Twice as Fast

Four years ago, I was boggled to realize that astronomers had been finding planets around other stars at an average rate of one per month since the first exoplanet around a main-sequence star was discovered in 1995.

On Monday, scientists from the European Southern Observatory (ESO) announced that they had found 32 new exoplanets in recent work. Moreover, that brings the total found to roughly 400. Instead of discovering a new planet every month, the average is now much closer to every two weeks.

What is the goal? The astronomers announced their findings at a conference titled, “Towards Other Earths: perspectives and limitations in the [Extremely Large Telescope] era.” The ESO instruments have led to the detection of 24 of the 28 known exoplanets with masses of less than 20 times the earth’s. The technology to spot earth-like planets around other stars is either on the drawing board or under construction. Key puzzles are now in how to characterize atmospheres around exoplanets, and how to deduce other characteristics of earth-like planets that the astronomers expect to find.

And in two weeks, astronomers will likely have found another planet around a different star.

25 thoughts on “Twice as Fast

  1. Problem is, they’re almost all fat gas giants inside Mercury’s orbit.

    Our system so far looks unique!

  2. Sure, the first ones were “hot Jupiters”, but since then there have been several multi-planet systems identified, some rocky planets inferred, and planets up to three AUs from their stars.

    Our system may be unique, but that’s not the way I would want to bet.

  3. Hot Jupiters are much easier to find using the methods and tools we currently have. That’s about to change, though.

    Our uniqueness remains an open question right now, but it’s likely to be resolved within a decade or less.

    Doug M.

  4. Very interesting post. Unusual in a political blog. But i can’t help bringing here some statistical and political extravaganza.

    Basically what the article argues is that even if the tools for spotting small rocky planets are being perfectioned fast the real challenge is not finding suitable planets but finding suitable planets in which life has evolved beyond its smallest building blocks. In earth it took almost 2 billion years of evolution to develop from single-cell life forms to complex multi-cell life. An eternity compared to later evolution ratio.

    Statistically this means that if you have a massive star it’s eventual (rocky) planets have no way of developing complex life simply because massive stars do have a short lifespan and go through all their (birth, childhood, midlife crisis, death) phases way faster than say sunlike stars. (They burn their fuel faster). So, sorry not enough time to let complex life evolve. Small stars live long but have little chances of sustaining planets at all. And in sunlike stars, if they have rocky planets, we are most probably not going to find anything beyond single cell organisms. The funny thing is that strictly statistically speaking if by some lightning strike of luck we do find something beyond the single cell life forms, most probably we would find a more intelligent life form then what we are (light speed and light travel times including for we actually always look in the past in the universe).

    But then this supposedly more intelligent life form should already have contacted/found us before we had found them. At a supposed exponential rate of technological evolution (something already happening in earth) they should have already found a way to travel long distances (beyond light speed) and destroy or approach us with the peace sign (something that hasn’t yet happened unless you have seen “men in black” and don’t eat government bedtime stories of course :)).

    What it means is that such an intelligent life form hasn’t been so smart after all because it is most probably extinct. And this would be really really a bad omen for humanity as it just means that in intelligence there is no hope. The universe just plain want’s us dumb (hooray for intelligent-design). So finally the more complex and intelligent life forms we find the worse this means for us. The simpler, dumber, or the complete lack of life elsewhere at all, the better it is because the more confident we can be that we are not finally doomed by our own intelligence and technology. I think we are condemned to schmaltzy, old-fashioned, romantic solitude no matter how many or at which rate we find rocky planets.

  5. Hopefully once Kepler finally gets launched, we’ll start getting some regular sightings of smaller planets. We’ve already got sightings down to about 3 times Earth mass, but only around red dwarfs (for the same reason we have an easier time finding “hot Jupiters” than other planets).

    Problem is, they’re almost all fat gas giants inside Mercury’s orbit.

    That’s because they’ve been detecting planets mostly by finding the “wobble” in the star created by the planet’s gravity and mass. That heavily, heavily favors finding “hot jupiters” over other types of planets.

    In earth it took almost 2 billion years of evolution to develop from single-cell life forms to complex multi-cell life. An eternity compared to later evolution ratio.

    Maybe. We’re really hampered on this by the fact that it’s very difficult to detect proof of life before the emergence of vertebrates, since they don’t preserve well.

    Statistically this means that if you have a massive star it’s eventual (rocky) planets have no way of developing complex life simply because massive stars do have a short lifespan and go through all their (birth, childhood, midlife crisis, death) phases way faster than say sunlike stars. (They burn their fuel faster). So, sorry not enough time to let complex life evolve.

    That’s only if it takes as long as it did on Earth to reach that point. That’s a big if – for all we know, the repeated “snowball” events killed off multi-cellular life on repeated occasions.

    The funny thing is that strictly statistically speaking if by some lightning strike of luck we do find something beyond the single cell life forms, most probably we would find a more intelligent life form then what we are (light speed and light travel times including for we actually always look in the past in the universe).

    Why? There’s nothing deterministic about intelligent life arising, much less tool-using life. As far as we can tell, the Earth went more than 500 million years without developing sentient, tool-using life forms.

    But then this supposedly more intelligent life form should already have contacted/found us before we had found them.

    There are some massive assumptions in this statement:

    1. Intelligent life develops tool-using capability.

    2. Intelligent tool-using life forms go beyond a certain stage before reaching relative equilibriam with their environments (look at humanity – we spent more than 100,000 years as hunter-gathers, and even when we have bursts of advancement in tool-using capabilities it was over tens of millenia).

    3. Intelligent tool-using life forms develop their technology in a way that leads to radio communication, space travel, etc.

    And those are just a few of them. What if, for example, you had a race that was entirely sea-borne? They’d never develop fire, much less radio. Or a race that is completely blind and navigates only by sound? They’d have no concept of a greater universe beyond the sky.

    At a supposed exponential rate of technological evolution (something already happening in earth)

    I presume you’re talking about Kurzweil’s nonsense about “exponential rate of technological advancement”.

    they should have already found a way to travel long distances (beyond light speed) and destroy or approach us with the peace sign (something that hasn’t yet happened unless you have seen “men in black” and don’t eat government bedtime stories of course :)).

    A couple of problems –

    1. Traveling beyond light-speed is, from what we know, impossible. There are some ways in theory to effectively get around that (wormholes), but they’re dependent on large quantities of “exotic matter”.

    2. As I mentioned, technological advancement is by no means linear. Humanity spent millenia as hunter-gatherers, only adopting agriculture over a relatively slow period of time. Even then, adoption of certain technologies was very rare until within the past 1000 years. I can easily imagine species not going beyond that, getting stuck in the equivalent of a steady-state.

    I think we are condemned to schmaltzy, old-fashioned, romantic solitude no matter how many or at which rate we find rocky planets.

    This is all guesswork, but my suspicion is that if we ever get seriously off this rock and start exploring other stars en masse, we’ll find a lot of rudimentary life, some intelligent life that will be alien to us in a number of ways (and “primitive”, depending on how you look at it), and possibly a couple of civilizations that reached a steady-state.

  6. Brett interesting points. Actually, the main points of what I wrote are derived from a very incorrect and sketchy memory footprint of the article “Where Are They?” by Nick Bostrom (which i read some one year ago and i managed to link incorrectly in my previous comment). An 8 or so pages of absolutely fascinating statistical reasoning. I think, most of your points were handled there in detail. Do find the full article and enjoy the read as i see that you are an astronomy/sience afficionado.

  7. Thanks eni and Brett, glad you both like the post. We’re not exclusively political here at afoe — I’ve written a good many book reviews, for example, and then there’s Eurovision — it only seems that way sometimes.

    I used “unique” in the sense of having terrestrial planets well outside the equivalent of Mercury’s orbit. Not sure how the other Doug was using it.

    Fermi’s Paradox (in its shortest form, “Where Are They?”) is another subject entirely, with a considerable literature in both fiction and non-fiction.

  8. If intelligent life does exist on other planets, they would have already seen goatse and decided to avoid us.

  9. Interesting article, Eni, although I think it’s a little dated in some parts. Apparently, they have actually had had some success as of late in generating self-replicating compounds, or at least part of them, for example. Moreover, several hundred million years (and this might very well be an artifact of our methods of detection) is an eye-blink in terms of cosmic history.

    Moreover, I’d question some of his arguments. He points out the “send Von Neumans”, but that actually sounds like it might be a dangerous proposition, sending out intelligent, self-replicating machines that might very well end up modifying their own programming and deviating from the exploration mission.

    He also seems to assume that if a civilization discovers the ability to successfully colonize throughout space, they will inevitably do so to the Nth degree. I can easily see scenarios where that doesn’t happen – where a civilization ends up reach some type of stability for long periods of time. Think of what would happen, for example, if we discovered a treatment that creates immortality for human beings. You’d probably see an initial burst of population explosion leading to denser cities and space colonization, but after that birth rates would probably plummet down to near zero. Population pressure has tended to be one of the big drivers for human beings, and it is probably the same for other types of sentient extraterrestials that don’t have a built-in mechanism for population control aside from infanticide and abstention from the reproductive act.

    As for “silence”, I can think of a couple reasons why:

    1. Intelligent civilization stop wastefully spamming the cosmos with their emissions after a while, assuming they put out a ton of them at all (not every civilization will invent the equivalent of television). Radio waves don’t remain easily perceptible for a long time, so it’s possible that we just weren’t around when they passed through our system.

    2. We’re really far apart. I’ve pointed out some of the reasons for why I don’t think there are tons of space-going civilizations in the vicinity, so I think it’s entirely possible that the space-goers are just really widely spread – possibly in their own galaxies.

  10. Eni, the article you quote by Nick Bostrom is very interesting and thought provoking, but I think it needs an update.

    Bostrom talks about “colonizing space”. This is good science fiction, but bad economics. It is a lot cheaper to colonize the Antarctica or the deep oceans. Presumably, advanced civilizations also have well educated economists who would give this sort of advice.

    Bostrom apparently overlooks the fact, that discovering signs of past life on Mars, will not necessarily make us any wiser. It is very likely, according to our present state of knowledge, that primitive life can be transported from Mars to Earth on meteorites ( we find quite a number of them in the Antarctica). As a matter of fact, it is now a commonly hold opinion, that the early ( not late as Brostrom says) occurrence of life on Earth, can best be explained if it was seeded from Mars, which was presumably hospitable to life at an earlier time than Earth.

    In discussing the “future filter”, Brostrom seems to overlook the two great threats to mankind in the next century: the climate crisis and the demographic crisis. The climate crisis happens if the climate reach a “tipping point”, which could make our planet inhospitable to advanced life forms. The “demographic crisis” threatens the so called “social contract” which every society depends on, and could lead to a run-away social collapse.

    If technological civilizations on other planets make neutrino experiments like the ones CERN is soon going to start up, then we will be able to detect them at a 1000 light-years distance with the Antarctic Neutrino Observatory which is ready in a year or two. These high energy neutrinos can only be produced artificially, by intelligent life. We only need one or two “hits” to know.

    I always found it odd, that Fermi who knew so much about the half-life of radioactive elements, didn’t think about the possibility of a half-life for civilizations, when he asked the question: “Where are they?” It was left to Frank Drake, when preparing a lecture, to stumble upon this possibility.

    The future prospect of neutrino observations and planet discoveries is, that we will be able to estimate the life-time of technological life on planets. According to Drake, if it is less than a thousand years, we probably have nobody to chat with.

  11. Moreover, I’d question some of his arguments. He points out the “send Von Neumans”, but that actually sounds like it might be a dangerous proposition, sending out intelligent, self-replicating machines that might very well end up modifying their own programming and deviating from the exploration mission.

    Brett, i’m somewhat familiar with advances in artificial intelligence and i can say that we are step by step beginning to understand the whole picture of the emergence of intelligence or more generally the behaviour of complex adaptive systems/networks and the evolutionary dynamics of natural or artificial systems. Especially through digital technologies we are increasingly able to develop and test in very short cycles the dynamic behaviour and evolutionary drive of complex systems. It wont be far when we will have enough knowledge to build stable goal-oriented intelligent tool/robot swarms that will be heavily used in space or earth exploration/exploitation. They don’t need to be completely independent, self-regenerating and general like Bostrom suggests. Instead most probably they will be designed to perform very specific tasks (build a space base, or build a radar for example etc. etc.).

    So, the choices are not only dumb, hardwired, programmed robots on one side and self-regenerating, general, intelligent, machines on the other. There is a whole segment between these two extremes which is good enough to help us solve most current problems in space exploration.

    Later to the other points.

  12. KB, while I agree with your thoughts about climate change and demographic pressure I don’t think space exploration is uneconomic.

    Yes it might be cheaper to exploit our resources in earth but it doesn’t mean that we should stop investing in space because it might not pay immediately. In the sixties, the space exploration frenzy served as a major drive for both communication (aka mobile) and digital technologies not to mention all sorts of other secondary technologies. As you might know, those technologies are a big chunk of todays economy and growth in developed countries.

    So if we make a strictly economic analyzis we should take into account the technological gains that you have from such innovation burts. Investment in space exploration and exploitation is almost certain to boost as a side effect exploitation of oceans or Antarctis.

  13. KB,

    Why can those neutrino’s only be created artificial. We have trouble to detect the neutrino flux from the sun. Why would it even be possible to detect a much smaller source much father away?

  14. Charly, We don’t have problems detecting neutrinos from the sun anymore. We used to be able to detect only one out of the three species of neutrinos, but not anymore. The “solar neutrino problem” has now been solved. It was found that neutrinos have a small mass (not exactly zero) which makes it possible for them to oscillate between three different states. Since our old detectors ( underground chambers filled with “cleaning fluid”) could only detect one of these states, it appeared as if the sun was only emitting a third of the number of neutrinos, that it ought to be emitting.

    The neutrinos produced in the coming experiments in CERN are of such high energy, that no known natural process in the universe can produce them. The “Antarctic Neutrino Observatory” can detect them. In a year or two, when this observatory is finished, we will be to say if anybody else, within a 1000 light-years distance, is performing the kind of high energy experiments that we are doing.

    Intelligent life probably wants to communicate peacefully, because that is what intelligence is about. Neutrinos is a fine option, because they are not absorbed along the way, and because you don’t have to tune in to them like on Radio. You see them all, and the high energy ones, are the ones that some kids on a far away advanced planet are broadcasting, when they do their school lab.

  15. Eni, I totally agree with you about the economics of space exploration. I was merely skeptical about space colonization, which is a very different matter.

    In the short term (100-200 years) it would probably be economic to extract He-3 from the moon to use for fusion energy. In the long term (200-400 years) it could be cheaper to implement technologies which use less energy. The problem is not that such technologies don’t exist at the moment, but that they are too expensive. To take an example, we know very well how to construct a “zero-energy” house. However such a house is unaffordable to most people, and anyways, the typical lifetime of a house in most western countries is about one century.

  16. I didn’t mean the missing neutrino but the simple fact that detecting solar neutrino’s is so incredible hard. The sun is next door and produces enormous amounts of neutrino’s and we only detect 1 a month or so. Why would we detect any from CERN. It will only produces a few neutrino’s.
    An alien CERN will also only produce a few neutrino’s but much further away. So far away that i doubt that any Alien neutrino will go trough the earth, let alone be detected by the detector.
    There is also the high energy angle. The highest energy particles aren’t found at CERN but in cosmic rays. How nature produces them is’t known but that nature produces them is certain and with it the assumption that only intelligent life can make those neutrino’s.
    IIRC the plan is to use Cosmic rays to find Higgs if CERN is not high energy enough.

  17. Charly, the reason why we will be able to detect more neutrinos with The Antarctic Neutrino Observatory (called “IceCube”)is, that it a lot bigger than the present neutrino observatories. Its detector volume is 1 cubic kilometer.

    For signs of extraterrestrial intelligent life, we would look for neutrinos with an energy of 6.3 petaelectron-volts , the so called “Glashow ressonance”. They are not produced by any natural processes. See this
    link

  18. As a matter of fact, it is now a commonly hold opinion, that the early ( not late as Brostrom says) occurrence of life on Earth, can best be explained if it was seeded from Mars, which was presumably hospitable to life at an earlier time than Earth.

    Not in the scientific community – hell, I’ve never heard this mentioned as anything other than one possible (if unproveable) way of getting life started on Earth.

    For that matter, we don’t know what the “hospitable conditions” were for the early formation of life on Earth – all we know is that is emerged at some point.

    They don’t need to be completely independent, self-regenerating and general like Bostrom suggests. Instead most probably they will be designed to perform very specific tasks (build a space base, or build a radar for example etc. etc.).

    There’s still always the possibility for corruption and/or tampering when you create a program that has extensive learning capabilities.

  19. Brett, the time when life started on Earth has been pushed back to a relatively short time after Earth became hospitable to life. Maybe even as far back as 4.25 billion years ago. See this link

    This has created a problem. How do we explain that life could develop so fast, when we don’t see any evidence of such processes happening now. We know that comets contain Amino Acids, the building blocks of life, and that they bombarded the early Earth, probably creating the oceans. Still, there is a big step from Amino Acids to life itself.

    This is where speculations, that we are all “little green men”, come into the picture. Mars would probably have been hospitable to life long time before Earth. Alternatively, some people speculate that comets not only contain Amino Acids but also primitive life forms. I don’t think there is much support for this theory.

  20. The scientific community doesn’t have one opinion on life starting on earth. It has two. The biologist see it as an almost impossible occurrence. The astronomers think it is so likely that Mars didn’t have time to spread its life to Earth before it self-organized on Earth.

    ps. 4.25 billion leads for enough time for Earthly life to be transported by asteroids to a wet Mars. In other words: “there should have been life on Mars”.

  21. If we find evidence of life on Mars, the interesting question is if it is similar to that on Earth, and if so, how long time ago these life forms shared a common ancestor. If this time is before 3.8 billion years, it would indicate a Martian Origin. If the time was before Earth and Mars were hospitable to life, it would support the “panspermia” hypothesis, which in its modern form says that a passing foreign solar system ( they visit us every 100 million years, with a passage time of 10.000 years) can seed the Oort cloud comets which in turn can seed the planets of our own solar system.

    It is considered unlikely that life can survive on comets, but it is considered equally unlikely that advanced life forms could have developed spontaneously on Earth in a less than a couple of hundred million years, which is now the time window of the archeological record.

  22. A simple problem with your statement. How can you measure how long ago they had a common ancestor as you don’t measure time but generations?

    Also the time difference between a hospitable Mars and Earth isn’t that large.

  23. Charly,

    How can you measure how long ago they had a common ancestor as you don’t measure time but generations? Good question. This is the problem of calibrating the “biological clock”. The oldest DNA found on Earth is about 0.5 billion years old. On Mars it would probably be older. It would not be easy to estimate the time of the earliest common ancestor.

    Also the time difference between a hospitable Mars and Earth isn’t that large Perhaps not measured in absolute time, but maybe in relative time. The geological record shows that relatively advanced life forms appeared very shortly after Earth became hospitable to life. It seems to be down to the order of a 100 million years. Since we are ignorant about how DNA based life is created, it is difficult to say if this is surprising or not. It seems though, that life evolved at a more sedate speed later on. Compared to this brief window of evolution, Mars enjoyed a 600 million year long, early period, where it was hospitable to life.

  24. Pingback: The Extraordinary Aside | afoe | A Fistful of Euros | European Opinion

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