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Tuning in the Epsilon Eridani Channel

Seth Shostak’s recent op-ed in the New York Times offers an unsettling title: ‘Boldly Going Nowhere.’ And Seth, an astronomer at the SETI Institute, gets right to his point: “…we’re not about to breach the final frontier. Piling into a starship and barreling into deep space may long remain — like perfect children or effort-free bathroom cleaners — a pipe dream.”


The homely similes reinforce the theme, one that also surfaces in Shostak’s new book Confessions of an Alien Hunter (National Geographic, 2009), which makes a strong case for continuing SETI as our digital capabilities expand. Indeed, given the daunting challenge of interstellar distances, it could be argued that our sole contact with extraterrestrial civilizations, if they exist, will take place through communications from afar, mediated by radio or light.

Let’s face it, the numbers are tough. The fact is that we can already do interstellar travel, provided we’re content with transit times of many tens of thousands of years, which is what our fastest spacecraft ever, New Horizons, would take to reach Proxima Centauri. A quick look at alternatives leads Shostak to note that ion engines aren’t up to the challenge, while antimatter requires the creation and storage of vast amounts of exotic, hard to contain particles. Wormholes? Fine, but we don’t know yet whether they exist or how to use them.

A Remote Presence in the Stars

If all this sounds depressing, consider Shostak’s alternative, the use of telepresence to extend human vision, hearing and touch to our stellar neighbors. Thus we go, but we go robotically, sending what he calls ‘proxy explorers’ to nearby stars, aided by ever increasing miniaturization that allows us to make payloads tiny. Perhaps the idea is a driver for nuclear-powered rocket technologies whose development has stalled:

A plausible solution would be to re-energize NASA’s development of nuclear-powered rockets, with the intention of building a craft able to send clusters of micro-bots into deep space at velocities of, say, one-tenth light speed. Depending on financing and our ability to garner international cooperation, these probes could be sent off before the 21st century starts to wane. By the middle of the following century, on-the-scene data from Epsilon Eridani, the nearest known planetary system, could be in our hands.


Image: An artist’s conception of a planet around Epsilon Eridani. A robotic probe with telepresence capabilities could allow us to experience such scenes without ever leaving our planet. Credit: Nova Celestia.

Virtual wanderings through a data feed from another star are compelling indeed, fueled by our telepresence proxies and data collectors. Who wouldn’t want to plug into the Epsilon Eridani Channel, immersing the senses in a wrap-around virtual experience that not only allows us to explore another planetary system, but also suggests that the wave of such exploration is ever outward?

Physics on the Edge

Here I want to plug in another Shostak quote, this one from Confessions of an Alien Hunter, which is a lively and satisfying account of what it’s like to be SETI’s major spokesman in today’s world. Here Seth is talking about various schemes for interstellar travel and he touches upon new physics:

Numerous and highly intriguing schemes have been proposed to do this. Alas, most of them require marshaling massive amounts of energy or rounding up exotic material that might not even exist. Scientists will not say that such schemes are impossible. We also can’t say whether they are possible, because theories in this field are still incomplete. Yet even if one of these schemes eventually looks right on the blackboard, there is no guarantee that it is feasible in practice.

Exactly so. The key statement is ‘theories in this field are still incomplete.’ Completing them is not the work of a single lifetime, nor is the resultant coupling of theory with technology that may develop. As we examine realistic technologies like telepresence via robotic probes, what can be done to keep our investigations of other possibilities alive?

Parallel Streams of Research

For as lively as telepresence would be, many of us would like to go one better. Propulsion research is a parallel stream, one that continues to flow even as we tune up and deploy the latest technologies available to us. Pushing its limits may or may not result in breakthroughs of the sort Shostak mentions. But one thing we can say for sure is that if we stop searching for them because of our current limits, we won’t find them.

And if they’re not there to be found? Here’s the point: By focusing our efforts on the nature of the possible, we should learn more about how the universe works, which is an end in and of itself. I’ve been asked on more than one occasion what will happen if scientists fail to find a way to achieve the kind of travel we see in Star Trek. The answer is that we’ll take different, slower methods to get to the stars, but we will still have learned a great deal about physics along the way, identifying key issues and sketching in many unknowns.

That’s a quest worth taking. And while it’s reassuring to realize that the kind of telepresence probes Shostak is talking about are feasible in a not terribly distant future, we still find ourselves confronted with a universe whose vast mysteries — dark energy, dark matter, the very nature of gravity — point to possibilities we have yet to explore. Nature yields up her secrets but slowly and often confronts us with surprises, which is why we must keep basic research alive. And if we create an Epsilon Eridani or Tau Ceti Channel along the way, count me an avid subscriber.

Comments on this entry are closed.

  • Marc Millis April 15, 2009, 14:50

    The power of observational interstellar exploration (letting the photons come to us), is indeed impressive and I look forward to more advancements and insights from that approach.

    But eventually, when the survival of humanity is at stake, getting out there will be more important. When I go to the grocery store, I go there in person rather than just looking from afar at all that fine food.

    By venturing beyond into the seemingly impossible, we will discover what the others are not even looking for. While some are content to watch and listen, we aim to be out there, being part of the show.

  • Ronald April 15, 2009, 15:48

    @Marc Millis:
    beautifully spoken, and so imperative for human survival, and the spreading of earthly life.

    Of course (open door), telescopic exploration will take place very elaborately and long before any actual mission to the stars. But then probably miniature, laser-driven robotic missions. And then finally, hopefully, human missions.
    Although I keep my doubts whether such manned missions to habitable/terraformable planets could ever be feasible at subluminar speeds.

    My hope, however slim, is on some breakthrough in anti-gravity (Heim, Tajmar, Chiao and the like). Hope springs eternal.

  • philw1776 April 15, 2009, 16:13

    Seth says, “Yet even if one of these schemes eventually looks right on the blackboard, there is no guarantee that it is feasible in practice.” Sure he’s referring to the physics of interstellar drives, but I believe the same applies to his SETI endeavours. In practice, there (a) may not BE anyone else or (b) they may not use eletromagnetic waves to communicate or beacon….etc.

    All such efforts require a leap of faith at present.

  • Craig Sanders April 15, 2009, 18:49

    I really think we will migrate to the stars as nomads. We will get there as humans after our robotic proxies. Eirc Jones and Ben Finney’s chapter “Fastships and Nomads” from “Interstellar Migrations and the Human Experience” says it. Have always been struck by that read.

    As long as humans build a robust cislunar civilization, human nature will take it’s course and we will migrate forever.


  • kurt9 April 15, 2009, 18:56

    So while there’s little doubt that humanity will soon explore and eventually colonize the Moon, Mars and the satellites and asteroids of the outer solar system, sending humans beyond that is impractical for the foreseeable future.

    Well, if you go with the O’niell scenario, the Solar System (including the Kuiper belt and whatever lies beyond) certainly offers a lot of room and resources for human expansion, and that’s not a bad thing at all.

  • John Hunt April 15, 2009, 19:41

    This interesting post brings up a number of important issues. I’d like to suggest that there are five major categories of rationales for interstellar missions:
    1) Scientific,
    2) Experiential,
    3) Economic,

        4) Destiny, and

        5) Survival
    Each results in rather different mission designs. Only the Survival argument provides a compelling argument for adequate funding whether public or private.

    The scientific motivation is pretty obvious. We want to send a probe in order to expand our knowledge for its own sake. But I would say that this rationale is not very competitive considering all of the science left to do within our own solar system and the advancing exoplanet knowledge based upon observations. The Scientific rationale will largely have to compete with other, much less expensive Sol system science and development missions.

    The Experiential rationale is related to the Scientific. First, consider a virtual experience, because it is more of a want than a need then likely it won’t expand the budgetary pie but will have to compete with other priorities. For really accurate simulations, flybys won’t be sufficient. Probes will have to decelerate, land and explore. Again, this rationale will probably compete unfavorably with Sol system science, development, and planetary simulation work. I downloaded Google Earth, played with it for a couple of days and then moved on. I don’t consider sims to be an extremely import part of most people’s lives.

    The second Experiential rationale would be to actually be there. This could be personally or vicariously through an “astronaut”. Although none of us (in this forum) have been to the Moon, I think that we would all say that it was money well spent for “us” to go to the Moon. Whereas this rationale worked in the past I have doubts that making the interstellar equivalent argument will work well currently. It seems logical to first establish a base on the moon, a colony on Mars, then on some moons before attempting to send a human to another star system. So this rationale puts an interstellar mission far into the future.

    I’ll continue this line of though with a post tomorrow,


  • bigdan201 April 15, 2009, 19:48

    one hundred years ago, the russian scientist Tsiolkovsky was coming up with ideas for multi-stage liquid rockets to get to space, space stations, and etc. these ideas probably seemed outlandish at the least to many of his contemporaries, but by the 60s we were flying into space, to the moon, and putting satellites in orbit.

    while interstellar distances are vast, technology that would allow us to go various fractions of c are not out of reach, and that would put the closest stars within range. i believe there are nuclear pulse propulsion ideas that would get to .1 c, and other theories that would perform better, up to .3 c.

    i agree that sending probes out first would be most prudent, and alot easier when long-distance trips first become more feasible.

    eventually civilization will expand into space, first colonizing the solar system, then expanding to the outer solar system, then eventually onto exoplanets (or exomoons around gas giants). the reach of probes will always be ahead of astronauts, but thats fine. the process will take time, but its essential.

  • Raffaele Antonio Tavani April 16, 2009, 6:52

    Innanzitutto, mi scuso se scrivo in lingua italiana, non conoscendo la lingua inglese.

    Questo blog l’ho leggo utilizzando il traduttore di lingue di “Google”, anche se, spesso, non è molto comprensibile, per me.

    Comunque, a grandi linee ho capito il senso di molte risposte a questo per altro, interessantissimo articolo.

    (Tutto il contenuto di questo blog, è di qualità, scientificamente superba).

    Quello che volevo sottolineare, e che mi ha colpito negativamente, è che nessuno si è posto il problema che, nel caso riuscissimo in un prossimo o lontano futuro, a raggiungere dei pianeti extrasolari, si potrebbe porre il problema di un incontro-scontro con degli eventuali “occupanti” più o meno intelligenti, di questi pianeti.

    Non è detto che noi “umani-terrestri”, saremmo bene accolti da eventuali “indigeni” extraterrestri…

    Un cordiale saluto a tutti voi da Antonio Tavani.

  • Administrator April 16, 2009, 9:19

    Antonio Tavani notes above that he has been reading Centauri Dreams through Google translation, which is how I’ve read his own message. I suppose our publishing software will one day come with automatic translation capabilities — that would be a useful breakthrough indeed. In any case, welcome, Antonio, and I hope you continue to read these pages.

    What Antonio is pointing out is the possible clash of cultures between two intelligent species when they make first contact. It’s a valid question, and one we’ve discussed here when talking about sending messages to other stars (METI). Antonio, if you have the chance, enter the term METI into the search box and you’ll see some of our earlier conversations about this issue. It causes major controversy here, to say the least…

  • Luis April 16, 2009, 10:38

    Virtual wanderings through a data feed from another star are compelling indeed, fueled by our telepresence proxies and data collectors.

    Hmmm, aren’t you forgetting light speed? It would take years for the movement you wanted to make could be interpreted by the “explorer”, and then more years until it sends back the input. That’s a hell of a lag!

    Of course, you *could* get around this problem through entanglement. If you entangled enough atoms and leave one part in Earth and the others would go with the “explorer”, then you would have real time response, always. I think that if this is possible, it is a brilliant solution. Hey, now get me the Nobel Prize, will’ya? Thanks.

  • John Hunt April 16, 2009, 11:36

    The Economic rationale hardly gets off the ground. Why would exploiting resources 4+ light-years away be any more advantageous than exploiting those same resources within Sol system?


The Destiny rationale means that we should go to the stars because it is our destiny as a species. I consider this to be a valid argument which probably works for most people. But like the others, there is no urgency in it. Why not instead first put our resources into our near-term destiny of spreading throughout Sol system? Yes, doing so will make us better able to make the interstellar jump. But that day would likely be pushed well into the 22nd century.

    The Survival rationale clearly stands out from the others. If the argument can be made that our species will only survive if we conduct an interstellar mission then any expense is justified — the pie can be expanded and dramatically.

    There are two lines of arguments supporting the idea that we are facing a near-term existential threat. First, the development of near-term self-replicating technology seems imminent. Self-replicating chemicals, biologicals, or nanobots could pose an existential threat. Their development can be reasonably placed in the middle to later part of this century. Secondly, a reasonable solution to Fermi’s Paradox is that all intelligent civilizations travel roughly the same technologic path we seem to be on.


To make the Survival argument, the development of a moon base or Mars colony will have to be insufficient to guarantee survival. This can be arguably made by:

    – considering the self-replicating existential threat to be very near,

    – arguing that contamination would doom either, or
 – that the nature of the event would destroy the solar system (e.g. a physics experiment gone bad)


But for an interstellar mission to achieve the survival of our species it needs to be soon and “manned”. Suspended animation and huge colony ships are well beyond our near-term capabilities. The only way that I see to achieve this would be through an EGR mission (frozen Embryo, automated Gestation, and child Rearing). I believe that every aspect of such a mission is already partially developed and should be within our capability by a 2050 or so launch.


  • ljk April 16, 2009, 11:38

    I believe what is being referred to here is what are our best
    chances of actually finding or even communicating with an
    alien society in our life times. Obviously a message sent at
    the speed of light has a much better chance than if we want
    to get a probe to visit other star systems at present.

    I agree with the other comments on this thread that we should
    not assume that interstellar travel is out or something for the
    very distant future using concepts and technologies that are as
    science fiction to us now. We have the Orion nuclear pulse
    spacecraft that could be built now and get us to Alpha Centauri
    in under two centuries. It may not be as elegant as a warp
    drive, but it is feasible now.

    Really advanced ETI may not need to use space probes to know
    what is going on in other star systems, though. Robert Bradbury’s
    Matroishka Brain concept envisions these artilects building telescopes
    the size of our Moon which could easily see details on exoplanets.
    We already have plans for space telescopes that could image
    continents on alien worlds, so why not something even better for
    the more sophisticated set?

    Conclusion: SETI as currently being done is probably our quickest
    and most likely way at present and for the near future to find out
    if We Are Not Alone, though the effort really needs to be ramped
    up, no offense to ATA and the Optical SETI projects happening now.
    I just think there needs to be a bigger international effort.

    But it is short-sighted to think we won’t have a means to physically
    get about the Milky Way in the not-so-far future. That’s what this
    Web site is all about for starters. Or that someone else with bigger
    brains and more resources and time hasn’t done it already.

    I think most people realize that Star Trek and Star Wars are
    essentially fantasies when it comes to interstellar travel. You
    don’t have to do too much educational digging to realize this.
    For those who haven’t or don’t, though, I am not terribly concerned
    that their lack of awareness on this subject is going to stop
    humanity from realizing this goal – though it may be foolish of
    me to ever understimate the destructive power of ignorance.

  • OldImortalSoul April 16, 2009, 12:30

    The issue with going such great distances is not so much the propulsion as it is our life spans. If we lived 400 years, then a 40 year jaunt would seem almost trivial.

  • James M. Essig April 16, 2009, 17:04

    Hi OldImortalSoul;

    You make a great point. In the case that human lifespan is medically enhanced to virtually unlimited values, than sub C, arbitrarilly high gamma factor travel through space will become more palitable for those who stay home on Earth.

    While I think we are going to the stars Ad Astra Incrementis, regardless of whether we learn to augment our life expectancy to arbitrarilly high values, there is something appealing to the notion of seeing a potential soul mate in an audio visual recording that originates from a distant star system, then traveling millions of lightyears to meet this person, and then taking this person with back to our home planet.

    Infinite lifespans in theory permit infinite travel distances at any arbitrary gamma factor sub-C travel through space. Medical science can and no doubt is likely to be very important regarding very long duration manned interstellar flight.

  • bigdan201 April 16, 2009, 23:32

    Long interstellar trips would be made more feasible with some form of hibernation or suspended animation, in which the travellers would not experience the majority of the voyage, and would not age much either.
    Ive read ideas about sending embryos out to stars, but in my opinion, that raises questions of just how human they would turn out… which could be a good scifi plot.

    economics will certainly be a driving motivator for colonizing the solar system, and over time we will expand to other stars… for many reasons.

  • Adam April 17, 2009, 3:47

    Hi Jim

    Infinity is awfully big and I’m not convinced the Universe is infinite. Certainly it seems likely that matter has only a finite useby, albeit a trillion trillion trillion years at least. Fred Pohl used high gamma-factors to send a multi-star system into the Long Night after matter’s end in one of his books – “The World at the End of Time” – and Stephen Baxter ably described it in “Time”.

    But as for Shostak’s idea of virtual presence, well we’ve covered that all before around these here parts. I still like the idea of beaming personalities between the stars – copies of the living or post-life of the bio-dead – who can then be embodied at destination. I still think that’d be the only way that John Hunt’s embryonic travellers could be guaranteed decent “robotic” parenting after their ectogenesis. But imprinting personalities onto cellular duplicates of adult bodies might be preferred if android bodies prove too limited for uploaded human minds. As far as we can tell a mind requires a body – at least our kind of minds require it.

  • ljk April 17, 2009, 9:23

    We let many very imperfect humans raise children, so why not
    a sophisticated AI program that can be made in the image of a
    “best” type of parent?

    I still think this talk of sending actual humans like us on long
    interstellar voyages is archaic, however. Unless we suddenly
    develop a means of going FTL, real starship “passengers” will
    not be organic – at least certainly not our type.

    The exceptions will be those groups who want to leave the
    Sol system, but even they may be different by the time that
    interstellar travel is feasible. This includes multigenerational

  • James M. Essig April 17, 2009, 10:26

    Hi Adam;

    Thanks for offering your insight.

    I like the idea of beaming personalities also. Perhaps some sort of quantum entanglement can be used as has been the discussion in Tau Zero previous threads.

    I suspect that proton decay will eventually be discovered but as of yet, I think the lower limit for proton half life has been set for 10 EXP 36 years. If we can develop mind transfer technology, that would be a tremendously game changing technology.

    I must say that I do not know if the universe is infinite either, but even if the universe is finite, it could nonetheless be unfathomably huge, perhaps a given infinity scrapper of light years accross. Perhaps there is more than one huge but finite universe, although once again, I would not know whether or not there are an infinite number of such finite universes or a finite number of such. I do not see a reason why nature has not or could have not and still maybe producing infinite numbers of finite universes. If such universes are casually, thermodynamically, existentially, ontologically, and topologically distinct or decoupled from ours, due to the condition of lack of defined simultaneity in the existence and birth of such universes, perhaps for all practical purposes, it could be said that some of these universes do not exist relative to our universe. I do not know if the state of existence or the concept of creation of a universe necessarilly needs to be defined casually by a temperal order of cause and effect sequencing, but that is a whole different topic.

  • kurt9 April 17, 2009, 11:55

    This interesting post brings up a number of important issues. I’d like to suggest that there are five major categories of rationales for interstellar missions:

    1) Scientific,
 2) Experiential,
 3) Economic,

    4) Destiny, and

    5) Survival

    You left one out. Number 6 (and the best argument for space) is freedom.


  • Peter April 17, 2009, 23:01

    Marc Millis should seriously consider giving a Ted Talk.


  • John Hunt April 19, 2009, 0:31

    Hi Kurt9,

    You left one out. Number 6 (and the best argument for space) is freedom.

    Thanks. That was clearly a major motivator for many people who came to the New World. Unfortunately, that would disrupt the easy-to-remember acronym SEEDS. Would you think that Freedom could be put within the category of Destiny as in establishing a new destiny for one’s self and for one’s posterity?

  • george scaglione April 19, 2009, 12:16

    had a look at all of the above from marc millis on down was especially impressed by the italian gentleman who wrote to us in italian.i do not speak italian but i was able to understand about 90% of what he wrote,lol, my name is scaglione after all!but as always the ideas expressed above where very good.will come back to read more really soon.thank you one and all your friend george

  • george scaglione April 19, 2009, 12:24

    hahahaha got exactly what i deserved! after i posted the above “bragging” about understanding what the italian gentleman who wrote in had said – then i went to a different part of this site and was confronted by a paper written in russian! :) was “greek” to me! thanks,george

  • Administrator April 19, 2009, 13:56

    John Hunt writes:

    Unfortunately, that would disrupt the easy-to-remember acronym SEEDS. Would you think that Freedom could be put within the category of Destiny as in establishing a new destiny for one’s self and for one’s posterity?

    Good solution! I had been pondering this myself, and appreciate the need to keep the acronym intact. In any case, I think we’re in agreement that the freedom motivation should fit in here some place.

  • Greg April 24, 2009, 14:58

    To put what Mr. Millis stated in a different terms, are we humans to become the couch potatoes of the universe?

  • Bill July 27, 2009, 17:30

    “You left one out. Number 6 (and the best argument for space) is freedom.”

    As in, freedom from big-L Libertarians and their markets-as-god-and-everyone-but-me-are-their-slaves gobblydeegook? Sign me up… Or perhaps, we could send them; the few that made it would soon perish from their own selfishness and arrogance.

    Either way, it would be refreshing to be shut of them.

  • ljk November 24, 2010, 6:24

    Star Trek writer reviews Shostak’s book:


  • ljk January 17, 2011, 12:15

    Seth Shostak on SETI

    January 14, 2011

    by Robert Naeye

    Seth ShostakIn the November 2010 issue of Sky & Telescope, radio astronomer and author Seth Shostak described the latest technologies and methods being employed by SETI (the search for extraterrestrial intelligence). Dr. Shostak also described some of the locations that are most likely to host other civilizations, and speculated that some of these societies might consist of machine intelligence.

    To follow up Dr. Shostak’s article, S&T editor in chief Robert Naeye recent interviewed him. Unfortunately, the original interview was lost due to a technical glitch, and we are only now getting around to posting a new interview.

    Dr. Shostak speaks about many various issues related to alien civilizations, such as the different search strategies being tried, whether we’re endangering ourselves by attempting to communicate, and whether they’re likely to exist in the first place. Dr. Shostak also discusses his thoughts on recent sci-fi movies that depict aliens, specifically Avatar and District 9.

    Click here to download the 22-Mb, 22-minute interview with Dr. Shostak.

    Full article here: