forum discussion #37

SETI: Searching the Skies for Signs of Life

Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.
Download MP3
Listen to our report on Alan Penny’s SETI work.

Penny is an Associate Professor and Visiting Scientist at the University of St. Andrews in Scotland. In the course of his career as an astronomer, he has worked on the photometry of bright stars, extra-solar planets and the Search for Extraterrestrial Intelligence, or SETI.

He spent a year at the SETI Institute in California, which has now been forced to put its search on hold due to funding issues. For now, its telescopes are in “hibernation.” The analysis of the data already collected, however, does continue at the SETI Institute.

Penny calls the SETI Institute’s funding crisis “a severe blow.” But he says he remains committed to searching for alien signals. He is currently the Principal Investigator on a project that hopes to use Europe’s Low Frequency Array, or LOFAR, radio telescope to scan the skies for what could be signals created by alien civilizations.

So what exactly is Penny listening out for, and how can LOFAR assist in that search? What would an alien signal sound like, and how would we respond if we heard it? Bring your thoughts and questions to the conversation.

The guest has left this discussion, but feel free to leave your thoughts.

Your Comments

  1. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny

    What do you think about SETI (the Search for Extraterrestrial Intelligence)? Is it a terribly exciting scientific endeavor which could have a tremendous pay-off? Or perhaps a boondoggle where scientists get paid for a wild goose chase with no chance of success? Or even a dangerous enterprise which could alert nasty aliens to our existence? 

    A lot of people have been working on these questions for the last 50 years, so there is much to discuss.

    And then what about using LOFAR – the new Dutch/European radio telescope described as “the largest telescope in the world” –  in a new SETI search? 

  2. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? David Baron

    Alan –

    If you did find a signal and could confirm it was real, who would make that earth-shattering announcement to the world? Would you and other scientists wait to publish the findings in a journal? Would some politician (presumably in Europe) hold a press conference? Might this be a matter for the United Nations?


    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


      The SETI community has paid a lot of attention to this and a “post-detection protocol” was agreed to by the major players in 1989. If a team becomes convinced that they have detected evidence of an ETI signal, they should not immediately announce it but seek confirmation from the other groups that have agreed to this protocol. If it is then agreed that a detection has been made, the discovery group should inform its national government, the other members, relevant scientific bodies and the media.

      This protocol is just an agreement, not a legally binding document. The full text can be seen at:

      However, the community experience indicates that the news will leak out in an uncontrolled fashion before this process is complete.

  3. Tom Briscoe

    I work at the Very Large Array in New Mexico, USA. We are often associated with SETI (thank you Jodie Foster ;) though, in reality, we don’t do that sort of work.

    My feeling is that it’s time to ramp up SETI at *least* an order of magnitude. Thanks to the Kepler space telescope we know of many extra-solar planets nearby that *might* harbor life. Organic materials are common in space. It’s likely that water once flowed on Mars even if we can’t see it today; water means an environment hospitable to some life. To me, the odds are that life of some kind is common throughout the universe.

    Even if we could conclusively establish that there is *no* life (or intelligence) elsewhere in the universe, that itself would be a discovery of profound importance.

    Go, Dr. Penny and colleagues!

  4. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


    Thanks for the encouragement. The VLA showed up nicely in the film “Contact” you refer to, and the film was a good depiction of SETI.

    The search for extraterrestrial life (not extraterrestrial intelligence) is indeed ramping up with the planned NASA/ESA missions to Mars, and the work on extrasolar planets. This is backed up by theoretical work on the origin and spread of life and on the formation of planets.

    However, this does not apply to SETI. Parts of the scientific community view it as premature, as we have no theory of what ETI is, so the search is much more uncertain. As a consequence there is very little government funding, and now less private funding. I think this is a shame.

  5. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Clark Boyd

    Alan —

    Over on our Facebook page, we have some people noting that they think it’s better to pay attention to problems here on earth, instead of searching the skies for alien signals. That’s a sentiment I imagine you encounter from time to time. I’m curious how you respond to arguments like that.


    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


      As an astronomer, it’s a comment I’ve heard all my working life.

      Basic scientific research in general has a great payback – medical advances, new materials, etc., etc.. And ‘blue sky’ research can have useful spin-offs. The World Wide Web came from the home of the Large Hadron Collider, and the ‘SETI@home’ software is used in many computer collaborations, including medical research.

      There are also longer-term paybacks. In the 1500s, the orbits of the planets were charted, leading to Newton’s work which kick-started the Industrial Revolution.

      SETI is part of this great scientific advance. It also promotes public interest in science, so vital for our modern society.

      The human race is always looking outwards.

      And there is the prospect of ‘Contact’ – with incalculable benefits.

  6. Noah Siegel


    How do SETI researchers decide where on the elecromagnetic spectrum to search for signals? I know that human radio uses only a small part of the spectrum. Is it possible that ETI could be using types of EM radiation with frequencies that fall above the radio frequencies range, such as infrared or microwave, to communicate? Thanks in advance for your time and all of your hard work.


    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


      ETI could indeed be broadcasting elsewhere in the EM spectrum. SETI has concentrated in the radio spectrum because the technology to do so is cheap(ish) and the galactic background is quiet. ETI may well chose this as the simplest method. And by looking for very narrow-band emission we can be sure the signal is artifical.

      But we can look at other wavelengths. Recent technology has given us the ability to look for optical and infrared nanosecond flashes (searches at Berkeley and Harvard).

      My own work with LOFAR below 200MHz is in a high background radio range and thus heretofore less examined, especially as it needs new technology.

      But we don’t know the nature of ETI(s), so we are really just guessing how to look for their signals.

  7. Sarah Miles

    I agree that we need to research what’s outside of our immediate galaxy. There is so much more out there that would expand our current knowledge and it would be a shame not to continue this research. I also feel that we should continue to put a lot of money toward researching how we can travel outside of our own galaxy. It’s a natural part of human evolution to explore further and further outside of what we already know. Like I said in my other wacky comment that hasn’t been posted, if I were billionaire, I’d contribute a LOT of funding towards maintaining SETI and any program that is focused on exploring ETI and life on other planets.

    Thanks for what you do and keep fighting the fight!!


    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


      Glad that you support SETI. If any billionaire is reading this, we could certainly put any money to good use.

      But SETI aside, other types of astrobiology (the study of the origin and spread of life, the search for life on Mars, studying extrasolar planets) are going ahead, if not as fast as they could with greater government funding.

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Rhitu Chatterjee

      Hi Sarah, and Alan,

      The World’s science reporter here. I just came across this news story on WIRED about SETI’s new fund raising campaign, and thought I’d add it to the discussion. In case, Sarah or other people stopping by this discussion want to contribute.


      • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


        Let’s hope that the efforts by the SETI Institute to raise funds to take the Allen Telescope Array out of ‘hibernation’ are quickly successful.

        There are also other SETI groups who need money – the SETI@home people at Berkeley – the Harvard SETI people – and a number of other smaller groups round the world.

  8. Hyunsu Do

    Well,I’m not an expert on this. Heck, I’m thirteen years old. what I want to know is this:(a part of our science project) Mystery circles. there was a signal sent to outer space, and out popped a mystery circle that was similar to it. did scientists work out the data in it, or was it too vague?(sorry for my foolishness)

  9. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


    I’m not sure what you mean by “mystery circles” and “a signal sent to outer space”.

    The first might be the “crop circles” patterns made in wheat fields here in the UK. These have been shown to be hoaxes. No replies have been seen.

    The second might be the radio signals that have been sent by us out into space. Again no replies have been seen.

    Hope this helps.

    • Hyunsu Do

      Thanks. I was considering the word ‘crop circles’ when I saw it on the internet. well, now I can add one more hoax to that gigantic board. Just How many more hoaxes will we find?

      • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny

        Unfortunately the world is full of hoaxers, some doing it just for a laugh, some with the desire to make money, some trying to support pre-conceived ideas, some coming from people with psychological problems.

        Some UFO reports are hoaxes like that, but most are just mistaken interpretations of lights in the sky. There have been no confirmed sightings of objects with extra-terrestrial origins.

        For an example of a scientific investigation of “lights in the sky”, see:

  10. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Clark Boyd

    Hi Alan:

    Another question from our Facebook page: If life is discovered elsewhere in the universe, how will that discovery fuel the desire for additional exploration activities from SETI and other organizations?

  11. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


    Is this “life” or “intelligent life”?

    “life” could be microbes on Mars or oxygen in the atmosphere of a
    nearby ‘Earth’ exoplanet. This would give a tremendous boost to
    Solar System exploration and exoplanet work. ‘Astrobiology’ – the
    science of the origin and distribution of life would get much more government funding. And probably some real government funding for SETI.

    “intelligent life” would change everything. Is there a message? Is there a cure for cancer, or a threat of destruction? Governments would take over. Many billions and billions of dollars for scientists to study the signal, and look for other ETIs. Should we reply? We SETIists would become the most important scientists on the planet. [And a big boost to Solar System and exoplanet work.]

  12. James Jefferson

    I have bee a ardent fan and beliecer in the quest for life in the universe. HOW can “WE” be so egotistical as to think the we are only life in this WIDE expanding space called the universe .Absolutely stupid of US !!

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


      You ask “How can we be alone?”. This is the “Copernican hypothesis” – we are not special. Copernicus showed we were not the centre of the Solar System. Later work showed we are not at the centre of our Milky Way galaxy, or the centre of the Universe.

      But whether we are alone is a complex question. We have no evidence or theory about how life starts and then proceeds to technological civilisation, so we cannot say how often ETI comes into being.

      Intelligent life may be so rare that it only comes into being once in the Universe.

      In fact, the Fermi Paradox (“If they are out there, why aren’t they here?”) points to us being alone. But there are many other explanations where ETI does exist.

      So it is crucial to do the SETI experiment to find out if ETI is in fact out there or not.

  13. Hyunsu Do

    Hi, it’s me again. Well, there are too many theories to explain how intelligent life exists on mars or any other planet, or dosen’t exist. Ifthere was a ailean race, how would all the people react?(I don’t mean journalists)

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


      There is much discussion about this. See for example the presentations at a conference last year on “The detection of extra-terrestrial life and the consequences for science and society”

      A simple detection of the existence of an ETI is sure to excite great interest and speculation. And there may be longer-term societal effects. Would it for example join the nations of the Earth closer together as they see themselves as members of an ‘Earth civilisation’?

      If there is a message or even a contact with an ETI in the Solar System, then we are speculating. Would the new knowledge help us? Or would it dispirit us as some say has happened to some ‘primitive’ peoples in the last 500 years on Earth when ‘advanced’ nations have met them?

  14. Mary Ellen

    This may be more a question for an earth science specialist, but have members of the SETI community discussed (among themselves, anyway) the possibility that the Earth’s very large moon is a factor in the development of technology-using intelligence here? I’ve seen scattered notes online that suggest that the moon’s influence may have been critical to the formation of a life-supportive terran environment AND an enviroment that has made basic technological development likely… more likely than it would have been if the moon had been as proportionately small as, say, Phobos or Daimos are to Mars.

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny

      Mary Ellen,

      As you say, this is more a matter for the biologists and Earth science people. But it is indeed relevant to SETI as factors in the Drake Equation used for estimating the number of ETIs.

      A big Moon means significant tides which may mean a good environment to get life started in seaside pools. A big Moon also stabilises the tilt of the Earth axis keeping it a good long-term home for life, so life can reach the ‘us’ stage. And our ideas on planetary formation have implied that big moons are rare, and so perhaps ETIs are rare – the ‘Rare Earth’ hypothesis.

      There is much debate on this – see e.g. a paper last month on big moons being common.

      Whether big moons are common or rare and what effect that has on life’s evolution is still up for grabs.

      • Mary Ellen

        Thank you for your very interesting answer, Alan. I got through the referenced paper to the best of my innumerate ability… the results of these computer models seem to be quite various, and I didn’t really understand a lot of it, but it’s fascinating to see the way this very basic issue about our home planet’s past (and the past of all the life forms on it) is being studied. I remember one article I found on the web that stated that we can thank our big moon’s powerful tidal effects for bringing heavy elements like iron, etc. close enough to the surface for our ancestors to find and learn how to use.

  15. Hi Alan, thks in the hope to find ETI i feel that we are hoping to find out so many things -as you mention the chance to learn more about science/medical matters. I think also we hope to find answers to really big our ETI brothers know more about the origin of things than we do? what do they feel about the question of a transcendant Creative influence -or even an Immanent influence. Is life emergent and not explainable by recourse to underlying physics? What then draws life forward? is it as S.Kaufmann suggests that there is a kind of wondrousness in the nature of universe that bootstraps life into ever creativity and into adjacent-possible evolution. Or could there even be transcendant influences from outide the universe that enters/guides life’s & intelligence’s emergence?

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny


      Any ETI we find will be in advance of us, perhaps by billions of years, since they must be very powerful emitters of E-M radiation or can do interstellar travel. So we should expect them to have much more knowledge than we do. But they may be advanced in ways we are now unaware of. As an example compare us to the ancient Greeks: we could not tell them much helping their interest in the natures of the gods of Olympus, but much about quantum mechanics, a topic they were unaware of. And that is for a difference of only 2500 years, rather than the millions or billions of years for ETIs.

      What they could tell us, including on the kinds of topics you mention, is a matter of some interest (some would say speculation or even idle fantasy) in the SETI community.

  16. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Alan Penny

    Thanks for all the questions. I hope I was able to respond to them in a useful way.

    SETI is such a mixture of hard science, general interest and speculation about a fascinating topic that has direct ramifications in many fields: the origin of life, the rise of civilisations, whether technological civilisations
    like ours survive and spread through the galaxy. There are biological, evolutionary, planet studies, communication, interstellar travel, linguistics and many other things to consider.

    Our SETI searches have only just started. My own personal opinion is that it will be decades or centuries before we find the answer. But what a grand quest the human race has begun. And what a pity that at this phase we are
    being starved for funds.

  17. Ray

    @Alan …”The human race is always looking outwards.”

    Therein lies the problem.

    I’m more inclined to agree with Clark’s Facebook page followers. I think looking outward that far is basically selfish when there are so many people on earth with huge problems.

    We may have benefited from SETI by virtue of spin off’s but let’s realign the telescopes and focus on the areas of human need rather than pipe dreams.

    If aliens were to point their telescopes on us and see the way we care for each other, would they want to relate to us?

    • Alan


      You discuss whether we should spend money on SETI when there are many other needs. As I said in my reply to Clark (see above), I think that the small amount (about 1 part in 10,000,000 of the world GDP) spent on SETI is justified for all the reasons (not just spin-off) that I gave.

      Just suppose that Newton, Darwin, Mendel, Einstein and Fleming had been told that their ‘blue sky’ research with no obvious practical pay-off could not be justified.

      Yes, SETI is the bluest of blue sky research. And that is why, in my opinion, an increase to say 2 parts in 10,000,000 of world GDP would come up to near a suitable upper bound in appropriate funding.

      But if you think SETI is of no value of any kind, then you would think that spending not even 1 part in 10,000,000 is justified.

  18. H Johnson

    I cannot, for the life of me, see why it matters at all whether there is ETI or for that matter ETL. Why does it matter, apart from the gee-whiz factor. Given the size of the universe we should simply take it as read that
    - ETL is highly likely, possibly within reach of robotic craft. If found, it will be extremely interesting, and physical searches for evidence should, IMHO continue.
    - ETI is also highly likely, but certainly not within reach of us.
    - even so, we can never communicate meaningfully with ETI for physical reasons, nor even exchange information passively in a useful way.
    The universe is way too big.
    So why bother with ETI? Move on to more important and more scientific questions, please….such as robotic exploration of that tiny part of the universe that is within reach

  19. Martin Andersen

    Alan, it’s exciting to hear that you are working on a SETI project with LOFAR.

    What are the plans for the future with LOFAR and SETI ?
    Why is LOFAR only complementary to the Allen telescope array, since LOFAR is much bigger ?
    How many stars can you listen to at the same time ?
    We probably need to scan millions of stars before there’s a reasonable chance of success. Will that be possible with LOFAR ?



Add your comments

 characters available