Search for Extra-terrestrial Intelligence – SETI

July 20, 2009

Cygnus Star Cloud

Cygnus Star Cloud

Photo Courtesy: http://celestialwonders.com/widefield/CygnusStarCloud_20061020.html (Image may be copyrighted by them, hence do not use for commercial purposes)

“Either we are totally alone in this universe. Or we are not. Both the possibilities are equally staggering”

Consider this: It’s been about 4.6 billion years since the formation of earth. The first micro-organisms were formed about 500 million years after that. The dinosaurs were extinct before 65 million years ago and the ancestor of human beings (homo sapiens) called Australopitheans came to existence about 5-6 million years ago. We have been studying the properties of radio waves (like light, sound and other communication waves etc) only for the last 100 years.

In this background, how difficult would it be to search for extra terrestrial organisms that are intelligent enough to transmit radio waves (Or laser beams), in the planets surrounding the stars in neighbouring galaxies? That’s one of the activities of an organization called SETI – Search for Extra Terrestrial Intelligence, which has contributing members and scientists from across the world and multiple observatories to conduct the research from. They use radio telescopes (which are either like a big dish antenna – largest being about 305 meters in diameters) or they use an array of smaller antenna systems and a central control unit to assimilate the data collected by these array of antennas.

The challenge facing such a research initiative is enormous – First, they need a lot of funding (Right now, they are partially funded by NASA and individuals like Allen, who is a Co-Founder of Microsoft), second they need to integrate cutting edge technology in various fields like optical lenses, radio astronomy, molecular biology, information systems and a lot more. The third – probability of finding out a radio wave communication from a distant galaxy may be very near to 0%, if at all they use the same ways of transmitting signals like us. There is only one consolation: The electro-magnetic spectrum, which comprehensively represents all the type of waves that we know of(light, etc.) can be completely scanned by the technology available today in a wide range of frequencies (comprehensive, as far as we know). And some of them do travel long distances.

Speaking of distances, to get a view of the universe that we know, consider this: The Sun is just one of the four billion stars (that we know), and the nearest star (Other than Sun) is 4.2 Light Years away. Make no mistake in reading it – If we travel at the speed of light (3 x 10 power 8 meters/sec), then we would take 4.2 years to reach our nearest star. With the current maximum speeds available (Even with Super Sonic Jet planes and space crafts), it would take thousands of years for us to physically reach there or send a space mission to these places. And our nearest galaxy is 2.5 million light years from us! There are thousands of such galaxies, as far as 200 – 300 light years.

To add to all those woes, a man called Albert Einstein has calculated that the speed of light is the fastest (or the best speed) that any particle could hope to travel. All the waves (Including light) travel in that speed. If that assumption is true, we may never be able to reach certain galaxies even if sufficient technology is developed in future. By the way, the light we see from the stars in the night were actually sent from the stars before many years but we are able to see them only now, as the light has to travel incredibly long distances to reach us!

Complicating things further is our ignorance of planets that surround the solar system – Though Mars and certain moons (Like Titan, one of the moons in Saturn) do seem to contain some favourable conditions for life (At least extinct life or micro-organic life), we have not been able to verify it till date. The farthest that a man made object has ever travelled is about 106 times as far as the Sun (By a satellite called Voyager 1) and the sun’s rays take just 8 minutes to reach earth!

But there are considerable advances made in the field of radio-astronomy. The light/radio waves from a planet, if detected, could be used to construct a spectrum that would tell what type of atmosphere a planet has, and some other vital information about the conditions of the planet, which could be used to determine if a planet in far away galaxy has a possibility of creating/ sustaining life. In fact, about 350 planets have been discovered orbiting far away stars.

One related piece of information is the launch of Kepler Spacecraft (March 2009) by NASA which seeks to observe and analyse light waves (Using CCD cells) from a galaxy called Cygnus (which has a large density of stars) and hence more probability of a planet coming in between the star and the spacecraft, for it to observe from an area in space, with out being blocked by the sun. The above picture is the star cloud of this Cygnus galaxy.

Whether they are able to detect extra terrestrial intelligence in a distant planet or not, their initiatives fuel the growth and development of cutting edge technologies that find applications in a lot of fields on earth!

You could visit the ‘Non-Fiction’ section of this blog, for similar articles.

Destination Infinity

You could also help the initiatives of SETI by participating in the SETI@home project.


  1. very interesting…

    as far as the speed of light being the fastest thing on earth… possibly so. thats why they say that once u learn to cross the speed of light, then u crack the concept of moving thru time. food for thot, eh?

    as for us being alone in this universe, no way! i refuse to believe it. in such a vast universe, how can it possibly be that only one earth contains the essence of life? i m sure that there will be some other forms of life (be it anything) somewhere else in this galaxy. earth is pretty young in age relatively. i m sure there must be other planets far older and evolved than earth is, and beings far technologically advanced than ours. i wont be surprised. they may be quite far away from us… or possibly using different methods than ours to detect life outside.

    i’ve heard that the best chances of life forms outside earth can be in the form crustaceans/insects. i forgot the theory supporting it… but i think it has something to do with the climatable conditions/environment. Dan Brown’s ‘Deception Point’ speaks of it a lot… where NASA seems to find a meteorite crashed into the earth. have u read it?

    • I have heard, but not understood the concept of travelling in time by travelling faster than light! I think, even if there are other forms of intelligent life somewhere else in this Galaxy, they will be wondering like us, as to what all this universe and the drama, is for! Thanks for the recommendation. I will read it soon. Long time since I read fiction.

      Destination Infinity

  2. Very interesting post! I’ve followed the SETI for many years now! Space interests me like none other!

    I’d like to believe that we are not alone in the universe! such a staggering space and us alone? No ways!

    • One of the arguments for SETI is this: The earth, though 4.6 billion years old, has been having living creatures on it for more than 4 billion years (which is a major part of its lifespan), intelligent or otherwise. So, there should be other planets surrounding other stars, where similar conditions could be possible. It could be, and I agree with you.

      Destination Infinity

  3. ha but how do we know that “life” on other galaxies/planet systems would have the same vital signs which we use to define life on earth?

    If you ask me the entire universe is alive..there is life everywhere..but maybe our lenses can pick up only those wavelengths…

    And comeon all you people, you aren’t alone…why take me , I am an alien hiding inside a human body!!

    • Life on other galaxies need not be based on the hydrocarbon basic structure, like ours! They are trying to analyse if the molecular composition of atmosphere on some other planet is suitable for sustaining life. It is a wild guess, and if there is a similar situation like ours, then it is easier for them. Yeah, there are severe technology constraints due to which we may not be able to pick up some wavelengths.

      Destination Infinity

  4. This subject has confused me always… i mean its there or not! and i believe (no scientific reason to say my belief) that humans today are still too ignorant about a lot of things in the universe!

    • I believe that humans are kept ignorant about a lot of things in the universe. For example, if we never had eyes – how can our brain understand sight and colours? Impossible. Now imagine: There could be additional senses, additional dimensions but we may not be able to understand all that. I think we are kept away from understanding certain things. Or the whole thing might just be an illusion!

      Destination Infinity

  5. Very interesting info DI.. 🙂
    universe is always a fascinating concept… its endless…
    its been a long time since I have read about it… thanks for that 🙂

    • Its been a long time since I have read about it, too. Thankfully, now we have Google!

      Destination Infinity

  6. Understanding space has always been difficult for me ! There are so many things yet unraveled !!

    • In a different perspective, very few things have been found out, till date! But we people are more interested in politics, defining the power centre and having the last word, amassing huge amounts of paper bits called money, controlling everything around us as we are the superior creatures and all such super important things!!

      Destination Infinity

  7. Interesting but I lean towards creation versus evolution. So definitely there could be life elsewhere too.

    • I too think, evolution may actually not be the answer. All the answers that we are looking for, will be got if the solve the puzzle of creation.

      Destination Infinity

  8. very interesting post.

    • Thanks, I too found it interesting to collect the information. Blogging enables us to learn – that’s something I like with Blogs.

      Destination Infinity

  9. DI, I think you need to read this : http://mashedmusings.wordpress.com/2008/04/04/invisible-dimensions/
    and let me know your views.

    • I read that article – In fact, that was the first article that I read on your blog, a long time back. I am yet to read through the links given there, so will comment after going through the references quoted by you.

      Destination Infinity

  10. Destination Infinity,

    This is the first post of your blog that I read, and am already quite impressed.

    I personally think nonexistence of life elsewhere is very unlikely (excuse the double-negative, but couldn’t phrase it better 🙂 ). But I also believe, we know enough of periodic table and the properties of individual elements that probability of finding carbon-based life is much higher than other forms that we can’t envisage. Also, as we encounter newer ‘life-like’ things, we might have to alter/expand out definition of ‘life’.

    One possible glitch in your post–sound waves are not electromagnetic waves. 🙂

    You might enjoy my post–‘Futuristic!’ and also the comments towards the end.


    • I have corrected that, but that has set me thinking!! I will read that post today, and let you know my views on the same. I hope we will find that newer life like things, sooner than later. That will be the first step to solving a lot of mysteries.

      Destination Infinity

      • “…,but that has set me thinking!”–set you thinking on what, may I know?

      • I was thinking about the types of waves, indeed! Should have done that long back, but better late than never!! Surprisingly, even the Wikipedia is quite silent on this topic. Need to search the web more to get info on that, I guess!

        Destination Infinity

  11. If life doesn’t exist anywhere else but here on earth, then ‘space’ is a huge waste of space. – Some scientist (forgot who).

    To believe that ‘life’ (not ‘humans’ or ‘animals’ as we know) exists only on earth is sheer arrogance.

    And to believe that no other intelligence exists in this universe except ours is height of ignorance, which reeks of non-acceptance of our insignificant position of existence as compared to this still mysterious universe.

    • I heard that quote in a video in TED where a Scientist from SETI speaks. In our field of view at least, the universe is very very large and we may take centuries more to understand this complex piece of engineering marvel! I think the universe is a planned creation, than formed randomly by some Big Bang!

      Destination Infinity

      • I agree.

        Randomness as a concept may sound cool and all, but to accept that all the things that are manifested by mere chance is absurd to me.

      • I agree. But there is a book called ‘Theory of everything’ by Stephen Hawkins and you should see how much sure he is about big bang theory and the theory of evolution! But he does accept that there are other possibilities as well!!

        Destination Infinity

        • At some point in time, pluto was a planet.

          Now? Oh, some ‘elite’ body *voted* its not a planet.

          Being sure of something and also accepting other possibilities at the same time means one is not sure about anything, IMHO.

  12. Very interesting…and educational post here. “By the way, the light we see from the stars in the night were actually sent from the stars before many years but we are able to see them only now, as the light has to travel incredibly long distances to reach us! ” I had actually never thought about that! Wow! Thank for researching and writing this. I found it very informative and intersting – more so than other ET articles I’ve ever read. 🙂

    • I got a lot of information in Wikipedia and their official website, and also a TED video on SETI. Now that we have the internet, we have almost all topics at our finger tips, literally but we are burdened with the over load and ignorance of what to search for!

      Destination Infinity

  13. I think that we humans don’t have a special place in the Universe and there definitely is life in some distant parts of the universe.

    The vastness of universe also remids us of the very little importance we are of in the grand scheme of universe.

    • I think we humans don’t even have a special place on earth! The earth is two-thirds water and there are a lot of fishes and other aquatic organisms which out number us by a huge margin! Just because we attach importance to ourselves, it may not mean we are special in the grand scheme of things – I agree with you on that point.

      Destination Infinity

  14. Possibilities indeed are endless.
    Very rightly pointed out the limited quest that has been done so far..We have covered so lttle of this vastness..I wish we could see an alien in my life time 🙂

    • Spotting an alien could be a first step to understand the complexities of the universe, if the aliens are not equally confused like us!!

      Destination Infinity

    • I am one. Rawr!

      Ok, not really… lol!

  15. Ah quite interesting!

    I firmly believe that there has to be multiple planets who are alive as we are and they might be searching for us as we are for them!

    Wouldnt that be fun? To meet them for sure!

    • That would be fun, but the only problem is the distance!

      Destination Infinity

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