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  • richardmitnick 3:22 pm on August 25, 2015 Permalink | Reply
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    From io9 via SETI: “How SETI Will Understand Messages Broadcast by an Alien Intelligence” 


    SETI Institute

    1

    8/24/15
    George Dvorsky

    NRAO VLA
    Karl V. Jansky Very Large Array

    Imagine the day when we finally receive a signal from an extraterrestrial intelligence, only to find that there’s a message embedded within. Given that we don’t speak the same language, how could we ever hope to make sense of it? We spoke to the experts to find out.

    Communication with Extraterrestrial Intelligence, aka “CETI”, is the branch of SETI concerned with both the transmission and reception of messages between ourselves and an alien civilization. Scientists have been trying to detect signals from an extraterrestrial intelligence (ETI) since the 1960s, but haven’t found anything.

    Allen Telescope Array
    SETI Institute’s Allen Telescope Array

    3
    SETI@home, a public distributed computing project running on BOINC software and using data from the Arecibo Observatory
    Arecibo Observatory
    Arecibo Observatory

    SETI@home
    BOINC

    At least not yet. If and when we do receive a signal, whether it be an intercepted transmission or a deliberate attempt to get our attention, we’ll be tasked with deciphering an alien message. It could prove to be a monumental task, but it’s a problem with no shortage of solutions.

    Natural or Unnatural Signals?

    The first challenge will be to recognize an incoming alien signal. This may prove easier said than done.

    When pulsars were first discovered, for example, their eerily precise spectral flashes convinced some scientists that we were actually looking at some sort of alien beacon. And in 1977, the 72-second-long Wow! signal was likewise interpreted as extraterrestrial in nature. More plausibly, it was just a natural, continuous signal, or some human-instigated artifact.

    2

    These episodes aside, most SETI researchers agree that an alien signal will be unambiguous.

    “Due to the random motions of the particles that are ultimately at the source of natural electromagnetic emission, these emissions tend to get spread out in frequency or in time,” says Andrew Siemion, a PhD candidate in astronomy at SETI-Berkeley. “Technology, on the other hand, is capable of producing very fine time and frequency structure. We can use this fine structure to distinguish between natural and ‘unnatural’ sources.”

    Siemion says it’s important to keep in mind that our knowledge of physics and the cosmos isn’t complete, and it’s conceivable that there are some natural processes that could mimic the types of signals we look for in SETI experiments.

    “But discovering these would be great as well,” he told io9.

    According to Douglas Vakoch, Director of Interstellar Message Composition at the SETI Institute, we should actively look for signals that stand out from the cosmic static as distinctly artificial.

    “The radio signals created by nature are spread out on the radio dial,” he says. “We’re looking for narrowband signals at one place on the radio dial.”

    Overcoming the Language Barrier

    Given that an ETI would most assuredly “speak” a different language than any found on Earth, it’s fair to ask how we could ever hope to overcome such a barrier.

    How SETI Will Understand Messages Broadcast by an Alien Intelligence

    2
    Linear A tablets. (Credit: University of Houston/CC BY 3.0)

    And indeed, linguists are already struggling with this issue as it pertains to Linear A—an undeciphered writing system used in ancient Greece. It’s not immediately obvious if we’ll ever crack the code of this ancient language. Likewise, if we ever intercept an unintentional alien message, say something akin to a radio or television transmission, we may never be able to decipher the message, save for any visual or acoustic information gleaned from the broadcast.

    But it would likely be a different story if the message was intentional.

    “If an advanced civilization did want to communicate with us, they would probably choose to base their communication on something we have in common, such as the fact that we live in the same physical universe,” says Siemion. “They might use the properties of astrophysical objects, like pulsars, quasars or the shape of our galaxy, as a first step at teaching us their language.”

    Siemion says that an advanced ETI, if they were fairly close to us, say within 40-50 light-years, might actually know quite a lot about us. They may have already taken it upon themselves to decipher parts of our early radio and television transmissions. If this is the case, Siemion says it may be very easy for them to communicate with us in a way we understand.

    Speaking in Math

    Alternately, we can forgo arbitrary symbolic communication altogether and use the logic of math as a communication medium. As Vakoch says, the ability to communicate mathematics will allow aliens to communicate virtually anything that can be quantified.

    “One of the most basic parts of mathematics is counting,” Vakoch told io9. “When we think of counting, we usually imagine counting 1, 2, 3, and so on. But there are other ways to count as well.”

    For example, Vakoch says we could tell an ETI about the Fibonacci series by starting with the simplest numbers, zero and one, and then add them together, and then repeat the process over and over, adding the last two numbers in the series. Zero plus one is one, one plus two is two, and so on until the Fibonacci series is obvious.

    Spencer Greenberg from Ask a Mathematician says it shouldn’t be too hard for an ETI to develop a signal that, if we received it, could tell us it was created by another intelligent life.

    To understand why, Greenberg considers how we ourselves might construct a signal if we wanted aliens to notice that we’re intelligent. To that end, he devised a (somewhat oversimplified) approach that assumes an ETI would have developed the notions of binary encodings of integers (which is by no means an overreaching assumption).

    3
    Talking in code: Greenberg says we could pulse our signal by emitting a relatively high frequency, and at other times emitting a relatively low frequency. Each high section of our signal could represent the digit 1, and each low section, the digit 0. “With this mechanism in place, it’s easy to transmit in binary,” says Greenberg.

    By sending out pulses in binary, Greenberg says we could let the receiver know how many bits we’re using to represent a single number. After settling on the number of bits per group (e.g. 16), we could communicate our system by simply starting the message off with counting.

    So for instance, if we wanted to signal that we are treating groups of 16 bits as a single number, we could transmit all the binary numbers from 0 to 65,535 in order, each of which would be represented by 16 binary digits. Therefore, our transmission would start 0, 1, 2, 3, 4, and so on, which in binary, with 16 bits per number, would be:

    0000000000000000, 0000000000000001, 0000000000000010, 0000000000000011, 0000000000000100, etc.

    Greenberg says that instead of sending each of these numbers a single time through, we might actually want to send each sequence of 16 bits a fixed number of times in a row (say, 100 times each) to provide for redundancy. That way if our signal gets corrupted in transit, it’s still easy to correct any mistakes that are introduced.

    It should be obvious to an alien receiver that we are sending digits in groups of 16, with each 16 digit block representing a number. That would allow us to transmit any number we please (so long as it’s between 0 and 65,535) by representing it in the next 16 digits of our binary code.

    At that point there would be plenty of options for what to send to prove that we’re reasonably intelligent. We could transmit all the prime numbers from 2 up to 65,521. We could also send triplets of numbers where the third number in the triplet is equal to the first two multiplied together, or we could send pairs of numbers that are twin primes. We could even convey mathematical formulas by creating special symbols like an equal sign.

    Other ways to Communicate

    6

    In 1974, scientists transmitted a message into space consisting of 1,679 bits, arranged into 73 lines of 23 characters per line. Called the Arecibo Message, it consisted of the Arecibo telescope itself, our Solar System, DNA, a stick figure of a human, the biochemicals of terrestrial life, and other things.

    Such messages aren’t perfect or overly sophisticated, but they can convey simple concepts, like our location relative to our Sun, and our physical appearance. Clearly, an ETI could send or transmit a similar pictorial message.

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    The Pioneer message: So simple even an alien could understand it. (Credit: NASA)

    Mathematics could also be used to send algorithmic messages. These systems, such as CosmicOS and logic gate matrices, use a small set of math and logic symbols to form the basis of a simple programming language that an alien receiver could conceivably run on a virtual machine. Algorithmic messages, if complex enough, could actually be used to convey advanced concepts—and even signs of intelligence—if run on a sufficiently advanced computer system.

    7
    Binary logarithms represent a microarray of expression data for 8,700 mouse genes. (Credit: Louis M. Staudt/National Cancer Institute/Public domain)

    As for natural language processing, we’re still a long ways off from having the ability to make sense of arbitrary symbols. But Laurance Doyle, a member of the SETI institute, is using math to do just that. Doyle is trying to use information theory—a branch of math that looks at the structure and relationships of information—to separate binary code from random 0’s and 1’s. The idea is to find linguistic substance within undefined symbols, whether they be written or oral, and an associated grammar and syntax. Fascinatingly, Doyle’s work is being applied by marine biologists in an effort to crack the dolphin language code.
    Hmm, What to Talk About…

    Assuming that an alien civilization wants to reach out to us and say “hello”, it’s reasonable to wonder what else they might want to say to us.

    Vakoch says the most important thing an alien civilization could communicate to another is their intention to make contact.

    Siemion says ETIs might offer tips on existential dangers to humanity, both intrinsic threats, like biological weapons or artificial superintelligence, and extrinsic threats, such as asteroid impacts or a looming nearby supernova.

    “Some people believe that technological progression and increased altruistic tendency go hand-in-hand—that is, that the more advanced a civilization becomes, the friendlier they get,” says Siemion. “Personally, I don’t think we have any evidence of that. In fact, I think we have evidence that the contrary may be the case.”

    The Risk Factor

    Indeed, this could be a rather dangerous exercise. We run the risk of receiving and translating a malign message, such as a trojan horse that contains a kind of computer virus, or the seeds of our own destruction.

    And as we’ve written before at io9, the effort to deliberately transmit messages to aliens—an endeavor known as METI—needs to be seriously re-considered. Our efforts to reach ETIs could alert an evil force to our presence.

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    Alien Outpost

    “Sending messages of our own creation to try to make any possible aliens aware that we exist, is an incredibly risky proposition,” says Greenberg. “Sure, they might be friendly, but then again, they might not—and that’s a big risk to take,” says Greenberg. “Attempting to wake up a force more powerful than ourselves that we do not understand is simply not a good plan.”

    Vakoch says that concerns of alerting an ETI to our presence are too late.

    “Any civilization with the ability to travel between the stars would already know we’re here from our accidental leakage radiation,” he says. “So a sufficiently advanced extraterrestrial might already have picked up ‘I Love Lucy.’ But they still don’t know that we’re attempting to communicate with them. That’s the most important reason for us to transmit powerful, intelligible signals to other stars—to let any intelligence out there know we’re ready to make contact.”

    See the full article here.

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  • richardmitnick 10:06 pm on August 19, 2015 Permalink | Reply
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    From Seth Shostak at SETI Institute: “Are You a Martian?” 


    SETI Institute

    8.19.15

    SETI Seth Shostak
    Seth Shostak, Senior Astronomer and Director of the Center for SETI Research

    1
    No image credit

    Could your favorite Earthling also be your favorite Martian?

    Allow me to respond: The answer is “yes.” It’s possible that billions of years ago, tiny bits of biology quit the Red Planet and infected ours. If so, your family tree — and that of every other terrestrial life form — has its deepest roots not in the ancient oceans of Earth, but in the vanished seas of Mars.

    The mechanism by which biology can spread through space without the benefit of expensive space-agency hardware is known as panspermia. Life hitches a ride on sunlight or inside rocks — not rockets.

    This is more than a curiosity. It has important implications for the search for life in the solar system — a search that’s heating up.

    Panspermia is hardly a new idea: the philosopher Anaxagoras was the first to publish on the subject more than two millennia ago. But its current vogue can be traced to thought experiments by the Swedish chemist Svante Arrhenius at the beginning of the twentieth century. He figured microorganisms, which can be tougher than old boots, might be pushed from one world to the next by the radiation pressure of stars.

    That idea might work if the emigres are tiny and don’t insist on going far. But a much better bet is to be a protoplasmic pilgrim inside a dirt clod kicked into space by a meteor impact. Sometimes called “lithopanspermia” for reasons that are obvious if you studied Greek, this mode of transport has the benefit of a protective environment. That’s a necessity if your travel time is really long – hundreds of thousands or millions of years. After all, space is hardly benign: cosmic rays, extreme temperatures, and prolonged desiccation will relentlessly corrode any biology that takes too much time en route. Being inside a rock helps.

    But is this Johnny Appleseed mechanism for spreading life between worlds likely to be for real?

    To answer that, you first need to ask whether enough rocks are actually kicked off a planet to ensure that at least a few will accidentally land on another world. And second, would any of their microscopic passengers survive the trip?

    Consider the panspermia prospects between Mars and Earth. Scientists estimate that in the early days of the solar system, billions of rocks between an inch and a yard in size were involuntarily shuttled from the Red Planet to ours. Their travel time might have been as short as a year, but most would have taken much longer, more like a million years. A rock can wander around the inner solar system for quite a while before actually hitting anything.

    So could any biology within these space-borne lumps survive such an extended trip? After all, the conditions on board are worse than RyanAir. The rocks and their passengers would have been bombarded by radiation, cut off from water, and subjected to temperature extremes as bad as the moon. But it turns out that some hardy earthly microbes could survive these steerage-class conditions. Astrobiologists have identified terrestrial bacteria able to zone out in spore form for a million years. If you eventually put them in contact with water, they’ll come back to life like sea monkeys.

    It seems that panspermia was possible between Mars and Earth roughly four billion years ago, assuming there was any life on the Red Planet to make the trip. And perhaps there was. In its youth, Mars was wetter and warmer than now, and could have spawned living things at a time when Earth was as lifeless as an octogenarian slumber party. Because so many martian rocks were kicked into space, it’s highly probable that at least some would have come from an inhabited patch of Mars — assuming it had inhabitants. And some of those would have landed in a suitably welcoming patch of Earth.

    In this way, our planet may have garnered its biota — not as the result of any processes here on Earth, but thanks to a rain of rocks from Mars. If sometime in the next few decades we discover the remnants of ancient life on the Red Planet that are based on DNA, then we’ll have good reason to believe that terrestrial biology is an import. We could say that not only men are from Mars; we all are.

    The possibility that Earth’s carpet of life might not be indigenous may sway our priorities in the search for life in the solar system. Should we continue to place our heavy bets on Mars, or would it be better to explore the moons of Jupiter and Saturn? Biology would be far more isolated on these latter worlds, and unlikely to be related to us. They would be true aliens — perhaps the most interesting sort of life to find.

    As intriguing as it is, panspermia doesn’t offer any clues about life’s origins. Indeed, it only seems to push the problem of biology’s beginnings to another planet. But there’s this: If life can spread, then countless worlds could be encrusted with biology even if generating it in the first place is difficult or highly improbable.

    Turning hydrocarbons into protoplasm might be a semi-miracle, but life itself could be as common as fast food.

    See the full article here.

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  • richardmitnick 4:09 pm on August 19, 2015 Permalink | Reply
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    From SETI Institute: “NATHALIE CABROL TO LEAD CARL SAGAN CENTER AT SETI INSTITUTE” 


    SETI Institute

    August 18 2015
    Nathalie Cabrol
    SETI Institute
    Ph: 650-810-0226
    Email: ncabrol@seti.org

    Bill Diamond
    SETI Institute
    Ph: 650-960-510
    Email: bdiamond@seti.org

    Seth Shostak
    SETI Institute
    Ph: 650-960-4530
    Email: seth@seti.org

    1

    The SETI Institute announces the appointment of Nathalie Cabrol as the lead for its multidisciplinary research programs into the nature and distribution of life beyond Earth. She will head the Institute’s Carl Sagan Center for the Study of Life in the Universe.

    Cabrol, who has been with the Institute since 1998, is an astrobiologist specializing in planetary science, and is deeply involved in efforts to explore and characterize Mars. She also develops exploration strategies for the moons of the outer solar system where the conditions essential for the origin and sustenance of life are present. She is conducting research at Mars analog sites in the Andes, and in particular the adaptation strategies of life in these extreme environments. Cabrol was the spokesperson for the selection of Gusev crater as the landing site for the Spirit Rover, and is a science team member for NASA’s Mars Exploration Rover mission.

    2
    The Martian crater Gusev, with Ma’adim Vallis snaking into it

    “Over its thirty-year history, the SETI Institute has grown from a group of visionary scientists who search for evidence of technologically advanced civilizations to an organization embracing the full breadth of astrobiology research,” says President and CEO Bill Diamond. “This includes solar system exploration, the discovery of exoplanets, fundamental astrophysics, and both radio and optical SETI experiments.”

    Cabrol has extensively published in academic journals, and is the author of several books on the subjects of planetary science and terrestrial extreme environments. She is the recipient of NASA and other research awards. Cabrol is a Wings Worldquest Carey Fellow and was elected Air and Space Wings Worldquest Woman of Discovery. She is a frequent lecturer in both academic and public settings.

    “Our Institute is often associated with SETI efforts only,” notes Senior Astronomer Seth Shostak. “But in fact the organization is heavily involved with a truly catholic range of studies, all bearing on the scientific study of life. This new appointment recognizes that breadth of effort and interest, and will increase cross-pollination of ideas and effort among the science teams.”

    Research programs at the SETI Institute include involvement in past and ongoing Mars missions, participation in the New Horizons Mission to Pluto, climate and geo-science, the study of asteroids and meteors, the hunt for, and characterization of, exoplanets with the Kepler telescope, discoveries of planetary moons and rings, and both optical and radio SETI searches, the latter using the Institute’s own Allen Telescope Array. The Institute also investigates and sponsors symposia on the societal consequences of the discovery of extraterrestrial life.

    NASA New Horizons spacecraft
    New Horizons

    NASA Kepler Telescope
    Kepler

    Allen Telescope Array
    Allen Telescope Array

    “We are building a new, vibrant and more relevant SETI Institute on the foundation of a proud past,” says Diamond. With Nathalie’s leadership of the Carl Sagan Center, we bring new strength and vitality to our mission of understanding the origins and nature of life in the universe.”

    See the full article here.

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  • richardmitnick 11:22 am on August 9, 2015 Permalink | Reply
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    From Daily Galaxy: “New Advances in the Search for Extraterrestrial Life –‘Will It Be Inconceivable to Us?'” 

    Daily Galaxy
    The Daily Galaxy

    August 09, 2015
    No Writer Credit

    1
    No image credit

    A thin layer near the surface of Earth is teeming with life of huge diversity: from micro-organisms to plants and animals, and even intelligent species. Up to now, this forms the only known sample of life in the Universe. We now readily accept that the laws and concepts of physics and chemistry apply throughout the cosmos. Is there a general biology as well: is there life beyond Earth?
    With the Sun just about half-way through its life-time, humankind as we know it is likely to constitute a rather short transient episode, and advanced extra-terrestrial life might be inconceivable to us in its complexity, just as human life is to amoebae.

    Pinpoints of light in the night sky have probably always made humankind speculate about the existence of other worlds, but the presence of planets orbiting stars other than the Sun has become a proven reality only within the last 15 years. While the vast majority of the more than 450 [number is far larger] extra-solar planets that are known to date are gas giants like Jupiter and Saturn, some spectacular discoveries of about 20 planets of less than 10 Earth masses have already indicated that rocky planets with conditions suitable to harbour life are probably rather common.

    One of the big unknowns is how likely it is for life to emerge once all conditions are right. There is no lack of its building blocks; the number of molecules fundamental to Earth’s biochemistry that have already been found in the interstellar medium, planetary atmospheres and on the surfaces of comets, asteroids, meteorites and interplanetary dust particles is surprisingly large. Giant “factories”, where complex molecules are being synthesised, appear to make carbonaceous compounds ubiquitous in the Universe.

    If the genesis of life arises from chemistry with a high probability, one might speculate whether this process occurred more than once on Earth itself, leading to the existence of a terrestrial “shadow biosphere” with a distinct Tree of Life. Moreover, there are several other promising targets within the Solar System, namely Mars, Europa, Enceladus, and, for biochemistry based on a liquid other than water, Titan. Evidence for life is not easy to gather; any chemical footprint needs to be unambiguously characteristic, and to exclude an abiogenic origin. The most powerful probe would result from returning a sample to a laboratory on Earth.

    The year 2010 marks the 50th anniversary of the first search for radio signals originating from other civilizations and up to now all “Search for Extra-Terrestrial Intelligence” (SETI) experiments have provided a negative result.

    Allen Telescope Array
    SETI Institut’s Allen Telescope Array

    SETI@home screensaver
    SETI@home massive personal computer project

    However these have probed only up to about 200 light-years distant, whereas the center of the Milky Way is 25,000 light-years away from us. And, even if there is no other intelligent life in the Milky Way, it could still be hosted in another of the remaining hundreds of billions of other galaxies.

    Advanced efforts are now on the drawing board or already underway for the further exploration of the Solar System and the detection of biomarkers in the atmospheres of extra-solar planets, while searches for signals of extra-terrestrial intelligence are entering a new era with the deployment of the next generation of radio telescopes.

    With the detection of extra-terrestrial life being technically feasible, one needs to address whether perceived societal benefits create an imperative to search for it, or whether such an endeavour may rather turn out to be a threat to our own existence.

    Evolutionary convergence, as seen in the biological history on Earth, suggests that the limited number of solutions to sensory and social organizational problems will make alien civilizations at a comparable stage of evolution not look too different from our own. As historical examples indicate, meeting a civilization similar to ours might actually turn into a disaster.

    Rather than aliens invading Earth, realistically expected detection scenarios will involve microbial organisms and/or extra-terrestrial life at a safe distance that prevents physical contact. As far as exploring other lifeforms is concerned, any applied strategy must exclude biological contamination – not only to protect ourselves, but also to support cosmic biodiversity. No legally enforceable procedures are in place yet, and a broad dialogue on the development of a societal agenda on extra-terrestrial life is required.

    The search for life elsewhere is nothing but a search for ourselves, where we came from, why we are here, and where we will be going. It encompasses many, if not all, of the fundamental questions in biology, physics, and chemistry, but also in philosophy, psychology, religion and the way in which humans interact with their environment and each other. The question of whether we are alone in the Universe still remains unanswered, with no scientific evidence yet supporting one possible outcome or the other. If, however, extra-terrestrial life does exist, an emerging new age of exploration may well allow living generations to witness its detection.

    See the full article here.

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  • richardmitnick 1:12 pm on August 8, 2015 Permalink | Reply
    Tags: , KQED, SETI Institute,   

    From KQED via UC Santa Cruz: “What Would Really Happen If a Tsunami Hit San Francisco?” 

    UC Santa Cruz

    UC Santa Cruz

    KQED bloc

    August 5, 2015
    Johanna Varner, KQED Science

    1

    As part of our series Bay Curious, we’re answering questions from KQED listeners and readers. This question comes from Steven Horowitz, who wanted to know:

    If a tsunami were to hit the Golden Gate, what would be its real effect on communities facing the San Francisco Bay?

    Steven’s question came from watching the summer’s action flick, “San Andreas.”

    “I was sitting there watching the giant tsunami course through the Golden Gate and into the bay,” he says. “I looked at that and thought: Wouldn’t there be some kind of dissipation coming through the Golden Gate?”

    It’s All About Our Faults

    Despite the terrifying image of a 500-foot wave about to wash over the Golden Gate Bridge, tsunamis do not actually pose a considerable threat to the Bay Area.

    It all has to do with the kinds of geologic faults that we have (and don’t have).

    Tsunamis are caused when a tectonic plate under the ocean smashes into and slides underneath a continent.

    6
    The tectonic plates of the world were mapped in the second half of the 20th century.

    That process, known as subduction, never happens smoothly or quietly. It shakes up the seabed, displacing a huge volume of ocean water that races across the ocean, and eventually floods the shore.

    But the San Andreas Fault is different.

    7
    Map of the San Andreas Fault, showing relative motion

    It’s called a slip-strike fault because the two plates slide past each other horizontally. Of course, any time plates move, the ground shakes. But here, there is no subduction and no displaced ocean.

    Meaning no killer tsunamis. Even San Francisco’s infamous 1906 earthquake generated only a 4-inch wave at the Presidio gauge station.

    Small Waves Still Pack a Punch

    Although they aren’t generated here, tsunamis do occasionally hit our shores. Since 1850, more than 50 tsunamis have been recorded in San Francisco Bay. Most were generated by earthquakes in subduction zones near Russia, Japan or Alaska.

    Eric Geist, a geophysicist at the U.S. Geological Survey in Menlo Park, says that size is the most important factor in evaluating risk.

    “We can look at anything, from huge waves to micro-tsunamis, that you’d never see with your eyes but our instruments can detect,” he says.

    The worst tsunami to hit the Bay Area was triggered in 1964 by a magnitude 9.4 earthquake in Alaska, Geist says. That wave rolled in at just under 4 feet and damaged marinas and private boats in Marin County.

    The infamous 2011 tsunami that devastated parts of Japan also arrived in the East Bay 10 ten hours later at just over a foot in height, and caused millions of dollars of damage in Crescent City.

    2
    The 2011 Japanese tsunami, photographed as it arrived in Emeryville.

    The Cascadia subduction zone, which runs roughly from Mendocino County to Vancouver Island, could also produce a massive earthquake and tsunami.

    8
    The area of the Cascadia subduction zone.

    But Geist says it’s unclear how a tsunami from “The Really Big One” would affect the Bay Area.

    “Oregon, Washington and California north of Eureka would really bear the brunt of that tsunami,” he explains.

    But What If a Big One Arrived?

    Although it’s unlikely, Steven Ward, a professor of Earth & Planetary Sciences at UC Santa Cruz, has created a series of animations to show how a big tsunami might spread through San Francisco Bay.

    In Ward’s simulations, the incoming wave stands just over 16 feet tall. This is much larger than historical tsunamis, but Geist agrees that a wave this size is theoretically possible.

    Approaching the Golden Gate at 55 mph, the wave would first hit the outlying areas of Point Reyes National Seashore and Montara. It would then start to flood low-lying areas like Half Moon Bay.

    “It’s not like splash and dash,” explains Ward. “When the water comes in, it’s going to flood.”

    It would feel like a 12-hour tidal cycle was packed into an hour.

    “And it will do as much damage when it goes back out and drags along cars and debris,” he adds.

    3
    A 30-foot-high tsunami would barely reach the top of the pylon on the Golden Gate Bridge. (Salim Virji/Flickr)

    The original wave and splashbacks from shore would then start to pile up as they squeeze through the 1-mile-wide Golden Gate Strait. In Ward’s simulations, the wave reaches a maximum height of about 30 feet.

    “That’s barely to the top the pylon,” says Ward, who is confident that the bridge would have no trouble withstanding the wave energy. “It probably wouldn’t even touch the steel.”

    Finally, the wave would fan out into San Francisco Bay. Parts of Mission Bay and the Marina could see significant flooding, but by the time it reached Treasure Island or the East Bay, the wave would be less than 3 feet tall. It would probably not even make it to the South Bay.

    4
    Red regions of San Francisco may be vulnerable to inundation by a tsunami.

    Verdict: San Francisco Is Relatively Safe

    Steven Horowitz, who asked Bay Curious the question, was glad to hear that the tsunami would be nothing like the movie.

    “By the time it gets to Berkeley, which is where I’m sitting right now, I think I’m pretty safe,” he says. “Sounds like it’s not going to come rushing up University Avenue.”

    Bay Area residents can also rest assured that there have been no recorded deaths from tsunami-related events in San Francisco. And even a worst-case-scenario Cascadia tsunami would take several hours to reach the city, providing ample time to mobilize a response.

    And just in case, the City and County of San Francisco has a tsunami plan in place. It includes a strategy for evacuating people from vulnerable areas like Ocean Beach, coordinating basic services (like shelter, water, food, and medical attention) and performing search and rescue.

    Still, “if you get a warning and are in a tsunami zone, follow the evacuation instructions,” says Ward. “What do you have to lose, a couple hours of your time?”

    See the full article here, and you can view the animations referred to above.

    Please help promote STEM in your local schools.

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    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
  • richardmitnick 1:57 pm on July 31, 2015 Permalink | Reply
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    From Space.com via SETI Institute: “SETI Targets Kepler-452b, Earth’s ‘Cousin,’ in Search for Alien Life” 


    SETI Institute

    q

    July 31, 2015
    Nola Taylor Redd, SPACE.com Contributor

    Temp 0
    An artist’s concept of the alien Kepler-452b in orbit around its star Kepler-452, which is located 1,400 light-years from Earth. NASA has billed the potentially habitable planet as Earth’s bigger, older cousin.

    Scientists with the SETI (Search for Extraterrestrial Intelligence) Institute have already begun targeting Earth’s “older cousin,” Kepler 452b, the first near-Earth-size world found in the habitable zone of a sun-like star.

    NASA announced the discovery of Kepler-452b last week, billing the planet as the closest thing yet to an Earth 2.0 beyond Earth’s solar system. Researchers have used the Allen Telescope Array [ATA], a collection of 42 radio antennas in northern California, to study the planet for radio signals that could indicate the presence of intelligent extraterrestrial life.

    SETI ATA
    ATA

    So far, the antennas haven’t tuned into any broadcasts.

    “That’s no reason to get discouraged,” Seth Shostak, senior astronomer with the SETI Institute, which is based in Mountain View, California, said during a July 26 webcast by the Slooh Community Observatory.

    “Bacteria, trilobites, dinosaurs—they were here but they weren’t building radio transmitters,” he said.

    Tens of billions of worlds

    Kepler-452 is a sunlike star, located 1,400 light-years from Earth, in the constellation Cygnus. The star’s newly discovered planet, Kepler-452b, has a radius approximately 1.6 times larger than Earth’s. The mass of the planet and its density, which would indicate its composition, have been a bit more challenging to pin down.

    “We would love to be able to do a direct mass measurement so we could measure density,” said Jon Jenkins of NASA’s Ames Research Center in Moffett Field, California, lead author on the paper that identified Kepler-452b. “That would be a big clue as to whether this is a rocky world or a water world or a gassy world.”

    Instead, the team relied on statistics to conclude that the planet has a “better than even chance” of having a composition similar to Earth.

    “The odds slightly favor this planet being rocky,” Jenkins said.

    Based on its size, orbit and star, Kepler-452b is the closest analogue to Earth yet discovered, its discoverers and NASA officials have said.

    Kepler-452b orbits its star once every 385 days, about three weeks longer than Earth takes to travel around the sun. This orbit places the planet squarely in what scientists call the “habitable zone,” the region around a star where liquid water could exist at a planet’s surface. Water is thought to be a key requirement for life to evolve, so Kepler-452b is one of the best potentially habitable worlds found to date.

    SETI Institute researchers are using the Allen Telescope Array, a collection of 6-meter (20 feet) telescopes in the Cascade Mountains of California, to observe Kepler-452b. So far, the array has observed the exoplanet on over 2 billion frequency bands, with no result. The telescopes will continue to observe over a total of 9 billion channels, searching for signals of alien intelligence.

    “There are three ways to find life in space,” Shostak said. The first is to “go there and look”, as humans are doing on Mars and the moons of the solar system, he said. For planets like Kepler-452b, which lie so far from the solar system, such a trip would be a challenge with today’s technology.

    The second is to “build big telescopes and analyze the light bouncing off of a planet,” Shostak said. NASA’s Hubble Space Telescope has already begun to probe the atmospheres of distant planets.

    NASA Hubble Telescope
    NASA/ESA Hubble

    However, Jenkins said, the host star is too dim to allow for this sort of examination with either Hubble or its successor, the James Webb Space Telescope.

    NASA Webb Telescope
    Webb

    The third way to find life in space is to search for signals that could indicate intelligence. “That’s what SETI does,” Shostak said.

    Both Shostak and Jenkins emphasized that what makes Kepler-452b truly important is what it indicates for the wide population of planets beyond the solar system. Before this planet’s discovery, no sun-like stars had been found to host rocky worlds in their habitable zones, making Earth fairly unique in the known galaxy. Although statistics suggested many such planets orbited other stars, no such worlds had been observed with modern instruments.

    Jenkins noted that the existence of Kepler-452b suggests similar finds will be made in the near future.

    “We have a really good opportunity in the future to find a similar-size planet in a similar-size orbit about a similar star far closer to us,” he said.

    Unlike the distant exoplanet, a closer exoplanet could have its atmosphere probed for potential signatures of life.

    “What you really want to know is what [fraction] of planets could be habitable,” Shostak said. He added that Kepler-452b suggests that fraction is perhaps one in five, or even one in three.

    “There could be tens of billions of such worlds in the galaxy,” Shostak said.

    See the full article here.

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  • richardmitnick 8:38 pm on July 6, 2015 Permalink | Reply
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    From SETI: “Pluto in Sight” 


    SETI Institute

    1

    It takes a village to pull off a decade-long mission to the outer pickets of the solar system.


    SETI Institute Senior Research Scientist, Mark Showalter briefly discusses the discovery of Pluto, its moons and the Kuiper belt then goes on to tell us what we might expect to see when the New Horizons spacecraft approaches Pluto.

    The SETI Institute is deeply involved with the New Horizons mission to Pluto, and several of our scientists are awaiting results that could truly revolutionize understanding of the solar system’s early history.

    We’ve listed these people below, together with brief descriptions of their interests. As you can imagine, they are eagerly awaiting the data that are already streaming back from the spacecraft. The flyby of Pluto will forever transform this storied world from an enigmatic dot of light to one that we will know far better than the ancients knew the Earth.

    New Horizons is about to shift the study of Pluto from astronomy to geology. Meet some of the scientists who are making this happen.

    2
    Mark Showalter

    Mark Showalter is a Senior Research Scientist at the SETI Institute, and a member of the New Horizons Science Team. His particular focus is making sure that the spacecraft sails past Pluto without suffering damage due to dust or small particles. Keep in mind that most of the information collected by this craft will only be radioed back after the flyby, so a smooth passage is absolutely essential.

    This is not the first time Mark has been uncovering new information about the outer solar system. In addition to finding two of Pluto’s five known moons, Styx and Kerberos, he discovered two moons of Uranus and one of Saturn.

    3
    David Hinson

    David is a Co-Investigator on the New Horizons mission, and a member of the Atmospheres Science Theme Team. By using an on-board transmitter, Hinson will be exploring the atmospheres of both Pluto and Charon by means of radio occultation measurements.

    4
    Angela Zalucha

    Planetary scientist Angela Zalucha makes analytic models of planet atmospheres. The New Horizons results will guide her work by accurately determining Pluto’s diameter, the temperature near the surface, and the distribution and composition of ices on its landscapes. This information will help solve mysteries about Pluto’s atmospheric circulation (i.e., its weather and climate) including such things as wind strength and direction.

    5
    Ross Beyer

    Ross is a member of the New Horizons Geology and Geophysical Imaging sub-team, and participates in image processing and geological interpretations. As data continue to stream back from the spacecraft over the next year, he will be building the first 3-D terrain models of Pluto’s surface. Ross will also be making sure the images are correctly mosaicked together, and will be one of the Pluto system’s first cartographers.

    6
    Cristina Dalle Ore

    Cristina studies organic compounds often found on the surfaces of planets, and in particular the types of compounds known as tholins – blackish materials that form when ultraviolet light from the Sun hits water, ice, methane, and nitrogen. This dark, low-temperature material may cover some of the worlds in the Pluto system, and understanding how it was formed and where it is found could offer us important clues to life’s origin.

    See the full article here.

    Please help promote STEM in your local schools.

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  • richardmitnick 2:29 pm on May 12, 2015 Permalink | Reply
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    From Seth Shostak at SETI Institute: “Super Civilizations: What Do They Really Want?” 


    SETI Institute

    May 11, 2015

    SETI Seth Shostak
    By Seth Shostak, Senior Astronomer and Director of the Center for SETI Research

    Highly advanced aliens seem MIA, according to a recent study by astronomers at Penn State University. These researchers checked out a huge gob of cosmic real estate — roughly 100,000 galaxies — and failed to find clear evidence for any super-sized alien empires.

    At first blush, this is an astounding result, given that the universe is more than 13 billion years old. Surely that’s enough time for at least a few ambitious alien species to establish the type of galactic-wide imperium so beloved by sci-fi fans.

    Could it be that no one is out there? Are we now free to declare ourselves the acme of brain power in this part of the cosmos, and certify that everything out to 50 million light-years is Klingon-free?

    That may be a bit overmuch. Let’s consider what the Penn State folks really did. In a truly clever piece of work, they used NASA’s WISE (Wide-Field Infrared Survey Explorer) space telescope to measure the infrared light coming from all those galaxies. Infrared is produced by anything warm — by heat.

    NASA Wise Telescope
    WISE

    The second law of thermodynamics mandates that heat is the final product of just about any type of engineered activity. Your auto shoots warm gases out the tailpipe, the local utility plant dumps waste heat in a pond, your TV gets warm… Waste heat is the elephant graveyard of all processes using energy, which is to say, all processes. Even writing a byte of data onto your hard drive produces some heat. So does erasing it.

    Now where there’s heat, there’s light (at least of the infrared variety), so the Penn State astronomers were hunting for galaxies that generated far more than the usual amounts of infrared. This could be a tipoff for what’s called a Type III civilization — the black belt of all societies — one that’s corralled the energy resources of an entire galaxy to power the ultra-advanced lifestyles of its residents. All that activity would generate prodigious amounts of waste heat, and that’s what the astronomers sought.

    Alas, their hunt failed to discover any interesting cases in which the total amount of heat energy was comparable to the total light energy radiated by all the stars in a galaxy. Bummer.

    But hang on. What does that really say?

    Allow me to vex you with some numbers. First, consider what the astronomers could have detected. If you add up all the star shine of a typical galaxy, it’s roughly 10 billion times more than is belched out by our Sun, or 4 trillion trillion trillion watts. So the Penn State survey was looking for galaxies producing roughly that amount of energy (or more) in waste heat.

    Possibly that number is beyond your everyday experience. But consider what it implies. We now know that a galaxy similar to our own could contain up to 100 billion habitable planets. Even if every one of these worlds is gilded with an advanced civilization, they would each have to be burning up a trillion times as much energy as all of Homo sapiens combined for that galaxy to register in the Penn State survey. That’s right, a trillion times as many kilowatts as all of humanity’s lighting, heating, transport, warfare and other entertainments — per planet.

    That’s asking a lot, and obviously these alien super civilizations would have to be much different than our own. Maybe their planets each house a trillion times as many people as Earth, or, at the other extreme, perhaps they have lifestyles that are a trillion times more profligate than ours. Call me timid, but neither seems very reasonable.

    The real problem here (if you consider there’s a problem) is that our concept of super civilizations assumes that they have the same mindset that we do; they want what we want. We suppose there’s a law of the universe insisting that advanced societies are always on a colonization binge, taking control of as much of a galaxy as they can — similar to the Galactic Federation or the Imperium of Man. Bigger is better.

    But while that view of upscale aliens comports with Darth Vader’s game plan, is that what sophisticated societies really do? There are serious problems with maintaining an empire spanning 100,000 light-years, not least of which is the finite speed of rockets and radio.

    In addition, there’s this: In the past few decades, we’ve finally begun to exploit the fact that there’s a lot of benefit to making things smaller rather than bigger (consider your personal electronics). As physicist Richard Feynman once put it when discussing the scale of things, “there’s plenty of room at the bottom.”

    Furthermore, we also tend to assume that big-dog extraterrestrials will relentlessly increase their energy use per capita — a number that has long been a proxy for the standard of living in our own society. But maybe what really happens is that technology becomes very efficient, and energy use ceases to steadily climb.

    In other words, the view that being highly advanced implies having more stuff gulping more energy might be an anthropocentric aberration.

    And by the way, in case the numbers bandied about here have numbed your neocortex, let’s clearly state their implication: the Penn State study has ruled out the existence of a certain type of society. But it hasn’t limited the possibilities for myriad other kinds of extraterrestrial civilizations. Those 100,000 galaxies could be positively stuffed with intelligent beings — be they biological or artificial — who happily exist with energy budgets that aren’t staggeringly extreme.

    So it’s still plausible that there’s a lot of cosmic company out there. No, the new observations don’t jibe with what’s portrayed in 21st century space opera. But what our species finds desirable today — 200,000 years after Homo sapiens 1.0 — will undoubtedly seem silly and quaint if we ever reach the point of colonizing the galaxy. Star Wars represents today’s view of the future, not necessarily that of our descendants or of other species.

    I recommend maintaining some perspective: The other inhabitants of the universe are alien — which is to say, they’re not like us.

    See the full article here.

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  • richardmitnick 8:42 am on March 28, 2015 Permalink | Reply
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    From SETI’s Seth Shostak at NYT: “Messaging the Stars” 

    New York Times

    The New York Times

    MARCH 27, 2015

    SETI Seth Shostak
    Seth Shostak

    SETI Institute

    1

    For more than a half-century, a small group of astronomers has sought intelligent company among the stars. They’ve done so by turning large radio antennas skyward, hoping to eavesdrop on signals from an advanced society. It’s a program known as SETI, the Search for Extraterrestrial Intelligence.

    But now some researchers propose that we should do more than simply don headphones and await E.T.’s call: We should make serious efforts to encourage a response from putative aliens by deliberately transmitting our own messages. It’s a simple idea, akin to tossing a bottle into the cosmic ocean. But recent arguments for what’s termed active SETI have loosed a storm of controversy, one that has even washed into the halls of academe.

    Why is this? Why has the sending of dispatches to worlds many trillions of miles distant suddenly become a hot-button issue? The simple answer is that there’s now a perception that advertising our existence could be a mortal threat to the planet.

    The reasoning is this: While no one has yet offered decisive proof for life beyond Earth, in the past two years astronomers have learned that tens of billions of habitable planets suffuse our galaxy. Consequently, to believe that only Earth has spawned intelligence is to insist that our world is the site of a miracle. That point of view rarely appeals to scientists.

    The aliens could very well be out there. And that realization has spurred a call by some for broadcasts intended to elicit a communication from at least the nearest other star systems. But we know nothing of the aliens’ possible motives or behavior. Therefore, it’s conceivable that betraying our existence might prompt aggressive action from space.

    Broadcasting is likened to “shouting in the jungle” — not a good idea when you don’t know what’s out there. The British physicist Stephen Hawking alluded to this danger by noting that on Earth, when less advanced societies drew the attention of those more advanced, the consequences for the former were seldom agreeable.

    It’s a worry we never used to have. Victorian-era scientists toyed with plans to use lanterns and burning pools of oil to contact postulated Martians. In the 1970s, NASA bolted greeting cards onto spacecraft that will leave our solar system and wander the vast reaches between the stars. The Pioneer and Voyager probes carry plaques and records with information about what humans look like and where Earth is, as well as a small sampling of our culture.

    NASA Pioneer 10
    NASA/Pioneer 10

    NASA Voyager 1
    NASA/Voyager 1

    Those messages move at the speed of rockets. But in 1974, a three-minute encoded pictogram was transmitted using the large radio antenna at Arecibo, Puerto Rico.

    Arecibo
    Arecibo Radio Observatory

    It moves at the speed of light, 20,000 times faster. More recent radio transmissions include a Beatles song beamed by NASA to the North Star, a Doritos advertisement launched to a planetary system in the Big Dipper, and a series of broadcasts sent to nearby stars using an antenna in Crimea.

    When most people believed that aliens were no more than easy black hats for Hollywood, the idiosyncratic nature of these messages could be easily dismissed. But if cosmic company is a legitimate possibility, shouldn’t we offer up something more edifying than pop music and snack food? A deliberate transmission should represent all of humanity — not short-circuit the important question of who will speak for Earth.

    Consequently, recent conferences on the merits of active SETI have sought the advice of social scientists. Among their worries is whether to be up front about humanity’s seamy side: Should we tell the extraterrestrials about war and injustice?

    Personally, I think this concern is overwrought. Any society that can pick up our radio messages will be at a level of development at least centuries beyond our own. They would be no more incensed by our bad behavior than historians who learned that Babylonians attacked one another with spears. It seems naïve to imagine that, by shielding aliens from the less flattering aspects of humanity, we would somehow lessen any incentive to do us harm. If there’s a danger, mincing words is unlikely to eliminate it.

    A better approach is to note that the nearest intelligent extraterrestrials are likely to be at least dozens of light-years away. Even assuming that active SETI provokes a reply, it won’t be breezy conversation. Simple back-and-forth exchanges would take decades. This suggests that we should abandon the “greeting card” format of previous signaling schemes, and offer the aliens Big Data.

    For example, we could transmit the contents of the Internet. Such a large corpus — with its text, pictures, videos and sounds — would allow clever extraterrestrials to decipher much about our society, and even formulate questions that could be answered with the material in hand. Sending the web on its way would take months if a radio transmitter were used. A powerful laser, conveying bits much like an optical fiber, could launch these data in a few days.

    Sending messages — even big ones — is technically feasible. However, there’s still the highly controversial matter of whether to broadcast at all. Who decides? One could simply let the public weigh in, but doing so wouldn’t address the security issue. Even if a majority is comfortable with a transmission, how does that mitigate the possible danger?

    The inability to gauge this peril prompts some critics to argue that, given the possibly existential threat posed by active SETI, we should choose the side of caution. We should simply forbid powerful transmissions to the skies. Indeed, a small consortium of academics in California has drafted a petition urging this.

    It’s a wary approach. It’s also poor insurance. Any extraterrestrials with technology advanced enough to threaten us will surely have antennas larger than our own, instruments that can pick up the television and radio signals broadcast willy-nilly since World War II. We are already shouting into the jungle, albeit with less volume than a deliberate signal. But the dangerous creatures may have good hearing.

    Additionally, if we forbid high-powered transmitters aimed at the sky, we shut out such obvious future technologies as better radars for aviation and tracking dangerous asteroids. Do we really want to hamstring our descendants this way?

    A decision to engage in active SETI has not been made. The benefit — learning our place in the cosmos — is only hypothetical, and so is the danger. But I, for one, would hesitate to let a paranoia based on nothing more than conjecture shackle the activities of our children and our children’s children. The universe beckons, and we can do better than to declare that future generations should endlessly tremble at the sight of the stars.

    Seth Shostak is the director of the Center for SETI Research at the SETI Institute, and a host of the radio program Big Picture Science.

    See the full article here.

    SETI Institute promoted the Allen Telescope Array for signal collection.

    Allen Telescope Array

    The Arecibo Radio Telescope is the prime source for data for SET@home a Citizen Science project that runs on personal computers with BOINC software from UC Berkeley.

    SETI@home screensaver

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  • richardmitnick 12:57 pm on February 14, 2015 Permalink | Reply
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    From New Scientist: “The search for ET: how close are we?” 

    NewScientist

    New Scientist

    23 December 2014
    Graham Lawton

    In 1950, Nobel prizewinning physicist Enrico Fermi posed his famous paradox: if extraterrestrial intelligence exists, why haven’t we found it?

    Why indeed? It is not as if we haven’t been trying. The search for extraterrestrial intelligence (SETI) has been going on for over half a century. It has mostly drawn a blank. But once in a while there is a flurry of excitement. Here are some of the highlights.

    First contact

    On 8 April 1960, Cornell University astronomer Frank Drake pointed a 26-metre radio telescope at two nearby stars. The telescope – based at the US National Radio Astronomy Observatory (NRAO) in West Virginia – was tuned to a frequency of 1420 megahertz, the wavelength of radiation naturally emitted by hydrogen in space. Thus began Project Ozma, the first experiment explicitly designed to look for aliens.

    Drake was hoping to detect radio waves sent by an extraterrestrial civilisation. He chose the emission frequency of hydrogen because it is the most abundant element in the universe, and hence an obvious signal for any intelligent civilisation trying to get itself noticed by another.

    Although the stars – Tau Ceti and Epsilon Eridani – were considered promising candidates, being nearby and sun-like, Project Ozma detected nothing in over 150 hours of observation.

    In 1972, astronomers at NRAO had a second go, this time using a bigger telescope that collected as much data in a minute as the older one could in 19 years. They sporadically monitored more than 650 stars for four years, again searching for the hydrogen signal – and again finding nothing. But the Ozma projects established SETI as a credible discipline and set the scene for many more attempts.

    The Wow! signal

    One of the projects inspired by Ozma was the “Big Ear” programme at Ohio State University, which ran from 1973 to 1995. On 15 August 1977, its 79-metre dish picked up a powerful burst of radio waves from the general direction of Sagittarius.

    2
    WOW signal

    3
    Big Ear

    The burst lasted 72 seconds and was very close to the emission frequency of hydrogen – considered a likely candidate for alien messages. When astronomer Jerry Ehman saw the signal recorded on a computer printout, he circled it in red pen and scrawled “Wow!” on the sheet of paper.

    The set-up of the telescope made it hard to work out exactly where the burst came from, but the general patch of sky was identified.

    The “Wow!” signal remains the most promising putative alien signal ever detected by SETI. But despite extensive searches of the same patch of sky it has never been seen since.

    Radio ga-ga

    In 2007, astronomers at West Virginia University discovered a previously unknown celestial phenomenon: a super-intense, very brief burst of radio waves apparently originating outside our galaxy.

    The Fast Radio Burst lasted for just 15 milliseconds but released more energy than the sun emits in about a month. Calculations suggested that it came from an object no more than 1500 kilometres across.

    At the time there was no obvious explanation for the FRB. Astronomers speculated that it came from a single cataclysmic event, such as the final collapse of a dying black hole or the merger of two neutron stars.

    A handful of other FRBs have since been detected but there is still no agreed explanation.

    Inevitably, the gap has been filled by speculation that FRBs are messages from aliens. Earlier this year, Nigel Watson, author of the UFO Investigations Manual, told the UK’s Daily Mail newspaper that FRBs could be evidence of a “vast alien communication network”. Or, he said, it could just be an as-yet-unknown astronomical phenomenon.

    Messages closer to home

    In the absence of a smoking gun from the sky, some alien hunters have looked for signs on our doorstep. For a while, crop circles – strange geometric patterns that began to appear in arable fields in southern England in the 1970s – were claimed by many people to be messages from ET. They are now known to be the work of artists and pranksters.

    Around a decade ago a slightly more serious idea began to circulate: perhaps there are alien messages in our DNA. As Paul Davies, author of The Eerie Silence: Renewing our search for alien intelligence, wrote in New Scientist in 2004: “Might ET have inserted a message into the genomes of terrestrial organisms, perhaps by delivering carefully crafted viruses in tiny space probes to infect host cells with message-laden DNA?”

    A decade on, we have no evidence whatsoever that ET did this. In the past couple of years the idea has been revived in a slightly different form: a pair of Kazakh researchers have proposed that the genetic code would be a better place to plant a signal, and even claim to have found what they call “the Wow! signal of the genetic code”.

    Comin’ atcha

    Our failure to detect alien messages has not deterred us from sending some of our own. As soon as humans learned to communicate using radio waves we began unwittingly broadcasting to the stars: the earliest radio shows are now about 100 light years away and counting.

    The first deliberate attempt to contact ET was in 1972, with the launch of NASA’s Pioneer 10 space probe.

    NASA Pioneer 10
    Pioneer 10

    This carried a gold-plated aluminium plaque bearing pictures of a male and a female nude and graphical information about the origin of the craft, in the (extremely unlikely) event of it being intercepted by aliens. Pioneer 10 is currently on the fringes of the solar system on course for a star 68 light years away. Pioneer 11, launched in 1973, also carries a plaque.

    NASA Pioneer 11
    Pioneer 11

    A more detailed message was loaded onto the Voyager 1 and 2 probes, launched in 1977.

    NASA Voyager 1
    Voyager 1

    NASA Voyager 2
    Voyager 2

    Both carry a gold-plated copper disc encoding over 150 images and sounds from Earth, greetings in 55 languages, and brief excerpts of music. (In 2010, Voyager 2 started sending some unusual signals back to Earth, prompting speculation that it had been hijacked by aliens. It turned out to be a computer glitch.)

    The chances of any of these physical messages ever being picked up is remote in the extreme, but they are not our only attempts at contact. At the dedication of Puerto Rico’s Arecibo radio telescope in November 1974, a digital message was beamed towards the star cluster Messier 13 (M13) 25,000 light years away.

    Arecibo Observatory
    Arecibo radio telescope

    The message – encoded in microwaves – included the numbers 1 to 10, various graphical representations of DNA and its constituent atoms, and drawings of a human figure, the planets of our solar system and a radio telescope. The message is currently just over 40 light years from Earth. It has yet to receive a reply.

    Since then, numerous other messages have been broadcast to the stars, including a giant Doritos advert beamed from the Arctic archipelago of Svalbard to a solar system 42 light years away. Such messages are controversial, however: some scientists believe we should keep our heads down so as not to alert malicious aliens to our feeble presence.

    See the full article here.

    There are two major efforts for contact: SETI Institute which operates the Allen Telescope Array.

    Allen Telescope Array

    and

    SETI@home, a project of “Radio SETI” in Citizen Science with processing of data running on home computers on BOINC software from UC Berkeley. SET@home gets its raw data from Arecibo radio telescope.

    SETI@home screensaver

    Please help promote STEM in your local schools.

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