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Pondering SETI Strategy

I try to keep my ear to the ground (rather than my eye to the sky) when it comes to SETI. What I mean is that there are enough scientists working SETI issues that it’s a challenge to know who is doing what. I try to track ongoing discussions even when, as at a conference, people keep ducking into and out of audibility. Hence the possibility of overlap in SETI efforts and, as Jason Wright points out in a discussion on his AstroWright site, the circulation of the same ideas without moving the ball forward.

This is hardly a new phenomenon, as a look back at my own grad school experience in a much different area reveals. I was a medievalist with an ear for language, and I was always struck by how compartmentalized we tended to be when discussing medieval linguistics. At that time, northern European tongues like Gothic, Old Icelandic, Anglo-Saxon and Old Saxon formed a scholarly thicket I happily wandered through, but in the absence of computerized resources back in the day, the Gothic scholars had a hard time keeping current with the Old Icelandic papers, and new work on the Anglo-Saxon alliterative line arrived mostly by rumor picked up at coffee time. These Germanic languages were definitely not talking to each other.

Bear in mind, that was a small, tightly focused community of scholars working on very esoteric stuff, and even then it was hard to keep up with the various strands of the tapestry. SETI’s problems are of a different sort. Here, the work is scattered across numerous journals and in particular, a wide range of disciplines — you might, for example, find a SETI paper in a journal of anthropology, well outside an astrophysicist’s normal range of sampling. Wright also makes the good point that SETI suffers from a lack of a curriculum, though he himself is working to change that at Penn State. What SETI does have going for it that my grad experience didn’t have is the proliferation of online resources, even if many are walled away like medieval monks behind monastic firewalls. Online access remains an emphatically moving target.

A useful paper that is helping to stabilize things is available on the arXiv site under the title “Furthering a Comprehensive SETI Bibliography.” It’s the background on the discovery process and categorization issues of an ongoing bibliographic update called SETI.news, which Centauri Dreams readers will want to know about. The newsletter began in 2016 as a way of gathering academic articles and occasional blog posts with high relevance to the SETI effort and I’m finding it indispensable.

The combined July/August SETI.news mailing is here, thanks to the efforts of Wright and Macy Huston. I should also mention while we’re talking about resource gathering that a bibliographic effort useful to those of us following interstellar exploration is available through the Interstellar Research Group. The database is searchable; updates appear every weekday. The IRG’s remit is obviously broad in scope, ranging through everything from propulsion issues to astrobiology, unlike the highly focused SETI.news. But I think both will be of interest to the Centauri Dreams audience.

Image: The Very Large Array (VLA) is a collection of 27 radio antennas located at the NRAO site in Socorro, New Mexico, since early 2020 a participant in the hunt for technosignatures. Credit: Alex Savello/NRAO.

I don’t want to leave Wright’s interesting Strategies for SETI III: Advice post without mentioning his comments on the Fermi Paradox and the Drake Equation. He’s wondering whether we haven’t in some ways exhausted the discussion, quoting Kathryn Denning on the matter:

Thinking about that future [of contact with ETI] was itself an act of hope. Perhaps it still is. But I want to suggest something else here: that the best way to take that legacy forward is not to keep asking the same questions and elaborating on answers, the contours of which have long been established, and the details of which cannot be filled in until and unless a detection is confirmed. Perhaps this work is nearly done.

Have we driven the Fermi question into the ground? As per the earlier part of this post, it does seem that the discussion ranges around to the same issues without moving the ball forward, but then, a ball this theoretical is a hard thing to push down-field! The Drake Equation reliably gets an indignant rebuttal every now and then in my email from people who don’t realize that it is, as Wright points out, a heuristic tool that is designed to make us ponder the odds. So when someone writes me to point out that it is not possible to solve the equation, I think I’ll start quoting Wright’s comment:

[The Drake Equation is]…not a foundational equation like the Schrodinger equation from which one derives results, it’s more like a schematic map of the landscape to help orient yourself.

Schematic maps can be quite useful, and the Drake Equation has served its role. Everything in its place as we move forward. My own interest is more tightly focused on papers that can help with actual search efforts rather than theoretical ones, papers that, as Wright puts it, ‘stay close to the data.’ Which is not to underplay the sheer fascination of the topic, but only to say that the nuts and bolts have to be tightened and maintained, and a contribution like SETI.news is tangible and productive.


Comments on this entry are closed.

  • Byron Rogers September 21, 2021, 9:55

    The problem with the Drake equation is calling it an equation. Maybe call it the Drake Heuristic.

    • Ron S. September 21, 2021, 12:38

      It is an equation. That there are some who misunderstand its purpose and content is no reason to call it something else.

  • ljk September 21, 2021, 10:19

    Quoting from Jason Wright’s paper linked in this article, because the general public lumps all scientists together as experts on every subject under and over the Sun.

    As we see here, the experts themselves sometimes think they know everything about everything too, just because they are smart in one field of science. Stephen Hawking comes to mind here on this very subject, with his views on advanced ETI that sound a lot like the plot from the 1996 science fiction film Independence Day.

    “4. Engage experts

    “Lots of SETI papers written by physicists (and others) go way outside the authors’ training. There’s a particular tendency among physicists (and others) to feel like since we’re good at physics and physics is hard and everything is fundamentally physics, that we can just jump into a field we know little about and contribute.

    “Engaging experts in those fields will both help us not make mistakes and broaden the field by bringing them into it so they can see how they can contribute. It’s win win! And we should do it more.”

    Glad to see someone is finally making an online library of all those SETI and related papers. Or at least advocating for proper organization and access.

  • ljk September 21, 2021, 10:21

    Carl Sagan’s nice take on the Drake Equation from his famous Cosmos series:


    Done without flashy CGI to boot!

    • Henry Cordova September 21, 2021, 16:01

      Yo, Larry!

      Don’t you think its about time you resurrected your old SETIQuest journal? The field needs a serious, popular periodical we can use to keep up with disparate and scattered developments in the field. As it is, we are forced more and more into obscure backwaters spotted intermittently with highly speculative and overly technical monographs mostly provided by writers more interested in publishing on something new and exotic than in keeping the SETI community up to date.

      As the great SETI communicator, Chuck Berry, once remarked (in another context, of course);

      “I got no kick against modern jazz,
      as long as they don’t play it too damn fast,
      and lose the beauty and the melody,
      until it all sounds like a symphony.”

      • ljk September 22, 2021, 14:18

        Hi Henry! Yes, that is a good idea. I just need time and especially funding and support. If anyone is serious in helping me bring back an idea and a publication that had merit and should not have died off in the first place, let me know.

        I will also have to change the name to make it my own, but that is fine with me.


  • Michael Fidler September 21, 2021, 11:06

    One area that needs to be included in SETI research is possible locations in the solar system that may hold clues or evidence of past civilizations reaching here. This could be equipment or efforts to modify planets in our system that may of ended up at certain sites that have extremely long periods of stability. A prime example is long range observations from LUCY spacecraft in the Trojan asteroids near Jupiter. Launch next month, this spacecraft could find unusual objects that do not fit the normal model for asteroids or comets. Instead of looking at any ambiguity as just a fluke or deformity a concentrated effort should be made to investigate by both the spacecraft and telescopes such as JWST or the extremely large telescopes that are coming online in the next few years. We are spending large amounts of time and money on researching exoplanets and signals from space but the time exterrestrial civilizations have existed in our galaxy has been 12 billion years. They have had at least 3 to4 billion years to see an interesting planet in our solar system. The last 500 million years they would have seen intelligent life on earth. (Octopuses)

    Any AI exploration system would immediately identify our planet as well worth exploring and would probably ponder the impossible coincidence of total solar eclipses as a sign of earlier intervention by some unknown super civilization… ;-}

    • Alex Tolley September 21, 2021, 14:06

      I agree about looking more thoroughly. I personally think that increasing the number of probes is the way to go – make them small, cheap, and in large quantities. Task them with just doing basic exploration – cameras, and comms. Let them spread out and wander around the possible target-rich areas. Solar sails for propulsion and navigation to loiter and search for interesting targets would be my preferred solution. Onboard AI to make most of the navigation and control decisions, with occasional commands from Earth. Just as social insects use their numbers to do do efficient searches for food, so should our probes use similar algorithms on larger numbers of them to search regions. With mass manufacturing, the unit costs would be low, leaving primarily the launch costs as the major funding hurdle – something that may come down very steeply over the coming decades.

  • Ron S. September 21, 2021, 11:13

    “My own interest is more tightly focused on papers that can help with actual search efforts rather than theoretical ones, papers that, as Wright puts it, ‘stay close to the data.’”

    I feel the same, and strongly. Despite my keen interest in SETI and the potential importance (pro or con) of a detection, I rarely pay attention to the subject any more. There is too much running around in circles or attempting to fund ‘more of the same’ with no clearly beneficial direction.

    Even so I tip my hat to those active in the field who are trying, in some fashion, to make progress. Due to the technical challenge and scattershot approaches we are mostly limited to, I am not hopeful of results in the foreseeable future. Nor do I have any useful advice to offer to those working to gather more and better data, or to pursue alternative directions. Instead I find myself, as do many others, easily dismissing too many proposals, either due to wishful thinking or poorly thought through technical difficulties.

    Hope is not a strategy.

  • Yvan Dutil September 21, 2021, 12:58

    I would like to note that Stéphane Dumas did a simialr work for the same reasons.


  • ljk September 21, 2021, 13:07
  • Jim Benford September 21, 2021, 13:08

    I have argued on this site that a strategy of exploring for alien artifacts near Earth is a credible alternate approach relative to the existing listening-to-stars SETI strategy. Stars come very close to our solar system frequently. About two stars per 10,00 years come within 10 light years. An extraterrestrial civilization that passes nearby can see there is an ecosystem here, due to the out-of-equilibrium atmosphere. They could send interstellar probes to investigate. In precious essays here I’ve estimated how many probes could have come here from passing stars.

    And where could we find them now? The Moon and the Earth Trojans have the greatest probability of success. Close inspection of bodies in these regions, which may hold primordial remnants of our early solar system, yields concrete astronomical research. (The Jupiter Trojans are far less likely to be practical sites to observe the distant Earth.) I suggest additional resources devoted to examining our existing images of the Moon’s surface (from the LRO), the Earth Trojans and Earth co-orbitals, and for probe missions to the latter two. The Search for Extraterrestrial Artifacts (SETA) concept can be falsified: if we investigate these near-Earth objects and don’t find artifacts, the concept is disproven for this nearby region. I constructed a ratio of a Drake Equation for alien artifacts to the conventional Drake Equation, so that most terms cancel out. This ratio is a good way to debate the efficacy of SETI vs. SETA. The ratio is the product of two terms: One is the ratio of the time Lurkers could be present in the solar system to the length of time extraterrestrial (ET) civilizations transmit electromagnetic signals. The second term is the ratio of the respective ‘origin volumes’: the volume from which Lurkers can come (which is affected by the long-term passage of stars nearby) to the volume of transmitting civilizations. This Drake Equation logic argues for emphasis on artifact searches, a strategy of ET archaeology.

    I’m presenting these ideas at the opening session of the 7th Interstellar Symposium on Saturday.

    • Michael Fidler September 22, 2021, 6:43

      Yes, you are right we should look closer first and this may be the best place to look:

      Earth has two extra, hidden ‘moons’.

      First spied in the 1960s, the huge dust clouds have now been confirmed—and may affect plans for future space exploration.

      Earth’s moon may not be alone. After more than half a century of speculation and controversy, Hungarian astronomers and physicists say they have finally confirmed the existence of two Earth-orbiting “moons” entirely made of dust.
      As they describe in the Monthly Notices of the Royal Astronomical Society, the team managed to capture snapshots of the mysterious clouds lurking just 250,000 miles away, roughly the same distance as the moon.
      Researchers previously inferred the presence of multiple natural companions to Earth, but the dust clouds weren’t actually seen until 1961, when their namesake, Polish astronomer Kazimierz Kordylewski, got a glimpse. Even then, their presence was questioned.
      According to the new findings, each Kordylewski cloud is about 15 by 10 degrees wide, or equal to 30 by 20 lunar disks in the night sky. This translates to an area in space about 65,000 by 45,000 miles in actual size—nearly nine times wider than Earth.
      The clouds themselves are enormous, but the individual particles that comprise them are estimated to measure just a micrometer across. Sunlight reflecting off these particles makes them glow ever so slightly—just like the pyramid-shaped glow of the zodiacal light that results from dust scattered between the orbits of the planets.


      Kordylewski cloud.


      And this is how we can possibly find a spacecraft hidden in the Moons Trojan clouds or in the Earth Trojans and Earth co-orbitals;

      The Moon’s Tycho Crater Revealed in Intricate Details – Powerful New Radar Technology Reveals Secrets of the Solar System
      September 22, 2021

      These promising early results have gained support for the project from the scientific community, and in late September, the collaboration received $4.5 million in funding from the National Science Foundation to design ways for the project to expand (Mid-scale Research Infrastructure). -1 design award AST-2131866). “If we can attract full funding after those designs, we can build a system hundreds of times more powerful than the current one and use it to explore the solar system,” Beasley said. “Such a new system would open a window to the Universe, allowing us to see our neighboring planets and celestial bodies in a whole new way.”

      This technology has been years in the making, part of a research and development collaboration agreement between NRAO, GBO and RI&S. A future powerful radar system combined with the GBT’s aerial coverage will image objects in the Solar System with unprecedented detail and sensitivity. Expect even more exciting images this fall, as processing this early data with tens of billions of pixels of information is worth the wait.


    • Alex Tolley September 22, 2021, 13:52

      I have come around to being persuaded by your argument that we should definitely do more to look for probes in our system. It certainly seems to have a better score on Sheikh’s Nine Axes of Merit. Know that the LRO has cameras with 0.5m/pixel resolution so that if the Moon was fully imaged to that resolution rather than the 100m/pixel baseline mapping, we could apply machine learning techniques (or citizen science) to look for artifacts or possible anomalies on the Moon. That in turn might discover things of interest and have benefits in improving our ML techniques for technosignatures.

      I am reminded that in Clarke’s short story “The Sentinel” that the crystalline tetrahedron was sitting on a lunar hilltop, visible to the exploring astronauts. In the movie “2001: A Space Odyssey”, the artifact became a monolith that was buried below the surface and discovered by a magnetic survey. While I don’t think “deliberately buried” is likely, I could see that lunar dust might cover or obscure an artifact left long ago on the lunar surface and that more sophisticated means of surveying the surface at high resolution may be employed for such searches – while developing the tools for detecting and mining smaller metal meteorites for lunar industry.

  • Alex Tru September 21, 2021, 13:13

    Modern SETI is not science, it is mix of hobby and religion.
    Good new , that SETI activists begin to understand that Drake equation is not Holly Grail.

  • Alex Tolley September 21, 2021, 15:39

    Wright’s reference to the Sheikh paper: “Nine Axes of Merit for Technosignature Searches” strikes me as arguing for “looking for the technosignatures here under the streetlights rather than over there under the bushes”. She does acknowledge some bias in teh choice of axes and determination of values, however. Some issues like cost are clearly helped by piggy-backing. Finding a local probe would have a high rank on this approach, suggesting that just maybe we should search harder for such artifacts.

    She seems to devalue biosignatures because they are more ambiguous than technosignatures, yet they should score highly on ancillary benefits, even helping to narrow the search for technosignatures.

  • Henry Cordova September 21, 2021, 16:31

    SETI goes through fashions. It reminds me of how contemporaries view the cowboy hat.

    If you actually look at old photographs of real cowboys, no two hats are alike, but all of them are ugly. Probably, this is the result of the fact most cowboys were poor and couldn’t afford a decent hat. The only style that fit a common pattern was the Mexican Sombrero, which is probably the closest we can get to the original concept. After all, the purpose of a hat was to protect the rider from the weather, especially the sun..

    When Hollywood starting depicting cowboy hats, you started seeing what we now call the Stetson, much like the original sombrero, but with a bigger crown and an elliptical (as opposed to circular) brim. It came in two varieties, black for the bad guys, white for the good ones.

    By the 1950s, hats in Western movies started becoming more varied, much smaller, fitted to each individual, and so stylized that popular actors in horse operas usually insisted on wearing the same hat in different movies because it suited their characters. Remember Gabby Hays? Lee van Cleef in the Spaghetti westerns? Duke Wayne and Clint Eastwood?

    Recently, the hats have become larger again, more ornate, sculpted into extravagant shapes, decorated with feathers. Have you been to a rodeo lately, or checked out the latest C&W bands out of Nashville? Even the Mexican vaquero only celebrates his traditional Sombrero in his Mariachi band charro costume. The South-of-the-Border bracero now wears a cheap straw version of the basic North of the Rio Bravo 40 liter hat.

    SETI studies have gone through similar fashions. After all, we know even less about extraterrestrial civilizations than we do about 19th century cattleman’s headgear. And changes in how we write or think about extraterrestrials do not necessarily reflect advances in our thinking, as they do schools and factions amongst the thinkers.

  • Robin Datta September 21, 2021, 19:17

    We’ve put a bathtub-full of seawater through a sieve and found no fish. We’ve pondered with the Drake Equation how many fish there may be in the sea, and wondered with the Fermi Paradox why we haven’t seen one yet.

    Mebbe there ain’t no fish in this here sea, but was it Carl Sagan who said “Absence of evidence is not evidence of absence”?

    • Alex Tolley September 22, 2021, 13:36

      I have seen that analogy used before – but is it correct? Is it not more like casting a net into the sea in a few places and coming up with no catch, a very different proposition?

      The SETI scientists want more money to “inspect more bathtubs”, whilst a better plan might be to just keep throwing the nets out into the sea hoping that a school of fish will happen to win into it eventually.

    • ljk September 22, 2021, 14:11

      Actually it was Martin C. Rees who said that. It just seems like Carl Sagan said everything. :^) I was lucky enough to meet Rees in person once and he confirmed this quote. I asked him because it was the quote I used in my high school yearbook!


      And you are right that we have done so little searching via mainly just a few methods for less than an average human lifetime. With 400 billion star systems across 100,000 light years in our Milky Way galaxy alone (out of at least 2 TRILLION galaxies in the known Universe), it is the height of hubris and ignorance to think Earth is the only planet with life. This is what happens when one is stuck on a single rock for generations.


  • Gary Wilson September 21, 2021, 20:16

    The problem with the Drake equation has nothing to do with the equation itself. It has to do with the fact we have no real accurate values for any of the variables. Some of the variables are probably not even accurately knowable (I’m thinking of L, the length of time civilizations release detectable signs of their existence into space. After all some of them will be underway at any particular time with an unknowable future ahead of them). We are just at the beginning of characterizing exoplanets as far as type, frequency, number of rocky planets in the habitable zone (also a very fuzzy concept), number of habitable moons (and they’re not even accounted for in the equation) and so on and we have no other accurate values. Ok I guess we do know something about the rate of star formation in our galaxy. We’ve all just been born a thousand years or more too soon and have incredibly short life spans. There is nothing wrong with saying that the equation is a decent first stab at getting a handle on the number of civilizations in our galaxy with which we might communicate, but that we are still almost wholly ignorant about any of the important numbers involved. It’s a very good thing indeed that there are some rational thinkers and organizers involved in SETI or SETI-like projects. Outside the box thinking is great once you have some accurate data to work with but otherwise it can be deceptive, misleading and lead people down dead end paths. I’m really excited to learn of some of the online resources that have been mentioned here.

  • Alex Tru September 22, 2021, 1:59

    … we know even less about extraterrestrial civilizations…

    To be correct – we know NOTHING about extraterrestrial civilizations.

    • Henry Cordova September 22, 2021, 10:40

      Actually, that’s not strictly true.

      We actually know quite a bit about extraterrestrial civilizations. For starters, we know for a fact THEY ARE NOT IMPOSSIBLE because we are one! We may be the only one, but we are proof positive that their existence cannot be ruled out. A mechanism exists in nature that can generate civilized communities, and homo sapiens is the incontrovertible proof.

      We also know that if we detect an extraterrestrial civilization it will be technologically advanced, probably more so than we are. There may be many advanced cultures that we have no hope of detecting because they do not build spaceships or radio telescopes or leave astronomical evidence of their industrial activities. But if we ever do find one, it will be because they have engineering capabilities comparable to ours. So not only do we know ETI is possible, we also know a little bit about the level of technological development they have achieved.

      Although we have no proof of the existence of alien cultures, we know their potential existence violates no known physical laws, and we further know that the natural precursors of life are common and widespread in the cosmos. It is not unreasonable to expect other cultures than ours have evolved and exist out there in the cold and dark.
      Yes, its only circumstantial evidence, but its still can get you hanged.

      I personally am convinced that ETI is extremely rare in the universe, and I have written before on this forum about this (see my essay “Reality Check”). My opinions and my reasoning lead me to believe that there are, at most, a handful of extraterrestrial civilizations in our Galaxy at any one time. They are widely separated in both space and time and they may be so remote from our expectations and prejudices that we may not even be able to recognize each other as such if we do encounter one another. But they still cannot be ruled out.

      We need to keep looking, and yes, we need to keep speculating, because this is important. It matters. Its what makes US entitled to call ourselves a “civilization”. Prester John, El Dorado and far Cipangu all existed, although perhaps not in the way we expected them to be.

      • Ron S. September 22, 2021, 14:03

        “Actually, that’s not strictly true. We actually know quite a bit about extraterrestrial civilizations.”

        It is strictly true, and Alex is correct.


        Yes, but a non-zero probability of existence tells us nothing about them.

        “we are one!”

        We are not extraterrestrial.

        • Henry Coedova September 23, 2021, 9:00

          So what do you suggest, Ron.? That we do nothing about SETI. No research, no speculation, no philosophizing, no planning, no dreaming? Then what are YOU doing here?

          As for the comment that SETI has some of the characteristics of a religion, well that is absolutely right. That is what all science is ultimately about. We want to know what is unknown, what can possibly never be known. We want to understand what really matters and what is just white noise. After all, we’ve gotten lucky before , maybe we will again.

          However, unlike religion, the question of whether or not we are alone in the cosmos CAN be answered, using scientific methods that have worked on other problems. Just because this is a hard question, maybe an ultimately unsolvable one, does not mean it can’t possibly ever be solved. And it certainly doesn’t mean we shouldn’t be trying.

          Science spends its time attacking impossible problems. What are those lights in the sky? What causes disease? Is matter infinitely divisible, how does the sun generate its power? How is the genetic information transmitted? And we spend a lot of effort on issues of questionable utility, like the mating habits of tidepool invertebrates or whether or not the ancient Greeks appreciated the beauty of landscapes . And of course, there are many questions that will probably never be answered. But sometimes we get lucky, and sometimes we stumble accidentally on something beautiful, something totally unexpected and extremely useful.

          The biggest question of all, the meaning of it all, may ever elude us . But whether or not we are alone in the universe, whether life and intelligence are unique or an extreme accident, is related intimately to that ‘biggest question’. It would be irresponsible to just ignore it.

          • Ron S. September 23, 2021, 21:20

            What am I doing here? What a peculiar question! SETI is one item of many that Paul covers in CD. Further, I never said that I am uninterested in SETI, so I don’t understand why you would make that false claim. I am, in fact, very interested. My general perspective is summarized in an earlier comment in this thread. You must have missed it.

      • Alex Tolley September 22, 2021, 15:16

        As with your earlier comment on fashion in SETI, I do think that technology tends to drive our speculations. Each new tool we develop means that ETI could have that tool too, and so our searches evolve. If we do develop mind uploading, then I have no doubt that there will be more searches for Matrioshka brain technosignatures. If AGI is demonstrated, then machine civilizations will become a focus. If we discover an FTL signaling method, then our searches will look for those signals. And so on.

      • Alex Tru September 23, 2021, 2:50

        Henry, your comment is best prove that modern SETI is religion, but not science, in every your argument you are using word know instead of believe.
        To use word “know” in this content we have to have in our “detected ETI” database at least one example.
        Our own civilization is terrestrial , is only prove than in some specific time period (let say 100 years) there is at least one “radio” civilization in Universe.
        Single ETI detection will change this number to next state “there is at least two civilizations in specific time period in Universe”.
        Only after first detection we can use word “know” in relation to ETI, till this detection in best case we can use “suppose”, when in reality most SETI activist simply believe – only Sci-Fi fantasy here, I like Sci-Fi, but realizing well that it is not reality.

    • Michael Fidler September 23, 2021, 10:31

      I find it very hard to believe we are the only civilization at this time in our galaxy, Alex Tru. The reason, because we are the only planet with intelligent life in our solar system, yet we live on a planet that is exactly 400 times further from the sun then our moon and our moon is 400 times smaller then the sun. This is what gives us the beautiful total solar eclipse where the moon just blocks enough of the sun to see the Prominence and Corona for just a few minutes. No other planet or satellite eclipses have this happen and we are the closest planet to our sun that evens has a large satellite that can block the one half degree sun in our skies. No mystery here, there has to be millions if not billions of civilizations in our galaxy to account for us, little humans seeing such an unusual sight. A one and a billion chance…

      This is not RELIGION but mother nature at her best!

      • Alex Tru September 24, 2021, 2:11

        ETI – is not religion, it is hypothesis.
        Modern SETI became religion after some years of fruitless searches.
        Beliefs in some hypothesis – it is not knowledge.
        The only knowledge that SETI brought to us – is “Big silence” after more than 50 years of radio searches, I do not think that SETI somewhere recognize “Big silence” as scientific fact, so even this single fact is not recognized by SETI as knowledge (opposite SETI should stop it’s researches) :-)

        • Harold Shaw September 24, 2021, 11:31

          The “Big Silence” and “50 years of radio searches” is a reductive, straw man, meme argument. The only conclusion we can draw is there don’t appear to be any people spending massive amounts of energy on communicating. All we have done, and this may even be stretching, is eliminate the upper limit. That is an absurd, thoroughly unscientific reason to stop radio SETI experiments.

          • Alex Tolley September 24, 2021, 13:11

            Can we say that an active “Galactic Club” communicating via radio is now falsified?

            The original guess of 10,000 contemporaneous actively radio communicating civilizations in the galaxy is likely a gross overestimate. That doesn’t mean that there aren’t that number of civilizations, but they may be either using different technology to communicate, not communicate at all, or even maintain a low technological culture rather than a hi-tech one. There are other possibilities. However, we should consider that we are the only contemporary hi-tech civilization in our galaxy. That can be proved by negative remote search results, although a physical search in the distant future may be able to test this hypothesis.

            • Harold Shaw September 24, 2021, 14:54

              Above certain energy levels, distributions of transmitters, and recruiting motivations, yes. However, that doesn’t eliminate the value of completing the search for high energy signals. We have little or inconclusive evidence of Life spending resources on altruism. Imo, a null result would be good news.

          • Alex Tru September 26, 2021, 2:28

            … The “Big Silence” and “50 years of radio searches” is a reductive, straw man, meme argument. …

            On, this you notes, I can only answer – wow!
            On one side you seams to be big SETI supporter, on second side you so hardly despise SETI research results :-)
            Bad news – there are no other scientific results from SETI , only “Big silence” during long project’s period…
            Those results add no any knowledge about ETI – this was my point in the first comment.
            Every hypothesis and/or speculation that try to explain unpleasant facts – is not knowledge, till it has no experimental proves.
            You can like or dislike those facts, you can discredit and “humiliate” all facts related to SETI: “Big silence” after long fruitless searches period – Fermi paradox etc., etc. this cannot change reality.

    • Dave Moore September 23, 2021, 18:48

      This is not true, and we we are learning more all the time. For instance, we know that there is not a Kardashev III civilization in this galaxy as we would have detected it, we we know there is not a Kardashev II civilization within say 15 lightyears of us as we would have detected its IR signature by now.

      Every time we do a search and come up with nothing, we limit the possibilities. And if we limit the possibilities enough, the result becomes incompatible with certain assumptions. We close in on the truth.

      Every year our instruments and detection methods become better, and if we don’t find anything with our improved search then that tells us something.

      • Alex Tru September 24, 2021, 7:44

        There can be millions of ETI civilization, but none can match any purely anthropocentric Kardashev classification , that somehow applicable to our own civilization only , even for us it is not for sure that even homo sapience will follow futuristic Kardashev’s way :-)
        Funny that someone can accept Kardashev classification seriously (meanwhile it is classification of not existing objects), It is exactly same classification like building heraldic tree of all demons in Hell…
        Your arguments is the best proves that meanwhile we do not know anything about ETI.

      • Ron S. September 24, 2021, 9:07

        “we know that there is not a Kardashev III civilization in this galaxy as we would have detected it”

        We don’t know that. You are *assuming* that a K3 civ will exhibit a specific set of observable behaviors.

        Trimming the tree of possibilities is more difficult that it is for natural phenomena.

        • Michael Fidler September 24, 2021, 10:43

          Kardashev is old from 1964, before western mankind started to realize that there are limits. Alien civilizations are not going to be like feeding yeast, that it will keep increasing till it takes over the whole universe. I would think more along the lines of limited consumption only to do or get what is required, like in many eastern philosophies. They limit their contact with younger cultures to only what is required, so the younger culture can find their way. We are the grasshopper…

          • Michael Fidler September 25, 2021, 7:04

            Well, maybe I’m wrong!

            Two of the galaxies they searched in had some unusual activity.

            Chen and co-author Michael Garrett looked at results from the LOFAR Two-metre Sky Survey (LoTSS), which is gradually capturing the entire northern sky in radio. Chen says he and his co-author took a sample of LoTSS in a hunt for unusual radio, hoping to narrow in on a Type III civilization. But to understand what they were looking for, first we’ll break it down a little.

            Across the vast universe, the possibility of life forms varies dramatically from primitive bacteria-like microbes to hyper-advanced alien civilizations.

            The Kardashev scale, developed by astrophysicist Nikolai Kardashev in 1964, measures how far technologically advanced a hypothetical alien civilization is based on the amount of energy it consumes.

            The scale has three types of civilizations:

            Type I civilization, which uses the energy available to it on its planet
            Type II civilization, one that consumes as much power at the scale of its entire star system (meaning its host star and the other planets that orbit it)
            Type III civilization, the most advanced kind which can harness as much energy as the entire galaxy


            Searching for Kardashev Type III civilisations from high q-value sources in the LoTSS-DR1 value-added catalogue
            H Chen, M A Garrett
            Monthly Notices of the Royal Astronomical Society, Volume 507, Issue 3, November 2021, Pages 3761–3770, https://doi.org/10.1093/mnras/stab2207
            Published: 04 August 2021

            Abstract: Kardashev Type III civilisations have by definition energy requirements that are likely to generate strong excess emission in the mid-infrared (MIR) that is associated with the waste heat they generate. For those civilisations that capture starlight via Dyson sphere like constructions, the Optical to MIR flux ratio of the host galaxies is also expected to be unusually low. Since a wide range of galaxy types adhere to the infrared-radio correlation (IRC), galaxies hosting Type III civilisations should also strongly deviate from this relation. Radio data can therefore play a crucial role in breaking the degeneracy between the effects of dust obscuration in a galaxy and the signature of an energy-intensive civilisation. We have used the newly released LoTSS-DR1 value-added catalogue to create a sample of 16 367 z < 0.2 sources with radio and MIR flux densities, optical photometry and (photometric) redshifts. We calculated the IRC parameter q22 μm150 MHz = log(S150 MHz/ S22 μm ) and identified 21 sources with exceptionally high values of q22 μm150 MHz , an indication of MIR emission enhanced by a factor of ~10. Out of the 21 high q-value sources, 4 sources have very red MIR colours, and appear to have relatively low optical/MIR ratios. Two of the four sources are not well known in the literature, they are considered as potential hosts of Type III civilisations. These sources deserve further study and investigation. Finally, we note that extending our analysis to the full LoTSS survey area can place very strong constraints on the incidence of Type III civilisations in the Universe.


  • Wojciech Jacyk September 22, 2021, 3:13

    I do recall that there are ambiguous observation of stars and astrophysical phenomena that could indicate artificially induced activity or mega-engineering projects, however until we get better telescopes or actual interstellar probes they can’t be positively confirmed. We simply don’t have the technology yet to obtain answers for questions we seek.
    Perhaps the next three decades with advent of space based telescopes of new generation will give us a glimpse of what other worlds look, and hints of other future discoveries.
    For now much of the discussion seems to be like Greeks debating the shape of the globe or structure of the universe. Some answers are correct, but there is no way of knowing that they are.

    • Ron S. September 22, 2021, 14:05

      Ambiguous data are not evidence of aliens. You are creeping uncomfortably close to a god-of-the-gaps argument.

  • Antonio September 22, 2021, 10:14

    SETI has become boring to me. All listening and no talking. Meh.

    • ljk September 22, 2021, 14:14

      So fund some more efforts so we can find them. There aren’t nearly enough institutions and people searching for ETI as it is, despite what our entertainment media makes it look like.

      • Antonio September 23, 2021, 10:22

        Why would I fund something that bores me?

        • ljk September 24, 2021, 13:37

          I was giving you the opportunity to make SETI less boring, at least in your eyes, but ah well.

          • Antonio September 25, 2021, 11:15

            When I said it’s boring for lack of funding? I already said why it’s boring in my first post.

  • Robin Datta September 22, 2021, 18:54

    After they had just climbed down from the trees, how would our primate ancestors react to an alien visit? Could entire civilizations become insular like the North Sentinel Island? Or as has been suggested on Centauri Dreams might we be as ants to humans to a civilization a billion years old? How might the size (and shape?) of the mesh holes in the nets we cast affect the catch?

    • Gary Wilson September 23, 2021, 15:04

      Or how would we react now Robin? I tend to think that no matter how hard an alien race tried we would react badly. A combination of terror, and because we tend to assume threats we make a threat response in return (even if it is laughably weak to them). I’m thinking of The Day the Earth Stood Still. It’s dated now and I don’t think we would be dealing with somebody who looked remarkably human under his space suit but the response of humans looks very realistic. We evolved from apelike ancestors and I imagine we would share a similar response (fear, followed by bluffs of aggression and rage). Highly advanced aliens probably would understand this and avoid us. It’s much more likely we will find some kind of artifact eventually. It’s a peaceful way to expose us to an alien intelligence with no threat implied (unless we realize the artifact is a weapon of course) ala Jack McDevitt for example. No easy answers to how a meeting with an intelligent race would go.

  • Ross Turner September 23, 2021, 16:43

    I’ve often wondered if part of SETI strategy could be to look at UFO reports. I know I’m risking ridicule here, since much of UFO info is based on false or misleading claims and information, but every once in a while a report shows up that can’t be easily explained as either natural or man made. Anyway it could be a branch that seriously tries to investigate some of these events, along with looking further out, as it has always done. If an event was clear enough to be accurately viewed, and all natural/manmade causes eliminated, a discussion could be had about what that actually tells us, scientifically. In other words as well as using the traditional methods of looking at the solar system and beyond, maybe a closer look at the earth itself is warranted in terms of SETI strategy.

    • Paul Gilster September 24, 2021, 6:19

      Jason Wright at Penn State has a good article explaining why SETI doesn’t get involved with UFOs:


      • Michael Fidler September 24, 2021, 10:48

        Yes, they have their reputations to consider… cough, cough

        • ljk September 24, 2021, 15:37

          Interesting piece from The Guardian:


          We know it is not impossible to travel from one star to another, even for humanity in the near future. We just need to be really careful about what to expect. Sadly the decades of poor (and non) science, hoaxes, ignorance, cultural and social ridicule, the refusal of the professional community to actually help, and bad science fiction have muddied the waters. Hopefully we can start separating the wheat from the chaff properly now.

          • Alex Tolley September 24, 2021, 21:42

            Hopefully we can start separating the wheat from the chaff properly now.

            Why should anything change? Why is there any wheat to find?

            What annoyed me about that article was the propagating of the idea that the pentagon now takes this seriously and has acknowledged UAP – which is immediately translated as “it might be aliens”. As somebody has pointed out, these UAPs are always beyond the edge of identification and will continue to be so. Add in the vagaries of human behavior and you have a mess.

            More recently, I am reminded that the problem of drones grounding flights at Gatwick airport was so thinly locked down that there is now doubt that this happened at all! If so, then so much for professionals who could be relied upon to report what they saw properly.

            Just because the militaries have better equipment and training to use the equipment, the personnel are not necessarily better than the average person to interpret what they think they see. Astronomers seem better able to deal with transient events compared to the military – possibly because their training is better to do so.

            • Michael Fidler September 25, 2021, 7:30

              Well, Alex I saw something in 1968 that I knew when I saw it was not of this world thru my telescope. My wife and I saw something in 1983 thru my much larger telescope that has no plausible explanation. At that time I worked for the FAA as an Air Traffic controller and had a direct line to NORAD which they reported no satellite reentries at that time. A sheriff in northern Utah also reported it and it was published in a paper.

              Some 55 years of observing with many different telescopes and 4 years in the Air Force working in NORAD and 24 years as an FAA ATC. I have not seen anything similar to these objects we observed. Take it from me, there is more to it then you think. My IQ is suppose to be above 135 and you have seen my comments. I know how you feel because most of the UFO community and most reports are of limited value. Plus there seems to be a effort to cloud the issue with disinformation and hoaxes. I’m not trying to convince you but explain the problem, BECAUSE IT ONLY TAKES ONE REAL EXTERESTRIAL SPACECRAFT to be identified! How do you know with all the radio noise that they have not sent crafts here and are being cautioned by are militaristic tendencies. Their point may be play a game of hid and seek so the powers that be do not and the vast majority of people do not freak out and cause major disruption of our civilization. Remember we are the dumb naïve civilization with most of the world population having an IQ below 100, think about it…

              • Alex Tolley September 25, 2021, 12:09

                I have not seen anything similar to these objects we observed.

                Can you post a drawing of what you think you saw? If it is nondescript, why do you think it may be something extraterrestrial?

                Misinformation creates a lot of noise. Some decades ago, prior to smartphones and wireless internet access, a friend told me about a sighting over Denver. The objects were huge, rectangular[?], and seen by hundreds of people. Now, this sounded rather convincing and difficult to dismiss. After I got home, I tried to find a newspaper report of this incident. There was none that fitted the description. There were some lights over Denver that were explained. So no looming, huge, spaceships. Why did my friend think there was? I have no idea, but there were a number of radio shows (e.g. Art Bell) on late night that reported and embellished such events. [Bell had also hyped a reactionless drive that proved nothing of the kind.]

                While I don’t know what you saw, what I do know is that there are a lot of amateur astronomers who not only have telescopes but have cameras attached so that any unusual object can be captured. The resolution can be quite extraordinary. One would think that this increased observational capacity would generate recorded quality UAP sightings, but AFAIK, this is not the case. Why not? I suspect that either the images are too poor or they don’t show what the observer thought they saw.

                I’m reminded that some astronomers once thought there were artificial canals on Mars. They drew maps that can be readily found. But these maps were based on human perceptual illusions. [As a side note, this was part of the last of Lem’s “More Tales of Pirx the Pilot” short stories – “Ananke”. A much earlier story had pilots chasing alien craft in space that proved to be an instrument bug. [Lem had some really interesting and quite sophisticated stories about the human condition in these tales.]
                As we saw with the recent navy videos, what was captured was not what one imagines was seen from the descriptions. Most have been given explanations that could identify the object or why the pilots thought what they saw was incorrect. The Pentagon didn’t want to say the observers were mistaken (we don’t need their competency questioned, especially when it comes to a shooting match), and as a result, we see stories proliferate about the US military accepting UAPs might be alien craft. After 70 years of UFO sightings, “abductions”, and other claims, one might think that just one might have incontrovertible corroborating evidence to support the claims. And yet…

                • Michael Fidler September 25, 2021, 21:15

                  Sure, if Paul does not mind, but I see your bias already; “Can you post a drawing of what you think you saw?”
                  Like the rabbit hole; I think you want to be the Queen… Off with his head!!!




                  The second observation after you give some feedback on this one.

                  One point, Astronomers look and study data from long tubes that see less then one degree, even amateur do not site under the stars looking up for hours on end. Same goes for pictures, digital only 20 years and the best so far are pictures of the space station planned well in advance and giant meteor impacts on Jupiter that the person looked thru their SER or AVI lucky imaging video and happened by chance to spot it. Yes, in the next few years we will have much more data on transient phenomena and Project Galileo is working on a valid AI tracking system to capture unknowns. So in 5 years we should have a clear image of something.

                  • Alex Tolley September 26, 2021, 9:52

                    Your first image is not so different from the bottom right drawing of Saturn by Huygens:

                    Early Views of Saturn: Galileo and Huygens over Two Saturn Years

                    Now I am not saying you mistook Saturn for this object, but rather that you interpreted the form of this moving object as you described in your letter to MUFON. That you felt the observation was suitable to report to that organization says something about your interpretation of the sighting, rather than a more prosaic one. What did you do to try to identify the object to eliminate a terrestrial phenomenon for it? For example, a bright object moving in the sky might be an aircraft reflecting sunlight off the fuselage (I once saw a beautiful orange lenticular light that proved to be an aircraft reflecting the setting sun, with most of the airplane hidden in the mist/polluted air that became obvious once it was much closer. Being under the flightpath to Heathrow would have been an obvious check too.).

                    A possible follow up given your stated profession would have been to call the nearest ATC for possible radar confirmation of the sighting to indicate its distance and velocity. IDK if that was possible or not.

                    As for the capture of images, we have many caught on camera. While telescopes and even binoculars have a smaller field of view, they are almost always focused on infinity, so an eyeball observation of something in the sky can be relatively quickly picked up by repointing the optical instrument and recording the images/video for later processing. I would expect that by chance someone would get decent quality images/video of a UAP. So far nothing.

                    The other possibility is that high definition satellite imaging of the Earth is becoming quite ubiquitous with excellent coverage in space and time. The resolution is more than enough to detect the shape of a UAP and track its movements over the surface if the sky is cloud free. Shouldn’t these satellites prove to be a good means to detect such transient phenomena if they are real and help make determinations? There must be lots of unidentified objects in their digital libraries that might be worth investigating.

                    • Michael Fidler September 26, 2021, 22:19

                      Here is a current update about my observation I sent to a friend on June 5, 2021. This may clarify some of the points you are making.

                      Hi, Below is the UFO report I sent to MUFON back in December, 1986 and also an article in the fall 1991 issue of the Electric Spacecraft Journal (ESJ) with a little better description and how it might work. That concept for the propulsion relied heavily on Tom Bearden’s research on Nikola Tesla’s and scalar waves. I was 14 when this object was observed and I was able to track it for about 6 seconds through the telescope. It was like nothing I had seen in the UFO magazines at newsstands or paperbacks and have not seen anything since in UFO literature. No flashing lights, no sound, and I had excellent vision and hearing back then. The object was in focus because I normally focused the scope on the distant mountains before sunset. The uncanny part was that the outside edges of the main object and the two objects inside had a sharp edge to them but the area inside of the edges was similar to extreme limb darkening that gave it an almost surreal look about it. The seven stars were pinpoint lights staying exactly lined up as they uniformly rotated around the main object. I would love to find a good CGI artist that would make an image of this object for me. I have many books on telescope and eyepiece optics and aberrations, but I know this was not lens flare or any other aberrations for the object and the stars stayed the same as it crossed the field of view. I have had of thousands of hours observing through telescopes and binoculars.
                      Michael C. Fidler

                      Here are the pages from ESJ:

                  • Alex Tolley September 26, 2021, 18:24

                    Possible explanation of your sighting.

                    A weather balloon with payload. The payload is the string of lights to the side of your drawing. The dark circles are elements of the payload seen against the underside of the balloon. The ballon itself is semi-transparent and meets your description of it.

                    This based on just a quick perusal of images on the web to show that such a prosaic object might account for your sighting.

                    high altitude balloon underside

                    balloon with payload

                    I don’t know if this is convincing enough, but weather balloons are often the explanation of UFO sightings and may explain your experience.

                    • Alex Tolley September 27, 2021, 9:56
                    • Michael Fidler September 27, 2021, 10:11

                      Sorry, not even close, you’re still back at Roswell, 53 years and you have not even reached past the first step. I’m afraid if I say anymore we’ll end up going down the biggest deepest rabbit hole you will ever see. I give you a hint: Grenada/UN

                      It’s a very long story…

                    • Paul Gilster September 27, 2021, 14:44

                      One best told elsewhere, perhaps, as we’re getting a long way from topic.

  • Harold Shaw September 23, 2021, 20:00

    By definition, abiogenesis and the evolution of intelligence becomes less extraordinary the more often they occur. The frequency of a phenomenon depends on the complexity of the mechanism that produces the phenomenon. Assuming an equal number of coin flips and six sided die roles, we should expect to see more tails than twos. Nonpareil humanity is the more extraordinary claim and any theory supporting that claim will have more conditions and assumptions than one that doesn’t. Wagering resources on SETI is sound reasoning.

    The notion that an experiment’s likelihood of generating a null hypothesis qualifies the experiment as religion is bizarre and thoroughly unscientific. Besides, radio SETI is nowhere close to delivering a null result for radio communicators. We can’t even claim traditional SETI is only looking for altruistic communicators. Life spends its energy on preservation. A search for high powered signals is also, perhaps predominately, searching for aggressive strategies of self preservation.

    General human exploration and curiosity will deliver SETI results. Astronomers and the general public are increasingly willing to accept ETI. I don’t see how we can target resources without understanding SETI/METI as a behavioral science. Technosignatures with be deliberate and motivations will vary widely, though some may dominate or be unavoidable. We would target SETI according to best hypotheses for dominate motivations.

    We do more METI experiments than SETI. The METI experiments just lack any scientific protocol and pay absolutely no attention to deliberate game theory. A quiet approach to METI that doesn’t increase our METI footprint wouldn’t increase our existential risk unless this tactic were a signal of ripeness or threat. If it is, our situation is already too grim for survival. METI must be approached as a behavioral science and experiments must be designed with ethical consideration. Quiet METI would provide space to focus on our message without increasing our ethical liability. If you can hear quiet METI you made a lot of effort to listen and already know a lot about us.

    All that said, a plausible, dominate motivation may be against loud METI and careless communication. If the laws of nature are finite, any organized and civilized people will hypothetically discover those laws and domesticate them with technology. Their technology will be unique to them and will include the ability to reproduce phenomenon in different mediums with high fidelity. A young people could always deliver value to a Deep Time people who listen and make no effort to communicate until they are discovered. Perhaps ideally, they would be discovered after the new people innovate on Deep Time survival strategies.

    If space faring intelligences are rare enough, it would be very hard for a people who survive into Deep Time to develop a data driven first contact with a new people strategy. A high survival rate for space faring intelligence may incline the older people towards avoiding influence.

  • Gary Wilson September 24, 2021, 16:59

    If you don’t mind my asking what would quiet METI involve Harold? It sounds like an oxymoron in some ways.

  • Gary Wilson September 25, 2021, 15:10

    After all the years of looking, we have no direct physical evidence of ETI visitations in the modern era and we have no idea whether anything the ancients saw was ETI based. That is one difficult fact to explain if we have been visited. Everybody immediately resorts to “oh the material and bodies were taken away by the military.” So nobody has ever arrived at a crash site and absconded with a piece of an alien craft or other alien artifacts before the military got there? It seems highly unlikely. I hear people say they have been abducted and even have had devices implanted in their bodies, but I have never read of any device being removed that contained elements unknown to us or functionality that was unexplainable. The UFO series presented a series of videos taken by military pilots and these are difficult to explain but they aren’t proven to be alien spacecraft. We would need material from one of the craft itself. I remain unconvinced by all of it. I think aliens have better things to do than give us a “tease visit” now and then. It doesn’t seem provable without physical evidence and all of it is hidden at Area 51 and other military bases around the world. Convenient isn’t it?

  • ljk October 6, 2021, 15:42


    Beyond “Fermi’s Paradox” XVII: What is the “SETI-Paradox” Hypothesis?

    Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that we haven’t heard from any aliens is because no one is transmitting!

    In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?”

    This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, including the possibility that everyone is listening, but no one is broadcasting – otherwise known as the “SETI-Paradox.”

    Full article here:


  • ljk October 7, 2021, 12:55

    As human history has shown, along with our current pandemic, it is safe to say that getting humanity to cooperate as one on just about anything is problematic at best…


    To quote:

    “In the past, we used to have an assumption: that if humanity was faced with a collective threat, people would throw away their differences, unite, join forces and overcome the crisis together,” Cixin told the WSJ. “Now I realize that might have been too perfect of a wish. Looking back at the past two years, the pandemic has pushed nations toward more divisions.”

    “So if the aliens really come to Earth, I see two possibilities: One is that we all pull together to face their arrival,” Cixin told the WSJ. “The other: They will come to Earth and we will become more and more fractured. It’s hard not to admit that the second possibility is probably more plausible. It’s the most likely conclusion that can be reached from what we’ve seen over the past two years.”

    So we failed the trial round and now Cixin suspects that humanity would be hosed, big whoop. Maybe next time we’ll actually learn to band together. But hey, it’s a good thing our leadership isn’t ignoring any extinction-level events coming our way.

  • Andrei October 13, 2021, 13:23

    And another nice signal that I am certain will start alien speculation. Though I still bet heavily on that it will turn out to have a natural origin.

  • ljk October 20, 2021, 14:16

    OCTOBER 19, 2021

    Why extraterrestrial intelligence is more likely to be artificial than biological

    by Martin Rees, The Conversation


    To quote:

    Human technological civilisation only dates back millennia (at most) – and it may be only one or two more centuries before humans, made up of organic materials such as carbon, are overtaken or transcended by inorganic intelligence, such as AI. Computer processing power is already increasing exponentially, meaning AI in the future may be able to use vastly more data than it does today. It seems to follow that it could then get exponentially smarter, surpassing human general intelligence.

    Perhaps a starting point would be to enhance ourselves with genetic modification in combination with technology—creating cyborgs with partly organic and partly inorganic parts. This could be a transition to fully artificial intelligences.

    AI may even be able to evolve, creating better and better versions of itself on a faster-than-Darwinian timescale for billions of years. Organic human-level intelligence would then be just a brief interlude in our “human history” before the machines take over. So if alien intelligence had evolved similarly, we’d be most unlikely to “catch” it in the brief sliver of time when it was still embodied in biological form. If we were to detect extraterrestrial life, it would be far more likely to be electronic than flesh and blood—and it may not even reside on planets.

    We must therefore reinterpret the Drake equation, which was established in 1960 to estimate the number of civilisations in the Milky Way with which we could potentially communicate. The equation includes various assumptions, such as how many planets there are, but also how long a civilisation is able to release signals into space, estimated to be between 1,000 and 100 million years.

    But the lifetime of an organic civilisation may be millennia at most, while its electronic diaspora could continue for billions of years. If we include this in the equation, it seems there may be more civilisations out there than we thought, but that the majority of them would be artificial.

    We may even want to rethink the term “alien civilisations.” A “civilisation” connotes a society of individuals. In contrast, extraterrestrials might be a single integrated intelligence.

    I’d argue it would even be worth looking for traces of aliens in our own solar system. While we can probably rule out visits by human-like species, there are other possibilities. An extraterrestrial civilisation that had mastered nanotechnology may have transferred its intelligence to tiny machines, for example. It could then invade other worlds, or even asteroid belts, with swarms of microscopic probes.

  • ljk October 22, 2021, 14:32


    [Submitted on 8 Jul 2021 (v1), last revised 4 Oct 2021 (this version, v2)]

    SETI in 2020

    Jason T. Wright

    In the spirit of Trimble’s “Astrophysics in XXXX’ series, I very briefly and subjectively review developments in SETI in 2020. My primary focus is 75 papers and books published or made public in 2020, which I sort into six broad categories: results from actual searches, new search methods and instrumentation, target and frequency selection, the development of technosignatures, theory of ETIs, and social aspects of SETI.

    Comments: 9 pp. Intended to be the first in an annual series. v.2 is the accepted version after proof corrections, and includes a description of one additional paper

    Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); Popular Physics (physics.pop-ph)

    Journal reference: Acta Astronautica 2022, vol. 190, pp. 24-29

    DOI: 10.1016/j.actaastro.2021.09.024

    Cite as: arXiv:2107.07512 [astro-ph.IM]
    (or arXiv:2107.07512v2 [astro-ph.IM] for this version)

    Submission history
    From: Jason Wright [view email]
    [v1] Thu, 8 Jul 2021 12:45:46 UTC (102 KB)
    [v2] Mon, 4 Oct 2021 16:06:50 UTC (101 KB)


  • ljk November 30, 2021, 16:52


    Panoramic SETI: Overall Mechanical System Design

    Source: astro-ph.IM

    Posted November 29, 2021 11:42 PM

    PANOSETI (Pulsed All-Sky Near-infrared Optical Search for Extra Terrestrial Intelligence) is a dedicated SETI (Search for Extraterrestrial Intelligence) observatory that is being designed to observe 4,441 sq. deg. to search for nano- to milli-second transient events.

    The experiment will have a dual observatory system that has a total of 90 identical optical 0.48 m telescopes that each have a 99 square degree field of view. The two observatory sites will be separated by 1 km distance to help eliminate false positives and register a definitive signal.

    We discuss the overall mechanical design of the telescope modules which includes a Fresnel lens housing, a shutter, three baffles, an 32×32 array of Hamamatsu Multi-Photon Pixel Counting (MPPC) detectors that reside on a linear stage for focusing.

    Each telescope module will be housed in a triangle of a 3rd tessellation frequency geodesic dome that has the ability to have directional adjustment to correct for manufacturing tolerances and astrometric alignment to the second observatory site. Each observatory will have an enclosure to protect the experiment, and an observatory room for operations and electronics.

    We will review the overall design of the geodesic domes and mechanical telescope attachments, as well as the overall cabling and observatory infrastructure layout.

    Aaron M. Brown, Michael L Aronson, Shelley A. Wright, Jérôme Maire, Maren Cosens, James H. Wiley, Franklin Antonio, Paul Horowitz, Rick Raffanti, Dan Werthimer, Wei Liu

    Comments: 11 pages, 10 figures, SPIE 2020

    Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

    Cite as: arXiv:2111.12771 [astro-ph.IM] (or arXiv:2111.12771v1 [astro-ph.IM] for this version)

    Submission history

    From: Aaron Brown

    [v1] Wed, 24 Nov 2021 20:05:38 UTC (782 KB)



    Astrobiology, SETI

  • ljk December 8, 2021, 13:59

    Another reason why SETI should also be conducted off Earth…


  • ljk December 9, 2021, 12:35

    U.S. and Chinese Astronomers Are Teaming Up to Hunt for Alien Lights

    For decades, SETI research has prioritized sounds over sights. That’s changing quickly thanks to newer and cheaper optical technologies.

    by David Axe

    Published Dec. 09, 2021 5:00 AM ET


    To quote:

    In a paper not yet peer-reviewed that was posted online in late November, the team described a new experiment it calls Panoramic SETI, or PanoSETI. It’s a proposal to use two assemblies of 45 telescopes each spread out across a wide area, and point them all toward the same broad swath of sky. Each telescope acts as a sort of check on all the others. Using two arrays to look at the same flicker from different points of view lets scientists triangulate the source.

    If the source seems close, it’s probably Cherenkov radiation. If it’s really, really far away, it just might be aliens. After all, “pretty much nothing makes nanosecond flashes of light, which is what a signaling civilization might send,” Paul Horowitz, a Harvard physicist on the team, told The Daily Beast.

    This light-based survey was a long time coming. “SETI has mostly been a radio exercise since 1960,” Seth Shostak, an astronomer with the California-based SETI Institute, told The Daily Beast. But that’s only because radio technology is old and inexpensive. Astronomers could easily afford the receivers needed to scan the cosmos for alien broadcasts.

    Charles Townes, the late Nobel laureate who invented the laser, theorized aliens might try communicating by way of lasers and proposed building visual SETI surveys as early as 1961. Find faraway laser flashes, he argued, and you might also find extraterrestrials.

    The technology to detect distant laser light didn’t exist in 1961. With the development of better sensors in the 1990s, optical SETI finally went mainstream. But early search efforts, each inspecting just a small piece of sky for a brief span of time, were quite narrow. And space happens to be a pretty big place.

    Hence the reason PanoSETI is getting so much attention—it could help us look at up to 18 percent of the sky. “Panoramic SETI represents the next step in the evolution of this strategy,” Douglas Vakoch, who heads the METI International research organization in San Francisco, told The Daily Beast.

    Link to the paper from the article above:


  • ljk January 5, 2022, 17:43



    JANUARY 3, 2022 6:00 AM

    Searching for alien technology in our backyard.
    One night in April, 1950, nine lights appeared among the stars above Palomar Observatory in California. They had not been seen there before, and haven’t been seen there since. What were they?

    The most likely explanation is that they’re a mirage—an illusion created by unknown contamination of the photographic plate taken by Palomar’s Samuel Oschin Telescope. But If contamination or mistakes can be ruled out, then there’s another startling possibility: that the transient light sources were glints of sunlight reflecting off metallic objects in near-geosynchronous orbit.

    This was more than seven years before the first artificial satellite, Sputnik 1, was launched by the Soviet Union. If those glimmers of light do belong to a swarm of passing satellites, then they are not of human construction. Instead, they could be the first evidence for extraterrestrial, technological intelligence.

    Those nine lights—referred to as transients because they came and went—were discovered by astronomers working on the VASCO (Vanishing and Appearing Sources during a Century of Observations) project, which is led by Beatriz Villarroel of Stockholm University. The idea is to scrutinize old photographic plates of the night sky taken at observatories such as Palomar, and compare them to modern images to see if anything has changed—have any faint stars, which might otherwise have gone unnoticed, appeared or disappeared in that time?

    If they have, then they could be evidence for all manner of astrophysical phenomena, including the afterglows of gamma-ray bursts and kilonovae, or eruptions from stellar mergers. However, the probability of nine cosmic explosions occurring all at the same time so close together in the sky is very low.

    It’s not been lost on the VASCO team that their project also has a SETI dimension. A disappearing star could be evidence for highly advanced extraterrestrial technology, such as some form of Dyson sphere, or a mysterious light could be a reflection from an alien probe present in our Solar System.

    Full article here:


  • ljk February 8, 2022, 16:28

    Astronomers searching for alien tech among billions of stars come up empty

    It’s all quiet in the galactic center. [Sure it is.]

    Jackson Ryan

    Feb. 8, 2022 4:00 a.m. PT

    Using one of the world’s most sensitive radio telescopes, a trio of Australian researchers has gone alien hunting in the heart of the Milky Way. In late 2020, they pointed their ears toward the galactic center, listening for alien technosignatures. In their field of view lay 144 known exoplanets and, potentially, billions of stars.

    But after keeping their ears to the sky for more than seven hours, they didn’t hear anything plausibly alien. It seems awfully quiet out there.

    Full article here:


    Yes, they searched for SEVEN WHOLE HOURS in one area of the radio range and didn’t detect anything. This is shocking.

    Here is their paper:


    SETI has such a long way to go.

  • ljk February 11, 2022, 13:49


    FEBRUARY 10, 2022

    Using epsilon machines to assist in the search for alien life

    by Bob Yirka , Phys.org

    A team of researchers from the California Institute of Technology and Sony Computer Science Laboratories has begun to search for life on other planets using a tool that analyzes statistical complexity. In their paper published in the journal Nature Astronomy, the group describes using epsilon machines to search for life on alien worlds.

    To date, space scientists have mostly relied on data characteristics of Earth as they search for life on other planets. The problem with doing so, the researchers note, is that life elsewhere could be completely different from that on Earth. So they sought other ways to analyze signals from other planets. As part of that effort, they noted that epsilon machines might help.

    Epsilon machines are not hardware devices, as their name implies; they are algorithms designed to calculate complexity by analyzing associated data. Such algorithms have been used to study bird flocks, for example, or how individual brain cells might give rise to human consciousness. They note that looking at Earth from a distance suggests something different from other planets in our solar system. It is clearly more complex, and much of that complexity is likely due to the presence of life. Thus, the researchers contend, it seems that instead of looking for oxygen signatures on other planets, or the presence of carbon, space scientists might want to look at the complexity of a given planet—and one way to do that is by using epsilon machines. To that end, they trained an epsilon machine on images of Earth taken from a distance. They then did the same for several of the other planets in the solar system to show the machine what lifeless planets look like. They also used other data meant to depict Earth as if there were no life on the planet.

    They data revealed that Earth is approximately 50 percent more complex than the other planets in the solar system. They also found that extra-solar planets known to have more surface types and complex atmospheric conditions scored higher as well. The researchers suggest that the use of epsilon machines could be a new tool for space scientists looking for life in other places.

    More information: Stuart Bartlett et al, Assessing planetary complexity and potential agnostic biosignatures using epsilon machines, Nature Astronomy (2022). DOI: 10.1038/s41550-021-01559-x

    Journal information: Nature Astronomy

    Article available online here: