Will the 21st Century be the Time we Discover Life Beyond Earth

good evening everyone my name is andrew frak noi i'm professor of astronomy emeritus here at Foothill College in Silicon Valley and it's a real pleasure to welcome everyone here in the Smithwick theater and everyone watching us on the web around the world to the 18th year of the Silicon Valley astronomy lectures sponsored by the Astronomical Society of the Pacific by NASA's Ames Research Center by the SETI Institute and by the Foothill College astronomy program were delighted to have these lectures at Foothill College where the facilities of the Smithwick theater are being made available for our lectures year round there are six lectures each school year tonight is a particularly exciting time for us because our speaker is one of the great scientific pioneers of our time dr. Jill tarter has led the international effort to search for signals from civilizations among the stars dr. tarter holds the Bernard Oliver chair for SETI at the SETI Institute serves on the management board for the Allen telescope array one of the prime instruments in this search is president emeritus of the board of the California Academy of Sciences and continues to make important contributions to the worlds of science education and the arts many of you know that Jodie Foster portrayed a fictionalized were version of Jill tarter in the film contact in 2004 she was on Time magazine's list of the 100 most influential people in the world after the talk she'll be made she'll be autographing Sara skulls recent popular biography of her life and work making contact which is published by Pegasus books and which I recommend to everyone here and everyone watching us on the web now ladies and gentlemen it is both a personal pleasure and a professional privilege to be able to introduce to you dr. Jill tarter and thank you Andy for that great introduction and Seth for we're talking about our Institute and thanks to all of you for braving the smoky skies and somewhat traumatic times in Northern California in 2004 craig Venter and Daniel Cohen made a very bold claim they claimed that whereas the 20th century had been the century of physics with fantastic success the 21st century would be the century of biology and of course they were talking about genomics and certainly that prediction has played out probably faster than they could ever have believed but nevertheless I think that prediction was a little bit pallid I actually think the 21st century is going to be the century of biology on earth and beyond and you don't have to just take my word for it here's the NASA's chief scientist Ellen stofan before she retired saying that there would be strong indications of life beyond Earth in a decade and definitive evidence in ten to twenty years and then we have the associate administrator for the space sciences division John Grunsfeld now retired saying reminding us that we are on a continuing currently on a continuing journey to Mars and we're going to Mars to look for evidence of extinct and extant life so life beyond Earth I think that this prediction can play out in one of three ways first we could discover it we could find it in situ by finding biomarkers on the surfaces of some of the bodies in our solar system we could find it remotely by finding bio signatures and the atmospheres of exoplanets around other stars we could communicate with it all right we could find techno Cigna that's what SETI is all about there could be a serendipitous detection while we are observing the universe trying to understand astrophysics and astronomy and lastly we can export it right we talked about going back to the moon to Mars to the asteroids and groups like breakthrough starshot or the hundred year starship study or the Icarus project are thinking about interstellar spacecraft so there's something that astronomers know and it's something that I think it's our job to talk to the world about and to share this particularly particular perspective it really does take a cosmos to make a human and this perspective I think is is very worthwhile and necessary this perspective is important to share because I think it will help us achieve a long future for Humanity and the rest of life on this planet and from this perspective we actually need to rethink what we mean by here and now so here well obviously we're here a Smithwick theater which is Foothill College sitting at the bottom south end of the San Francisco Bay in the Silicon Valley and from the altitude of low-earth orbiting satellites we'd see ourselves here since 1968 on Christmas Eve when Bill Anders took this earth rise picture coming around the limb of the Moon and Apollo 8 we've been able to understand ourselves as being here on a world a world that floating in the vastness of space and in the summer of 2013 the Cassini spacecraft which was studying Saturn until last month it turned around and it took a selfie it took a picture of all of us here actually right there below the tip of the arrow there is a little white dot and that's you and me and all of us so I hope you got the memo put on your best clothes when out on the lawn and wave to Cassini when it took this this image but that's us and that's following in a tradition that was started in 1990 when Voyager 1 passed by Neptune on its way out of the solar system and it turned around and it saw Earth caught in a Sun a beam of sunlight and dust and this is Carl Sagan's pale blue dot this is us and our Sun and the planets that orbit it are actually at the very out towards the edge in the boondocks of a beautiful spiral galaxy now nobody went outside the galaxy to take that picture right right until now it's actual photographs of what I was talking about this is a galaxy that we think looks very much like the Milky Way galaxy would if you could get outside and take a picture and we're reminded that our Sun is one of some 400 billion stars in this galaxy and our Milky Way galaxy is one of about 200 billion other galaxies in the observable universe and this beautiful famous Deep Field picture by the Hubble Space Telescope makes us remember that as we look farther out in space and we see these dots getting smaller and dimmer we realize that we're also looking back in time because of the finite speed of light so what do we mean by now we have to rethink that too from this cosmic perspective and so we realize that we are now in the current epoch of the universe is 13.8 billion year continuing evolution from the Big Bang two big brains and beyond and I have to confess that even astronomers and other scientists are not yet quite comfortable with this picture because we realize that what we have been studying for centuries amounts to only four percent of the mass energy density of the universe the rest of it dark matter dark energy dark is just code for we don't know we don't and we are trying to figure this out cosmologists are struggling with the earliest times where we can't yet make our physics of gravity and quantum mechanics play nice together but nevertheless this story of cosmic evolution is the very best creation myth that we have ever as a species been able to assemble and it is beautifully self-consistent for the most part with the observations that we make today but observations that we make tomorrow may in fact cause us to rethink this cosmic evolution story and that's what science is all about being able to change what we think we understand on the basis of new evidence and it's self-correcting so we humans we're all a part of that big picture of space and that long history of time right we humans trace our lineage not just back through the centuries of our families not just back through the millennia of human civilization with its art and its many experienced experiments with with governance we trace our heritage not that just back over the millions of years since we branched off from the Apes not just back the 2.4 billion years during which the Earth's atmosphere has been perfused with oxygen thanks to the photosynthetic labors of cyanobacteria not just back to the formation of the Sun and our solar system 4.6 billion years ago but maybe back another 4 or 5 million years to some giant molecular cloud that was contaminated by the winds of wolf ray a stars and supernovae explosions like this modern version this modern supernova remnant and we are deeply connected to these faraway times and places the hemoglobin in our blood the calcium in our bones and all the elements heavier than helium that make you you they all started here in the explosion of a massive star billions of years ago and those products the debris of that explosion was incorporated into a new generation of our star and planets just as this modern debris may in fact be incorporated into a new generation of stars and planets and perhaps life tomorrow so it's taken really millennia for humans to piece together this story and we're still continuing on this journey because we're curious about who we are and where we are and why we are and who else might be there and over my rather long career there have been two game-changers in this conversation the first is extremophiles the second is exoplanets and perhaps exomoons now extremophiles our life as we actually did not yet know it a few decades ago these organisms are illuminating the amazing possibilities for life on our own planet in environments that you and I couldn't tolerate for a millisecond they live in boiling battery acid they live frozen and ice they live at the bottom of the oceans with huge pressures high temperatures no sunlight they're happy they're right we call them extremophiles but maybe it's us that our extreme as seth has always already suggested that we have such a narrow range of conditions that we find comfortable so they're these organisms are suggesting to us that their mate might be a lot more potentially habitable real estate out there then we might have expected and so there is this picture that we get from doing classifications of life right and we know that it's an absolutely abundant highly branched tree of life of which there are essentially three categories bacteria archaea and eukaryotes and we're just one tiny tiny little twig on that tree and we find ourselves so self-important but you know nature actually doesn't agree with that in fact we're also now rewriting that tree of life with microbial biology and it turns out that this is a bacterial world right bacteria are expanding explosively our understanding our knowledge of different bacterial species and the eukaryotes and the archaea are in fact we in smaller and smaller fractions of life as we know it and is this hinting at looking for life as we don't yet know it either on this planet may be a shadow biosphere or on another planet such as Mars and this beautiful up-close-and-personal picture of Mars is coming from the Curiosity rover now curiosity wasn't built to find life it was built to tell us whether the conditions that we think are necessary for life ever existed on Mars and for how long and so curiosity has now shown us unequivocal unequivocally that liquid water flowed on the surface of Mars for a significant period of time looking at this laminated structure this is essentially what you'd see at the edge of a river delta and when curiosity uses its Sam drill to drill into that structure it finds carbonates something we had that had eluded us until now and something that indicates that yes indeed conditions might have been right for life for a very long time it's it's really a question of the water and more recently now we know that liquid water still flows on the surface of Mars these recurrent slope lineae which show up in the Martian spring when it gets a bit warmer and are very extensive and recur Martian year after Martian year are changing our ideas about the surface of Mars and how we can explore it in fact it's it's actually caused a bit of a riff in the astrobiology community about the question of the degree to which we have to sterilize the instruments that we send there now that we know that there is liquid water near or on the surface of Mars and so some some scientists want to go right now well we can and others say no we really have to rethink the whole idea of protected regions and levels of sterilization that we subject our explorers to so Mars hot topic as Seth said in our in our Institute lots of folks are studying Mars but it might be that we have to go farther out in the solar system to find life in fact we're interested in the giant moons of Jupiter Ganymede Callisto and Europa these are ice-covered worlds Europa's about the size of our moon and underneath the ice of Europa there's probably twice as much liquid salty briny water as all of the Earth's oceans right and further out go out to Saturn and it has a giant moon Titan and Titan has liquid lakes on its surface they're just not water it's too cold it's methane rains it rains hydrocarbons on on Titan and we wonder what kind of chemistry might be going on what this might tell us about origins of life early on earth and then you know there's this little pipsqueak moon called Enceladus and again the Cassini spacecraft studying Saturn and its moons showed us this really astonishing picture from the South Pole of Enceladus there are cryovolcanoes which are serving up into space the contents of a liquid salty ocean beneath the ice on this tiny little moon and once we know about those we went back to Europa and there are also plumes from cryovolcanoes not as reliably as we see on Enceladus but very intriguing these two plumes systems to me it seems like you know this might be the free lunch in the solar system if you want to know what's in that ocean you don't have to think about how you're going to melt or drill sterile II through all the kilometres of ice you can just fly through the plumes and sample what's down there so there are a number of studies that are now ongoing about plume missions in the Solar System and these might before very long end up giving us evidence of life beyond Earth now beyond our solar system there's the question of planets orbiting other stars and starting in 1995 when we found the first planet orbiting a solar type or a main-sequence type star we compiled a number of exoplanets quite rapidly but they were all big we had to wait to the launch of this mission the Kepler mission that Natalie Battaglia is going to tell you about at the next lecture we needed Kepler to show us the smaller planets and it's done that amazingly well and we can now say that there are more stars more planets excuse me then stars in the Milky Way and therefore there really is potentially a lot of habitable real estate out there we from Kepler we've learned about planets of a type that we don't have in our own solar system there are super-earths and there are many Neptune's and we use those terms but we actually don't know whether those bodies are like the earth or like Neptune they're just good classification tools and these worlds are some of the many that we want to explore in the future and what are all of my astrobiology colleagues at the SETI Institute and astrobiologists everywhere interested in they're interested in finding bio signatures they're interested in looking at the chemical composition of the atmosphere of some of these distant exoplanets looking for the signatures that we find in the atmosphere of Earth the signatures of biology so you can see there we have spectra right we have we have spectra absorption spectra of Venus Earth and Mars Venus and Mars lots of co2 co2 in the Earth's atmosphere as well but also oxygen and water and at longer wavelengths methane now carbon dioxide I'm sorry oxygen and methane molecules are very reactive you put those two gases together and they're gonna turn into carbon dioxide and water and that's indeed happening all the time in the Earth's atmosphere but because there's such a strong biological source function on the planet we have methanogens and bovine flatulence cow fart putting methane into the air and we have plants and photosynthesis putting oxygen into the air and we can see that in the spectra that we take of the Earth's atmosphere now if you had a really sensitive instrument and could isolate the image of the planet from the light from its nearby star and investigate its spectra you might be able to find such bio signatures now it's a really tricky problem because you can't do this in a vacuum you have to have context you have to have planetary history in order to decide whether the chemistry that you're seeing is possibly bio signatures so in some sense there's not really a smoking gun yet if you see that yeah that's life because it could have been produced a biologically but the space agencies around the planet are in fact all on board with this with this concept of going to look for bio signatures and I think they've got this covered but what about if you don't want to just find mass of microbes but what if you're interested in finding mathematicians well now what you have to do is look for techno signatures right you have to look for some evidence of the actions of an intelligent civilization that's using technology and makes a lot of sense because here on earth we do things that are visible over interstellar distances and it might be that a distant technological civilization is also doing something and particularly emitting electromagnetic radiation some kind of signals that a concerted effort and search program might be able to find so that's what's behind SETI we're looking for extraterrestrial technologies and we began our search over 50 years ago using radio telescopes at the turn of the century 2000 we started to do optical SETI and right now we're trying to move our searches down to the infrared where they're less susceptible to obscuration and scattering by dust than optical wavelengths radio goes right through radio isn't bothered by the dust optical is infrared is less so we're trying to move into that regime and what we're all looking for is some sort of engineered signal something that looks like what nature can't do all right so here's what we call a waterfall plot frequency on the horizontal axis time on the vertical axis and I don't have to tell you anything more about that chart for you to know that there's a noise there and there's something that isn't noise and this noise is from the cosmos right and it's from the instrumentation and these tracks are narrowband compressed in frequency radio signals and this is what the planet Mars looks like sometimes when we use our SETI instrumentation to look in that direction so when the Mars Reconnaissance Orbiter and Mars Express are on our side of Mars and they are communicating with the DSN and sending back information we see their carrier signals like this and it this is the kind of artifact that we're looking for and in the radio we look for this frequency compression in the optical we look for time compression we also look for narrowband lasers that are just at a single tone and single frequency but we look for time compression we look for very bright laser pulses that last a billionth of a second or less and these artifacts are clearly engineered and not something that nature can produce so whether or not our searches succeed is going to depend on a is anybody else out there and B how long the technological civilizations out there last what is their longevity how long are these signals transmitted because if over time civilizations rise up are there for a little while and then turn themselves off or do themselves in it's not very likely that any two technological civilizations will be close enough in space to be sensitive enough to detect one another and Co temporal around at the same time over this very long 10 billion year history of the Milky Way galaxy so longevity is the key and that's why Phil Morrison who is the co-author on the first modern SETI science paper has called SETI the archeology of our future right it's archaeology because signals coming from a long distance traveling over these very large distances between the stars if there's any information content that information will tell us about their past by the time it reaches us but because we made a detection because SETI was successful at finding that signal it tells us that on average technological civilizations survived for a long time that their longevity average longevity of technological civilizations is long that's what a successful SETI detection tells us and it also tells us that they those folks they made it through to a long future so we can - that's the hopeful piece of the message and as we're looking for these signals this electromagnetic radiation not to mention the other possible messengers particles like neutrinos or gravitational waves which we have no way yet of looking for engineered signals we just keep up we just keep reminding our colleagues who are doing that hmm let us know about any anomalies please right and we are concentrating on electromagnetic radiation even so the haystack we're trying to search through is incredibly vast and nine dimensional right there's three space dimensions a dimension of time two senses of polarization we have to search we don't know what frequency to look at if there's information we don't know what modulation scheme is being used and how that might perturb the nature of the signal and lastly we don't know how strong the transmitter is out there and how far away it is so we don't know how sensitive we need to be we could get all the other eight items correct in our in our searches but we might just not be sensitive enough yet to find it just like LIGO needed that last upgrade by a factor of two before it was finally successful finding gravitational waves so until recently Project Phoenix from the SETI Institute was the most extensive search that has been done we used pairs of antennas here in Australia at the Parkes telescope and another telescope called Mafra we used the 140 foot telescope at Green Bank West Virginia at the National Radio Astronomy Observatory and a telescope that was constructed or we refurbished by graduate students at Georgia Tech and a bunch of back end signal processing equipment and then we finished the search using a large telescope in Arecibo and our second telescope was all the way across the Atlantic in at shadow bank and we had a new set of equipment so over 10 years digital processing better fast enough so that you need to be refreshing your equipment and in terms of what we actually covered well a star times how many megahertz of the spectrum we looked at and we did about a billion I'm sorry a million star megahertz in that ten-year project and we were on the air about five percent of the time as we did this search for a decade now we really wanted to be on the air all the time and so we decided to build our own telescope in Northern California and in 2007 we commissioned the first stage of the Allen telescope array with 42 telescopes it's the first time that we've built a large large telescope out of a large number of small dishes right and that makes and they're all connected with computational power which makes silicon is important as aluminum and steel and in these constructions and so it gives us two paths forward for growth potential we can build more dishes for more sensitivity and we can increase our computational capacity at the back end of these telescopes to search for different types of signals over wider frequency ranges and from 2007 till I'm sorry from 2011 when the Kepler spacecraft announced the first list of confirmed exoplanets until just last year we used as our targets the exoplanets that we knew about and we observe them three at a time doing that helps us to discriminate our technology we call it interference from something that's potentially their technology but last year 2015 we switched once Kepler told us that every star as planets we switch to a survey of the 20,000 nearest stars and they are overwhelmingly small dwarf stars much less massive than the Sun and here you have a coordinate system that astronomers like to use for the sky right Ascension and declination and each of these dots is a target that we have studied and you can see that here that's the Kepler field and we spend a lot of time there and that left this declination strip fairly undersampled and we're back now trying to fill that in and here's another strip that we will not fill in because that's where the geosynchronous belt of satellites projects and we're certainly not looking there because they absolutely drowned out our very sensitive equipment so this is a piece of the sky that is not within our sights and if you'd like to follow our observations every day and night you can go to WWE quest info and John Richards has compiled a really nice site that lets you know what we're doing but what the computer is doing to be precise we very seldom get called until the computer has automatically checked in in real time for signals that it's found and it requires that they pass five levels of additional tests in the follow-up and only then do humans get called otherwise the computer says you've seen it before now seeing it again it's interference and so that's what what we're doing at the SETI Institute at the Allen telescope array but there are new players in the summer of 2015 Yuri Milner announced a 10 million a hundred million dollar grant over ten years to support SETI research and that has been going to the Berkeley SETI Research Center and they have a plan an observational plan over the next 10 years that will build really good signal processing equipment recorders and they will look from 1 to 10 gigahertz that's the portion of the radio spectrum where Nature has given us a quiet window lower frequencies have a lot of noise from synchrotron radiation electrons that are spinning around the magnetic fields of the galaxy's higher frequencies we get emission from our own atmosphere from water vapor and oxygen one to ten the quietest place in the radio spectrum and they'd like to systematically search through that they'd like to do a million stars and a hundred galaxies so where as project Phoenix two decades before did a thousand stars over a few gigahertz and we got that million star megahertz number just as you would predict from 20 years of improvement in digital signal processing the breakthrough listen project will be doing a factor of 10 to the 4 or more better with new equipment and so they've been renting time on here the Green Bank telescope in West Virginia and they have time and equipment on the Parkes telescope in New South Wales in Australia and also time on this automated planet finder telescope at Lick Observatory just down the road looking for optical SETI and they've also signed memorandum of agreements with the fast telescope that's coming online in China with meerkat an array that's coming online in South Africa and both the level telescope at Jarrah Bank and the Emer land array at in in the UK and we can expect that they will be putting recording equipment and signal processing equipment at these sites in the in the future so besides the SETI Institute and the breakthrough listen there is more SETI going on SETI at home how many of you have SETI at home on your computer or ever had right yeah right it's 12 years old I think you put distributed computing and citizen science on the map all right you can use your computer the the spare cycles from your computer to look at data that's been recorded and look for the same kinds of signals that we're looking for in real time and it's been running now at the Arecibo Observatory with the 7 beam feed we actually after the hurricane Maria there's been damage and it's not clear whether or who will be able to repair it it's not exhibition of funds to repair and continue operating that telescope so I put a question mark there sadly all right there's a low-frequency array that runs through the Netherlands across Europe and up into the United Kingdom it's begun looking for transient signals at low frequencies there's a uh Italian group called SETI Italia that has time on the 64 meter telescope and Mehta chena the Jet Propulsion Laboratory which was a part of NASA's SETI project until it was cancelled in 93 are now have moved one of the telescopes outside the fence and so now they can use it again for for SETI and so there is a project being run at the Gabbard Goldstone Apple Valley radio telescope with students doing a Sky Survey for SETI and the Japanese organized campaigns that put optical and radio telescopes looking at the same targets occasionally and then both the United UK and Sweden have started new SETI groups that are thinking about new search strategies and we welcome them in the radio and in the optical well Harvard has been doing an all-sky or the 80% of the sky that Harvard can see is drift scans and with student built telescopes and equipment the Keck Observatory has been doing studies to find exoplanets recording optical spectra that have now been reexamined looking for monochromatic laser signals or bright laser pulses there's a small amateur optical SETI Observatory in vachetta in Panama and a team at Penn State run by Jason Wright has been looking at the data from the infrared wives spacecraft looking for evidence of waste heat the actions of technology usage by a super civilization Kardashev two or three a lot more capable than we are and it's been suggested many times that what we really should be looking for is not maybe big wet biology running telescopes and transmitters like us but it all may be machines from an advanced technological civilization and so this generalized artificial intelligence if that's what it is out there where should we be looking for that well if it's really very advanced machines that want to do a lot of computing they're going to need power you might imagine that the computing was nested like matryoshka dolls these Russian dolls one inside another and at the very core around the power source is the fastest computing in the waste heat from that runs the next generation in the next generation on out to to low processing speeds at the outside and where might they be getting their power well black holes good idea neutron stars pulsars perhaps or maybe we should actually be looking for miniaturized artificial intelligence within our own solar system something like the solar sail the star shot or other sail projects from science fiction dragonfly and star wisp right somewhere within our solar system these might be good places to look if it's this machine intelligence that we're interested in so there are many unknowns but there are all kinds of compelling reasons to search all the sky all the time at all frequencies so we don't miss those transient fleeting signals and we understood this when we wrote SETI 2020 in 2000 saying here's what we should do for the next 20 years and we said we got to build an omnidirectional sky survey system at all these frequencies well haven't been able to do that yet but in fact we may be getting there there are three projects right now that are in early prototyping stages that we'll be looking at 20,000 square degrees all the time at a thousand square degrees and here in the infrared 0.1 square degrees and I like to share a little bit of my excitement about these new projects so at the SETI Institute we've just finished a crowdfunding campaign on IndieGoGo and thank you to anyone in the audience who helped support this we are wanting to build a total of 96 cameras in 12 observatories around the globe and these cameras have very fine gratings they have a very complicated fast readout process that can find pulses that last a thousandth of a second or less and by spreading these cameras out around the planet we can actually look at all sky all the time in the optical another those two other projects have now gotten munched into one as a collaboration based on using one meter Fornell lenses and that's Shelley right behind the lens and imagine a geodesic dome structure covered with these fernell lenses and then another layer below that of advanced photo detectors and the lenses focus a large area of the sky on the detectors and two of these would be in the infrared the rest of these would be operating in the optical so you get a thousand square degrees or a tenth of a square degree and maybe you build two of them for redundancy and to help discriminate against false positives so we've been thinking that in it for imaging and bio signatures the future is going to be in space and so the JWST will be launching in 2019 now it can do some transmission spectra of hot Jupiters probably not places we want to live but will tell us more about the atmospheres of these exoplanets we might we're going to launch something that is - what is it - point 4-metre class telescopes that the Department of Defense said to NASA oh you don't we built two of these and we only needed one so here and a nice we hope that it will be equipped with a coronagraph to block out the bright light from the star or we might in fact fly a star shape way out in front of it again you want to block the light from the star so you can hopefully see the very faint planets close to the star and we're beginning to talk about a big Space Telescope being 10 meters 16 meters that will eventually be able to detect those bio signatures that I spoke about before not very classy name at the moment we call it the large ultraviolet optical infrared telescope right we don't know where the sweet spot is for bio signature detection this is in the future all right well we thought that the future was always going to be in space for detecting bio signatures but recently there's been an idea that's come that we're beginning to look at about how you might build very lightweight mirrors and out of new materials and focus them all and it might be able to look for bio signatures very close by and it's going to be a privately funded project all right now what about SETI in the future an optical SETI well there are large glass telescopes being constructed as we speak the 30-meter telescope which I guess we now know is going to go to Hawaii the extremely large European telescope 39 meters and the large synoptic survey telescope to give you a movie of things that are changing on the sky every day every other day all right and we'd like to get SETI instrumentation onto these big pieces of glass we'd also like to get some manifestation of this OSS omnidirectional Sky Survey that we've seen saying all along that we need to do hopefully it will be one or all of those optical projects that we're talking about and then we need to figure out how to do it in the radio and in the radio we've got fast coming on board and said he is in its science case we've got the Square Kilometre Array being built as an international project sometime 20 20 20 20 s 20 30 s 3,000 telescopes over the carew desert right we're in their science case as well and maybe if we get lucky we will be able to build in the u.s. the next generation Very Large Array are very very successful telescope in Socorro New Mexico it's going to depend on the decadal review and what astronomers say they want to do but we'd like to be in their science case as well and lastly this is you know the granddaughter of the XO life finder telescope all these mirrors phased up with the ability to detect the infrared leakage the infrared signature from the second law of thermodynamics of advanced technologies out there we call it Colossus does that give you an idea how big it's going to be it's something like 74 meters across there all right nobody has stepped up to fund that one yet but we're doing the first baby steps with the prototyping so SETI is certainly one way that we could find life beyond Earth but even while we're searching even if it never detects a signal said he has another job to do and that's to help us share this cosmic perspective with everybody else in the world because the process of thinking about SETI the process of doing SETI getting involved with setting forces you to have this different perspective it essentially holds up a mirror and says hey you guys you earthlings you're all the same when compared to something that evolved out there independently and so this mirror this perspective can help to trivialize the differences among humans that we find so difficult to deal with today and I think this is absolutely critical for men the challenges that we face in the future challenges that do not respect national boundaries so if we can use SETI kind of as training wheels a pilot project get the world working together right then I think that we have a chance at solving these larger more divisive challenges climate water food security poverty we've got to work on all of us and we have to work on them together and I think SETI can help us get there so my last slide these words are from Caleb Scharf the chairman of the astrobiology department in columbia caleb reminds us that on a finite world and we are certainly on that a cosmic perspective isn't a luxury it's a necessity so when you leave here tonight not while you're in the car if you're driving but when you get home pick up your devices and change your profiles and make the first thing in your personal profile the first thing you say about yourself that you're an earthling and then act like it thank you the the kind of radio transmissions we're looking for presumably have to be fairly high energy if they're going very long distances are are we anywhere kind of putting out really high energy radio transmissions so that others can find us well we are in fact leaking we're leaking radio and television broadcasts but being engineered signals the engineers haven't put any more power into those than as needed to get to the receivers right so they're not very high power I think maybe our most detectable leakage is coming from airport radars but we are not deliberately transmitting not now there is another debate within the community about whether we should because if everybody listens and nobody transmits mmm it's not gonna work too well so but think about it think about transmitting how long are you gonna transmit a day a year a century I think transmission probably if it's your strategy and if you decide to do it I think you need to sign up for something like a 10,000 year program and we're not good at two-year plans yet 10,000 years is a big stretch for us and I think what that means is that we transmission is in our future when we grow up when we become an advanced technology but people disagree with me I mean yeah over here is this thing on okay hi dr. Carter my question is how do you reconcile the Fermi paradox with your line of work because I think you'd have to be pretty optimistic about that when it comes to the furni pair okay the Fermi paradox for those of you who haven't heard of it is usually phrased this way if there had ever been anywhere and any win in the history of the Milky Way galaxy another technological civilization then on a short on a time that's scale that's really short they would they would transition from the detection of or the the invention of science to interstellar travel very short time scale and then with interstellar travel again on a short time scale compared to the age of the galaxy they would eventually colonize the entire galaxy right it doesn't matter much what kind of model you use it all comes out that doesn't take very long once you start and so then they we say well but they're not here and I know that some people think about Aunt Alice being abducted for medical experiments but let me say in terms of the evidence they are not here therefore there can never have been anywhere anywh in another technological civilization so we're the first well my problem with that is that structure is that I don't think we can say they are not here I showed you pictures of miniaturized artificial intelligence that might be within our solar system I think we could probably rule out big battlestar galactica kinds of things that the Lagrange points in our Sun Earth system but not if they were cloaked and and not if they were dark right and not anywhere else we really not even looked beyond our doorstep there could be rocks out there 150 meters in size and they have our name on it and their incoming and we don't know about them yet so we've really very poorly explored our local surroundings and if you take that cosmic haystack and now you're talking about signals not spacecraft that cosmic haystack that nine dimensional volume let's set that equal to the volume of the Earth's oceans so how much of the ocean have we searched fifty years must have searched a lot well it's more like one 12-ounce glass out of there so shion's it's huge the space that signals could be hiding is huge the universe the real physical universe is also vast our galaxy's very large I'm not impressed I don't think we can say they're not here and therefore there's no strength to that so-called paradox thank you okay hi um you spoke about the longevity or the duration of technological civilizations and you said that our detection of any signal from such a civilization would indicate that they are long-lived but I don't understand why that would be it could be very temporary okay but if if civilizations on average are short long short lived right we've got we've had technology for about a hundred years if we do ourselves in tomorrow it's Donald Trump tweets the wrong message to North Korea if we turn ourselves off tomorrow the chance and so a hundred years is the average longevity of a technological civilization then if it only lasts a hundred years and we have to be around the same time right to receive that message more or less and it's ten billion years of the galaxy's history then the probability is very small the technology's only last for a short time that that any two would overlap in time that's what I was trying to say so that probability gets greater and greater as the longevity expands does that make sense yes I'll still keep going yes I'll let you know okay thank you okay over that hello I just wanted to thank you first of all for all your work you've inspired me and said he from when I was a young child so I appreciate that my question is has any thought been given to what I've heard called the dark forest theory where if there are technologically advanced civilizations out there their first prerogative is to hide themselves because if they let themselves be known then that lets seems you know it alerts other civilizations to a possible threat and so the first thing you would want to do is hide yourself well that I think probably says more about our own internal fears then perhaps anything to do with the actual universe out there so we're afraid that there's something that we need to hide from okay well if they can hurt us then they have to get here and that means their technology's a lot more advanced than ours because we aren't going anywhere anytime soon well through the solar system but the stars still seem to be far away in the future okay so now this is an advanced technology how did they get to be that advanced you know if in fact everybody out there is mean and intent on evil then I don't see how they can survive for that long I think there's another alternative and that's Steven Pinker and I think the book is the better angels of our nature I mean nine hundred pages in which he demonstrates that over time we have become kinder and gentler and that that is a type of cultural evolution that one can expect if you don't do that you do yourself in and if that's the case then I think that advanced technologies may not be something that we need to fear it's one hypothesis Stephen Hawking you may have heard thinks it's another way around and tells us that didn't work out very well for the natives when Columbus showed up in the Caribbean but I think old advanced technology can't survive cannot become old unless they evolve beyond those aggressive tendencies that probably helped them get intelligent in the first part so it's not something that I particularly lose sleep over I don't know the answer I don't know any way of finding the answer except seeing if we can detect evidence of someone else's technology all right thank you thank you for your perspective I thank you for the talk um I have a question so if you had to make kind of a guess as to what would be the first signal we would ever you know receive what would it be and also to follow up what do you think the impact it would have on like you know our society or governments etc well I don't know what the first signal is likely to be I know what we're looking for and therefore what we might find because we've built special equipment to do that but indeed if we make a serendipitous discovery because we build some new instrumentation to look at the universe because we want to understand and suddenly we stumble on something unexplained the the best example being the original detection of pulsars which were called LGM one two three by the time they got to four they figured that can't be that many of them out there but again it was because a new instrument was built and looked at the universe the sky in a different way so I don't know what is most likely in terms of the impact on society we've actually held meetings we've held a number of meetings on that topic trying to bring in a broad range of expertise and domain knowledge when all is said and done the best they could tell us was that the world will respond to the announcement of a signal in accord with the belief systems that are upheld at the time and you go we paid your airfare for this right there's a lot of the population that already believes again without definitive evidence that we have detected them that they are here so those folks aren't going to be a real upset there might be some fundamentalist religious groups which are very upset because they postulate a particular special relationship between humans and Jesus Christ that's probably not going to be a real winner for them in terms of the rest of the world I think this global communication is a crazy 24-hour cycle we're in still does have some real news not just fake news and I think probably that helps us avoid any irrational responses so that's my best guess okay over here good evening you mentioned that we don't know what bio and techno signatures to look for are we not spending at least some effort looking back at Earth to see what sort of bio and techno signatures the earth is emitting yes we are and in fact how do you take a look at the Earth's atmosphere from a distance and do a chemical assay of the Earth's atmosphere as if you were very far away well we don't have spacecraft now that far away but we can do something we can look at the moon we can look at earth shine reflecting off the moon and that is a full disk spectrum of the earth and so we have done that and that is one of the kinds of things that's helping us look at what spectral region should we build these bio signature detectors to investigate so yeah you can see the earth shine on the moon and you know what the chemistry of our atmosphere looks like thank you yeah you have a question about extremophiles on earth and possibly on Mars are the I understand extremophiles are found in rocks on earth just plain rocks and I don't know if they're found where there's permafrost on rocky areas and then again going to Mars how deep is the permafrost on Mars yeah how do do we have to dig to get below it well certainly you're right that Crypt endo crypto lithic mic ins are found in rocks in the Dry Valleys of the Antarctic they've actually permeated the porous rock and are leeching the minerals that they need for chemosynthesis out of the rock in terms of Mars and looking in the permafrost I think that the first place we'll be trying to look is for underground liquid aquifers because all that water that we think was on Mars early on we see some of it frozen in the caps the polar caps of the planet it's certainly lost a bunch of the water but models for how much water could have been lost to photodissociation indicate the is probably still a lot there it's going to be underground and I think that's probably going to be our first attempt how deep Joe no we see shadowy things that look like they might be entrances to caves penny Boston now the chair of the NASA Astrobiology Institute over at Ames she's the woman to talk to about how deep these caves might be and what we might find her shallow net for a probe hello so a couple of questions the first one is if we are focusing our efforts into trying to find civilizations that are more advanced than us how do we reconcile the fact that they have not found us yet I mean there are they not looking or you know how they find us and we just don't know or you know how do you explain that and the second question real quickly is how so more than the impact on the world have what do you think the impact on you would be if we find life next week I'm sorry the last question what would the impact of on yourself as a person yes well I've got the answer to that one I've got a very good bottle of champagne in the refrigerator at the observatory and at the SETI Institute as well she will drink champagne for short after we say holy so in terms of them finding us well they may have we have an expanding bubble of our leakage radiation going out let's say 80 90 hundred light years since our first transmissions they may be within that bubble and may have detected us but if they're farther away than say half the distance 50 light-years we won't have had time to receive any response from them hi there got your message right so it may be a question of time and and for billions of years they would have been able see our bio signature so they would know that this place was good for life technology they have to wait a while one more okay sorry Marquess truth question I'm interested in the biology of extremophiles do we know whether all of them have are based on DNA that's chemically similar to ours and if so is there any kind of life anywhere that's ever been discovered that doesn't have the same DNA structure as ours yes the extremophiles that we study are all DNA right they seem to have as she trait looked back with the moderate mitochondrial DNA they seemed to have a thermophilic structure they were heat lovers we don't know whether that means that they originated in hot places or that they were the only organisms that could survive the late heavy bombardment which vaporized our oceans 3 plus 3.8 billion years ago we don't know and the so you had another piece of the question so they are all DNA based yes and the North Academy of Sciences issued a report now about five years ago essentially we call it weird life life that uses some other bio solvents life that has some other metabolic processes than the standard life that were aware and their conclusion was it could be here existing on this planet and we haven't found it because all the tools that we use to look for life are based on DNA let's thank dr. Carter

Channel: SVAstronomyLectures

Views: 72,466

Rating: 4.492857 out of 5

Keywords: astronomy, science, astrophysics, science news, SETI, Jill Tarter, Search for Extra-terrestrial Intelligence, Allen Telescope Array, SETI Institute, Aliens, radio astronomy, life in the universe

Id: wYcM0BOYHyw

Length: 74min 23sec (4463 seconds)

Published: Sun Oct 29 2017