Earth 2.0: Nasa says scientists have found ‘closest twin’ outside solar system

Jul 29, 2015

by Alan Yuhas

Scientists on the hunt for extraterrestrial life have discovered “the closest twin to Earth” outside the solar system, Nasa announced on Thursday.

Working off four years’ worth of data from the Kepler space telescope, researchers from Nasa, the Seti Institute and several universities announced the new exoplanet along with 12 possible “habitable” other exoplanets and 500 new candidates in total.

The new planet, named Kepler 452b, is “the closest twin to Earth, or the Earth 2.0 that we’ve found so far in the dataset”, said John Grunsfeld, associate administrator for Nasa’s mission directorate.

“This is the first possibly rocky, habitable planet around a solar-type star,” said Jeff Coughlin, a Seti scientist. All 11 previously discovered exoplanets of a similar size and orbit travel around stars that are smaller and cooler than the sun.

“It is the closest thing that we have to another place that somebody might call home,” said Jon Jenkins, a Nasa scientist. The planet is like Earth’s “older, bigger first cousin”, he said.


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37 comments on “Earth 2.0: Nasa says scientists have found ‘closest twin’ outside solar system

  • @OP -Working off four years’ worth of data from the Kepler space telescope, researchers from Nasa, the Seti Institute and several universities announced the new exoplanet along with 12 possible “habitable” other exoplanets and 500 new candidates in total.

    While such planets are indicative of possibilities within the potentially vast numbers of planets within the universe, and within out galaxy, the odds against particular Earth size planets being habitable are quite high, and the odds against them having been stable enough for life to evolve over geological time are even higher.

    The indications are that the Earth-Moon system and the Solar-System are quite rare types.



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  • I suspect the moon is a bonus to life, but I doubt a necessary feature. Life does fine in lakes without tides. I am so looking forward to atmosphere analysis. That will at least let us know about simple life forms.



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  • Roedy
    Jul 30, 2015 at 1:55 am

    I suspect the moon is a bonus to life, but I doubt a necessary feature. Life does fine in lakes without tides.

    The key effect of Earth’s large moon, is stabilising the axis, the seasonal climate, and daily temperature variations.
    The tides are simply an additional feature.



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  • I think that this is more of a “wonder” evidence than anything. This is just a tiny tiny fraction of a fraction of what’s out there. I think we are well on course to great things, might be a long time coming, or not, crazy odds were against life wherever but we evolved here!



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  • 5
    NearlyNakedApe says:

    I’m hoping that the discoveries made by Kepler will help guide the new SETI radiotelescope endeavour by having them point their telescopes in the direction of those potential worlds and make the search for possible ET signals less blind and random than it was back in the 80’s and 90’s.



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  • NearlyNakedApe
    Jul 30, 2015 at 1:23 pm

    I’m hoping that the discoveries made by Kepler will help guide the new SETI radiotelescope endeavour by having them point their telescopes in the direction of those potential worlds

    If there is other intelligent life in our galaxy, I suspect that suitable planets are much more rare than many SETI enthusiasts anticipate.

    They are also likely to be VERY far apart in both time and space.
    Having said that, it is reasonable to expect high metalicity star-systems with planets with the elements needed for life, to come in clusters.



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  • If there is other intelligent life in our galaxy, I suspect that suitable planets are much more rare than many SETI enthusiasts anticipate.

    Yes. The SETI experiment seems fatally misguided by anthropocentrism. It’s reasonable to imagine a plethora of exoplanets and moons with conditions favorable to some form of life. When SETI talks about intelligent forms of life, they seem to mean either literally us or humanoid creatures with abilities to think, act and communicate like us.

    Imagine, for example, by way of a thought experiment, an exoplanet identical to Earth inhabited by the identical range of species. With one exception. No species of the genus homo -hominids including Homo sapiens have evolved. The planet would have robust counterparts to apes, dolphins, wolves not to mention lions and tigers and bears, oh my! But no humans. These other animal species by consensus are intelligent- -some highly intelligent- forms of life. Since they have not evolved the unique human ability to acquire and use language they could neither receive SETI signals nor respond to them. Perhaps the greatest wonder of the cosmos is that we evolved just in time to gather in Earth’s twilight and chat for a while until nighttime brings extinction.



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  • The planet would have robust counterparts to apes, dolphins, wolves not to mention lions and tigers and bears, oh my! But no humans. These other animal species by consensus are intelligent- -some highly intelligent- forms of life.

    I’ve pondered this myself and somewhat agree. Intelligence, to Homo Sapiens levels has only evolved once. There are intelligent animals, but none come near Homo Sapiens. It is very expensive as far as energy usage and hasn’t been found to be an advantage to any other species. Maybe we’re a highly improbable evolutionary adaption. Prof Brian Cox in one of his Universe series, concluded we are alone in the universe. They did the SETI thing, and the equation, and figured we should have heard a myriad of signals by now. Since we hear none, the documentary inferred that we’re Homo Solo.

    Which, as an aside, makes it infinitely important that we’re don’t commit self inflicted species suicide, which we are currently charging towards at a ludicrous rate. Maybe we should change our species name to Homo Stupidicus, or Homo Sheeple.



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  • I find it amazing that we can detect such small planets that far away, 1400 light years. Assuming this planet with 5 times the mass of the earth has a similar density then it’s about 1.7 times earth’s diameter or 13600 miles.

    To put things in perspective that’s about the same as being able to detect something 0.6mm in diameter on the moon, about the size of this full stop.



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  • David R Allen
    Jul 31, 2015 at 1:49 am

    They did the SETI thing, and the equation, and figured we should have heard a myriad of signals by now. Since we hear none, the documentary inferred that we’re Homo Solo.

    There is of course the possibility that any advanced technical civilisations would be aware of other intelligent species, and would:-
    a) Take care not to advertise their presence to possible hostiles from other planets.

    and
    b) avoid wasting energy by using tight communication beams targeted accurately on their destination receivers.

    and….

    c) be separated in their periods of existence by deep time.

    Which, as an aside, makes it infinitely important that we’re don’t commit self inflicted species suicide, which we are currently charging towards at a ludicrous rate. Maybe we should change our species name to Homo Stupidicus, or Homo Sheeple.

    It is also possible that the species will branch into Homo interlectualus subspec. technicalus, and Homo sheeple subspec. stupidicus – after the style of H. G. Wells “Time Machine”! – With sheeple-herding mechanisms to prevent over-grazing the planet or sheeples acquiring hi-tech weapons.



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  • Arkrid Sandwich
    Jul 31, 2015 at 4:00 am

    I find it amazing that we can detect such small planets that far away, 1400 light years.

    http://astro.unl.edu/naap/esp/detection.html
    Astrometric Methods look for the motion of the star (wobbles) about the center of mass.

    Radial Velocity Methods look for the periodic doppler shifts in the star’s spectral lines as it moves about the center of mass.

    Transit Methods look for the drop in the star’s brightness as an exoplanet cuts across its disk along our line of sight. Even when the system geometry allows transits (eclipses) to occur they happen infrequently. Thus, only a couple of exoplanets have been discovered through this method. Several discovered by the radial velocity method have been confirmed by observing transits.



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  • I suspect you and Alan may be right, however there is also the possibility that anthropocentricism may be blinding us to other possibilities as well. It’s sensible to look for planets that might have life based on the conditions of the only planet we know it to exist. And there are good reasons to think many of these may be reasons for any life to exist, however I think, it would be folly to discount the fact that there may be many other ways for life to exist than we can currently imagine, also there are one hell of a lot of planets out there. If we for example found any other form of life even microbial life in say the oceans under Enceladus, it would show life having evolved twice in one system it would both expand the range of possibilities for all life including intelligent life exponentially. We’ve hardly started looking, probably a bit early to tell either way at this stage. What the search will do however is highlight just what it takes for us to be here and that has to be worth it. But I agree people do get very enthusiastic.



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  • Hi David R Allen,

    Alan’s already mentioned many possibilities, but it could also be because no-one has heard from us yet, our signals would only have traveled a very short distance in the past 60 years or so perhaps they only contact us when they have heard from us. The other possibility is civilizations get noisy then quite, we are shifting away from massive signals in local noise to fibre optics etc. We are quieter now than we were 30 years ago. Eventually we may be very quite indeed in which case there may be 1000’s years old advanced civilisations who are only noisy for short periods. What if they live under oceans and transmit low frequency sound waves for their communications equipment they may have very advanced civilizations and still not be transmitting to us. If you did have some intelligent aquatic life would they for example know as little about the surface as we know about the depths of the ocean, perhaps they evolved at great depths and need diving bells full of high pressure water to ascend the shallows at great peril, hence they have only thus far send up a few probes onto the bobbing surface to take some cursory snaps of these lights in the super thin fluid surrounding the life giving ocean.

    Douglas Adams proposed a civilization that lived under complete cloud cover and had never seen a star, would such a civilization even think about contacting another species?



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  • Reckless Monkey
    Jul 31, 2015 at 5:52 am

    What if they live under oceans and transmit low frequency sound waves for their communications equipment they may have very advanced civilizations and still not be transmitting to us. If you did have some intelligent aquatic life would they for example know as little about the surface as we know about the depths of the ocean, perhaps they evolved at great depths and need diving bells full of high pressure water to ascend the shallows at great peril,

    Given the movement and evolved adaptations of marine Earth life, in travelling from ocean depths to the surface and vice-versa, I don’t think that is likely to be a problem.
    Surface radiation or a thick surface ice crust could be.

    There is also the issue, that as with solar-systems, galaxies have “habitable” zones.

    http://astro.unl.edu/naap/habitablezones/ghz.html
    The GHZ depends on the balance of two opposing trends. Metallicity decreases as one moves outward in the Milky Way, decreasing the number of potential planets. On the other hand, there are a number of environmental dangers to life associated with the packed inner regions of the Milky Way. Keep in mind that although all of the GHZ factors mentioned above are rooted in solid science, several are very difficult to quantify. The GHZ is an area of research that is still in its infancy and its validity has been challenged by some researchers.



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  • The Earth-Moon system is rare – as are other “local” features.

    https://astrobiology.nasa.gov/articles/2001/5/18/galactic-habitable-zones/
    Our Milky Way Galaxy is unusual in that it is one of the most massive galaxies in the nearby universe. Our Solar System also seems to have qualities that make it rather unique. According to Guillermo Gonzalez, Assistant Professor of Astronomy at the University of Washington, these qualities make the Sun one of the few stars in the Galaxy capable of supporting complex life.

    For one thing, the Sun is composed of the right amount of “metals.” (Astronomers refer to all elements heavier than hydrogen and helium as “metals.”) Moreover, the Sun’s circular orbit about the galactic center is just right; through a combination of factors it manages to keep out of the way of the Galaxy’s dangerous spiral arms. Our Solar System is also far enough away from the galactic center to not have to worry about disruptive gravitational forces or too much radiation.

    When all of these factors occur together, they create a region of space that Gonzalez calls a “Galactic Habitable Zone.” Gonzalez believes every form of life on our planet – from the simplest bacteria to the most complex animal – owes its existence to the balance of these unique conditions.



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  • This is why I love this web page. Never, ever boring. I’ll ponder these possibilities tonight while I make another futile attempt to get to sleep….. TURN OFF BRAIN. TURN @#$%ING OFF NOW.



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  • http://www.bbc.co.uk/news/science-environment-33720951

    The spacecraft which made a spectacular landing on a comet last year has discovered a rich array of carbon compounds.

    One leading scientist has even described the chemicals as “a frozen primordial soup”.

    This supports the theory that comets may have seeded the early Earth with the ingredients for life.

    The findings came after the lander, known as Philae, touched down on comet Churyumov-Gerasimenko 67P in November.



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  • This is a wonderful time to be interested in astronomy, cosmology, exobiology.

    There appear to be two camps, philosophically opposed:

    those who prefer to believe that we are Special, Unique etc, and that our existence depends on such a chain of low probability events that we’re not going to find it repeated elsewhere, and we are alone in the Cosmos.
    those who prefer to believe that Life is something that atoms do, given a chance, and will be found to be ubiquitous, anywhere it’s not utterly impossible, including many places where our kind of life could not exist.

    The odds between these two viewpoints shifts with each new discovery, in both directions. As ever more exoplanets are discovered, Camp Special refines its demands: Life needs a galaxy like ours, a part of the galaxy like ours, a sun like ours, life needs a planetary system like ours (and no other), life needs a Moon, life needs an asteroid hit at just the right time, intelligence needs a thumb, intelligent life needs [insert another unique aspect of Our World here]….

    It’s a philosophic argument at its core. The benefit is, both sides of the debate are doing (and not denying) science, perhaps to bolster their own case, but in any case, discoveries keep rolling in. I expect the jury to stay out on this topic well beyond our lifetimes.

    I don’t care which side of the debate anyone favours, as long as they keep on doing the science, and are not faking results to favour their particular bias. Personally I feel more in tune with #2, but that’s not a reasoned position. Reason tells me it’s not decidable.



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  • My logic tells me there are trillions of advanced life forms throughout the cosmos. Just too far away from us to be detected. A cosmic joke played on us by the speed of light and the size of the universe. I believe that if conditions are favourable then life will spring into being as it seems to do in every habitable niche on earth. I hope to live long enough to see this proven.



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  • Personally I feel more in tune with #2, but that’s not a reasoned position.

    Lovely summary post. I hope it’s #2. Won’t it be a magnificent day when the signal is detected, and we’re not alone. I can’t wait for the reaction of the religious and the conspiracy theories.



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  • Arkrid Sandwich
    Jul 31, 2015 at 7:49 am

    I believe that if conditions are favourable then life will spring into being as it seems to do in every habitable niche on earth.

    One of the features protecting Earth life from radiation is our magnetic shield.

    http://www.smithsonianmag.com/science-nature/earths-magnetic-field-least-four-billion-years-old-180956114/?no-ist

    Earth’s Magnetic Field Is at Least Four Billion Years Old
    Tiny grains of Australian zircon hold evidence that our magnetic shielding was active very soon after the planet formed




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  • OHooligan
    Jul 31, 2015 at 7:31 am

    There appear to be two camps, philosophically opposed:

    those who prefer to believe that we are Special, Unique etc, and that our existence depends on such a chain of low probability events that we’re not going to find it repeated elsewhere, and we are alone in the Cosmos.
    those who prefer to believe that Life is something that atoms do, given a chance, and will be found to be ubiquitous, anywhere it’s not utterly impossible, including many places where our kind of life could not exist.

    Odds for and against cut both ways.

    On the one hand the conditions required for life seem rare.
    On the other hand is the likely astronomical number of planets.

    Hubble reveals an estimated 100 billion galaxies in the universe or so, but this number is likely to increase to about 200 billion or even 500 billion.

    These numbers are considered rough estimates. … Most of the galaxies in the Universe are probably tiny dwarf galaxies.

    The best estimates suggest that our galaxy – the Milky Way, contains about 500 thousand million stars.

    Many minds, are simply boggled by the numbers.



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  • My logic tells me there are trillions of advanced life forms throughout the cosmos. Just too far away from us to be detected. A cosmic joke played on us by the speed of light and the size of the universe.

    Speaking of jokes there was a cartoon in the New Yorker that depicted long rows of chimps at typewriters in some gigantic office. Two scientists in lab coats are reading the output of one chimp as they stand over him at his typewriter. One man says, “Harold, I believe we have something here, [reading] ‘to be or not to be that is the spzgnxt.'”

    Seriously, when we speak of intelligent life, we often ignore the underlying assumption that this life has evolved not only to resemble us in many ways, if not physically, then in exact duplication cognitively in order to invent receivers and transmitters which are identical in function to ours.

    The most intelligent octopus that evolved in some alien sea under an ice cap is not going to respond to SETI. Intelligent land animals evolving in a protected life-supporting atmosphere and environments like those of Earth must still be contingently identical to us in one unlikely respect. They must have constructed a radio receiver-transmitter (or comparable devices) consistent with the exact specifications required to interact with our anthropocentric electronic SETI equipment for purposes of communication. Obviously even the brightest ape cannot do this. Moreover we have no reason to believe that “more intelligent” creatures would ever get on the same wavelength or invent the same devices necessary for two-way communication over unimaginable distances in space and time. Cutting away all the dross, we must virtually assume that they are us or the rest is silence.



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  • I see this claim a lot. ‘We all think intelligence = us, ‘ what is this we you speak of?
    It must be a technological civilization or we can’t get in contact. Intelligence is just applying experience and is required for technology. Physical form and mental form could be anything.



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  • Intelligence is just applying experience and is required for technology. Physical form and mental form could be anything.

    Because we feel the power of imagination on an intuitive level we believe that anything we can imagine has the logical and/or empirical potential to materialize. A traditional proof of God argues that because we can imagine His existence that therefore he must exist. A more mundane example holds that we can imagine ourselves in an invisible state walking down the street unseen by other people. The fallacy is that we have no such power to cognitively experience such a state. Am I naked? Do my clothes disappear? Am I seeing with my eyes? How do I turn my head to look across the street? Etc. The language of “imagination” is imposing a delusion.

    On topic, the alien life forms we could potentially contact must have many points identical in function to homo Sapiens even if they “look” different. If the civilization we contact is not technological then what is it? Somehow the alternative implies a disembodied free floating intelligence with linguistic ability and the paranormal capacity to receive and transmit communications over vast distances of space and time. Mental telepathy? An ameliorated alternative might posit a creature which is very, very different from us mentally and physically. Even this concept is fatally vague and unhelpful. What do you have in mind? The folks at SETI are operating on the anthropocentric assumption that any life form we could communicate with would have to be very much like us when we ring the doorbell or nobody home.



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  • I speculate (To myself mostly) on what properties would be required, or universal to species, that it could advance technologically, and thus, maybe come within range of SETI.

    Binocular vision as a minimum. Depth perception. Colour vision would be helpful. The ability to be able to manipulate objects. Enough easy energy intake, to allow for think time. Time to tinker and contemplate. Hard to do if you are starving.

    Communication. Technological advances require the carriage of ideas forward in time. It’s no good if every generation has to invent the same stuff. You must be able to record your advances and pass them on. A life cycle long enough to overlap with young to pass on knowledge. Time to experiment with design and improve.

    Intellect / intelligence. Not sure how to put this so I will use a layman’s term. Life has to be smart. They have to be able to come up with an analogue of the scientific method, although I suspect this, like the laws of physics would be a universal constant. Stability of society, or whatever grouping they use. You can’t advance if you are constantly fighting or being oppressed.

    A crude equation. Time + Intellect = technology.



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  • David R Allen
    Aug 1, 2015 at 1:36 am

    I speculate (To myself mostly) on what properties would be required, or universal to species, that it could advance technologically, and thus, maybe come within range of SETI.

    Binocular vision as a minimum. Depth perception. Colour vision would be helpful.

    We need to break away from human senses. Whales and other cetaceans, see in shades of sonar where they are blind in the black dark. Technical devices see wavelengths invisible to humans. Insects see in UV.

    If we look at intelligent species on Earth, Competition is a key factor. Intelligent species are predators which have to out-wit prey and species which navigate travelling distances.

    The ability to be able to manipulate objects. Enough easy energy intake, to allow for think time. Time to tinker and contemplate. Hard to do if you are starving.

    They also need to beneficially manipulate their environment.

    Communication.

    Communication and cooperation to build team efforts is also needed for intelligent civilisations.

    Stability of society, or whatever grouping they use. You can’t advance if you are constantly fighting or being oppressed.

    That is so in regard to individuals and classes, but fighting oppressors or oppressors dominating others, can lead to scientific advances from lavish funding of military research. If we look at the ancient Greeks, Egyptians, Romans, etc. or rocket science, technical skills were highly valued, funded, and encouraged, even if political objectives were dubious.



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  • 29
    NearlyNakedApe says:

    They are also likely to be VERY far apart in both time and space.

    Indeed. If we as a civilization have only been emitting radio signals for a little over 100 years, then any other advanced civilation in the galaxy who may be pointing radio-telescopes at us would only receive our signals in thousands or tens of thousands of years from now.

    Similarly, if the roles are reversed, if there are intelligent beings elwhere in the galaxy who haven’t yet acquired radio wave technology or only have acquired it recently, then we won’t receive any of their signals from time for a long time.

    So the odds are definitely low. There are so many conditions required for the existence of intelligent life to begin with anyway… They also have to be in a state of evolution and technology comparable to or more advanced than ours…

    Thinking about this make me realize how improbable our very existence really is… And by extention, intelligent life elsewhere. It is possible but most likely very very rare.



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  • I applaud the astute inputs that David R and Alan4 offer about the physical features, abilities and social behavior that likely constitute intelligent ET life forms. By “intelligence” we inevitably mean cognitive intelligence that resembles our own. In the scheme of evolution, “intelligence” used as a commendatory term might signify something very different; namely, longer-term survivability through adaptations to the pressures of natural selection in changing environments. In this sense a cockroach -insects in general- may prove “more intelligent” than Homo sapiens. Our brief species is far more vulnerable to threats of extinction, whether natural or anthropogenic, than insects.

    Communicating with SETI, requires “something like” human intelligence or human intelligence itself. Exceeding specialized sense capabilities of animals with the invention of “technical devices” derives from uniquely evolved cognitive abilities needed at a minimum to conceptualize this task let alone to undertake and wishfully accomplish it. A whale, a bat, a bloodhound, an insect capable of ultraviolet vision still remain a whale, a bat, a bloodhound, an insect with specialized sense organs lacking the brain power necessary for entertaining let alone constructing the complex technological devices necessary for SETI communication. Because human brains evolved the unique ability, combined with compatible physical capabilities, to acquire and use language in social arrangements where accumulated knowledge could be preserved and transmitted from generation to generation, Homo sapiens became the lone unique animal in evolutionary history with cerebral powers to manipulate the environment for their needs and purposes by unimaginable orders of magnitude beyond those of other animals. If we are to communicate with intelligent life forms on extraterrestrial bodies, we have no other viable alternative than to hope that such life forms have reached our unique Earthly level of evolutionary sophistication.



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  • I forgot to mention metals. If SETI is going to hear something, the other life form must had developed metals. You can’t generate an electromagnetic signal of any strength without metal. There may be myriad “intelligence” life forms out there, many have been posited above, but to hear from them, requires the ability to generate a strong electromagnetic signal at some wavelength, that it can propagate through space over long distances. Radio waves and microwaves are the obvious choices.

    As we get better at detecting planets, and the James Webb telescope gets up and running, we may see the signature of life in the analysis of the atmosphere of a planet. Even if it is only a cyano-bacteria analogue.

    Carbon is the obvious chemical to build life, with it property to be able to form organic molecules. Energy source. Oxygen is a likely starter to provide the oxidizing agent. The by product of oxidization involving carbon is C02. I’m going for my walk now. Might think of some more stuff.



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  • This is from a study referenced in New Scientist.

    The cosmos may have good and bad neighbourhoods. Life is most likely to evolve in giant elliptical galaxies whereas dwarf galaxies are thought to be the least hospitable – with the spiral Milky Way falling somewhere in between.

    The idea that the universe might have more and less hospitable regions is speculative, especially since we have yet to find any instances of alien life. But “habitable zones” – where water should be stable and Earth-like creatures have a fighting chance of surviving – have been proposed for alien solar systems and regions within galaxies.

    Now two studies have zoomed out even further in an attempt to identify the most habitable types of galaxies.

    “If we can look at regions around stars that are benign, and regions around galaxies that are benign, then why don’t we look at the cosmic volume?” says Duncan Forgan at the University of St Andrews in the UK.

    One approach, led by Pratika Dayal at the University of Durham, UK, compares different galaxies to the one known example of an inhabited galaxy, the Milky Way. Dayal proposes that life-friendly galaxies need lots of stars that can host planets, but a low rate of star formation to cut down on the number of supernovae.

    https://www.newscientist.com/article/dn27985-giant-old-galaxies-not-milky-ways-are-best-for-life-to-thrive/



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  • David R Allen
    Aug 1, 2015 at 9:07 pm

    From your N.Sc. link:-

    Dayal proposes that life-friendly galaxies need lots of stars that can host planets, but a low rate of star formation to cut down on the number of supernovae.

    Ticking time bombs
    That’s because supernovae’s violent explosions – which occur when massive stars die after only a few million years – may lead to mass extinctions on nearby worlds. So a low rate of recent star formation would mean there are fewer of these ticking time bombs waiting to go off.

    The clear winners are giant elliptical galaxies more than twice the mass of the Milky Way, but with less than a tenth the number of volatile young stars. “If the Milky Way is capable of hosting one habitable planet, giant elliptical galaxies would host as many as 10,000 habitable planets,” Dayal says, based on the observed supernova rate in our galaxy.

    The worst places to find life in the universe might be small, irregular galaxies with lots of newborn stars. Here, regular supernova blasts could sterilise the whole galaxy. There might also be insufficient elements heavier than hydrogen to form planets, Dayal says.

    This is applying the issue I linked earlier about habitable zones within the Milkyway, to the wider issue of habitable zones in other types of galaxies.

    David R Allen
    Aug 1, 2015 at 7:03 pm

    I forgot to mention metals. If SETI is going to hear something, the other life form must had developed metals. You can’t generate an electromagnetic signal of any strength without metal.

    I think we can take this for granted to a certain extent, as fairly high metalicity, (ie. heavier denser atoms), is required for the formation of rocky planets and the complex molecules of life.

    @ your N.Sc. link – There might also be insufficient elements heavier than hydrogen to form planets, Dayal says.

    Chemistry suggests, there is unlikely to be life (or rocky planets) made of pure hydrogen and helium.

    It is a matter of balance. Supernovae’s violent explosions are needed to create the heavy elements for second-generation high metalicity solar-systems, rocky planets, and life’s complex chemicals, but cause extinctions if they occur near such planets where there is already life.



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  • “If Kepler 452b is indeed a rocky planet,” he said, its location “could mean that it is just entering a runaway greenhouse phase of its climate history. Its ageing sun might be heating the surface and evaporating any oceans. The water vapor would be lost from the planet forever.”

    If memory serves me, we discussed speculations that life forms may have evolved in the seas under the ice caps of Mars, the moons of Saturn and/or other bodies. Volcanic activity may have heated the water sufficiently in locations where organic-foundational elements are present to “cook” a soup containing microbial life forms.

    The necessary ingredient for life is apparently water. Our “closest twin” seems to be losing its life sustaining environment, assuming that life forms in fact ever evolved there, at an accelerating -likely already fatal- rate. Apart from detecting the presence of water and chemical “metal” elements on some extraterrestrial bodies in the Milky Way Galaxy, raising the possibility that (microscopic) microbial life forms may have evolved, the chances of finding environmental conditions robust enough to generate even the semblance of organisms we would recognize as an animal -even an insect- are vanishingly small. Extreme heat and cold, radiation saturation, and windswept barren surfaces of rock, dust and ice seem to be the rule to date.

    If we could thoroughly explore other galaxies , we’d probably hit on the intelligent life SETI is looking for. Unfortunately the Milky Way and other galaxies are mutually moving away from one another, with the exception of the Andromeda Galaxy on a collision course with the Milky Way, at an exponential velocity and have become impossible to explore and soon in cosmic time will no longer be visible. Lawrence Krauss rightly concludes that that we humans are situated at just the right point in cosmic time to be able to observe other galaxies and light-energy sources going back to the big bang. If “we” are alive two billion years from now, all we will be able to observe is our own galaxy and no evidence of the big bang origin of the universe. The Cosmos as we know it today will have disappeared from view.



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  • bonnie
    Aug 3, 2015 at 11:30 am

    voyager-s-golden-record-audio-to-soundcloud

    I think the Voyagers’ messages are about wishful thinking to inspire the public, rather than any sort of serious space endeavours!

    @ link – Specifically, Voyager 1 is thought to have passed through the heliosphere at the boundary of our Solar System, and is on its way to a star called AC +79 3888 – although the journey will take it some 40,000 years. Voyager 2 is still in the heliosphere.

    It is regularly mis-stated that crossing the heliopause = “leaving the Solar-System”, but it will be hundreds of years before the Voyagers “leave the Solar-System”, and tens of thousands of years before they encounter any other star-systems. They have not yet passed through the Kuiper-Belt or the Oort Cloud.
    The heliopause is the edge of the Sun’s atmosphere, not “the edge of the Solar-System”.



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  • As well as Earth size planets, astronomers are also taking an interest in young stars with young planetary systems, illustrating the evolution of solar systems.

    http://sese.asu.edu/news/astronomers-discover-young-jupiter-exoplanet

    One of the best ways to learn how our solar system evolved is to look to younger star systems in the early stages of development. Now, a team of astronomers has discovered a Jupiter-like planet within a young system that could serve as a decoder ring for understanding how planets formed around our sun.

    The new planet, called 51 Eridani b, is the first exoplanet discovered by the Gemini Planet Imager (GPI). It is a million times fainter than its star and shows the strongest methane signature ever detected on an alien planet, which should yield additional clues as to how the planet formed.

    The results are published in the current issue of Science.



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