Listen signal of interest blc1 with a technosignature confirmation structure (Open Access Research Paper led by Dr. Sofia Z. Sheikh).
Day 1: Breakthrough Discuss 2021: Alpha Centauri System: A Beckoning Neighbor– YouTube Interview video with Dr. Sofia Sheikh hosted by Berkeley SETI Research.
A Very Interesting Radio Signal was Just Detected Coming from Proxima Centauri– Universe Today.
Project Phoenix|SETI Institute.
About MeerKAT– SARAO.
Murriyang: Parkes radio telescope receives Indigenous name– CSIROscope.
Breakthrough Initiatives.
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If the signal stays when the telescope is moved away from the target, the source of the signal is more likely from Earth and not from the target.
One signal stayed– a signal also so narrow in frequency, it could not be developed by any known natural phenomenon. The slope of the signal line is the signals drift over time which might show a signal source in relative movement to Earth. Blc1s similarity to these other signals suggests it is most likely one of a set of signals that are all RFI. Since blc1 so carefully matches this set of signals, and the set can be determined as RFI, blc1 itself can likewise be ruled out as RFI.

Huge thanks to Dr. Sofia Sheikh for contributing remarks to this piece!