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  • richardmitnick 4:43 pm on June 1, 2021 Permalink | Reply
    Tags: "Scientists find molecular patterns that may help identify extraterrestrial life", Abiological signatures, Biosignatures, Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry, Mass spectrometry (MS) is a principal technique that scientists will rely on in spacecraft-based searches for ET life., Recent mass spectroscopy data from NASA's Mars Curiosity rover suggest there are organic compounds on Mars but they still do not provide evidence for life., Scientists have begun the search for extraterrestrial life in the Solar System in earnest.,   

    From Tokyo Institute of Technology [東京工業大学](JP): “Scientists find molecular patterns that may help identify extraterrestrial life” 


    From Tokyo Institute of Technology [東京工業大学](JP)

    June 1, 2021

    Henderson James Cleaves
    Specially Appointed Professor
    Earth-Life Science Institute (ELSI),
    Tokyo Institute of Technology
    Tel +1-85-83663049

    Thilina Heenatigala
    Director of Communications
    Earth-Life Science Institute (ELSI),
    Tokyo Institute of Technology
    Tel +81-3-5734-3163
    Fax +81-3-5734-3416

    Scientists have begun the search for extraterrestrial life in the Solar System in earnest, but such life may be subtly or profoundly different from Earth-life, and methods based on detecting particular molecules as biosignatures may not apply to life with a different evolutionary history. A new study by a joint Japan/US-based team, led by researchers at the Earth-Life Science Institute (ELSI) at the Tokyo Institute of Technology, has developed a machine learning technique which assesses complex organic mixtures using mass spectrometry to reliably classify them as biological or abiological.

    Scientists are at the brink of being able to detect ET Life, which was predicted to be difficult decades ago. New techniques suggest there might be clever analytical tricks using machine learning for doing so. Credit: National Aeronautics Space Agency (US).

    In season 1, episode 29 (Operation: Annihilate!) of Star Trek, which aired in 1966, the human-Vulcan hybrid character Spock made the observation “It is not life as we know or understand it. Yet it is obviously alive; it exists.” This now 55-year old pop-culture meme still makes a point: how can we detect life if we fundamentally don’t know what life is, and if that life is really different from life as we know it?
    The question of “Are we alone?” as living beings in the Universe has fascinated humanity for centuries, and humankind has been looking for ET life in the Solar System since NASA’s Viking 2 mission to Mars in 1976.

    There are presently numerous ways scientists are searching for ET life. These include listening for radio signals from advanced civilisations in deep space, looking for subtle differences in the atmospheric composition of planets around other stars, and directly trying to measure it in soil and ice samples they can collect using spacecraft in our own Solar System. This last category allows them to bring their most advanced chemical analytical instrumentation directly to bear on ET samples, and perhaps even bring some of the samples back to Earth, where they can be carefully scrutinised.

    Exciting missions such as NASA’s Perseverance rover will look for life this year on Mars; NASA’s Europa Clipper, launching in 2024, will try to sample ice ejected from Jupiter’s moon Europa, and its Dragonfly mission will attempt to land an “octacopter” [no image available] on Saturn’s moon Titan starting in 2027.

    These missions will all attempt to answer the question of whether we are alone.

    Mass spectrometry (MS) is a principal technique that scientists will rely on in spacecraft-based searches for ET life. MS has the advantage that it can simultaneously measure multitudes of compounds present in samples, and thus provide a sort of “fingerprint” of the composition of the sample. Nevertheless, interpreting those fingerprints may be tricky.

    As best as scientists can tell, all life on Earth is based on the same highly coordinated molecular principles, which gives scientists confidence that all Earth-life is derived from a common ancient terrestrial ancestor. However, in simulations of the primitive processes that scientists believe may have contributed to life’s origins on Earth, many similar but slightly different versions of the particular molecules terrestrial life uses are often detected. Furthermore, naturally occurring chemical processes are also able to produce many of the building blocks of biological molecules. Since we still have no known sample of alien life, this leaves scientists with a conceptual paradox: did Earth-life make some arbitrary choices early in evolution which got locked in, and thus life could be constructed otherwise, or should we expect that all life everywhere is constrained to be exactly the same way it is on Earth? How can we know that the detection of a particular molecule type is indicative of whether it was or was not produced by ET life?

    It has long troubled scientists that biases in how we think life should be detectable, which are largely based on how Earth-life is presently, might cause our detection methods to fail. Viking 2 in fact returned odd results from Mars in 1976. Some of the tests it conducted gave signals considered positive for life, but the MS measurements provided no evidence for life as we know it. More recent MS data from NASA’s Mars Curiosity rover suggest there are organic compounds on Mars but they still do not provide evidence for life. A related problem has plagued scientists attempting to detect the earliest evidence for life on Earth: how can we tell if signals detected in ancient terrestrial samples are from the original living organisms preserved in those samples or derived from contamination from the organisms which presently pervade our planet?

    Scientists at the Earth-Life Science Institute at the Tokyo Institute of Technology in Japan and the National High Magnetic Field Laboratory at FSU (US) in the US decided to address this problem using a combined experimental and machine learning computational approach. The National MagLab is supported by the National Science Foundation (US) through NSF/ DMR-1644779 and the State of Florida to provide cutting-edge technologies for research. Using ultrahigh-resolution MS (a technique known as Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (or FT-ICR MS)) they measured the mass spectra of a wide variety of complex organic mixtures, including those derived from abiological samples made in the lab (which they are fairly certain are not living), organic mixtures found in meteorites (which are ~ 4.5 billion-year-old samples of abiologically produced organic compounds which appear to have never become living), laboratory-grown microorganisms (which fit all the modern criteria of being living, including novel microbial organisms isolated and cultured by ELSI co-author Tomohiro Mochizuki), and unprocessed petroleum (or raw natural crude oil, the kind we pump out of the ground and process into gasoline, which is derived from organisms which lived long ago on Earth, providing an example of how the “fingerprint” of known living organisms might change over geological time). These samples each contained tens of thousands of discrete molecular compounds, which provided a large set of MS spectra that could be compared and classified.

    In contrast to approaches that use the accuracy of MS measurements to uniquely identify each peak with a particular molecule in a complex organic mixture, the researchers instead aggregated their data and looked at the broad statistics and distribution of signals. Complex organic mixtures, such as those derived from living things, petroleum, and abiological samples present very different “fingerprints” when viewed in this way. Such patterns are much more difficult for a human to detect than the presence or absence of individual molecule types.

    The researchers fed their raw data into a computer machine learning algorithm and surprisingly found that the algorithms were able to accurately classify the samples as living or non-living with ~95% accuracy. Importantly, they did so after simplifying the raw data considerably, making it plausible that lower-precision instruments, spacecraft-based instruments are often low power, could obtain data of sufficient resolution to enable the biological classification accuracy the team obtained.

    The underlying reasons this classification accuracy is possible to remain to be explored, but the team suggests it is because of the ways biological processes, which modify organic compounds differently than abiological processes, relate to the processes which enable life to propagate itself. Living processes have to make copies of themselves, while abiological processes have no internal process controlling this.

    “This work opens many exciting avenues for using ultra-high resolution mass spectrometry for astrobiological applications,” says co-author Huan Chen of the US National MagLab.

    Lead author Nicholas Guttenberg adds, “While it is difficult if not impossible to characterise every peak in a complex chemical mixture, the broad distribution of components can contain patterns and relationships which are informative about the process by which that mixture came about or developed. If we’re going to understand complex prebiotic chemistry, we need ways of thinking in terms of these broad patterns – how they come about, what they imply, and how they change – rather than the presence or absence of individual molecules. This paper is an initial investigation into the feasibility and methods of characterisation at that level and shows that even discarding high-precision mass measurements, there is significant information in peak distribution that can be used to identify samples by the type of process that produced them.”

    Co-author Jim Cleaves of ELSI adds, “This sort of relational analysis may offer broad advantages for searching for life in the Solar System, and perhaps even in laboratory experiments designed to recreate the origins of life.” The team plans to follow up with further studies to understand exactly what aspects of this type of data analysis allows for such successful classification.

    Science paper:
    Classification of the Biogenicity of Complex Organic Mixtures for the Detection of Extraterrestrial Life

    See the full article here .


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  • richardmitnick 9:38 am on January 11, 2021 Permalink | Reply
    Tags: "Astrochemist brings search for extraterrestrial life to Center for Astrophysics" Clara Sousa-Silva, A good biosignature has a final characteristic: It has limited or accountable false positives., , , , Biosignatures, , Phosphine has a unique spectral signature because the spectrum for phosphine is composed of the behavior of the bonds between hydrogen and phosphorus and that’s a very rare bond in gas molecules.,   

    From Harvard Gazette: “Astrochemist brings search for extraterrestrial life to Center for Astrophysics” Clara Sousa-Silva 

    Harvard University

    From Harvard Gazette

    January 4, 2021
    Alvin Powell

    Clara Sousa-Silva explores telltale biosignature gases on other planets.

    Although the size and mass of Venus are similar to the Earth, its thick carbon-dioxide atmosphere has trapped heat so efficiently that the surface temperature usually exceeds 700 kelvins, hot enough to melt lead. Credit: SSV, MIPL, Magellan Team, NASA.

    In September, a team of astronomers announced a breathtaking finding: They had detected a molecule called phosphine high in the clouds of Venus, possibly indicating evidence of life [Nature Astronomy].

    That discovery shook the scientific establishment. Once thought of as Earth’s twin, Venus — though nearby and rocky — is now known to have a hellish environment, with a thick atmosphere that traps solar radiation, cranking surface temperatures high enough to melt metal, and accompanied by surface pressure akin to that thousands of feet below Earth’s ocean surface.

    But the detection, led by researchers from Cardiff University in Wales, the Massachusetts Institute of Technology, and the University of Manchester in England, was high in the atmosphere, where conditions are far more hospitable and the idea of microbial life more plausible. It was accomplished using spectroscopy, a method of determining the presence of different molecules in a planet’s atmosphere by analyzing how those molecules alter the light reflected from the planet. A key member of the team was fellow Clara Sousa-Silva, who had spent years studying the molecule’s spectroscopic signature and who believes that phosphine is a promising way to track the presence of extraterrestrial life.

    Sousa-Silva shifted her fellowship from MIT to the Center for Astrophysics | Harvard & Smithsonian and will spend the next two years advancing her work on biosignatures and life on other planets.

    She spoke with the Gazette about the recent discovery and what the future of the search for life may hold.

    Clara Sousa-Silva

    GAZETTE: You study biosignature gases, and your website says phosphine is your favorite. What is a biosignature gas and what’s so special about phosphine?

    SOUSA-SILVA: A biosignature gas is any gas in the planetary atmosphere that is produced by life. That by itself is not particularly interesting because molecules that can be produced by life can often be produced by many other things. So another question is: What is a good biosignature? And the answer to that also explains why phosphine is my favorite.

    A good biosignature isn’t just produced by life and released into an atmosphere. It is also able to survive in that atmosphere and be both detectable and distinguishable. So, if we’re looking at an atmosphere from far away, say from a different planet, and we detect an interesting molecule, that’s great. But maybe, because of low resolution in the instruments, lots of molecules look very similar to one another and the spectral signature also corresponds to a different molecule than one we thought we saw. So, you want a biosignature to be distinguishable.

    A good biosignature has a final characteristic: It has limited or accountable false positives. That means if it is produced by life, if it survives in the atmosphere, and you can detect it unambiguously, you still need to know if it was in fact produced by life or if it was accidentally produced by some other nonbiological process like photochemistry or volcanism. So, a good biosignature is all of these things: It is produced by life in large quantities and survives; it’s unambiguously detectable; and is unambiguously assigned to life.

    Famous biosignatures like oxygen and methane rank very well in the first few of these parameters. But methane, for example, looks an awful lot like every other hydrocarbon. And so knowing if you’re looking at methane versus a different molecule that also has carbons and hydrogens is quite hard. And even if you can unambiguously assign the thing you saw to methane, you don’t know if you can unambiguously assign it to life.

    Phosphine has a unique spectral signature, because the spectrum for phosphine is composed of the behavior of the bonds between hydrogen and phosphorus, and that’s a very rare bond in gas molecules. So phosphine is quite easy to distinguish, meaning it’s easy-ish to detect, and it is also produced by life. But it’s not produced by life in large quantities, so that’s a negative point for phosphine. But then, it’s so hard to produce without the intervention of life on rocky planets that it’s very low on false positives. I think phosphine is a well-balanced biosignature: produced in detectable quantities by life, being distinguishable, and having low false positives. That’s why it’s my favorite.

    Clara Sousa-Silva, a fellow who grabbed headlines in September because of new findings of a potential signature for life on Venus, discusses that research. Credit: Kris Snibbe/Harvard.

    GAZETTE: Your site also says that phosphine is toxic to life that uses oxygen metabolism. So why is it a likely sign of life on Venus?

    SOUSA-SILVA: I don’t know if it’s likely. I wouldn’t dare put a probability on that. It is toxic to life on Earth that uses oxygen. And that is, obviously, us and everything we love. But lots of life on Earth does not rely on oxygen, and for the majority of time that life existed on Earth it also didn’t rely on oxygen. Granted, it wasn’t the most thrilling life. It wasn’t writing great works of literature, but it was nevertheless popular on Earth and seemingly very happy, thriving in forms that had no need for oxygen.

    The reason why phosphine on Venus, if it’s there, may signify life is more that we cannot explain it in any other way. We have no good explanation for the presence of phosphine on Venus, and we do know it can be produced by life. That doesn’t mean that’s what’s happening on Venus. That’s just, as extraordinary as it might sound, the best guess we have at this point.

    GAZETTE: Let’s talk specifically about the findings from September. What did you and your colleagues find on Venus?

    SOUSA-SILVA: It was an analysis of two separate observations done about 18 months apart. One was done with the JCMT, the James Clerk Maxwell Telescope, which is on Mauna Kea [in Hawaii].

    East Asia Observatory James Clerk Maxwell telescope, Mauna Kea, Hawaii, USA,4,207 m (13,802 ft) above sea level.

    That observation has a tentative signal that could be assigned to phosphine. We then applied for time on ALMA [Atacama Large Millimeter/submillimeter Array in Chile], which is a much more powerful array of telescopes and which seemingly got a slightly stronger signal that also corresponded to phosphine.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres.

    This is encouraging because the odds that a random signal will appear in the same place 18 months apart, using two different instruments, are very slim.

    The analysis was figuring out: One, is the signal real, because both of these instruments were collecting data very much at the limits of their capabilities. Two, if the signal is real, is the most plausible candidate phosphine rather than a different molecule? And three, if indeed the signal is real and it is phosphine, who or what is making it? Those are the three steps of the main article. This was about two years of work on top of my many years of work investigating phosphine as a biosignature.

    It took a long time and a large international team, including Anita [Richards, of the University of Manchester, U.K.] and Jane [Greaves, of Cardiff University (UK)]. Jane is the lead author of the paper that came out in September specifically extracting the signal from the data. Then lots of us were trying to figure out if the signal belongs to phosphine and if so, at what abundances. My contribution is that I know the pure spectroscopy of phosphine very well. My entire Ph.D. was dedicated to the spectroscopy of phosphine. So I was able to help figure out, if it was phosphine, what kind of abundances it was present in.

    I was also able to provide a list of other candidate molecules that could mimic the signal. The most promising one is phosphine, but the second-most-promising one is SO2 (sulphur dioxide), which would be a strange molecule to find in that location of Venus, but not anywhere near as strange as finding phosphine. So it was an important candidate to check. Then, if it is indeed phosphine and the signal is real, figuring out what is producing it was led by William Bains [at MIT]. It was also a large team, figuring out every process that might make phosphine and excluding a near-infinite list of negatives. It’s very, very hard to know if you’ve reached the end of that list.

    GAZETTE: So they’re working through the ways you might make phosphine that likely didn’t occur on Venus?

    SOUSA-SILVA: We’re trying to find an explanation, any explanation, and we did find a few methods that could produce small amounts of phosphine, but they were always quite trivial and always many orders of magnitude below what our estimates were for the signal detected in the clouds of Venus.

    GAZETTE: Is this discovery a warmup for finding phosphine and detecting biosignatures on planets around other stars?

    SOUSA-SILVA: I think it’s exactly a warmup for the search for life. It’s an excellent case study in the world of astrobiology.

    The odds that we find life beyond Earth from a booming, unambiguous, intelligent signal from the heavens is very slim. It’s likely, if we ever find life, that it is going to be something with quite a lot of uncertainty, and it will be really hard to even estimate that uncertainty. We won’t be able to say, “Oh, we found life with 80 percent certainty.” Those numbers are not ones we can do right now.

    What we can do is look at planets that have potentially habitable environments, look for molecules that can be associated with life, and then try to explain what’s going on there. We found a biomarker in a place that is potentially habitable. That’s a crucial first step, but it’s very far from the final step. We now need to figure out what other molecules would that biosphere produce? How will they interact with one another? How do we disentangle those behaviors from the spontaneous behaviors of a dead atmosphere?

    So, it’ll take a lot of work. We are very lucky to have Venus right next door so that we can use it as a lab. We can test all these theories in a way that we won’t be able to when we find a biomarker on an exoplanet, where there’s no hope of actually going in and probing the atmosphere to check. So this is a really important step.

    This has been reasonably controversial — and it should be — but we will have to do this many times. And every time we hope to be better prepared and have a better tool kit so that there’s less uncertainty. But it’ll take a long time before we can unambiguously confirm life elsewhere.

    GAZETTE: Before this discovery, Venus had been largely dismissed as a place for life because of its surface conditions. Your discovery has highlighted that a biosphere can be in places that may not immediately come to mind: high in the clouds where conditions are different. Is there a lesson here for thinking unconventionally when we evaluate places for life, especially since even here on Earth we’ve found life to be tough and enduring and in surprising places?

    SOUSA-SILVA: Life is very resilient and very resourceful on Earth and there’s no reason to think that’s some special characteristic of life on Earth rather than of life itself. We have ignored Venus because Venus is quite horrid to us. When we sent probes, they melted dramatically so we didn’t feel particularly welcome. It seems easier to imagine a place like Mars as habitable, even though actually there’s so little atmosphere and so little protection from the sun’s radiation that it’s really not an easily habitable surface.

    Mars is mostly uninhabitable, like Venus, just in a much quieter way. Mars will kill you, but it doesn’t melt you, so it feels more habitable, though I have no loyalty to either planet as a place to find life. This is hopefully going to help us think of habitability in a less anthropocentric way — or at least a less terra-centric way — and to think of habitability not just as a rocky planet with liquid water on the surface, but to think of subterranean habitats, moons of gas giants — something people already consider — and envelopes of an atmosphere as potentially habitable places in an otherwise uninhabitable planet.

    GAZETTE: What did you think when it became apparent that it might be life on Venus? Was that an exciting moment?

    SOUSA-SILVA: It was kind of a strange reversal. I had for years been working on this completely hypothetical investigation: If we found phosphine on a terrestrial planet what would it mean? I had concluded that because it has so few false positives on terrestrial planets that it could only mean life. I submitted the paper with this conclusion, and it was not controversial. The reviewers were fine with the idea — they had issues with other parts of the paper, but this didn’t bother them at all. No one cared because it was hypothetical: I was imagining this exotic, distant planet.

    When I was contacted by Jane, who had this tentative detection of phosphine on Venus, my not-so-controversial statement was now really extraordinary. And Venus is next door, so my hypothetical scenario became very concrete, very quickly. That was two years ago. We spent about a year and a half basically redoing and refining the analysis that we had done for my paper. This was, again, led by William Bains to try to figure out whether this is what happened on Venus. Venus is not your classic, potentially habitable exoplanet. It’s a pretty infernal place and maybe there phosphine could be made abiotically. So I never got to be as excited as I might at the first mention that phosphine had been found on a terrestrial planet. I expected this to happen hopefully before I die, but probably after I retire, not within months of submitting my hypothesis.

    I also immediately felt like I could not be trusted because I’m so biased. I’ve been working on phosphine for so long. I am a junior scientist without a permanent job. It would be so valuable to me for it to be life that I can’t be trusted to assess this accurately. So I was very careful to not get too excited. I had a strong glass of whiskey that evening, but that was it. Then I went and did the same work that we always do, which was to check every possible mechanism that can make phosphine, every possible molecule that can mimic the signal, and look again at everything I’ve done before and check for mistakes. It was nerve-racking to explore this expression of my prediction so nearby, so quickly.

    GAZETTE: Have you had a chance since the original paper was published?

    SOUSA-SILVA: Well, we did a good thing and paid a cost. Unlike a lot of observations of this kind, we published all our data and all our code. Everything was ready for people to come and tear it apart. So people did, which meant I never did get a little time off to enjoy it. It was great because they found a calibration mistake, and ALMA was able to rectify that, which allowed our team to reanalyze the data — they’re still doing it now. There was just way too much press and then way too much criticism, and I still haven’t taken time off.

    GAZETTE: About the scientific debate, how to you respond to the failure of other research groups to replicate the results?

    SOUSA-SILVA: This is the part of the work where I’m only tangentially involved, since I’m not doing any data reduction [of readings from Venus’ atmosphere]. This debate is a consequence of working at the edge of instrument capabilities, and the data are always going to be very noisy and delicate until we have better telescopes. Any discoveries made from these data, from the edges of our ability, are always going to be up for discussion. It’ll be nice when there’s a gold standard method for reducing these data, but there isn’t, so people disagree on the best way of extracting a signal without introducing spurious signals.

    The disagreement comes in a variety of forms, but the teams that didn’t replicate the results, don’t replicate the results in different ways. For example, the [Ignas] Snellen team [from Leiden University in the Netherlands] looked at the ALMA data before the calibration error had been corrected. I’m looking forward to seeing their revised analysis of the better data. The Villanueva team [led by Geronimo Villanueva at the NASA-Goddard Space Flight Center] that looked at both the ALMA data and the JCMT data, did find signals in the JCMT data, which, of course, begs the question of “Where does the signal go in the ALMA data?”

    They do disagree on the source of the JCMT signal, though. SO2 [sulfur dioxide], our second-most-plausible candidate, is their first-most-plausible candidate. And that is an even more complicated question of how you choose between two molecules that can simulate the same signal at these resolutions. Our team’s argument is that the SO2 [spectra] is a little off — you would expect SO2 to show up in different areas of the white bandpass. There also isn’t enough SO2 to justify the signal, so phosphine would need to complement the size of the signal. It’s a difficult argument to make — and we’re at the edge of the statistical significance of the signal — but it’s a totally valid argument.

    Then there’s the archival Pioneer data that was revisited and that they think could correspond to phosphine. It’s hard to bring all of this data to a place where they agree with one another, sadly, because people want to know the truth — I do, too. But the only real conclusion we have is that we don’t know Venus well enough, and we need more data. We need more observations that are not at the edge of instrument capabilities so that there’s no ambiguity in what we’re looking at.

    GAZETTE: Let’s talk a little bit about what you’ll be doing here at Harvard. You’ve been a fellow at MIT. Is the fellowship split between there and here?

    SOUSA-SILVA: No, I moved it. I am 100 percent Harvard — for the last two months, I think. It’s very new.

    GAZETTE: Who will you be working with and what will you be doing?

    SOUSA-SILVA: The 51 Pegasi b Fellowship is a wonderful three-year prize fellowship that is provided by the Heising-Simons Foundation. I did one year at MIT, and I’ve moved to Harvard for the last two years of the fellowship. My host is Dave Charbonneau — part of the reason I moved to Harvard is because of the expertise he has — and the team that surrounds him — on exoplanet atmospheres. There’s also the HITRAN [High resolution Transmission molecular absorption database] group, led by Iouli Gordon — and previously, Larry Rothman — who are world leaders in spectroscopic databases, which is the bread and butter of my work. So that combination of expertise made Harvard perfect.

    GAZETTE: Are you doing most of your work out of your home now or are you able to commute to the CfA physically?

    SOUSA-SILVA: No, I don’t even know where my office is yet. I would love to be commuting to the CfA, but because my work can be done remotely, it shall be done remotely.

    GAZETTE: Are you continuing to work on phosphine and Venus or are you moving on to other topics?

    SOUSA-SILVA: I’ll give it the same percentage of my time as I have in the past. Phosphine is very much my expert molecule, but 50 percent of my work is pushing against the notion of looking for single indicators of life. Because unless we get a radio signal in prime numbers or an unambiguous sign of CFCs [chlorofluorocarbons] or other really complex pollutants, we are going to need more than one molecule; we’re going to need a whole array of molecules that together paint the picture of a biosphere with all its complexity and interactions.

    So most of my work is trying to provide a tool kit that can detect every molecule that could potentially be in a habitable atmosphere. I started the work at MIT. They had come up with a list of all the possible molecules that could form in the context of a biosphere: 16,367. I know that number because I’ve been working on it for so long.

    Out of those thousands, we have spectra of some quality — and some of them are rough — for less than 4 percent of them. For the majority of molecules, we don’t even have even a crude ability to detect them. So most of my work is trying to simulate that spectra so we have at least some idea of what these molecules look like. That’s the connection to HITRAN. They have extremely high accuracy and extremely careful data on a handful of molecules, a little over 50. That is wonderful, but only a small dent in the list of 16,000-plus.

    I created a small program called RASCALL, for Rapid Approximate Spectral Calculations for All. The idea is to make really rough, very quick spectra for all of these molecules, and then build on it. Without RASCALL, the way I did my phosphine spectra took me a bit over four years and many extremely expensive supercomputers. I can’t repeat that for the 16,000 molecules. I calculated that it would take me over 62,000 years. I’m trying to shorten that timescale into something that resembles my lifetime, and that’s where RASCALL comes in.

    GAZETTE: Folks like you will be helping answer an interesting question in the decades to come: whether life is something rare or whether it’s not really that rare after all. It seems the thinking on that has been shifting in recent decades.

    SOUSA-SILVA: I do like that the shift is happening and that people are thinking that life is more common. I’m hoping that shift will go so far as thinking that life is not that special. It’s just an inevitable occurrence in a variety of contexts. If it can appear in places as different as Earth and Venus, which are at first glance similar because of their size and location but otherwise very different, then it must be extremely common because it would be the height of hubris to think that only the solar system can have life, but it has arisen twice in totally different environments.

    That seems really implausible. The sun is average, rocky planets are extremely common, the molecular cloud that formed the solar system was not special. Life on Earth came to be in a huge diversity of forms, and life changed Earth’s atmosphere many times. We only have one planet where we know life existed, but Earth has been many planets, which is something an astronomer colleague of mine, Sarah Rugheimer, likes to say. We have quite a lot of data points that basically show that life is pretty good at making itself happen in many ways throughout history.

    See the full article here .


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  • richardmitnick 1:10 pm on August 18, 2020 Permalink | Reply
    Tags: "New tool helps interpret future searches for life on exoplanets", , Biosignatures, , The use of gas spectroscopy to detect biosignatures in planets’ atmospheres will become an increasingly important element of astronomy.   

    From École Polytechnique Fédérale de Lausanne: “New tool helps interpret future searches for life on exoplanets” 

    From École Polytechnique Fédérale de Lausanne

    Sarah Perrin

    One way to determine whether there is life on another planet is to look for biosignatures in the light that is scattered off its atmosphere. Scientists at EPFL and University of Rome Tor Vergata have developed an original model that interprets the results of that analysis.

    Is there life on a distant planet? One way astronomers are trying to find out is by analyzing the light that is scattered off a planet’s atmosphere. Some of that light, which originates from the stars it orbits, has interacted with its atmosphere, and provides important clues to the gases it contains. If gases like oxygen, methane or ozone are detected, that could indicate the presence of living organisms. Such gases are known as biosignatures. A team of scientists from EPFL and Tor Vergata University of Rome has developed a statistical model that can help astronomers interpret the results of the search for these “signs of life”. Their research has just been published in Proceedings of the National Academy of Sciences (PNAS).

    Since the first exoplanet – a planet that orbits a star other than the Sun – was discovered 25 years ago, over 4,300 more have been identified. And the list is still growing: a new one is discovered every two or three days. Around 200 of the exoplanets found so far are telluric, meaning they consist mainly of rocks, like the Earth. While that’s not the only requirement for a planet to be able to host life – it also needs to have water and be a certain distance from its sun – it is one criterion that astronomers are using to focus their search.

    In the coming years, the use of gas spectroscopy to detect biosignatures in planets’ atmospheres will become an increasingly important element of astronomy. Many research programs are already under way in this area, such as for the CHEOPS exoplanet-hunting satellite, which went into orbit in December 2019, and the James-Webb optical telescope, scheduled to be launched in October 2021.


    Starting with an unknown

    While much progress has been made on detecting exoplanetary biosignatures, several question marks remain. What are the implications of this kind of research? And how should we interpret the results? What if just one biosignature is detected on a planet? Or what if no biosignatures are detected – what should we conclude? Those kinds of questions are what the EPFL-Tor Vergata scientists set out to answer with their new model.

    Their work tackles the problem from a new angle. Traditionally, astronomers have looked for life on another planet based on what we know about life and biological evolution on Earth. But with their new method, the scientists started with an unknown: how many other planets in our galaxy have some form of life. Their model incorporates factors like the estimated number of other stars in the galaxy similar to the Sun and how many telluric planets might be orbiting within a habitable distance from those stars. It uses Bayesian statistics – particularly well suited to small sample sizes – to calculate the probability of life in our galaxy based on how many biosignatures are detected: one, several or none at all.

    “Intuitively it makes sense that if we find life on one other planet, there are probably many others in the galaxy with some type of living organism. But how many?” says Amedeo Balbi, a professor of astronomy and astrophysics in Tor Vergata’s Physics Department. “Our model turns that intuitive assumption into a statistical calculation, and lets us determine exactly what the numbers mean in terms of quantity and frequency.”

    “Astronomers already use various assumptions to evaluate how credible life is on a given planet,” says Claudio Grimaldi, a scientist at EPFL’s Laboratory of Physics of Complex Matter (LPMC) who is also affiliated with the Enrico Fermi Research Center in Rome. “One of our research goals was thus to develop a method for weighing and comparing those assumptions in light of the new data that will be collected over the coming years.”

    Spreading from one planet to another

    Given the small number of planets that will likely be examined in the near future, and assuming that life will emerge independently on any one planet, the EPFL-Tor Vergata study found that if even just one biosignature is detected, we can conclude with a greater than 95% probability that there are over 100,000 inhabited planets in the galaxy – more than the number of pulsars, which are objects created when a massive star explodes at the end of its life. On the other hand, if no biosignatures are detected, we cannot necessarily conclude that other forms of life do not exist elsewhere in the Milky Way.

    The scientists also looked at the theory of panspermia, which states that instead of emerging independently on a given planet, life forms could be carried over from another planet – such as through organic matter or microscopic organisms being carried on comets or spreading between neighboring planets. This implies that the probability of life on a planet also depends on how far it is from other planets and how easily various life forms – whose physical characteristics could be extremely different from those we are familiar with – are able to resist the extreme conditions of space travel and adapt to the new planet. Factoring in panspermia alters the inferred number of inhabited planets elsewhere in the galaxy.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    EPFL bloc

    EPFL campus

    EPFL is Europe’s most cosmopolitan technical university. It receives students, professors and staff from over 120 nationalities. With both a Swiss and international calling, it is therefore guided by a constant wish to open up; its missions of teaching, research and partnership impact various circles: universities and engineering schools, developing and emerging countries, secondary schools and gymnasiums, industry and economy, political circles and the general public.

  • richardmitnick 10:22 am on July 26, 2020 Permalink | Reply
    Tags: "The real science behind SETI’s hunt for intelligent aliens", , , , , Biosignatures, , ,   

    From ars technica: “The real science behind SETI’s hunt for intelligent aliens” 

    From ars technica

    Madeleine O’Keefe

    Aurich Lawson / Getty

    In 1993, a team of scientists published a paper in the scientific journal Nature that announced the detection of a planet harboring life. Using instruments on the spacecraft Galileo, they imaged the planet’s surface and saw continents with colors “compatible with mineral soils” and agriculture, large expanses of ocean with “spectacular reflection,” and frozen water at the poles.

    NASA/Galileo 1989-2003

    An analysis of the planet’s chemistry revealed an atmosphere with oxygen and methane so abundant that they must come from biological sources. “Galileo found such profound departures from equilibrium that the presence of life seems the most probable cause,” the authors wrote.

    But the most telltale sign of life was measured by Galileo’s spectrogram: radio transmissions from the planet’s surface. “Of all Galileo science measurements, these signals provide the only indication of intelligent, technological life,” wrote the authors.

    The paper’s first author was Carl Sagan, the astronomer, author, and science communicator. The planet that he and his co-authors described was Earth.

    Twenty years later, as far as we can tell, Earth remains the only planet in the Universe with any life, intelligent or otherwise. But that Galileo fly-by of Earth was a case study for future work. It confirmed that modern instruments can give us hints about the presence of life on other planets—including intelligent life. And since then, we’ve dedicated decades of funding and enthusiasm to look for life elsewhere in the Universe.

    But one component of this quest has, for the most part, been overlooked: the Search for Extraterrestrial Intelligence (SETI). This is the field of astronomical research that looks for alien civilizations by searching for indicators of technology called “technosignatures.” Despite strong support from Sagan himself (he even made SETI the focus of his 1985 science-fiction novel Contact, which was turned into a hit movie in 1997 starring Jodie Foster and Matthew McConaughey), funding and support for SETI have been paltry compared to the search for extraterrestrial life in general.

    Throughout SETI’s 60-year history, a stalwart group of astronomers has managed to keep the search alive. Today, this cohort is stronger than ever, though they are mostly ignored by the research community, largely unfunded by NASA, and dismissed by some astronomers as a campy fringe pursuit. After decades of interest and funding dedicated toward the search for biological life, there are tentative signs that SETI is making a resurgence.

    At a time when we’re in the process of building hardware that should be capable of finding signatures of life (intelligent or otherwise) in the atmospheres of other planets, SETI astronomers simply want a seat at the table. The stakes are nothing less than the question of our place in the Universe.

    The Arecibo Radio Telescope on Puerto Rico [recently unfunded by NSF and now picked up by UCF and a group of funders] receives interplanetary signals and transmissions. And it was in the movie Contact!

    How to search for life on other worlds

    You may have heard of searching for life on other planets by looking for “biosignatures”—molecules or phenomena that would only occur or persist if life were present. These could be microbes discovered by directly sampling material from the planet (known as “in-situ sampling”) or using spectroscopic biosignatures, like chemical disequilibria in the atmosphere and images of water and agriculture, like those detected by the Galileo probe in 1990.

    The biosignature search is happening now, but it comes with limitations. In-situ sampling requires sending a spacecraft to another planet; we’ve done this, for example, with rovers sent to Mars and the Cassini spacecraft that sampled plumes of water erupting from Saturn’s moon Enceladus. And while in-situ sampling is the ideal option for planets in the Solar System, with our current technology, it will take millennia to get a vehicle to a planet orbiting a different star—and these exoplanets are far, far more numerous.

    To detect spectroscopic biosignatures we will need telescopes like the James Webb Space Telescope (JWST) or the ground-based Extremely Large Telescope, both currently under construction.

    NASA/ESA/CSA Webb Telescope annotated

    ESO/E-ELT, 39 meter telescope to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).

    To directly image an exoplanet and obtain more definitive spectra will require future missions like LUVOIR (Large Ultraviolet Optical Infrared Surveyor) or the Habitable Exoplanet Imaging Mission. But all of these lie a number of years in the future.

    NASA Large UV Optical Infrared Surveyor (LUVOIR)

    NASA Habitable Exoplanet Imaging Mission (HabEx) The Planet Hunter depiction

    SETI researchers, however, are interested in “technosignatures”—biosignatures that indicate intelligent life. They are signals that could only come from technology, including TV and radio transmitters—like the radio transmission detected by the Galileo spacecraft—planetary radar systems, or high-power lasers.

    The first earnest call to search for technosignatures—and SETI’s formal beginning—came in 1959. That was the year that Cornell University physicists Giuseppe Cocconi and Philip Morrison published a landmark paper in Nature outlining the most likely characteristics of alien communication. It would make the most sense, they postulated, for aliens to communicate across interstellar distances using electromagnetic waves since they are the only media known to travel fast enough to conceivably reach us across vast distances of space. Within the electromagnetic spectrum, Cocconi and Morrison determined that it would be most promising to look for radio waves because they are less likely to be absorbed by planetary atmospheres and require less energy to transmit. Specifically, they proposed a narrowband signal around the frequency at which hydrogen atoms emit radiation—a frequency that should be familiar to any civilization with advanced radio technology.

    What’s special about these signals is that they exhibit high degrees of coherence, meaning there is a large amount of electromagnetic energy in just one frequency or a very small instance of time—not something nature typically does.

    “As far as we know, these kinds of [radio] signals would be unmistakable indicators of technology,” says Andrew Siemion, professor of astronomy at the University of California, Berkeley. “We don’t know of any natural source that produces them.”

    Such a signal was detected on August 18, 1977 by the Ohio State University Radio Observatory, known as “Big Ear.”

    Ohio State Big Ear Radio Telescope, Construction of the Big Ear began in 1956 and was completed in 1961, and it was finally turned on for the first time in 1963

    Astronomy professor Jerry Ehman was analyzing Big Ear data in the form of printouts that, to the untrained eye, looked like someone had simply smashed the number row of a typewriter with a preference for lower digits. Numbers and letters in the Big Ear data indicated, essentially, the intensity of the electromagnetic signal picked up by the telescope, starting at 1 and moving up to letters in the double-digits (A was 10, B was 11, and so on). Most of the page was covered in 1s and 2s, with a stray 6 or 7 sprinkled in.

    But that day, Ehman found an anomaly: 6EQUJ5. This signal had started out at an intensity of 6—already an outlier on the page—climbed to E, then Q, peaked at U—the highest power signal Big Ear had ever seen—then decreased again. Ehman circled the sequence in red pen and wrote “Wow!” next to it.

    Alas, SETI researchers have never been able to detect the so-called “Wow! Signal” again, despite many tries with radio telescopes around the world. To this day, no one knows the source of the Wow! Signal, and it remains one of the strongest candidates for alien transmission ever detected.

    NASA began funding SETI studies in 1975, a time when the idea of extraterrestrial life was still unthinkable, according to former NASA Chief Historian Steven J. Dick. After all, no one then knew if there were even other planets outside our Solar System, much less life.

    In 1992, NASA made its strongest-ever commitment to SETI, pledging $100 million over ten years to fund the High Resolution Microwave Survey (HRMS), an expansive SETI project led by astrophysicist Jill Tarter.

    Jill Tarter

    One of today’s most prominent SETI researchers, Tarter was the inspiration for the protagonist of Sagan’s Contact, Eleanor Arroway.

    But less than a year after HRMS got underway, Congress abruptly canceled the project. “The Great Martian Chase may finally come to an end,” said Senator Richard Bryan of Nevada, one of its most vocal detractors. “As of today, millions have been spent and we have yet to bag a single little green fellow. Not a single Martian has said take me to your leader, and not a single flying saucer has applied for FAA approval.”

    The whole ordeal was “incredibly traumatic,” says Tarter. “It [the removal of funding] was so vindictive that, in fact, we became the four-letter S-word that you couldn’t say at NASA headquarters for decades.”

    Since that humiliating public reprimand by Congress, NASA’s astrobiology division has been largely focused on searching for biosignatures. And it has made sure to distinguish its current work from SETI, going so far as to say in a 2015 report that “the traditional Search for Extraterrestrial Intelligence… is not a part of astrobiology.”

    Despite or because of this, the SETI community quickly regrouped and headed to the private sector for funding. Out of those efforts came Project Phoenix, rising from the ashes of the HRMS. From February 1995 to March 2004, Phoenix scanned about 800 nearby candidate stars for microwave transmission in three separate campaigns with the Parkes Observatory in New South Wales, Australia; the National Radio Astronomy Observatory in Green Bank, West Virginia; and Arecibo Observatory in Puerto Rico [above].

    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia, 414.80m above sea level

    Green Bank Radio Telescope, West Virginia, USA, now the center piece of the GBO, Green Bank Observatory, being cut loose by the NSF

    The project did not find any signs of E.T., but it was considered the most comprehensive and sensitive SETI program ever conducted.

    At the same time, other projects run by the Planetary Society and UC Berkeley (including a project called SERENDIP, which is still active) carried out SETI experiments and found a handful of anomalous radio signals, but none showed up a second time.

    To search or not to search

    There is plenty of understandable skepticism surrounding the search for extraterrestrial intelligence. At first glance, one might reason that biosignatures are more common than technosignatures and therefore easier to detect. After all, complex life takes a long time to develop and so is probably rarer. But as astronomer and SETI researcher Jason Wright points out, “Slimes and fungus and molds and things are extremely hard to detect [on an exoplanet]. They’re not doing anything to get your attention. They’re not commanding energy resources that might be obvious at interstellar distances.”

    Linda Billings, a communications consultant for NASA’s Astrobiology Division, is not so convinced that SETI is worth it. She worked with SETI in the early 1990s when it was still being funded by the space agency.

    “I felt like there was a resistance to providing a realistic depiction of the SETI search, of how limited it is, how little of our own galaxy that we are capable of detecting in radio signals,” Billings says.

    While she supports NASA’s biosignature searches, she feels that there are too many assumptions embedded into the idea that intelligent aliens would emit signals that we can intercept and understand, so the likelihood of successfully detecting technosignatures is too low.

    What is the likelihood of encountering extraterrestrial intelligence? Astronomers have thought about this question and have even tried to quantify it, most famously in the Drake equation, introduced by radio astronomer Frank Drake in 1961. The equation estimates the number of active and communicative alien civilizations in the Milky Way galaxy by considering seven factors:

    Frank Drake with his Drake Equation. Credit Frank Drake

    Drake Equation, Frank Drake, Seti Institute

    Since these values have been largely conjectural, the Drake equation has served as more of a thought exercise than a precise calculation of probability. But SETI skeptics reason that the equation’s huge uncertainties render the search futile until we know more.

    Plus, the question remains as to whether we are looking the “right” way. By assuming aliens will transmit radio waves, SETI researchers also assume that alien civilizations must have intelligence similar to humans’. But intelligence—like life—could develop elsewhere in ways we can’t possibly imagine. So for some, the small chance that aliens are sending out radio transmissions isn’t enough to justify the search.

    Seth Shostak, senior astronomer at the SETI Institute, defended the radio approach in a blog post honoring Frank Drake’s 90th birthday earlier this year. “…[A] search for radio transmissions is not a parochial enterprise,” he wrote. “It doesn’t assume that the aliens are like us in any particular, only that they live in the same Universe, with the same physics.”

    SETI researchers can also cast a much wider net with their radio searches: Optical telescopes looking for biosignatures can only resolve data from exoplanets within a few tens of light-years, totaling to no more than 100 tractable targets. But existing radio observatories, like those at Green Bank and in Arecibo, can detect signals as far as 10,000 light-years away, producing 10-million more targets than biosignature search methods.

    The SETI community has no desire to stop the search for biosignatures. “Technosignatures and biosignatures both lie under the same umbrella that we call ‘astrobiology,’ so we are trying to learn from each other,” says Tarter.

    The current state of SETI

    Since the 1990s, new discoveries have strengthened the case to search for technosignatures. For example, NASA’s Kepler Space Telescope has identified over 4,000 exoplanets, and Kepler data suggest that half of all stars may harbor Earth-sized exoplanets, many of which may be the right distance from their stars to be conducive to life.

    NASA/Kepler Telescope, and K2 March 7, 2009 until November 15, 2018

    NASA/MIT TESS replaced Kepler in search for exoplanets

    Plus, the discovery of extremophiles—organisms that can grow and thrive in extreme temperature, acidity, or pressure—has shown astrobiologists that life exists in environments previously assumed to be inhospitable.

    But of the two arms of the search for life, SETI is still up against a perception problem—what some call a “giggle factor.” What does it take for SETI to be taken seriously? There are some indications that the perception problem is solving itself, albeit slowly.

    In 2015, SETI got a much-needed injection of cash—and faith—when Russian-born billionaire Yuri Milner pledged $100 million over 10 years to form the Breakthrough Initiatives, including Breakthrough Listen, a SETI project based at UC Berkeley and directed by Andrew Siemion.

    Breakthrough Listen Project


    UC Observatories Lick Autmated Planet Finder, fully robotic 2.4-meter optical telescope at Lick Observatory, situated on the summit of Mount Hamilton, east of San Jose, California, USA

    GBO radio telescope, Green Bank, West Virginia, USA

    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia

    SKA Meerkat telescope, 90 km outside the small Northern Cape town of Carnarvon, SA

    Newly added

    CfA/VERITAS, a major ground-based gamma-ray observatory with an array of four Čerenkov Telescopes for gamma-ray astronomy in the GeV – TeV energy range. Located at Fred Lawrence Whipple Observatory,Mount Hopkins, Arizona, US in AZ, USA, Altitude 2,606 m (8,550 ft)

    As the name suggests, Breakthrough Listen’s goal is to listen for signs of intelligent life. Breakthrough Listen has access to more than a dozen facilities around the world, including the NRAO in Green Bank, the Arecibo Observatory, and the MeerKAT radio telescope in South Africa.

    A few years later in 2018, NASA—prodded by SETI fan and Texas Congressman Lamar Smith—hosted a technosignatures workshop at the Lunar and Planetary Institute in Houston, Texas. Over the course of three days, SETI scientists including Wright and Siemion met and discussed the current state of technosignature searches and how NASA could contribute to the field’s future. But Smith retired from Congress that same year, which put SETI’s future with federal funding back into question.

    In March 2019, Pennsylvania State University announced the new Penn State Extraterrestrial Intelligence Center (PSETI)—to be led by Wright, who is an associate professor of astronomy and astrophysics at the school. One of just two astrobiology PhD programs in the world (the other is at UCLA), PSETI plans on hosting the first Penn State SETI Symposium in June 2021.

    Some of PSETI’s main goals are to permanently fund SETI research worldwide, train the next generation of SETI practitioners, and support and foster a worldwide SETI community. These elements are important to any scientific endeavor but are currently lacking in the small field, even with initiatives like Breakthrough Listen. According to a recent white paper, only five people in the US have ever earned a PhD with SETI as the focus of their dissertations, and that number won’t be growing rapidly any time soon.

    “If you can’t propose for grants to work on a topic, it’s really difficult to convince young graduate students and postdocs to work in the field, because they don’t really see a future in it,” says Siemion.

    Tarter agrees that community and funding are the essential ingredients to SETI’s future. “We sort of lost a generation of scientists and engineers in this fallow period where a few of us could manage to keep this going,” she says. “A really well-educated, larger population of young exploratory scientists—and a stable path to allow them to pursue this large question into the future—is what we need.”

    Wright often calls SETI low-hanging fruit. “This field has been starved of resources for so long that there is still a ton of work to do that could have been done decades ago,” says Wright. “We can very quickly make a lot of progress in this field without a lot of effort.” This is made clear in Wright’s SETI graduate course at Penn State, in which his students’ final projects have sometimes become papers that get published in peer-reviewed journals—something that rarely happens in any other field of astronomy.

    In February 2020, Penn State graduate student Sofia Sheikh submitted a paper to The Astrophysical Journal outlining a survey of 20 stars in the “restricted Earth Transit Zone,” the area of the sky in which an observer on another planet could see Earth pass in front of the sun. Sheikh didn’t find any technosignatures in the direction of those 20 stars, but her paper is one of a number of events in the past year that seem to signal the resurgence of SETI.

    In July 2019, Breakthrough Listen announced a collaboration with VERITAS, an array of gamma-ray telescopes in Arizona [above]. VERITAS agreed to spend 30 hours per year looking at Breakthrough Listen’s targets for signs of extraterrestrial intelligence starting in 2021. Breakthrough Listen also announced, in March 2020, that it will soon partner with the NRAO to use the Very Large Array (VLA), an array of radio telescopes in Socorro, New Mexico.

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    (Coincidentally, the VLA was featured in the film Contact but was never actually used in SETI research.)

    And there are other forthcoming projects that take advantage of alternate avenues to search. Optical SETI instruments, like PANOSETI, will look for bright pulses in optical or near-infrared light that could be artificial in origin. Similarly, LaserSETI will use inexpensive, wide-field, astronomical grade cameras to probe the whole sky, all the time, for brief flickers of laser light coming from deep space. However, neither PANOSETI nor LaserSETI are fully funded.



    Just last month, though, NASA did award a grant to a group of scientists to search for technosignatures. It is the first time NASA has given funding to a non-radio technosignature search, and it’s also the first grant to support work at PSETI. The project team, led by Adam Frank from the University of Rochester, includes Jason Wright.

    “It’s a great sign that the winds are changing at NASA,” Wright said in an email. He credits NASA’s 2018 technosignatures workshop as a catalyst that led NASA to relax its stance against SETI research. “We have multiple proposals in to NASA right now to do more SETI work across its science portfolio and I’m more optimistic now that it will be fairly judged against the rest of the proposals.”

    Despite all the obstacles in their path, today’s SETI researchers have no plans to stop searching. After all, they are trying to answer one of the most profound and captivating questions in the entire Universe: are we alone?

    “You can certainly get a little tired and a little beat down by the challenges associated with any kind of job. We’re certainly not immune from that in SETI or in astronomy,” admits Siemion. “But you need only take 30 seconds to just contemplate the fact that you’re potentially on the cusp of making really an incredibly profound discovery—a discovery that would forever change the human view of our place in the universe. And, you know, it gets you out of bed.”

    SETI Institute

    Laser SETI, the future of SETI Institute research

    SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA, Altitude 986 m (3,235 ft), the origins of the Institute’s search.


    Further to the story

    UCSC alumna Shelley Wright, now an assistant professor of physics at UC San Diego, discusses the dichroic filter of the NIROSETI instrument, developed at the Dunlap Institute, U Toronto and brought to UCSD and installed at the Nickel telescope at UCSC (Photo by Laurie Hatch)

    Shelley Wright of UC San Diego, with NIROSETI, developed at Dunlap Institute U Toronto, at the 1-meter Nickel Telescope at Lick Observatory at UC Santa Cruz

    NIROSETI team from left to right Rem Stone UCO Lick Observatory Dan Werthimer UC Berkeley Jérôme Maire U Toronto, Shelley Wright UCSD Patrick Dorval, U Toronto Richard Treffers Starman Systems. (Image by Laurie Hatch)


    And separately and not connected to the SETI Institute

    SETI@home a BOINC project based at UC Berkeley

    SETI@home, a BOINC project originated in the Space Science Lab at UC Berkeley

    For transparency, I am a financial supporter of the SETI Institute. I was a BOINC cruncher for many years.

    My BOINC

    I am also a financial supporter of UC Santa Cruz and Dunlap Institute at U Toronto.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Ars Technica was founded in 1998 when Founder & Editor-in-Chief Ken Fisher announced his plans for starting a publication devoted to technology that would cater to what he called “alpha geeks”: technologists and IT professionals. Ken’s vision was to build a publication with a simple editorial mission: be “technically savvy, up-to-date, and more fun” than what was currently popular in the space. In the ensuing years, with formidable contributions by a unique editorial staff, Ars Technica became a trusted source for technology news, tech policy analysis, breakdowns of the latest scientific advancements, gadget reviews, software, hardware, and nearly everything else found in between layers of silicon.

    Ars Technica innovates by listening to its core readership. Readers have come to demand devotedness to accuracy and integrity, flanked by a willingness to leave each day’s meaningless, click-bait fodder by the wayside. The result is something unique: the unparalleled marriage of breadth and depth in technology journalism. By 2001, Ars Technica was regularly producing news reports, op-eds, and the like, but the company stood out from the competition by regularly providing long thought-pieces and in-depth explainers.

    And thanks to its readership, Ars Technica also accomplished a number of industry leading moves. In 2001, Ars launched a digital subscription service when such things were non-existent for digital media. Ars was also the first IT publication to begin covering the resurgence of Apple, and the first to draw analytical and cultural ties between the world of high technology and gaming. Ars was also first to begin selling its long form content in digitally distributable forms, such as PDFs and eventually eBooks (again, starting in 2001).

  • richardmitnick 3:49 pm on February 15, 2020 Permalink | Reply
    Tags: "New Technologies Strategies Expanding Search for Extraterrestrial Life", Biosignatures, , , ,   

    From National Radio Astronomy Observatory: “New Technologies, Strategies Expanding Search for Extraterrestrial Life” 

    From National Radio Astronomy Observatory

    NRAO Banner

    February 15, 2020
    Dave Finley, Public Information Officer
    (575) 835-7302

    Credit: Bill Saxton, NRAO/AUI/NSF

    Emerging technologies and new strategies are opening a revitalized era in the Search for Extraterrestrial Intelligence (SETI).

    New discovery capabilities, along with the rapidly-expanding number of known planets orbiting stars other than the Sun, are spurring innovative approaches by both government and private organizations, according to a panel of experts speaking at a meeting of the American Association for the Advancement of Science (AAAS) in Seattle, Washington.

    New approaches will not only expand upon but also go beyond the traditional SETI technique of searching for intelligently-generated radio signals, first pioneered by Frank Drake’s Project Ozma in 1960.

    Frank Drake with his Drake Equation. Credit Frank Drake

    Scientists now are designing state-of-the-art techniques to detect a variety of signatures that can indicate the possibility of extraterrestrial technologies. Such “technosignatures” can range from the chemical composition of a planet’s atmosphere, to laser emissions, to structures orbiting other stars, among others.

    The National Radio Astronomy Observatory (NRAO) and the privately-funded SETI Institute announced an agreement to collaborate on new systems to add SETI capabilities to radio telescopes operated by NRAO. The first project will develop a system to piggyback on the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) that will provide data to a state-of-the-art technosignature search system.

    “As the VLA conducts its usual scientific observations, this new system will allow for an additional and important use for the data we’re already collecting,” said NRAO Director Tony Beasley. “Determining whether we are alone in the Universe as technologically capable life is among the most compelling questions in science, and NRAO telescopes can play a major role in answering it,” Beasley continued.

    “The SETI Institute will develop and install an interface on the VLA permitting unprecedented access to the rich data stream continuously produced by the telescope as it scans the sky,” said Andrew Siemion, Bernard M. Oliver Chair for SETI at the SETI Institute and Principal Investigator for the Breakthrough Listen Initiative at the University of California, Berkeley. “This interface will allow us to conduct a powerful, wide-area SETI survey that will be vastly more complete than any previous such search,” he added.

    Siemion highlighted the singular role the $100-million Breakthrough Listen Initiative has played in reinvigorating the field of SETI in recent years. Siemion also announced the latest scientific results from Listen, a SETI survey in the direction of stars where a distant civilization could observe the Earth’s passage across the sun, and the availability of nearly 2 PetaBytes of data from the Listen Initiative’s international network of observatories.

    Other indicators of possible technologies include laser beams, structures built around stars to capture the star’s power output, atmospheric chemicals produced by industries, and rings of satellites similar to the ring of geosynchronous communication satellites orbiting above Earth’s equator.

    “Such indicators are becoming detectable as our technology advances, and this has renewed interest in SETI searches at both government agencies and private foundations,” Siemion said.

    Life forms, whether intelligent or not, also can produce detectable indicators. These include the presence of large amounts of oxygen, smaller amounts of methane, and a variety of other chemicals. Victoria Meadows, Principal Investigator for NASA’s Virtual Planetary Laboratory at the University of Washington, described how scientists are developing computer models to simulate extraterrestrial environments and to help support future searches for habitable planets and life beyond the Solar System.

    “Upcoming telescopes in space and on the ground will have the capability to observe the atmospheres of Earth-sized planets orbiting nearby cool stars, so it’s important to understand how best to recognize signs of habitability and life on these planets,” Meadows said, “These computer models will help us determine whether an observed planet is more or less likely to support life.”

    NASA/ESA/CSA Webb Telescope annotated

    ESO/E-ELT, 39 meter telescope to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).

    TMT-Thirty Meter Telescope, proposed and now approved for Mauna Kea, Hawaii, USA4,207 m (13,802 ft) above sea level, the only giant 30 meter class telescope for the Northern hemisphere


    Giant Magellan Telescope, 21 meters, to be at the Carnegie Institution for Science’s Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high

    As new programs implement the expanding technical capabilities for detecting extraterrestrial life and intelligence, it’s important to define what constitutes compelling, credible evidence, according to Jill Tarter, of the SETI Institute.

    Jill Tarter Image courtesy of Jill Tarter

    “How strong does the evidence need to be to justify claiming a discovery? Can we expect to find smoking guns? If the evidence requires many caveats, how do we responsibly inform the public,” Tarter asked.

    Tarter pointed out that projects such as the University of California at San Diego’s PANOSETI visible-light and infrared search, and the SETI Institute’s Laser SETI search are being built with co-observing sites to reduce false positives. Such measures, she said, will boost confidence in reported detections, but also add to the expense of the project.

    The news media also share responsibility for communicating accurately with the public, Tarter emphasized. She cited cases in recent years of “exuberant reporting” of bogus claims of SETI detections. “A real detection of extraterrestrial intelligence would be such an important milestone in our understanding of the Universe that journalists need to avoid uncritical reporting of obviously fake claims,” she said.

    “As continuing discoveries show us that planets are very common components of the Universe, and we are able to study the characteristics of those planets, it’s exciting that at the same time, technological advances are giving us the tools to greatly expand our search for signs of life. We look forward to this new realm of discovery,” said Beasley, who organized the AAAS panel.

    “We also look forward to the coming decade, when we hope to build a next-generation Very Large Array, which will be able to search a volume of the Universe a thousand times larger than that accessible to current telescopes — making it the most powerful radio technosignature search machine humanity has ever constructed,” Beasley added.

    The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

    See the full article here .


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    NRAO/Karl V Jansky VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

    The NRAO operates a complementary, state-of-the-art suite of radio telescope facilities for use by the scientific community, regardless of institutional or national affiliation: the Very Large Array (VLA)



    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    Access to ALMA observing time by the North American astronomical community will be through the North American ALMA Science Center (NAASC).

    *The Very Long Baseline Array (VLBA) comprises ten radio telescopes spanning 5,351 miles. It’s the world’s largest, sharpest, dedicated telescope array. With an eye this sharp, you could be in Los Angeles and clearly read a street sign in New York City!

    Astronomers use the continent-sized VLBA to zoom in on objects that shine brightly in radio waves, long-wavelength light that’s well below infrared on the spectrum. They observe blazars, quasars, black holes, and stars in every stage of the stellar life cycle. They plot pulsars, exoplanets, and masers, and track asteroids and planets.

    largest, sharpest, dedicated telescope array. With an eye this sharp, you could be in Los Angeles and clearly read a street sign in New York City!

    Astronomers use the continent-sized VLBA to zoom in on objects that shine brightly in radio waves, long-wavelength light that’s well below infrared on the spectrum. They observe blazars, quasars, black holes, and stars in every stage of the stellar life cycle. They plot pulsars, exoplanets, and masers, and track asteroids and planets.

    The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  • richardmitnick 1:09 pm on February 15, 2020 Permalink | Reply
    Tags: , , , Biosignatures, , , , ,   

    From University of Washington via phys.org: “Earth’s cousins: Upcoming missions to look for ‘biosignatures’ in exoplanet atmospheres” 

    From University of Washington



    February 15, 2020

    Credit: CC0 Public Domain

    Scientists have discovered thousands of exoplanets, including dozens of terrestrial—or rocky—worlds in the habitable zones around their parent stars. A promising approach to search for signs of life on these worlds is to probe exoplanet atmospheres for “biosignatures”—quirks in chemical composition that are telltale signs of life. For example, thanks to photosynthesis, our atmosphere is nearly 21% oxygen, a much higher level than expected given Earth’s composition, orbit and parent star.

    Finding biosignatures is no straightforward task. Scientists use data about how exoplanet atmospheres interact with light from their parent star to learn about their atmospheres. But the information, or spectra, that they can gather using today’s ground- and space-based telescopes is too limited to measure atmospheres directly or detect biosignatures.

    Exoplanet researchers such as Victoria Meadows, a professor of astronomy at the University of Washington, are focused on what forthcoming observatories, like the James Webb Space Telescope, or JWST, could measure in exoplanet atmospheres.

    NASA/ESA/CSA Webb Telescope annotated

    On Feb. 15 at the American Association for the Advancement of Science’s annual meeting in Seattle, Meadows, a principal investigator of the UW’s Virtual Planetary Laboratory, will deliver a talk to summarize what kind of data these new observatories can collect and what they can reveal about the atmospheres of terrestrial, Earth-like exoplanets. Meadows sat down with UW News to discuss the promise of these new missions to help us view exoplanets in a new light.

    Q: What changes are coming to the field of exoplanet research?

    In the next five to 10 years, we’ll potentially get our first chance to observe the atmospheres of terrestrial exoplanets. This is because new observatories are set to come online, including the James Webb Space Telescope and ground-based observatories like the Extremely Large Telescope.

    ESO/E-ELT, 39 meter telescopeto be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).

    TMT-Thirty Meter Telescope, proposed and now approved for Mauna Kea, Hawaii, USA4,207 m (13,802 ft) above sea level, the only giant 30 meter class telescope for the Northern hemisphere

    Giant Magellan Telescope, 21 meters, to be at the Carnegie Institution for Science’s Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high

    A lot of our recent work at the Virtual Planetary Laboratory, as well as by colleagues at other institutions, has focused on simulating what Earth-like exoplanets will “look” like to the JWST and ground-based telescopes. That allows us to understand the spectra that these telescopes will pick up, and what those data will and won’t tell us about those exoplanet atmospheres.

    Q: What types of exoplanet atmospheres will the JWST and other missions be able to characterize?

    Our targets are actually a select group of exoplanets that are nearby—within 40 light years—and orbit very small, cool stars. For reference, the Kepler mission identified exoplanets around stars that are more than 1,000 light years away.

    NASA/Kepler Telescope, and K2 March 7, 2009 until November 15, 2018

    The smaller host stars also help us get better signals on what the planetary atmospheres are made of because the thin layer of planetary atmosphere can block more of a smaller star’s light.

    So there are a handful of exoplanets we’re focusing on to look for signs of habitability and life. All were identified by ground-based surveys like TRAPPIST and its successor, SPECULOOS—both run by the University of Liège—as well as the MEarth Project run by Harvard.

    ESO Belgian robotic Trappist National Telescope at Cerro La Silla, Chile

    ESO Belgian robotic Trappist National Telescope at Cerro La Silla, Chile

    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 ft above sea level

    The most well-known exoplanets in this group are probably the seven terrestrial planets orbiting TRAPPIST-1.

    A size comparison of the planets of the TRAPPIST-1 system, lined up in order of increasing distance from their host star. The planetary surfaces are portrayed with an artist’s impression of their potential surface features, including water, ice, and atmospheres. NASA

    The TRAPPIST-1 star, an ultracool dwarf, is orbited by seven Earth-size planets (NASA).

    TRAPPIST-1 is an M-dwarf star—one of the smallest you can have and still be a star—and its seven exoplanets span interior to and beyond the habitable zone, with three in the habitable zone.

    We’ve identified TRAPPIST-1 as the best system to study because this star is so small that we can get fairly large and informative signals off of the atmospheres of these worlds. These are all cousins to Earth, but with a very different parent star, so it will be very interesting to see what their atmospheres are like.

    Q: What have you learned so far about the atmospheres of the TRAPPIST-1 exoplanets?

    The astronomy community has taken observations of the TRAPPIST-1 system, but we haven’t seen anything but “non-detections.” That can still tell us a lot. For example, observations and models suggest that these exoplanet atmospheres are less likely to be dominated by hydrogen, the lightest element. That means they either don’t have atmospheres at all, or they have relatively high-density atmospheres like Earth.

    Q: No atmospheres at all? What would cause that?

    M-dwarf stars have a very different history than our own sun. After their infancy, sun-like stars brighten over time as they undergo fusion.

    M-dwarfs start out big and bright, as they gravitationally collapse to the size they will then have for most of their lifetimes. So, M-dwarf planets could be subjected to long periods of time—perhaps as along as a billion years—of high-intensity luminosity. That could strip a planet of its atmosphere, but volcanic activity can also replenish atmospheres. Based on their densities, we know that many of the TRAPPIST-1 worlds are likely to have reservoirs of compounds—at much higher levels than Earth, actually—that could replenish the atmosphere. The first significant JWST results for TRAPPIST-1 will be: Which worlds retained atmospheres? And what types of atmospheres are they?

    I’m quietly optimistic that they do have atmospheres because of those reservoirs, which we’re still detecting. But I’m willing to be surprised by the data.

    What types of signals will the JWST and other observatories look for in the atmospheres of TRAPPIST-1 exoplanets. Probably the easiest signal to look for will be the presence of carbon dioxide.

    Q: Is CO2 a biosignature?

    Not on its own, and not just from a single signal. I always tell my students—look right, look left. Both Venus and Mars have atmospheres with high levels of CO2, but no life. In Earth’s atmosphere, CO2 levels adjust with our seasons. In spring, levels draw down as plants grow and take CO2 out of the atmosphere. In autumn, plants break down and CO2 rises. So if you see seasonal cycling, that might be a biosignature. But seasonal observations are very unlikely with JWST.

    Instead, JWST can look for another potential biosignature, methane gas in the presence of CO2. Methane should normally have a short lifetime with CO2. So if we detect both together, something is probably actively producing methane. On Earth, most of the methane in our atmosphere is produced by life.

    Q: What about detecting oxygen?

    Oxygen alone is not a biosignature. It depends on its levels and what else is in the atmosphere. You could have an oxygen-rich atmosphere from the loss of an ocean, for example: Light splits water molecules into hydrogen and oxygen. Hydrogen escapes into space, and oxygen builds up into the atmosphere.

    The JWST likely won’t directly pick up oxygen from oxygenic photosynthesis—the biosphere we’re used to now. The Extremely Large Telescope and related observatories might be able to, because they’ll be looking at a different wavelength than the JWST, where they will have a better chance of seeing oxygen. The JWST will be better for detecting biospheres similar to what we had on Earth billions of years ago, and for differentiating between different types of atmospheres.

    Q: What are some of the different types of atmospheres that TRAPPIST-1 exoplanets might possess?

    The M-dwarf’s high-luminosity phase might drive a planet toward an atmosphere with a runaway greenhouse effect, like Venus. As I said earlier, you could lose an ocean and have an oxygen-rich atmosphere. A third possibility is to have something more Earth-like.

    Q: Let’s talk about that second possibility. How could JWST reveal an oxygen-rich atmosphere if it can’t detect oxygen directly?

    The beauty of the JWST is that it can pick up processes happening in an exoplanet’s atmosphere. It will pick up the signatures of collisions between oxygen molecules, which will happen more often in an oxygen-rich atmosphere. So we likely can’t see oxygen amounts associated with a photosynthetic biosphere. But if a much larger amount of oxygen was left behind from ocean loss, we can probably see the collisions of oxygen in the spectrum, and that’s probably a sign that the exoplanet has lost an ocean.

    So, JWST is unlikely to give us conclusive proof of biosignatures but may provide some tantalizing hints, which require further follow-up and—moving forward—thinking about new missions beyond the JWST. NASA is already considering new missions. What would we like their capabilities to be?

    That also brings me to a very important point: Exoplanet science is massively interdisciplinary. Understanding the environment of these worlds requires considering orbit, composition, history and host star—and requires the input of astronomers, geologists, atmospheric scientists, stellar scientists. It really takes a village to understand a planet.

    See the full article here .


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  • richardmitnick 4:21 pm on August 28, 2019 Permalink | Reply
    Tags: "Canadian astronomers determine Earth’s fingerprint in hopes of finding habitable planets beyond the Solar System", , , , Biosignatures, , , , SCISAT-1 is a Canadian satellite designed to make observations of the Earth's atmosphere., this is the first empirical infrared transit spectrum of Earth., Transit spectroscopy of exoplanets   

    From McGill University: “Canadian astronomers determine Earth’s fingerprint in hopes of finding habitable planets beyond the Solar System” 

    McGill University

    From McGill University

    28 Aug 2019

    Media Contact
    Nathalie Ouellette
    Institute for Research on Exoplanets, Université de Montréal, Montréal, Canada
    514-343-6111 x3195

    Scientific Contact
    Evelyn Macdonald
    McGill Space Institute, McGill University, Montréal, Canada

    Nicolas Cowan
    McGill Space Institute, McGill University, Montréal, Canada

    Two McGill University astronomers have assembled a “fingerprint” for Earth, which could be used to identify a planet beyond our Solar System capable of supporting life.


    McGill Physics student Evelyn Macdonald and her supervisor Prof. Nicolas Cowan used over a decade of observations of Earth’s atmosphere taken by the SCISAT satellite to construct a transit spectrum of Earth, a sort of fingerprint for Earth’s atmosphere in infrared light, which shows the presence of key molecules in the search for habitable worlds.

    SCISAT-1 is a Canadian satellite designed to make observations of the Earth’s atmosphere. Image from NASA

    This includes the simultaneous presence of ozone and methane, which scientists expect to see only when there is an organic source of these compounds on the planet. Such a detection is called a “biosignature”.

    “A handful of researchers have tried to simulate Earth’s transit spectrum, but this is the first empirical infrared transit spectrum of Earth,” says Prof. Cowan. “This is what alien astronomers would see if they observed a transit of Earth.”

    The findings, published Aug. 28 in the journal Monthly Notices of the Royal Astronomical Society, could help scientists determine what kind of signal to look for in their quest to find Earth-like exoplanets (planets orbiting a star other than our Sun). Developed by the Canadian Space Agency, SCISAT was created to help scientists understand the depletion of Earth’s ozone layer by studying particles in the atmosphere as sunlight passes through it. In general, astronomers can tell what molecules are found in a planet’s atmosphere by looking at how starlight changes as it shines through the atmosphere. Instruments must wait for a planet to pass – or transit – over the star to make this observation. With sensitive enough telescopes, astronomers could potentially identify molecules such as carbon dioxide, oxygen or water vapour that might indicate if a planet is habitable or even inhabited.

    Cowan was explaining transit spectroscopy of exoplanets at a group lunch meeting at the McGill Space Institute (MSI) when Prof. Yi Huang, an atmospheric scientist and fellow member of the MSI, noted that the technique was similar to solar occultation studies of Earth’s atmosphere, as done by SCISAT.

    Since the first discovery of an exoplanet in the 1990s, astronomers have confirmed the existence of 4,000 exoplanets. The holy grail in this relatively new field of astronomy is to find planets that could potentially host life – an Earth 2.0.

    A very promising system that might hold such planets, called TRAPPIST-1, will be a target for the upcoming James Webb Space Telescope, set to launch in 2021.

    A size comparison of the planets of the TRAPPIST-1 system, lined up in order of increasing distance from their host star. The planetary surfaces are portrayed with an artist’s impression of their potential surface features, including water, ice, and atmospheres. NASA

    ESO Belgian robotic Trappist National Telescope at Cerro La Silla, Chile

    ESO Belgian robotic Trappist-South National Telescope at Cerro La Silla, Chile, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    NASA/ESA/CSA Webb Telescope annotated

    Macdonald and Cowan built a simulated signal of what an Earth-like planet’s atmosphere would look like through the eyes of this future telescope which is a collaboration between NASA, the Canadian Space Agency and the European Space Agency.

    The TRAPPIST-1 system located 40 light years away contains seven planets, three or four of which are in the so-called “habitable zone” where liquid water could exist. The McGill astronomers say this system might be a promising place to search for a signal similar to their Earth fingerprint since the planets are orbiting an M-dwarf star, a type of star which is smaller and colder than our Sun.

    “TRAPPIST-1 is a nearby red dwarf star, which makes its planets excellent targets for transit spectroscopy. This is because the star is much smaller than the Sun, so its planets are relatively easy to observe,” explains Macdonald. “Also, these planets orbit close to the star, so they transit every few days. Of course, even if one of the planets harbours life, we don’t expect its atmosphere to be identical to Earth’s since the star is so different from the Sun.”

    According to their analysis, Macdonald and Cowan affirm that the Webb Telescope will be sensitive enough to detect carbon dioxide and water vapour using its instruments. It may even be able to detect the biosignature of methane and ozone if enough time is spent observing the target planet.

    Prof. Cowan and his colleagues at the Montreal-based Institute for Research on Exoplanets are hoping to be some of the first to detect signs of life beyond our home planet. The fingerprint of Earth assembled by Macdonald for her senior undergraduate thesis could tell other astronomers what to look for in this search. She will be starting her Ph.D. in the field of exoplanets at the University of Toronto in the Fall.

    Funding for the research was provided by the Natural Sciences and Engineering Research Council of Canada, the Fonds de recherche du Québec – Nature et technologies, and a McGill Science Undergraduate Research Award.

    See the full article here .


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    All about

    With some 300 buildings, more than 38,500 students and 250,000 living alumni, and a reputation for excellence that reaches around the globe, McGill has carved out a spot among the world’s greatest universities.
    Founded in Montreal, Quebec, in 1821, McGill is a leading Canadian post-secondary institution. It has two campuses, 11 faculties, 11 professional schools, 300 programs of study and some 39,000 students, including more than 9,300 graduate students. McGill attracts students from over 150 countries around the world, its 8,200 international students making up 21 per cent of the student body.

  • richardmitnick 10:02 am on May 13, 2019 Permalink | Reply
    Tags: Biosignatures, , , NASA’s Astrobiology Program, NExSS 2.0, Nexus for Exoplanet System Science or “NExSS”, Signatures of life on distant planets, Teams from seventeen academic and NASA centers   

    From Many Worlds: “NExSS 2.0” 

    NASA NExSS bloc


    Many Words icon

    From Many Worlds

    May 13, 2019
    Marc Kaufman

    Finding new worlds can be an individual effort, a team effort, an institutional effort. The same can be said for characterizing exoplanets and understanding how they are affected by their suns and other planets in their solar systems. When it comes to the search for possible life on exoplanets, the questions and challenges are too great for anything but a community. NASA’s NExSS initiative has been an effort to help organize, cross-fertilize and promote that community. This artist’s concept Kepler-47, the first two-star systems with multiple planets orbiting the two suns, suggests just how difficult the road ahead will be. ( NASA/JPL-Caltech/T. Pyle)

    The Nexus for Exoplanet System Science, or “NExSS,” began four years ago as a NASA initiative to bring together a wide range of scientists involved generally in the search for life on planets outside our solar system.

    With teams from seventeen academic and NASA centers, NExSS was founded on the conviction that this search needed scientists from a range of disciplines working in collaboration to address the basic questions of the fast-growing field.

    Among the key goals: to investigate just how different, or how similar, different exoplanets are from each other; to determine what components are present on particular exoplanets and especially in their atmospheres (if they have one); to learn how the stars and neighboring exoplanets interact to support (or not support) the potential of life; to better understand how the initial formation of planets affects habitability, and what role climate plays as well.

    Then there’s the question that all the others feed in to: what might scientists look for in terms of signatures of life on distant planets?

    Not questions that can be answered alone by the often “stove-piped” science disciplines — where a scientist knows his or her astrophysics or geology or geochemistry very well, but is uncomfortable and unschooled in how other disciplines might be essential to understanding the big questions of exoplanets.

    The original NExSS team was selected from groups that had won NASA grants and might want to collaborate with other scientists with overlapping interests and goals but often from different disciplines. (NASA)

    The original idea for this kind of interdisciplinary group came out of NASA’s Astrobiology Program, and especially from NASA astrobiology director Mary Voytek and colleague Shawn Domogal-Goldman. It was something of a gamble, since scientists who joined would essentially volunteer their time and work and would be asked to collaborate with other scientists in often new ways.

    But over the past four years NExSS has proven itself to be very active and useful in terms of laying out strategies for tackling the biggest questions in the field of exoplanets and whether they might harbor life. In two major reports last year, the private, congressionally-mandated National Academies of Sciences, Engineering and Medicine held up NExSS as a successful model for moving the science forward.

    One of the study co-chairs, David Charbonneau of Harvard University, said after the release of the study that the “promise of NExSS is tremendous…We really want that idea to grow and have a huge impact.”

    This major report from the National Academy of Sciences last year endorsed NExSS as a program that substantially aided the exoplanet community. The report recommended that the organization be expanded. (NAS)

    So with that kind of affirmation, it was hardly surprising that the first gathering of a newly constituted NExSS at the University of California, Santa Cruz featured 34 teams, double the original 17. (The team members, both new and original, are here.)

    As explained at the opening of the gathering by Voytek and others, the NExSS approach is all about creating, expanding and promoting the fast-growing fields of exoplanet habitability and astrobiology more generally.

    “The original NExSS members were in service to all of you,” she told the group. “They provided the opportunity to help your community to push questions further and also to get NASA headquarters to give some necessary attention to what you are doing.”

    And in many ways they succeeded. The NExSS teams may not have gotten funded additionally for their work, but the group’s rising profile created important advisory opportunities for participants.

    From the first NExSS groups, for instance, scientists were selected for leadership roles in the main exoplanet science group and several for science and technology definition teams. These groups established by NASA are putting together four proposals for a grand observatory for the 2030s — a hoped-for successor to the Hubble Space Telescope and the James Webb Space Telescope.

    NExSS members also were called on to organize in-depth workshops on subjects ranging from defining and interpreting biosignatures on distant planets, to the centrality of exoplanet interiors and most recently to what signs of advanced technological civilizations might be detectable. Major white papers were generally written, submitted and published in journals following these NExSS workshops.

    “I think putting together NExSS is most successful thing I’ve done in my career in NASA,” said Voytek who, in her decade-plus at the agency, has worked to change attitudes about astrobiology and interdisciplinary work. “I’m proud of what you did and we did.”

    What’s more, as Voytek explained at the beginning of the meeting, the NExSS approach will spread with the creation of four new networking groups based on the model of NExSS.

    They will use the same cross-disciplinary, get-to-know-your-fellow scientists approach to jump-start collaborations and cross-fertilizing in other aspects of the search for life beyond Earth, as well as the effort to understand how life on Earth (and potentially elsewhere) might have started and grown more complex.

    (The four, below, focus on planetary chemistry before life, on biosignatures, on the transition from early single cell organisms to more complex ones, and on what can be learned from ocean worlds.)

    This expansion, which will be part of a reorganization of NASA’s astrobiology program, will change the way that science teams will be funded and also, as Voytek put it, would “democratize” the process that NExSS began. The original program had selected many of its principal investigators from large teams and organizations, but the expanded NExSS and the four other groups to come will be more widely open to teams and individuals from smaller institutions who are earlier in their careers.

    This is important, Voytek and other NExSS organizers said, because the NExSS approach allows scientists to network in ways that create science opportunities, as well as those avenues into the major prioritizing organizations in their exoplanet/astrobiology community writ large.


    One value of this approach can be seen in the person of planetary scientist Sarah Morrison, a postdoc at the large Pennsylvania State University exoplanet program who has been hired to teach at the much smaller Missouri State University program.


    She is a co-principal investigator on one of two NExSS teams at Penn State and was at last week’s Santa Cruz meeting in that capacity.

    Her research focuses on protoplanetary disks and planet formation within them. In particular, she studies the many different types of interactions — collisions, migrations, atmosphere losses — that forming planets can have within their natal disks. She is also intrigued by solar systems where the planets orbit in resonance to each other.

    These factors, and many others, have implications for the composition of planets and then for the possibility of life starting on them. Factors such as the eccentricity of a planet’s orbit or where it was formed within the disk can make a planet a good candidate for habitability or one where life is impossible.

    For Morrison, NExSS is an avenue for keeping her research vibrant.

    “I’m going to a smaller institution, with not so many people doing exoplanets,” she told me. “For me to remain active in the field and work, and to have the collaborators I need to open possibilities for students working with me, this type of network can be very important – on the research side and education side.”

    She said that it isn’t always easy to find scientists whose work overlaps with hers, but that at the NExSS meeting it was easy.

    “I can definitely see projects down the line as a result of conversations I had with those folks,” she said. “And developing collaborations now is very important to me.”

    As described by Voytek and other NExSS leaders, another major focus of the group has been to encourage NASA headquarters to embrace some of the interdisciplinary approach they practice and are convinced is necessary.

    This is part of a much longer effort by Voytek and other to include the search for life beyond Earth in the missions large and small that NASA develops. There was certainly resistance at times, but the agency has, in the past decade, made that search an increasingly central NASA goal.

    As described by NExSS leader (or “Jedi”) Dawn Gelino, deputy director of the agency’s Exoplanet Science Institute, NASA headquarters has responded in other ways as well, and in recent months made two of its major research grant programs interdivisional.

    That means scientists from quite different but nonetheless related disciplines can — for the first time — together propose projects for funding by those NASA programs. Thomas Zurbuchen, NASA’s associate administrator of the Science Mission Directorate, has been forceful in his support for this kind of approach.

    “As a result of NExSS, we are definitely making a difference at headquarters in terms of the structure of teams responding to calls for proposals,” Gelino said.

    A NExSS interdisciplinary approach is not for everyone, and some question its value. Many researchers would prefer to spend their time at the telescope, in the lab, with their modeling computers, writing papers — with laser focus on their areas of expertise. NExSS leaders regularly make the point that those decisions are understood and perfectly fine.

    But especially in inherently interdisciplinary fields such as exoplanets and astrobiology, the pool of scientists willing to pitch in to advance the community appears to be large and has proven go be quite useful.

    (Since I am writing about NExSS, I want to be clear in saying that the program helps support Many Worlds. A second column about NExSS brain-storming about the future of exoplanet and habitability studies will be coming soon.)

    See the full article here .


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    About Many Worlds
    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

  • richardmitnick 11:36 am on May 4, 2019 Permalink | Reply
    Tags: "When it comes to planetary habitability it’s what’s inside that counts", A true picture of planetary habitability must consider how a planet’s atmosphere is linked to and shaped by what’s happening in its interior, , , Biosignatures, , , , , , ,   

    From Carnegie Institution for Science: “When it comes to planetary habitability, it’s what’s inside that counts” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    May 01, 2019

    Which of Earth’s features were essential for the origin and sustenance of life? And how do scientists identify those features on other worlds?

    A team of Carnegie investigators with array of expertise ranging from geochemistry to planetary science to astronomy published this week in Science an essay urging the research community to recognize the vital importance of a planet’s interior dynamics in creating an environment that’s hospitable for life.

    With our existing capabilities, observing an exoplanet’s atmospheric composition will be the first way to search for signatures of life elsewhere. However, Carnegie’s Anat Shahar, Peter Driscoll, Alycia Weinberger, and George Cody argue that a true picture of planetary habitability must consider how a planet’s atmosphere is linked to and shaped by what’s happening in its interior.

    Reprinted with permission from Shahar et. al., Science Volume 364:3(2019).

    For example, on Earth, plate tectonics are crucial for maintaining a surface climate where life can thrive. What’s more, without the cycling of material between its surface and interior, the convection that drives the Earth’s magnetic field would not be possible and without a magnetic field, we would be bombarded by cosmic radiation.

    “We need a better understanding of how a planet’s composition and interior influence its habitability, starting with Earth,” Shahar said. “This can be used to guide the search for exoplanets and star systems where life could thrive, signatures of which could be detected by telescopes.”

    It all starts with the formation process. Planets are born from the rotating ring of dust and gas that surrounds a young star. The elemental building blocks from which rocky planets form—silicon, magnesium, oxygen, carbon, iron, and hydrogen—are universal. But their abundances and the heating and cooling they experience in their youth will affect their interior chemistry and, in turn, things like ocean volume and atmospheric composition.

    “One of the big questions we need to ask is whether the geologic and dynamic features that make our home planet habitable can be produced on planets with different compositions,” Driscoll explained.

    The Carnegie colleagues assert that the search for extraterrestrial life must be guided by an interdisciplinary approach that combines astronomical observations, laboratory experiments of planetary interior conditions, and mathematical modeling and simulations.

    Artist’s impression of the surface of the planet Barnard’s Star b courtesy of ESO/M. Kornmesser.

    “Carnegie scientists are long-established world leaders in the fields of geochemistry, geophysics, planetary science, astrobiology, and astronomy,” said Weinberger. “So, our institution is perfectly placed to tackle this cross-disciplinary challenge.”

    In the next decade as a new generation of telescopes come online, scientists will begin to search in earnest for biosignatures in the atmospheres of rocky exoplanets. But the colleagues say that these observations must be put in the context of a larger understanding of how a planet’s total makeup and interior geochemistry determines the evolution of a stable and temperate surface where life could perhaps arise and thrive.

    “The heart of habitability is in planetary interiors,” concluded Cody.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile

    Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena,Chile

    Carnegie Institution Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena. near the north end of a 7 km (4.3 mi) long mountain ridge. Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile


  • richardmitnick 3:28 pm on January 28, 2019 Permalink | Reply
    Tags: , Biosignatures, DLR specializes in developing technology for space missions including photometric technology radiometers laser altimeters thermal probes and spectrometers and contributes to NASA and ESA projects, German Aerospace Center: Institute of Planetary Research, Where to look for life   

    From Astrobiology Magazine: “German Aerospace Center: Institute of Planetary Research” 

    Astrobiology Magazine

    From Astrobiology Magazine

    Jan 28, 2019
    Starre Vartan

    The BIOMEX experiment, performed by DLR, being attached by astronauts to the exterior of the International Space Station. Image credit: ESA.

    Each of NASA’s international astrobiology partners take a different tack in looking for the answer to the question of whether there is life elsewhere in the Universe.

    A creative, multi-pronged investigation is necessary with such a complicated problem – the answer will draw on a collaborative approach among biologists, geologists, chemists and many others.

    In the case of the German Aerospace Center (DLR)’s Institute of Planetary Research, there are two areas on which they focus their attention.

    DLR specializes in developing technology for space missions, including photometric technology, radiometers, laser altimeters, thermal probes and spectrometers, and contributes to NASA projects including Cassini, InSight and Dawn, plus European Space Agency (ESA) missions such as CoRoT, Rosetta and ExoMars and the forthcoming JUICE (JUpiter ICy moons Explorer) spacecraft. In particular, cameras are a speciality.

    NASA/ESA/ASI Cassini-Huygens Spacecraft

    NASA/Mars InSight Lander

    NASA Dawn Spacescraft


    ESA/Rosetta spacecraft


    ESA/Juice spacecraft

    “For example, we built a high-resolution stereo camera for Mars Express, which is the oldest camera on a European Space Agency mission still in operation,” says Professor Heike Rauer, the new Director of the DLR Institute of Planetary Research. “It’s been running for 15 years, and takes 3D images.”

    Those high-resolution, color images have revealed details about Mars’ geologic and climate history, including evidence of ancient water flows that have led to evidence-based discussions of human habitability and settlement on the red planet.

    In addition, DLR has performed astrobiological experiments, for example BIOMEX (BIOlogy and Mars Experiment) [above] on board the International Space Station, which tests the extent to which extremophiles can survive in particular space environments. Furthermore, Rauer is head of a consortium developing an instrument for the planet-finding PLATO mission that will detect and characterize Earth-like planets in the habitable zone of Sun-like stars.


    This ties in with their second focus, which is to understand the evolution of planets, both in ourSolar System and around other stars.By understanding the planetary processes that make life possible, the search for life elsewhere can be concentrated on the places where it’s most likely to have evolved.

    Helmholtz Alliance

    This aspect of DLR’s work began with the Helmholtz Alliance‘Planetary Evolution and Life’ project. The Helmholtz Alliance is a science-focused program of the German government designed to solve “the grand challenges of science, society and industry.” Helmholtz gives out five-year grants to scientists who work in German institutions and elsewhere to come together on collaborative projects that especially aim to involve young people and promote equal opportunity.

    DLR’s planetary research work was funded in 2008 by Helmholtz and continued through 2015, having received an extension on the work in order to use up all the funds.

    In the framework of the Helmholtz Alliance, DLR became an affiliated partner of the NASA Astrobiology Institute (NAI) in early 2013. The Helmholtz program was only meant to be a one-time ‘jump-start’ for a research area, which is exactly what was accomplished with the $5 million euro per annum fund that made Germany one of the leading nations in planetary research. The planetary evolution work at DLR is now a regular research program with a long-term funding perspective, says the Alliance’s former director, Professor Tilman Spohn. While funding isn’t quite as robust as it once was under Helmholtz, it still stands as an independent program at the DLR.

    During the six years that planetary evolution research was a Helmholtz program, “We did some exoplanetary research, but we had a strong focus on Mars,” says Spohn. “We made major contributions using the data from Mars Express to look into the various [potentially] habitable provinces on Mars to find where life could have originated and could still be present.

    ESA Mars Express Orbiter

    It was good to start something new and interesting and then make it sustainable [under the aegis of DLR].”

    Where to look for life

    The big question that the planetary research program is currently attempting to answer is the same as before: how can we figure out which of the many planets outside our Solar System might harbor life? Scientists need to set defined parameters in order to make smart guesses about where to look. So they look for what life might leave behind, or signs that might reveal indirect evidence for life. Life might exist now, but may not be obvious, so looking for coincident or non-obvious signs of life is important. Elsewhere in the Solar System, life is more likely to have existed in the past than in the present, so what might it have left behind?

    “We are looking for a better understanding of habitability and of biosignatures,” says Rauer. “In one case –our Solar System –we can go and look, but with extrasolar planets we cannot go there, which means the only way we can detect life is by studying the atmospheres of exoplanets.”

    That’s why DLR is looking closely at “the link between interiors, surface and atmosphere,” of planets, says Rauer. Understanding how each of those planetary regions affects the others enables scientists to see what might be produced by normal geologic or chemical processes, for example – and what might be anomalous.

    DLR is looking at some big questions that could apply to a wide variety of types of life, from single-celled to multicellular. “How does life leave imprints on the atmosphere? That’s important for places where we can’t send rovers,” says Rauer. She says that knowing what signs to look for could enable future researchers to scan for life simply by looking at the atmosphere of a planet. Of course, it’s also important for astrobiologists to study how life has “interactions with the surface and could leave its impact there.”

    Other related questions include how life might affect the evolution of an entire planet over time. “This is a novel look at planetary geophysics – how do tectonics and interior structures influence the development of lifeforms?” asks Rauer. Since Earth has developed in tandem with life, and life has been affected by the geophysics of the Earth, we know that both of these things have happened at least once, here. So, looking for those signs and asking those questions elsewhere makes sense.

    To that end, DLR works on modeling planet formation and tectonics, the inner structures of planets, how magnetic fields originate, and how meteor impacts affect all of the above. They also engage, along with their partners, in laboratory investigations of extremophiles in conditions similar to Mars or space, and how water behaves in different environments. And, of course, they are figuring out how to detect organisms on the surface of a planet.

    Research areas

    All of these questions fit within six specific areas that DLR’s Planetary Evolution and Life program tackles, often interdependently:

    Biosphere–Atmosphere–Surface Interaction and Development
    Planet–Interior Atmosphere Interaction
    Magnetic Field and Planetary Evolution
    Impacts and Planetary Evolution; Geological Context of Life
    Physics and Biology of Interface Water
    Strategies and Realizations of Missions for Exploration of planetary habitability.

    The Planetary Evolution and Life program started, as many great projects do, with the feeling that there was an understudied area that needed attention. Spohn says that he has long looked at the evolution of planets, including Earth, Mars, Venus and others. “But we never looked at the potential effect of life on these planets. I thought to myself that maybe we should include the interaction of life with planetary processes in our modeling. Nobody in the previous astrobiology community had really looked into a combination of geophysical tools and modeling together with the effects of life.”

    Under the Helmholtz Alliance, the Planetary Evolution program worked with – and plans to continue working with, as part of DLR – international partners across Europe and beyond, including ESA, NASA Ames, NASA’s Jet Propulsion Laboratory, the Johns Hopkins University Applied Physics Laboratory, the Japan Aerospace Exploration Agency (JAXA), the French Centre national de la recherche scientifique (CNRS) and Centre national d’études spatiales (CNES), and many other institutions and universities around the world.

    An important part of DLR’s work under Helmholtz was supporting and involving grad students and early-career scientists in both the questions and the work the institute undertook. “Much of the work has been done by students, young grad students and post-docs,” says Spohn. “We let students in on many aspects of the work, and they also looked into missions – how they are devised and managed, and put into space, so they see the whole process.”

    This aspect of the program is likely to continue, as young scientists are drawn to the still-unanswered question: “Are we alone in the Universe?”

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

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