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  • 'Spacesuits' protect microbes destined to live in space
    Donnerstag, 04.10.2018, 02:06:39 Uhr
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    'Spacesuits' protect microbes destined to live in space Berkeley CA (SPX) Oct 04, 2018 -
    Just as spacesuits help astronauts survive in inhospitable environments, newly developed "spacesuits" for bacteria allow them to survive in environments that would otherwise kill them.University of California, Berkeley, chemists developed the protective suits to extend the bacteria's lifespan in a unique system that pairs live bacteria with light-absorbing semiconductors in order to capture carbon dioxide and convert it into chemicals that can be used by industry or, someday, in space colonies.The system mimics photosynthesis in plants. But while plants capture carbon dioxide and, with the energy from sunlight, convert it to carbohydrates that we often eat, the hybrid system captures CO2 and light to make a variety of carbon compounds, depending on the type of bacteria.The bacteria used in the experiment are anaerobic, which means they are adapted to live in environments without oxygen. The suit - a patchwork of mesh-like pieces called a metal-organic framework, or MOF - is impermeable to oxygen and reactive oxygen molecules, like peroxide, which shorten their lifespan.The hybrid system could be a win-win for industry and the environment: It can capture carbon dioxide emitted by power plants and turn it into useful products. It also provides a biological way to produce needed chemicals in artificial environments such as spaceships and habitats on other planets."We are using our biohybrid to fix CO2 to make fuels, pharmaceuticals and chemicals, and also nitrogen fixation to make fertilizer," said Peidong Yang, the S. K. and Angela Chan Distinguished Chair in Energy in UC Berkeley's Department of Chemistry. "If Matt Damon wants to grow potatoes on Mars, he needs fertilizer."Yang, a faculty scientist at Lawrence Berkeley National Laboratory and a co-director of the Kavli Energy Nanoscience Institute, was referring to the actor who played the protagonist in the movie The Martian. Damon's character was marooned on Mars and had to use his own waste as fertilizer to grow potatoes for food.The research, funded by NASA through UC Berkeley's Center for the Utilization of Biological Engineering in Space, will be posted online this week in advance of publication in the journal Proceedings of the National Academy of Sciences.A hybrid of bacteria and semiconductor
    Yang and his colleagues developed the hybrid bacterial system over the past five years based on their work on light-absorbing semiconductors such as nanowires: solid wires of silicon a few hundred nanometers across, where a nanometer is a billionth of a meter. Arrays of nanowires can be used to capture light and generate electricity, promising cheap solar cells.The hybrid system takes advantage of efficient light capture by semiconductors to feed electrons to anaerobic bacteria, which normally scavenge electrons from their environment to live. The goal is to boost carbon capture by the bacteria to churn out useful carbon compounds."We are interfacing these bugs with a semiconductor that overwhelms them with electrons, so they can do more chemistry," Yang said. "But at the same time this process also generates all these reactive oxygen species, which are detrimental to the bugs. We are putting these bacteria in a shell so that if any of these oxidative species comes in, this first defense, the shell, decomposes them."The suit is made of a MOF mesh that wraps around the bacteria, covering it in patches. Wearing these MOF suits, the bacteria live five times longer at normal oxygen concentrations - 21 percent by volume - than without the suits, and often longer than in their natural environment, Yang said. Their normal lifespan ranges from weeks to months, after which they can be flushed from the system and replaced with a fresh batch.In this experiment, the researchers used bacteria called Morella thermoacetica, which produce acetate (acetic acid, or vinegar), a common precursor in the chemical industry. Another one of their test bacteria, Sporomusa ovata, also produces acetate."We picked these anaerobic bacteria because their selectivity toward one chemical product is always 100 percent," he said. "In our case, we picked a bug that gives us acetate. But you could select another bug to give you methane or alcohol."In fact, the bacteria that ferment the alcohol in beer and wine and turn milk into cheese and yoghurt are all anaerobic.While Yang's first experiments with the hybrid system paired bacteria with a bristle of silicon nanowires, in 2016 he discovered that feeding the bacteria cadmium encouraged them to decorate themselves with a natural semiconductor, cadmium sulfide, that acts as an efficient light absorber feeding the bacteria electrons.In the current experiment, the researchers took bacteria decorated with cadmium sulfide and enshrouded them with a flexible, one nanometer thick layer of MOF. While a rigid MOF interfered with the bacteria's normal process of growth and splitting, a zirconium-based MOF patch turned out to be soft enough to allow the bacteria to swell and divide while still clothed with MOF, after which new MOF in the solution re-clothed them."You can think of the 2D MOF like a sheet of graphene: a one-layer-thick cloak that covers the bacteria," said co-author Omar Yaghi, a pioneer of MOFs and the James and Neeltje Tretter Chair in the Department of Chemistry. "The 2D MOF is floating in solution with the bacteria, and as the bacteria replicate they are covered further with the 2D MOF layer, so it protects the bacteria from oxygen."Yang and his colleagues are also working to improve the hybrid system's efficiency of light capture, electron transfer and production of specific compounds. They envision combining these optimized capabilities with new metabolic pathways in these bacteria to produce ever more complex molecules."Once you fix or activate CO2 - and that is the most difficult part - you can use many existing chemical and biological approaches to upgrade them to fuels, pharmaceuticals and commodity chemicals," he said.Research paper
  • Astronomers find first evidence of possible moon outside our Solar System
    Donnerstag, 04.10.2018, 02:06:39 Uhr
    Astronomers find first evidence of possible moon outside our Solar System Baltimore MD (SPX) Oct 04, 2018 -
    Using NASA's Hubble and Kepler space telescopes, astronomers have uncovered tantalizing evidence of what could be the first discovery of a moon orbiting a planet outside our solar system.This moon candidate, which is 8,000 light-years from Earth in the Cygnus constellation, orbits a gas-giant planet that, in turn, orbits a star called Kepler-1625. Researchers caution that the moon hypothesis is tentative and must be confirmed by follow-up Hubble observations."This intriguing finding shows how NASA's missions work together to uncover incredible mysteries in our cosmos," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate at Headquarters, Washington. "If confirmed, this finding could completely shake up our understanding of how moons are formed and what they can be made of."Since moons outside our solar system - known as exomoons - cannot be imaged directly, their presence is inferred when they pass in front of a star, momentarily dimming its light. Such an event is called a transit, and has been used to detect many of the exoplanets cataloged to date.However, exomoons are harder to detect than exoplanets because they are smaller than their companion planet, and so their transit signal is weaker when plotted on a light curve that measures the duration of the planet crossing and the amount of momentary dimming. Exomoons also shift position with each transit because the moon is orbiting the planet.In search of exomoons, Alex Teachey and David Kipping, astronomers at Columbia University in New York, analyzed data from 284 Kepler-discovered planets that were in comparatively wide orbits, longer than 30 days, around their host star. The researchers found one instance in planet Kepler-1625b, of a transit signature with intriguing anomalies, suggesting the presence of a moon."We saw little deviations and wobbles in the light curve that caught our attention," Kipping said.Based upon their findings, the team spent 40 hours making observations with Hubble to study the planet intensively - also using the transit method - obtaining more precise data on the dips of light. Scientists monitored the planet before and during its 19-hour transit across the face of the star. After the transit ended, Hubble detected a second, and much smaller, decrease in the star's brightness approximately 3.5 hours later. This small decrease is consistent with a gravitationally-bound moon trailing the planet, much like a dog following after its owner. Unfortunately, the scheduled Hubble observations ended before the complete transit of the candidate moon could be measured and its existence confirmed.In addition to this dip in light, Hubble provided supporting evidence for the moon hypothesis by finding the planet transit occurring more than an hour earlier than predicted. This is consistent with a planet and moon orbiting a common center of gravity that would cause the planet to wobble from its predicted location, much the way Earth wobbles as our Moon orbits it.The researchers note the planetary wobble could be caused by the gravitational pull of a hypothetical second planet in the system, rather than a moon. While Kepler has not detected a second planet in the system, it could be that the planet is there, but not detectable using Kepler's techniques."A companion moon is the simplest and most natural explanation for the second dip in the light curve and the orbit-timing deviation," Kipping explained. "It was definitely a shocking moment to see that Hubble light curve, my heart started beating a little faster as I kept looking at that signature. But we knew our job was to keep a level head and essentially assume it was bogus, testing every conceivable way in which the data could be tricking us."In a paper published in the journal Science Advances, the scientists report the candidate moon is unusually large - potentially comparable to Neptune. Such large moons do not exist in our own solar system. The researchers say this may yield new insights into the development of planetary systems and may cause experts to revisit theories of how moons form around planets.The moon candidate is estimated to be only 1.5 percent the mass of its companion planet, and the planet is estimated to be several times the mass of Jupiter. This mass-ratio is similar to the one between Earth and the Moon. In the case of the Earth-Moon system and the Pluto-Charon system, the moons are thought to be created through dust leftover after rocky planetary collisions. However, Kepler-1625b and its possible satellite are gaseous and not rocky, so the moon may have formed through a different process.Researchers note that if this is indeed a moon, both it and its host planet lie within their star's habitable zone, where moderate temperatures allow for the existence of liquid water on any solid planetary surface. However, both bodies are considered to be gaseous and, therefore, unsuitable for life as we know it.Future searches for exomoons, in general, will target Jupiter-size planets that are farther from their star than Earth is from the Sun. The ideal candidate planets hosting moons are in wide orbits, with long and infrequent transit times. In this search, a moon would have been among the easiest to detect because of its large size. Currently, there are just a handful of such planets in the Kepler database. Whether future observations confirm the existence of the Kepler-1625b moon, NASA's James Webb Space Telescope will be used to find candidate moons around other planets, with much greater detail than Kepler."We can expect to see really tiny moons with Webb," Teachey said.
  • Breakthrough Listen expands SETI to Southern Hemisphere with MeerKAT
    Donnerstag, 04.10.2018, 02:06:39 Uhr
    Breakthrough Listen expands SETI to Southern Hemisphere with MeerKAT Washington DC (SPX) Oct 03, 2018 -
    Breakthrough Listen has announced at the International Astronautical Congress the commencement of a major new program with the MeerKAT telescope in partnership with the South African Radio Astronomy Observatory (SARAO).Breakthrough Listen's MeerKAT survey will examine a million individual stars - 1,000 times the number of targets in any previous search - in the quietest part of the radio spectrum, monitoring for signs of extraterrestrial technology. With the addition of MeerKAT's observations to its existing surveys, Listen will operate 24 hours a day, seven days a week, in parallel with other surveys"Collaborating with MeerKAT will significantly enhance the capabilities of Breakthrough Listen," said Yuri Milner, founder of the Breakthrough Initiatives. "This is now a truly global project."Built and operated by the South African Radio Astronomy Observatory (SARAO), and inaugurated in July 2018, MeerKAT is a powerful array of 64 radio antennas in the remote Karoo Desert of South Africa. By partnering with SARAO, Breakthrough Listen gains access to one of the world's premier observing facilities at radio wavelengths.Signals from the 64 dishes (each 13.5 meters in diameter) are combined electronically to yield an impressive combination of sensitivity, resolution and field of view on the sky. MeerKAT also serves as a precursor for the Square Kilometre Array, which will expand and enhance the current facility in the coming decades, eventually spanning a million square meters across South Africa and Australia to create by far the world's largest radio telescope.The Breakthrough Initiatives' Executive Director, Pete Worden, commented, "Listen and MeerKAT are developing next-generation technology and techniques that will ultimately lead to proposals for searches with the Square Kilometre Array. This is an exciting moment for SETI and radio astronomy in general."Breakthrough Listen's involvement adds the capability to search for technosignatures - signals that indicate the presence of technology on an alien world, and hence provide evidence that intelligent life exists elsewhere. MeerKAT was constructed in pursuit of a number of key science goals, from surveying distant galaxies, studying explosive events such as supernovae and mapping the distribution of hydrogen gas in the early universe.As at other facilities undertaking Listen's radio search, the new capabilities have been enabled by the latest digital instrumentation installed by scientists and engineers from the University of California, Berkeley, SETI Research Center (BSRC). Unlike the case with the Green Bank and Parkes telescopes, however, the Breakthrough Listen team will rarely use MeerKAT as its sole observer.Rather, observations will occur in a commensal mode - at the same time as other astrophysics programs. Using sophisticated processing, Breakthrough Listen scientists will digitally point the telescope at targets of interest. This means that the Breakthrough Listen instrument at MeerKAT will be operating almost continuously, scanning the skies for signs of intelligent life."With this new instrument we'll be able to form many beams at the same time, obtaining high resolution data for multiple objects simultaneously" said Listen's principal investigator Dr. Andrew Siemion. "This complements and extends our capabilities at other telescopes, enabling us to survey our cosmic neighborhood for technosignatures faster than ever before."Justin Jonas, Chief Technologist at SARAO, said, "We designed MeerKAT to be a flexible instrument that would provide standard interfaces to user-supplied equipment and also allow for commensal observing. It is very satisfying that these two design elements have made the Breakthrough Listen project possible, allowing for a significant expansion of the original MeerKAT functionality.""Our new system is a small supercomputer," explained Dr. Griffin Foster, Project Scientist for Breakthrough Listen on MeerKAT. "The powerful Breakthrough Listen hardware will enable us to look for interesting signals in real time and save the relevant data products to our on-site data archive."The Breakthrough Listen system on the MeerKAT telescope will have a total input data rate of about 4 terabits per second (4,000 gigabits per second), which is about 40 thousand times faster than a typical home internet connection.Prof. Michael Garrett, Director of the Jodrell Bank Centre for Astrophysics (JBCA) in the United Kingdom (a Breakthrough Listen partner facility) and a co-investigator on Breakthrough's MeerKAT Program, remarked, "This development represents a step-change for SETI research. Employing a large distributed array of hugely sensitive radio telescopes like MeerKAT is really a no-brainer, offering many advantages over large single dish surveys. The Breakthrough Listen MeerKAT project can be a powerful new tool for SETI with the potential to completely transform the field."
  • New tool helps scientists better target the search for alien life
    Donnerstag, 04.10.2018, 02:06:39 Uhr
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    New tool helps scientists better target the search for alien life Lausanne, Switzerland (SPX) Oct 03, 2018 -
    Could there be another planet out there with a society at the same stage of technological advancement as ours? To help find out, EPFL scientist Claudio Grimaldi, working in association with the University of California, Berkeley, has developed a statistical model that gives researchers a new tool in the search for the kind of signals that an extraterrestrial society might emit. His method - described in an article appearing in PNAS - could also make the search cheaper and more efficient.Atrophysics initially wasn't Grimaldi's thing; he was interested more in the physics of condensed matter. Working at EPFL's Laboratory of Physics of Complex Matter, his research involved calculating the probabilities of carbon nanotubes exchanging electrons.But then he wondered: if the nanotubes were stars and the electrons were signals generated by extraterrestrial societies, could we calculate the probability of detecting those signals more accurately?This is not pie-in-the-sky research - scientists have been studying this possibility for nearly 60 years. Several research projects concerning the search for extraterrestrial intelligence (SETI) have been launched since the late 1950s, mainly in the United States.The idea is that an advanced civilization on another planet could be generating electromagnetic signals, and scientists on Earth might be able to pick up those signals using the latest high-performance radio telescopes.Renewed interest
    Despite considerable advances in radio astronomy and the increase in computing power since then, none of those projects has led to anything concrete. Some signals without identifiable origin have well been recorded, like the Wow! signal in 1977, but none of them has been repeated or seems credible enough to be attributable to alien life.But that doesn't mean scientists have given up. On the contrary, SETI has seen renewed interest following the discovery of the many exoplanets orbiting the billions of suns in our galaxy.Researchers have designed sophisticated new instruments - like the Square Kilometre Array, a giant radio telescope being built in South Africa and Australia with a total collecting area of one square kilometer - that could pave the way to promising breakthroughs.And Russian entrepreneur Yuri Milner recently announced an ambitious program called Breakthrough Listen, which aims to cover 10 times more sky than previous searches and scan a much wider band of frequencies. Milner intends to fund his initiative with 100 million dollars over 10 years."In reality, expanding the search to these magnitudes only increases our chances of finding something by very little. And if we still don't detect any signals, we can't necessarily conclude with much more certainty that there is no life out there," says Grimaldi.Still a ways to go
    The advantage of Grimaldi's statistical model is that it lets scientists interpret both the success and failure to detect signals at varying distances from the Earth. His model employs Bayes' theorem to calculate the remaining probability of detecting a signal within a given radius around our planet.For example, even if no signal is detected within a radius of 1,000 light years, there is still an over 10% chance that the Earth is within range of hundreds of similar signals from elsewhere in the galaxy, but that our radio telescopes are currently not powerful enough to detect them.However, that probability rises to nearly 100% if even just one signal is detected within the 1,000-light-year radius. In that case, we could be almost certain that our galaxy is full of alien life.After factoring in other parameters like the size of the galaxy and how closely packed its stars are, Grimaldi estimates that the probability of detecting a signal becomes very slight only at a radius of 40,000 light years.In other words, if no signals are detected at this distance from the Earth, we could reasonably conclude that no other civilization at the same level of technological development as ours is detectable in the galaxy. But so far, scientists have been able to search for signals within a radius of "just" 40 light years.So there's still a ways to go. Especially since these search methods can't detect alien civilizations that may be in primordial stages or that are highly advanced but haven't followed the same technological trajectory as ours.Research paper
  • The only known white dwarf orbited by planetary fragments has been analyzed
    Donnerstag, 04.10.2018, 02:06:39 Uhr
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    The only known white dwarf orbited by planetary fragments has been analyzed Canary Islands, Spain (SPX) Oct 03, 2018 -
    The article, published recently in the journal Monthly Notices of the Royal Astronomical Society (MNRAS), confirms the ongoing evolution of the transits produced by remnants of a planetesimal orbiting the white dwarf WD 1145 017.This "debris" passes in front of the star every 4.5 hours, blocking a fraction of the light from the star. Continuous interaction and fragmentation of these chunks of debris brings about major changes in the depth and the shape of the observed transits.WD 1145 017 is a white dwarf, the remaining core of a star which has exhausted its nuclear fuel. Most white dwarfs have masses less than that of the Sun, and sizes similar to Earth. Many studies indicate that 95% of all the stars in the universe will end their lives as white dwarfs, among them our own Sun."Studying this system will give us information about the future of our Solar System", explains Paula Izquierdo, the lead author of the paper. For that reason WD 1145 017 is special. It is the first white dwarf for which changes in brightness due to occultations (part of the light from the star is blocked by the fragments of a rocky body in a 4.5-hour orbit) have been detected and undergoing continuous collisions resulting ultimately in their disintegration.Although this system was discovered only in 2015 it has already drawn the attention of a large number of research groups. This most recent study presents the first simultaneous spectroscopic data, obtained with the Gran Telescopio Canarias (10.4m) and photometric data from the Liverpool Telescope (2m), both of which at the Roque de los Muchachos Observatory (Garafia, La Palma)."When the system is out of transit, we assume that we detect 100% of the flux, because nothing gets in the way of the light emitted by the white dwarf", explains the researcher at the IAC/ULL."But when the planetary debris orbiting the star crosses our sight line", she adds, "which happens during a transit, the amount of light we receive is reduced. This reduction is as large as 50% in the deepest transit we have observed: large clouds of dust blowing off the planetesimal fragments are able to occult half the light from the white dwarf."The study also confirms that the transits in the visible range of light are "grey". That is to say there is no relation between the depth of the transits and their colour, which causes the transits to be equally deep in the five wavebands studied.The authors discuss a new hypothesis in which the observed drop in the amount of light is due to an optically-thick structure, not to an optically-thin structure as previously proposed."The deepest transit shows a complex structure which we have been able to model using the superposition of different dust clouds, as if it was produced by six equally spaced fragments coming from the planetesimal", explains Pablo Rodriguez-Gil, coauthor of the article, researcher at the IAC, and associate professor at the ULL.Among the different findings, the team has observed a reduction in the quantity of absorption produced by iron during the deepest transit detected: "Part of this absorption", states coauthor Boris Gansicke, an astronomer at the University of Warwick (United Kingdom), "does not originate in the atmosphere of the white dwarf, but in a disc of gas also orbiting around it, so we have demonstrated that the disc of fragments and the gas disc must be spatially related".Finally, they used the distance at which WD 1145 017 is placed, obtained from the Gaia mission, to derive the mass, radius, temperature, and age of the system.Scientific article: Izquierdo, P. et al. "Fast spectrophotometry of WD?1145 017" Monthly Notices of the Royal Astronomical Society, V. 481, Pp. 703-714. DOI: 10.1093/mnras/sty2315
  • Liquid crystals and the origin of life
    Donnerstag, 04.10.2018, 02:06:39 Uhr
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    Liquid crystals and the origin of life Washington DC (SPX) Oct 04, 2018 -
    The display screens of modern televisions, cell phones and computer monitors rely on liquid crystals - materials that flow like liquids but have molecules oriented in crystal-like structures.However, liquid crystals may have played a far more ancient role: helping to assemble Earth's first biomolecules. Researchers reporting in ACS Nano have found that short RNA molecules can form liquid crystals that encourage growth into longer chains.Scientists have speculated that life on Earth originated in an "RNA world," where RNA fulfilled the dual role of carrying genetic information and conducting metabolism before the dawn of DNA or proteins.Indeed, researchers have discovered catalytic RNA strands, or "ribozymes," in modern genomes. Known ribozymes are about 16-150 nucleotides in length, so how did these sequences assemble in a primordial world without existing ribozymes or proteins? Tommaso Bellini and colleagues wondered if liquid crystals could help guide short RNA precursors to form longer strands.To find out, the researchers explored different scenarios under which short RNAs could self-assemble. They found that at high concentrations, short RNA sequences (either 6 or 12 nucleotides long) spontaneously ordered into liquid crystal phases.Liquid crystals formed even more readily when the researchers added magnesium ions, which stabilized the crystals, or polyethylene glycol, which sequestered RNA into highly concentrated microdomains.Once the RNAs were held together in liquid crystals, a chemical activator could efficiently join their ends into much longer strands. This arrangement also helped avoid the formation of circular RNAs that could not be lengthened further.The researchers point out that polyethylene glycol and the chemical activator would not be found under primordial conditions, but they say that other molecular species could have played similar, if less efficient, roles.Research paper
  • Cosmologists use photonics to search Andromeda for signs of alien life
    Donnerstag, 04.10.2018, 02:06:39 Uhr
    Cosmologists use photonics to search Andromeda for signs of alien life Santa Barbara CA (SPX) Oct 01, 2018 -
    "Are we alone in the universe?" The question has fascinated, tantalized and even disconcerted humans for as long as we can remember.So far, it would seem that intelligent extraterrestrial life - at least as fits our narrow definition of it - is nowhere to be found. Theories and assumptions abound as to why we have neither made contact with nor seen evidence of advanced extraterrestrial civilizations despite decades-long efforts to make our presence known and to communicate with them.Meanwhile, a steady stream of discoveries are demonstrating the presence of Earth analogues - planets that, like our own, exist at a "Goldilocks zone" distance from their own respective stars, in which conditions are "just right" for liquid water (and thus life) to exist. Perhaps even more mind-blowing is the idea that there are, on average, as many planets as there are stars."That is, I think, one of the amazing discoveries of the last century or so - that planets are common," said Philip Lubin, an experimental cosmologist and professor of physics at UC Santa Barbara. Given that, and the assumption that planets provide the conditions for life, the question for Lubin's group has become: Are we looking hard enough for these extraterrestrials?That is the driver behind the Trillion Planet Survey, a project of Lubin's student researchers. The ambitious experiment, run almost entirely by students, uses a suite of telescopes near and far aimed at the nearby galaxy of Andromeda as well as other galaxies including our own, a "pipeline" of software to process images and a little bit of game theory."First and foremost, we are assuming there is a civilization out there of similar or higher class than ours trying to broadcast their presence using an optical beam, perhaps of the 'directed energy' arrayed-type currently being developed here on Earth," said lead researcher Andrew Stewart, who is a student at Emory University and a member of Lubin's group."Second, we assume the transmission wavelength of this beam to be one that we can detect. Lastly, we assume that this beacon has been left on long enough for the light to be detected by us. If these requirements are met and the extraterrestrial intelligence's beam power and diameter are consistent with an Earth-type civilization class, our system will detect this signal."From Radio Waves to Light Waves
    For the last half-century, the dominant broadcast from Earth has taken the form of radio, TV and radar signals, and seekers of alien life, such as the scientists at the Search for Extraterrestrial Intelligence (SETI) Institute, have been using powerful radio telescopes to look for those signals from other civilizations.Recently however, and thanks to the exponentially accelerating progress of photonic technology, optical and infrared wavelengths are offering opportunities to search via optical signals that allow for vastly longer range detection for comparable systems.In a paper published in 2016 called "The Search for Directed Intelligence" or SDI, Lubin outlined the fundamental detection and game theory of a "blind-blind" system where neither we, nor the extraterrestrial civilization are aware of each other but wish to find each other.That paper was based on the application of photonics developed at UC Santa Barbara in Lubin's group for the propulsion of small spacecraft through space at relativistic speeds (i.e. a significant fraction of the speed of light) to enable the first interstellar missions.That ongoing project is funded by NASA's Starlight and billionaire Yuri Milner's Breakthrough Starshot programs, both of which use the technology developed at UCSB. The 2016 paper shows that the technology we are developing today would be the brightest light in the universe and thus capable of being seen across the entire universe.Of course, not everyone is comfortable with advertising our presence to other, potentially advanced, extraterrestrial civilizations."Broadcasting our presence to the universe, believe it or not, turns out to be a very controversial topic," Stewart said, citing bureaucratic issues that arise whenever beaconing is discussed, as well as the difficulty in obtaining the necessary technology of the scale required. Consequently, only a few, tentative signals have ever been sent in a directed fashion, including the famous Voyager 1 probe with its message-in-a-bottle-like golden record.Tipping the concept on its head, the researchers asked, 'What if there are other civilizations out there that are less shy about broadcasting their presence?'"At the moment, we're assuming that they're not using gravity waves or neutrinos or something that's very difficult for us to detect," Lubin said. But optical signals could be detected by small (meter class) diameter telescopes such as those at the Las Cumbres Observatory's robotically controlled global network."In no way are we suggesting that radio SETI should be abandoned in favor of optical SETI," Stewart added. "We just think the optical bands should be explored as well."Searching the Stars
    "We're in the process of surveying (Andromeda) right now and getting what's called 'the pipeline' up and running," said researcher Alex Polanski, a UC Santa Barbara undergraduate in Lubin's group. A set of photos taken by the telescopes, each of which takes a 1/30th slice of Andromeda, will be knit together to create a single image, he explained.That one photograph will then be compared to a more pristine image in which there are no known transient signals - interfering signals from, say, satellites or spacecraft - in addition to the optical signals emanating from the stellar systems themselves.The survey photo would be expected to have the same signal values as the pristine "control" photo, leading to a difference of zero. But a difference greater than zero could indicate a transient signal source, Polanski explained. Those transient signals would then be further processed in the software pipeline developed by Stewart to kick out false positives. In the future the team plans to use simultaneous multiple color imaging to will help remove false positives as well."One of the things the software checks for is, say, a satellite that did go through our image," said Kyle Friedman, a senior from Granada Hills High School in Los Angeles, who is conducting research in Lubin's group. "It wouldn't be small; it would be pretty big, and if that were to happen the software would immediately recognize it and throw out that image before we actually even process it."Other vagaries, according to the researchers, include sky conditions, which is why it's important to have several telescopes monitoring Andromeda during their data run.Thanks to the efforts of Santa Barbara-based computer engineer Kelley Winters and the guidance of Lubin group project scientist Jatila van der Veen, the data is in good hands. Winters' cloud-based Linux server provides a flexible, highly connected platform for the data pipeline software to perform its image analysis, while van der Veen will apply her digital image processing expertise to bring this project to future experimental cosmologists.For Laguna Blanca School senior and future physicist Caitlin Gainey, who joins the UCSB physics freshman class this year, the project is a unique opportunity."In the Trillion Planet Survey especially, we experience something very inspiring: We have the opportunity to look out of our earthly bubble at entire galaxies, which could potentially have other beings looking right back at us," she said. "The mere possibility of extraterrestrial intelligence is something very new and incredibly intriguing, so I'm excited to really delve into the search this coming year."The search, for any SETI-watcher, is an exercise in patience and optimism. Andromeda is 2.5 million light-years away, van der Veen pointed out, so any signal detected now would have been sent at least 2.5 million years ago - more than long enough for the civilization that sent it to have died out by the time the light reaches us."That does not mean we should not look," van der Veen said. "After all, we look for archaeological relics and fossils, which tell us about the history of Earth. Finding ancient signals will definitely give us information about the history of evolution of life in the cosmos, and that would be amazing."While the data run and processing time for this particular project could occur in a span of weeks, according to the researchers this sequence could be repeated indefinitely. Theoretically, like all the sunrise and sunset watchers, and stargazers before us, we could look at the sky forever."I think if you were to take someone outside and you were to point at some random star in the night sky and see that is where life is, I think you would be hard pressed to find anyone who would not look at that star and just feel something very deep within themselves," Polanski said. "Some very deep connection to whatever is up there or some kind of solace, I think, knowing that we're not alone."The latest UCSB data and game theory of the "blind-blind" detection strategy used is being presented at the NASA Technosignatures workshop in Houston on September 28.
  • Did key building blocks for life come from deep space?
    Donnerstag, 04.10.2018, 02:06:39 Uhr
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    Did key building blocks for life come from deep space? Manoa HI (SPX) Oct 01, 2018 -
    All living beings need cells and energy to replicate. Without these fundamental building blocks, living organisms on Earth would not be able to reproduce and would simply not exist.Little was known about a key element in the building blocks, phosphates, until now. University of Hawaii at Manoa researchers, in collaboration with colleagues in France and Taiwan, provide compelling new evidence that this component for life was found to be generated in outer space and delivered to Earth in its first one billion years by meteorites or comets. The phosphorus compounds were then incorporated in biomolecules found in cells in living beings on Earth.The breakthrough research is outlined in "An Interstellar Synthesis of Phosphorus Oxoacids," authored by UH Manoa graduate student Andrew Turner, now assistant professor at the University of Pikeville, and UH Manoa chemistry Professor Ralf Kaiser in the September issue of Nature Communications.According to the study, phosphates and diphosphoric acid are two major elements that are essential for these building blocks in molecular biology. They are the main constituents of chromosomes, the carriers of genetic information in which DNA is found. Together with phospholipids in cell membranes and adenosine triphosphate, which function as energy carriers in cells, they form self-replicating material present in all living organisms.In an ultra-high vacuum chamber cooled down to 5 K (-450 F) in the W.M. Keck Research Laboratory in Astrochemistry at UH Manoa, the Hawaii team replicated interstellar icy grains coated with carbon dioxide and water, which are ubiquitous in cold molecular clouds, and phosphine. When exposed to ionizing radiation in the form of high-energy electrons to simulate the cosmic rays in space, multiple phosphorus oxoacids like phosphoric acid and diphosphoric acid were synthesized via non-equilibrium reactions."On Earth, phosphine is lethal to living beings," said Turner, lead author. "But in the interstellar medium, an exotic phosphine chemistry can promote rare chemical reaction pathways to initiate the formation of biorelevant molecules such as oxoacids of phosphorus, which eventually might spark the molecular evolution of life as we know it."Kaiser added, "The phosphorus oxoacids detected in our experiments by combination of sophisticated analytics involving lasers, coupled to mass spectrometers along with gas chromatographs, might have also been formed within the ices of comets such as 67P/Churyumov-Gerasimenko, which contains a phosphorus source believed to derive from phosphine." Kaiser says these techniques can also be used to detect trace amounts of explosives and drugs."Since comets contain at least partially the remnants of the material of the protoplanetary disk that formed our solar system, these compounds might be traced back to the interstellar medium wherever sufficient phosphine in interstellar ices is available," said Cornelia Meinert of the University of Nice (France).Upon delivery to Earth by meteorites or comets, these phosphorus oxoacids might have been available for Earth's prebiotic phosphorus chemistry. Hence an understanding of the facile synthesis of these oxoacids is essential to untangle the origin of water-soluble prebiotic phosphorus compounds and how they might have been incorporated into organisms not only on Earth, but potentially in our universe as well.Turner and Kaiser worked with Meinert and Agnes Chang of National Dong Hwa University (Taiwan) on this project.Research paper
  • Plans for European Astrobiology Institute Announced
    Donnerstag, 04.10.2018, 02:06:39 Uhr
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    Plans for European Astrobiology Institute Announced Berlin, Germany (SPX) Sep 27, 2018 -
    Astrobiology, the study of the origin, evolution and future of life on Earth and beyond, is a multidisciplinary field that has expanded rapidly over the last two decades. Now, a consortium of organisations has announced plans to establish a European Astrobiology Institute (EAI) to coordinate astrobiology research in Europe.The new institute is being created in accordance with the recommendations of a White Paper addressing the scientific and social implications of astrobiology research in Europe, were presented at the European Planetary Science Congress (EPSC) 2018 in Berlin.The White Paper includes contributions from authors in twenty countries and over thirty scientific institutions worldwide. The contributions draw on the experiences of other astrobiology research communities around the world and recognise the societal implications of the field as well as addressing the scientific goals."We are increasingly well-placed to answer major questions concerning the possibility of extraterrestrial life, the origins of life on Earth and the evolution of our planet," said Wolf Geppert, co-author of the White Paper chapter on leading the future of astrobiology in Europe."By its nature, astrobiology is multidisciplinary field that requires collaboration. This White Paper shows that Astrobiology has the potential to be a flagship of European cooperation. The formation of the EAI will provide a structure that will bring together many organisations involved in the field to coordinate research and provide a proactive voice for the community."Missions and research programmes related to astrobiology have led to some of the most significant and high-profile discoveries in recent years. Thousands of planets have been discovered in other solar systems.The Rosetta mission confirmed a connection between comets and the life-supporting atmosphere on Earth. There is the potential that, in the near future, we will discover living or fossilized microbes on planets or moons within our own Solar System, or we could find signs of biological processes in exoplanetary systems."Regardless of whether or not we find evidence for life beyond Earth, astrobiology can provide paradigm-changing scientific advances in our understanding of our origins and our place in the universe," said Nigel Mason, who edited and co-authored the White Paper chapter on science and research."Key areas of research identified in the White Paper include understanding the formation of habitable planets and moons, the pathway to produce the complex organics needed for life from simple molecules, how the conditions for life evolved on the early Earth and the study of life under extreme conditions."The White Paper includes sections on environmental protection and sustainability, current regulation, education, training, careers, technical innovation and commerce. In particular, the White Paper emphasises the role of social sciences and humanities in astrobiology and how the field has the capacity to change the view of how humans look at themselves and what it means to be alive."Astrobiology has clear existential implications. The social sciences and humanities can play a key role in helping us to prepare for the discovery of life beyond Earth, whether microbial or intelligent, and to understand the likely theological, ethical and worldview impacts on society," said Klara Anna Capova, co-editor of the White Paper and author of chapters on the social study of astrobiology as a science and public understanding of astrobiology."Astrobiology is a subject of intrinsic interest to the general public and to school students but it is also vulnerable to misinterpretation. The formation of the EAI will enable us to make sure that reliable information is distributed to Europe's citizens and classrooms and that they are actively engaged with the field."Astrobiology also presents environmental challenges in ensuring that any extraterrestrial life forms or remains are not compromised by scientific investigations (forward planetary protection), and protecting the Earth from contamination by potentially harmful biological material of extraterrestrial origin (backward planetary protection)."The preservation of biodiversity and of pristine environments on Earth is of the greatest importance for our ability to study life, its origin, distribution and future. Both forward and backward planetary protection must be understood within a broader context of ensuring the sustainability of scientific and commercial practices," said Erik Persson, co-editor of the White Paper and author of chapters on the international context of astrobiology and environment and sustainability.An interim board has been established to map out the tasks, structure, governing bodies, activities, funding and administration of a EAI. The presentation of the White Paper at EPSC 2018 is the first step in a community consultation on its recommendations and plans for the EAI. The formal launch of the EAI is planned for the spring of 2019.Research Report: "Astrobiology and Society in Europe Today," edited by K. Capova, E. Persson, T. Milligan and D. Duner, 2018, is published through the SpringerBriefs in Astronomy book series, Springer Nature Switzerland AG
  • Gaia finds candidates for interstellar 'Oumuamua's home
    Donnerstag, 04.10.2018, 02:06:39 Uhr
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    Gaia finds candidates for interstellar 'Oumuamua's home Paris (ESA) Sep 26, 2018 -
    Using data from ESA's Gaia stellar surveyor, astronomers have identified four stars that are possible places of origin of 'Oumuamua, an interstellar object spotted during a brief visit to our Solar System in 2017.The discovery last year sparked a large observational campaign: originally identified as the first known interstellar asteroid, the small body was later revealed to be a comet, as further observations showed it was not slowing down as fast as it should have under gravity alone. The most likely explanation of the tiny variations recorded in its trajectory was that they are caused by gasses emanating from its surface, making it more akin to a comet.But where in the Milky Way did this cosmic traveller come from?Comets are leftovers of the formation of planetary systems, and it is possible that 'Oumuamua was ejected from its home star's realm while planets were still taking shape there. To look for its home, astronomers had to trace back in time not only the trajectory of the interstellar comet, but also of a selection of stars that might have crossed paths with this object in the past few million years."Gaia is a powerful time machine for these types of studies, as it provides not only star positions but also their motions," explains Timo Prusti, Gaia project scientist at ESA.To this aim, a team of astronomers led by Coryn Bailer-Jones at the Max Planck Institute for Astronomy in Heidelberg, Germany, dived into the data from Gaia's second release, which was made public in April.The Gaia data contain positions, distance indicators and motions on the sky for more than a billion stars in our Galaxy; most importantly, the data set includes radial velocities - how fast they are moving towards or away from us - for a subset of seven million, enabling a full reconstruction of their trajectories. The team looked at these seven million stars, complemented with an extra 220 000 for which radial velocities are available from the astronomical literature.As a result, Coryn and colleagues identified four stars whose orbits had come within a couple of light years of 'Oumuamua in the near past, and with relative velocities low enough to be compatible with likely ejection mechanisms.All four are dwarf stars - with masses similar to or smaller than our Sun's - and had their 'close' encounter with the interstellar comet between one and seven million years ago. However, none of them is known to either harbour planets or to be part of a binary stellar system; a giant planet or companion star would be the preferred mechanism to have ejected the small body.While future observations of these four stars might shed new light on their properties and potential to be the home system of 'Oumuamua, the astronomers are also looking forward to future releases of Gaia data. At least two are planned in the 2020s, which will include a much larger sample of radial velocities, enabling them to reconstruct and investigate the trajectories of many more stars."While it's still early to pinpoint 'Oumuamua's home star, this result illustrates the power of Gaia to delve into the history of our Milky Way galaxy," concludes Timo.Research Report: "Plausible home stars of the interstellar object 'Oumuamua found in GaiaDR2"
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