Science & Technology

A Mysterious Signal Looked Like a Sign of Alien Technology – Here’s What the Investigation Revealed

Abstract Astrophysics Alien Signal Concept

In December final yr, the media reported an intriguing signal we at the Breakthrough Listen undertaking present in our radio telescope knowledge. Dubbed BLC1, the sign didn’t seem like the end result of any recognizable astrophysical exercise or any acquainted Earth-based interference.

The difficulty was, we weren’t prepared to debate it. While you’re looking for indicators of extraterrestrial life, you wish to be very cautious about getting it proper earlier than you make any bulletins. Final yr we had solely simply began secondary verification exams, and there have been too many unanswered questions.

Right now we’re able to report that BLC1 is, sadly, not a sign from clever life past Earth. Moderately, it’s radio interference that intently mimics the sort of sign we’ve been in search of. Our outcomes are reported in two papers in Nature Astronomy.

The story of BLC1 begins in April 2019, when Andrew Zic, who at the time was a PhD pupil at the College of Sydney, started observing the close by star Proxima Centauri with a number of telescopes to seek for flare exercise. At 4.22 gentle years away, Proxima Centauri is our nearest stellar neighbor, however it’s too faint to see with the bare eye.

Flares from stars are bursts of power and scorching plasma which will influence (and certain destroy) the environment of any planets of their path. Although the Solar produces flares, they don’t seem to be robust or frequent sufficient to disrupt life on Earth. Understanding how and when a star flares teaches us a lot about whether or not these planets may be appropriate for all times.

The Parkes radio telescope in Australia. Credit score: CSIRO

Proxima Centauri hosts an Earth-sized exoplanet known as Proxima Centauri b, and Andrew’s observations advised the planet is buffeted by fierce “space weather.” Whereas unhealthy area climate doesn’t rule out life current in the Proxima Centauri system, it does imply the planet’s floor is prone to be inhospitable.

Nonetheless, as our nearest neighbor, Proxima Centauri b stays a compelling goal for the seek for extraterrestrial intelligence (or SETI). Proxima Centauri is one of the solely stars we might doubtlessly ever go to in our lifetime.

At the velocity of gentle, a two-way journey would take 8.4 gentle years. We will’t ship a spaceship that quick, however there may be hope that a tiny camera on a light sail might attain there in 50 years and beam again photos.

As a result of of this, we joined forces with Andrew Zic and his collaborators, and used CSIRO’s Parkes telescope (also called Murriyang in the Wiradjuri language) to run SETI observations in parallel with the flare exercise search.

The BLC1 sign. Every panel in the plot is an commentary towards Proxima Centauri (‘on supply’), or towards a reference supply (‘off supply’). BLC1 is the yellow drifting line, and is simply current when the telescope is pointed at Proxima Centauri. Credit score: Smith et al., Nature Astronomy

We thought looking these observations could be a wonderful undertaking for a summer season pupil. In 2020, Shane Smith, an undergraduate pupil from Hillsdale School in Michigan, United States, joined the Berkeley SETI Analysis Expertise for Undergraduates program and commenced sifting via the knowledge. Towards the finish of his undertaking, BLC1 popped out.

The Breakthrough Pay attention staff rapidly grew to become intrigued by BLC1. Nonetheless, the burden of proof to assert a detection of life past Earth is exceedingly excessive, so we don’t let ourselves get too excited till we’ve utilized each take a look at we will suppose of. The evaluation of BLC1 was spearheaded by Sofia Sheikh, at the time a PhD pupil at Penn State, who ran an exhaustive set of exams, many of which had been new.

There was a lot of proof pointing towards BLC1 being a real signal of extraterrestrial know-how (or “technosignature”). BLC1 has many traits we anticipate from a technosignature:

However, Sofia’s evaluation led us to conclude BLC1 is almost definitely radio interference from proper right here on Earth. Sofia was in a position to present this by looking throughout the complete frequency vary of the Parkes receiver and discovering “lookalike” alerts, whose traits are mathematically associated to BLC1.

In contrast to BLC1, the lookalikes do seem in off-source observations. As such, BLC1 is responsible by affiliation of being radio interference.

We don’t know precisely the place BLC1 was coming from, or why it wasn’t detected in off-source observations like the lookalike alerts. Our greatest guess is that BLC1 and the lookalikes are generated by a course of known as intermodulation, the place two frequencies combine collectively to create new interference.

In the event you’ve listened to blues or rock guitar, you might be most likely conversant in intermodulation. When a guitar amp is intentionally overdriven (while you flip it as much as 11), intermodulation provides a pleasant-sounding distortion to the clear guitar sign. So BLC1 is – maybe – simply an disagreeable distortion from a machine with an overdriven radio frequency amplifier.

Regardless of what precipitated BLC1, it was not the technosignature we had been in search of. It did, nonetheless, make for a wonderful case examine, and confirmed that our detection pipelines are working and choosing up uncommon alerts.

Proxima Centauri is just one of many tons of of billions of stars in the Milky Approach. To look all of them, we have to maintain our momentum, to proceed to enhance our instruments and verification exams, and to coach the subsequent technology of astronomers, like Shane and Sofia, who can proceed the search with the subsequent technology of telescopes.

Written by Danny C Worth, Senior analysis fellow, Curtin College.

This text was first printed in The Conversation.The Conversation


“Evaluation of the Breakthrough Pay attention sign of curiosity blc1 with a technosignature verification framework” by Sofia Z. Sheikh, Shane Smith, Danny C. Worth, David DeBoer, Brian C. Lacki, Daniel J. Czech, Steve Croft, Vishal Gajjar, Howard Isaacson, Matt Lebofsky, David H. E. MacMahon, Cherry Ng, Karen I. Perez, Andrew P. V. Siemion, Claire Isabel Webb, Andrew Zic, Jamie Drew and S. Pete Worden, 25 October 2021, Nature Astronomy.
DOI: 10.1038/s41550-021-01508-8

“A radio technosignature search in direction of Proxima Centauri leading to a sign of curiosity” by Shane Smith, Danny C. Worth, Sofia Z. Sheikh, Daniel J. Czech, Steve Croft, David DeBoer, Vishal Gajjar, Howard Isaacson, Brian C. Lacki, Matt Lebofsky, David H. E. MacMahon, Cherry Ng, Karen I. Perez, Andrew P. V. Siemion, Claire Isabel Webb, Jamie Drew, S. Pete Worden and Andrew Zic, 25 October 2021, Nature Astronomy.
DOI: 10.1038/s41550-021-01479-w
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