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Breakthrough Listen: SETI Data Release

On Monday I was talking about the rise of open access scientific journals, using the European Space Agency’s Acta Futura as just one example. The phenomenal arXiv service, not itself a journal but a repository for preprints of upcoming papers, is already well known in these pages. Now we have the largest public release of SETI data in the history of the field, a heartening follow-through on a trend that broadens the audience for scientific research.

Breakthrough Listen is presenting two publications in the scientific literature (available as full text, citation below) describing the results of three years of radio and optical observations, along with the availability of a petabyte of data from its work at the Green Bank instrument in West Virginia and the Parkes Radio Telescope in Australia. This covers a sample of 1327 nearby stars (within 160 light years from Earth) and builds on the team’s results on 692 stars as presented in 2017.

No signs of extraterrestrial civilizations turn up in the analysis, says Parkes project scientist Danny Price, who emphasizes that the search will continue:

“This data release is a tremendous milestone for the Breakthrough Listen team. We scoured thousands of hours of observations of nearby stars, across billions of frequency channels. We found no evidence of artificial signals from beyond Earth, but this doesn’t mean there isn’t intelligent life out there: we may just not have looked in the right place yet, or peered deep enough to detect faint signals.”

Image: The Green Bank site in West Virginia, where Breakthrough Listen observations continue. Credit: NRAO/AUI.

There are reasons why making such data public benefits the SETI effort. Both within the public and the astronomical community, those interested can now download the results of these observations and examine them independently. Those with programming skills may well develop algorithms for the detection of signals and filtering out of background noise that improve on the current model. And there may be information within the datasets that will prove useful in the investigation of unrelated astrophysical phenomena.

The existing tools developed by the Breakthrough Listen science team at the Berkeley SETI Research Center (BSRC) include both radio frequency searches as well as optical scans and algorithms designed to flag unexplained astrophysical phenomena. Go to this UC-Berkeley page for the overview, including the two just released papers. Likewise available to the public are software tools used in the analysis such as blimpy (for loading raw format data files), and turboSETI (for running Doppler drift searches). The datasets are examined in the analysis paper by Dr. Price and made available at the Breakthrough Listen Open Data Archive and via BSRC (more search options available at the latter).

For those wanting to get into data crunching themselves, the second paper (lead author Matt Lebofsky at Berkeley) goes into the intricacies of the current analysis, the tools used, the data formats and the archival systems now in play. “While we have been making smaller subsets of data public before in varying forms and contexts,” says Lebofsky, “we are excited and proud to offer this first cohesive collection along with an instruction manual, so everybody can dig in and help us search. And we’re just getting started – there’s much more to come!”

Considering the complexities involved in creating a search ‘pipeline’ that can scan through billions of radio channels, the more eyes on search algorithms and filtering techniques, the better. Thus far the detected signals have come from human technologies, with the Breakthrough Listen team filtering for narrow-band signals showing a Doppler drift, meaning they change in frequency with time because of their motion with respect to the telescope.

A second filter in the pipeline removes signals that do not appear to originate from a fixed point on the sky. The application of both techniques reduces millions of signals down to a comparative few, all of which have been examined and found to be human-generated frequency interference. From the Price paper, which notes that in its search for narrowband signals showing Doppler drift, 51 million hits emerged, with 6154 that cleared the automated filtering process, leading to a final round of manual inspection and cross-referencing against known sources of interference:

…these observations constitute the most comprehensive survey for radio evidence of advanced life around nearby stars ever undertaken, improving on the results of Enriquez et al. (2017) in both sensitivity and number of stars. Together with other recent work from the resurgent SETI community, we are beginning to put rigorous and clearly defined limits on the behavior of advanced life in the universe. We note that significant additional observational and theoretical work remains to be done before we are able to make general statements about the prevalence of technologically capable species.

Be aware that the archive also includes data from Breakthrough Listen observations of the first repeating fast radio burst ever detected, FRB 121102, as well as scans of the ‘Oumuamua object, along with optical data from the Automated Planet Finder at Lick Observatory. The search of nearby stars continues while also being expanded into the galactic disk at Parkes, and a one-million star sample with the MeerKAT telescope in South Africa is forthcoming.

The papers are Price et al., “The Breakthrough Listen Search for Intelligent Life: Observations of 1327 Nearby Stars over 1.1-3.4 GHz,” submitted to The Astrophysical Journal (preprint) and Lebofsky et al., “The Breakthrough Listen Search for Intelligent Life: Public Data, Formats, Reduction and Archiving,” submitted to Publications of the Astronomical Society of the Pacific (preprint).

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{ 22 comments… add one }
  • Robin Datta June 19, 2019, 16:07

    With unintelligible signals, cryptographic techniques may translate them into intelligibility by humans. Perhaps the NSA and similar agencies in other countries could make a useful contribution.

  • Thomas W. Hair June 19, 2019, 22:01

    Abiogenesis is a tough nut to crack. We can now start to find these special places where the organic chemistry that made us can take place via exoplanet methods and long stare campaigns with radio telescopes, but that does not mean we are are not special (if not unique). Until we understand precisely how life arose on earth from basic elements this is needle in a hay stack stuff…but you never know, so keep on looking.

    • Bruce D. Mayfield June 20, 2019, 12:40

      Some think that it (abiogenesis) is an impossibly tough nut to crack.

      Some used to avoid the origin of the universe question by reasoning that the universe never had a beginning. That Steady State Theory died out after it was discovered that the universe is expanding from the Big Bang.

      In common observation we always find that life has come from earlier life. What if Life itself is the condition that has always existed?

  • Steve Muise June 20, 2019, 11:44

    Is this database suitable for searching for twice-sent signals as described by Messershmitt and detailed in https://arxiv.org/abs/1305.4684 ?

    • wsguerin June 20, 2019, 13:19

      Steve,

      I’m looking forward to the next month’s bedtime reading! Tx for the link.

  • ljk June 20, 2019, 16:46

    How much longer will radio dominate SETI as it has for decades now? There are other methods of signaling across interstellar distances, many of them far more efficient and sophisticated – especially in terms of keeping information intact and not being mistaken for natural phenomenon.

    Here are some examples:

    http://www.coseti.org/lemarch1.htm

    Technosignatures are a step in the right direction, though of course it means we have to hope and assume some ETI are into Dyson Shells and similar astroengineering projects.

    What if the whole Milky Way galaxy were already a Kardashev Type 3 civilization? Would we recognize it? Think carefully before answering.

    • David M Ocame June 24, 2019, 12:51

      The answer is simple. It will dominate until others start using the tech you describe. The problem is that radio detection is the simplest, and most sensitive, method we have, at present. But, nothing is stopping anyone, such as yourself, from developing what’s needed to do other searches. Go for it!

  • Laintal June 20, 2019, 22:15

    I wounder what impact Elon’s Startrain will have in this area.

    Best to keep the Far side of the moon as a Radio reserve for the future

    • ljk June 21, 2019, 9:19

      Yes, but when will that happen? We have not sent humans back to the Moon since 1972 and I have my reservations that this current NASA goal of 2024 will slip and slip badly. China and maybe Russia will pick up the slack, but that will not be for a decade or more. None of these plans entail a farside lunar base of any kind any time soon.

      Humanity only just put the first functioning probe on the lunar farside since we started sending vessels to the Moon in 1958.

      There are other ways and methods to search for (and communicate with) ETI that do not require our entire civilization and planet being blocked off to remove interference. Better and more sophisticated ways at that.

      Perhaps it is time we started making a much better and cleaner break with radio when it comes to SETI. We already have a fairly good idea that alien civilizations are not blaring across the galaxy in radio frequencies on a regular basis, at least not in our neck of the cosmic woods.

      Not saying we cannot or should not conduct radio SETI any more, but since this is now the 21st Century and the majority of original SETI pioneers who favored it so much to the point that they deliberately excluded other methods (just ask Dr. Stuart Kingsley regarding Optical SETI) for decades are either gone or essentially retired, it is time to match our technology, knowledge, and mindset with our current era.

  • DCM June 22, 2019, 15:11

    Maybe the nearest intelligent life lives where planets are relatively nearby each other and, having attained a technology combining some 1950s level accomplishments with some 1890s level. They might reach planetary neighbors without radio, sending messages by flashing brilliant lights and sending small messenger craft carrying types and handwritten reports with black&white photos.

  • Harry R Ray June 24, 2019, 10:10

    A few interesting thoughts. First, The search for extra-terrestrial intelligence has been abbreviated to SETI, but the search for extraterrestrial life has NOT been abbreviated to SETL. I wonder why? This is a lead-in to my next “interesting thought. It has been well over a week since NEAR concluded its first observational run. ESO stated that raw image data would be made available to the scientific community “as soon as possible”. There has not been ANY indication of this already happening. Could it be that there was something so “interesting” in the unprocessed image that it is being checked to see if it is an artifact before the image is made public. Finally, it is just four weeks to the 50’th anniversary of the Apollo 11 moon landing. This is my “wildest dreams” scenario as to how that day will go. In the wee hours of the morning ESO will reveal an image of a 3 Earth radius planet orbiting Alpha Centauri A on the inner edge of the star’s “conservative” habitable zone with a spectra that indicates unimpeachable evidence of the presence of water on the planet. Then, at noon, Eastern Daylight Time, NASA holds an impromptu unplanned news conference regarding the methane “superspike ” on Mars observed by Curiosity last weekend. After many days of re-analysing the data, NASA announces two things. First, it has concluded that there was sufficient methane to accurately determine the isotope ratio for the first time. Second, preliminary analysis indicates that this isotope ratio is consistent with methane generated from biological processes. In the same press conference, NASA also announces that a very careful re-analysis of the Viking One labeled release experiment has led to the conclusion that those results now lean heavily towards the presence of microbial life on Mars. Finally, many years in the future, after the presence of life has been confirmed on Alpha Centauri Ab and microbial life has been brought back from Mars to Earth and a determination has been made that it ORIGINATED on Mars and not on Earth, a new holiday has been decreed worldwide that henceforth, July 20 shall be observed as Origins Day in honor of the Apollo 11 moon landing, the Viking One Mars landing, and the two epochal scientific announcements also made on that day!

    • David M Ocame June 24, 2019, 12:53

      Please try and maintain a scientific frame of reference. Your “widest dreams” should be reserved for ufology.

      • Thomas W. Hair June 24, 2019, 16:01

        David M, that’s what reading too much bad science fiction will do to you.

    • Alex Tolley June 24, 2019, 14:03

      Origins Day

      I like the idea. But how about calling it “New Genesis” or “Genesis II” day? With the Pope’s blessing, it should override any fundamentalist objections to the use of the term. ;)

      • Harry R Ray June 25, 2019, 10:01

        “New Genesis Day” is absolutely out, because New Genesis is the homeworld of the DC comics’ New Gods. “Genesis II Day” sounds confusing because it implies a second creation that came after the first one. And by the way, the moniker “SETL” has already been used to define the mathematical “language” of sets. Too bad astrobiologists didn’t coin it first.

  • Harry R Ray June 28, 2019, 10:02

    A hardly ever talked about type of ETI communication would be a mathematical “message” generated by several mega-lightsail type objects transiting a star. The main reason for this is the cost relative to the cost of sending the SAME message via other means(i.e. microwave or laser transmission). However, recent papers by Hippke and others point out the problems with degradation of these types of signals over very long timescales. So, the following paper REALLY piqued my interest: ArXiv: 1906.11268. “The random Transiter – EPIC 249706694/HD 139139.” by S. Rappaport et al. KEY QUOTE FROM THE ABSTRACT: “The unusual aspect of these dips…is that they exibit no periodicity, and their arrival times could just as well have been produced by a random number generator.” My question would be: Could the randomness of this pattern be some kind of encryption that could be DECODED, revealing some kind of message?

    • Harry R Ray June 30, 2019, 14:20

      Curiouser and curiouser! All but two of the dips are at 200 parts per million, implying objects roughly 1.5 Earth radii if they were all solid. The other two dips imply possibly solid objects with almost exactly 3 Earth radii, also possibly implying TWO of the more common objects transiting the primary star at exactly the same time with ingresses and egresses ALSO occurring at the exact same time.

  • Mike Serfas July 1, 2019, 6:21

    I just saw a news item about self-torque of light: https://phys.org/news/2019-06-property.html They think that they can “modulate the orbital angular momentum of light the same way frequency is modulated in communications”. I don’t know whether you could use the existing data to look for this information or would need new instruments.

  • ljk September 3, 2019, 16:10

    Mysterious radio bursts from space may soon have an explanation

    Seth Shostak

    September 3, 2019

    http://www.msn.com/en-us/news/technology/mysterious-radio-bursts-from-space-may-soon-have-an-explanation/ar-AAGKAyg?ocid=ientp

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