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  • richardmitnick 5:55 pm on March 13, 2019 Permalink | Reply
    Tags: Astrochemistry, , , , , , Trihydrogen or H3+ is acknowledged by scientists as the molecule that made the universe.   

    From Michigan State University: “Understanding and controlling the molecule that made the universe” 

    Michigan State Bloc

    From Michigan State University

    March 13, 2019

    Layne Cameron
    Media Communications office
    (517) 353-8819
    cell: (765) 748-4827
    Layne.Cameron@cabs.msu.edu

    Marcos Dantus
    Chemistry office
    (517) 355-9715
    dantus@msu.edu

    Trihydrogen, or H3+, is acknowledged by scientists as the molecule that made the universe. In recent issues of Nature Communications and the Journal of Chemical Physics, Michigan State University researchers employed high-speed lasers to shine a spotlight on the mechanisms that are key in H3+ creation and its unusual chemistry.

    H3+ is prevalent in the universe, the Milky Way, gas giants and the Earth’s ionosphere. It’s also being created and studied in the lab of Marcos Dantus, University Distinguished Professor in chemistry and physics. Using ultrafast lasers – and technology invented by Dantus – a team of scientists is beginning to understand the chemistry of this iconic molecule.

    “Observing how roaming H2 molecules evolve to H3+ is nothing short of astounding,” Dantus said. “We first documented this process using methanol; now we’ve been able to expand and duplicate this process in a number of molecules and identified a number of new pathways.”

    Astrochemists see the big picture, observing H3+ and defining it through an interstellar perspective. It’s created so fast ­– in less time than it takes a bullet to cross an atom – that it is extremely difficult to figure out how three chemical bonds are broken and three new ones are formed in such a short timescale.

    That’s when chemists using femtosecond lasers come into play. Rather than study the stars using a telescope, Dantus’ team literally looks at the small picture. The entire procedure is viewed at the molecular level and is measured in femtoseconds – 1 millionth of 1 billionth of a second. The process the team views takes between 100 and 240 femtoseconds. Dantus knows this because the clock starts when he fires the first laser pulse. The laser pulse then “sees” what’s happening.

    The two-laser technique revealed the hydrogen transfer, as well as the hydrogen-roaming chemistry, that’s responsible for H3+ formation. Roaming mechanisms briefly generate a neutral molecule (H2) that stays in the vicinity and extracts a third hydrogen molecule to form H3+. And it turns out there’s more than one way it can happen. In one experiment involving ethanol, the team revealed six potential pathways, confirming four of them.

    Since laser pulses are comparable to sound waves, Dantus’ team discovered a “tune” that enhances H3+ formation and one that discourages formation. When converting these “shaped” pulses to a slide whistle, successful formation happens when the note starts flats, rises slightly and finishes with a downward, deeper dive. The song is music to the ears of chemists who can envision many potential applications for this breakthrough.

    “These chemical reactions are the building blocks of life in the universe,” Dantus said. “The prevalence of roaming hydrogen molecules in high-energy chemical reactions involving organic molecules and organic ions is relevant not only for materials irradiated with lasers, but also materials and tissues irradiated with x-rays, high energy electrons, positrons and more.”

    This study reveals chemistry that is relevant in terms of the universe’s formation of water and organic molecules. The secrets it could unlock, from astrochemical to medical, are endless, he added.

    MSU scientists who contributed to the Nature Communications paper included Nagitha Ekanayake, Muath Nairat, Nicholas Weingartz, Benjamin Farris, Benjamin Levine and James Jackson. Researchers from Kansas State University also contributed to this study.

    MSU scientists who contributed to the Journal of Chemical Physics paper included Ekanayake, Nairat, Matthew Michie, Weingartz and Levine.

    This research was funded by the Department of Energy and the National Science Foundation.

    (Note to media: Please include link to the original papers in online coverage: https://www.nature.com/articles/s41467-018-07577-0; https://aip.scitation.org/doi/10.1063/1.5070067)

    See the full article here .


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    Michigan State Campus

    Michigan State University (MSU) is a public research university located in East Lansing, Michigan, United States. MSU was founded in 1855 and became the nation’s first land-grant institution under the Morrill Act of 1862, serving as a model for future land-grant universities.

    MSU pioneered the studies of packaging, hospitality business, plant biology, supply chain management, and telecommunication. U.S. News & World Report ranks several MSU graduate programs in the nation’s top 10, including industrial and organizational psychology, osteopathic medicine, and veterinary medicine, and identifies its graduate programs in elementary education, secondary education, and nuclear physics as the best in the country. MSU has been labeled one of the “Public Ivies,” a publicly funded university considered as providing a quality of education comparable to those of the Ivy League.

    Following the introduction of the Morrill Act, the college became coeducational and expanded its curriculum beyond agriculture. Today, MSU is the seventh-largest university in the United States (in terms of enrollment), with over 49,000 students and 2,950 faculty members. There are approximately 532,000 living MSU alumni worldwide.

     
  • richardmitnick 12:29 pm on February 7, 2019 Permalink | Reply
    Tags: , Astrochemistry, , , “When we look at the information ALMA has provided we see about 60 different transitions – or unique fingerprints – of molecules like sodium chloride and potassium chloride coming from the disk", , , , Liberal Sprinkling of Salt Discovered around a Young Star, , Orion Source I, , The chemical fingerprints of sodium chloride (NaCl) and other similar salty compounds emanating from the dusty disk surrounding Orion Source I, The Orion Molecular Cloud 1   

    From ALMA: “Liberal Sprinkling of Salt Discovered around a Young Star” 

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

    From ALMA

    7 February, 2019

    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory Santiago – Chile
    Phone: +56 2 2467 6258
    Cell phone: +56 9 7587 1963
    Email: valeria.foncea@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    Phone: +1 434 296 0314
    Cell phone: +1 202 236 6324
    Email: cblue@nrao.edu

    Calum Turner
    ESO Assistant Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: calum.turner@eso.org

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    1
    Artist impression of Orion Source I, a young, massive star about 1,500 light-years away. New ALMA observations detected a ring of salt — sodium chloride, ordinary table salt — surrounding the star. This is the first detection of salts of any kind associated with a young star. The blue region (about 1/3 the way out from the center of the disk) represents the region where ALMA detected the millimeter-wavelength “glow” from the salts. Credit: NRAO/AUI/NSF; S. Dagnello

    2
    ALMA image of the salty disk surrounding the young, massive star Orion Source I (blue ring). It is shown in relation to the Orion Molecular Cloud 1, a region of explosive starbirth. The background near infrared image was taken with the Gemini Observatory. Credit: ALMA (NRAO/ESO/NAOJ); NRAO/AUI/NSF; Gemini Observatory/AURA

    Gemini South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile, at an altitude of 7200 feet

    A team of astronomers and chemists using the Atacama Large Millimeter/submillimeter Array (ALMA) has detected the chemical fingerprints of sodium chloride (NaCl) and other similar salty compounds emanating from the dusty disk surrounding Orion Source I, a massive, young star in a dusty cloud behind the Orion Nebula.

    “It’s amazing we’re seeing these molecules at all,” said Adam Ginsburg, a Jansky Fellow of the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, and lead author of a paper accepted for publication in The Astrophysical Journal. “Since we’ve only ever seen these compounds in the sloughed-off outer layers of dying stars, we don’t fully know what our new discovery means. The nature of the detection, however, shows that the environment around this star is very unusual.”

    To detect molecules in space, astronomers use radio telescopes to search for their chemical signatures – telltale spikes in the spread-out spectra of radio and millimeter-wavelength light. Atoms and molecules emit these signals in several ways, depending on the temperature of their environments.

    The new ALMA observations contain a bristling array of spectral signatures – or transitions, as astronomers refer to them – of the same molecules. To create such strong and varied molecular fingerprints, the temperature differences where the molecules reside must be extreme, ranging anywhere from 100 kelvin to 4,000 kelvin (about -175 Celsius to 3700 Celsius). An in-depth study of these spectral spikes could provide insights about how the star is heating the disk, which would also be a useful measure of the luminosity of the star.

    “When we look at the information ALMA has provided, we see about 60 different transitions – or unique fingerprints – of molecules like sodium chloride and potassium chloride coming from the disk. That is both shocking and exciting,” said Brett McGuire, a chemist at the NRAO in Charlottesville, Virginia, and co-author on the paper.

    The researchers speculate that these salts come from dust grains that collided and spilled their contents into the surrounding disk. Their observations confirm that the salty regions trace the location of the circumstellar disk.

    “Usually when we study protostars in this manner, the signals from the disk and the outflow from the star get muddled, making it difficult to distinguish one from the other,” said Ginsburg. “Since we can now isolate just the disk, we can learn how it is moving and how much mass it contains. It also may tell us new things about the star.”

    The detection of salts around a young star is also of interest to astronomers and astrochemists because some of constituent atoms of salts are metals – sodium and potassium. This suggests there may be other metal-containing molecules in this environment. If so, it may be possible to use similar observations to measure the amount of metals in star-forming regions. “This type of study is not available to us at all presently. Free-floating metallic compounds are generally invisible to radio astronomy,” noted McGuire.

    The salty signatures were found about 30 to 60 astronomical units (AU, or the average distance between the Earth and the Sun) from the host stars. Based on their observations, the astronomers infer that there may be as much as one sextillion (a one with 21 zeros after it) kilograms of salt in this region, which is roughly equivalent to the entire mass of Earth’s oceans.

    “Our next step in this research is to look for salts and metallic molecules in other regions. This will help us understand if these chemical fingerprints are a powerful tool to study a wide range of protoplanetary disks, or if this detection is unique to this source,” said Ginsburg. “In looking to the future, the planned Next Generation VLA would have the right mix of sensitivity and wavelength coverage to study these molecules and perhaps use them as tracers for planet-forming disks.”

    Orion Source I formed in the Orion Molecular Cloud I, a region of explosive starbirth previously observed with ALMA. “This star was ejected from its parent cloud with a speed of about 10 kilometers per second around 550 years ago,”1 said John Bally, an astronomer at the University of Colorado and co-author on the paper. “It is possible that solid grains of salt were vaporized by shock waves as the star and its disk were abruptly accelerated by a close encounter or collision with another star. It remains to be seen if salt vapor is present in all disks surrounding massive protostars, or if such vapor traces violent events like the one we observed with ALMA.”

    1. Light from this object took about 1,500 years to reach Earth. Astronomers are seeing it as if looking through that window of time, which reveals how it looked 550 years after it was ejected from its stellar nursery.

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small
    ESO 50 Large
    NAOJ

     
    • iptv 1:43 am on February 13, 2019 Permalink | Reply

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  • richardmitnick 7:22 pm on November 9, 2018 Permalink | Reply
    Tags: , Astrochemistry, , , , , , , , , , , , , Understanding our own backyard will be key in interpreting data from far-flung exoplanets   

    From COSMOS Magazine: “The tech we’re going to need to detect ET” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    09 November 2018
    Lauren Fuge

    1
    Searching for biosignatures rather than examples of life itself is considered a prime strategy in the hunt for ET. smartboy10/Getty Images

    Move over Mars rovers, new technologies to detect alien life are on the horizon.

    A group of scientists from around the world, led by astrochemistry expert Chaitanya Giri from the Tokyo Institute of Technology in Japan, have put their heads together to plan the next 20 years’ worth of life-detection technologies. The study is currently awaiting peer review, but is freely available on the pre-print site, ArXiv.

    For decades, astrobiologists have scoured the skies and the sands of other planets for hints of extraterrestrial life. Not only are these researchers trying to find ET, but they’re also aiming to learn about the origin and evolution of life on Earth, the chemical composition of organic extraterrestrial objects, what makes a planet or satellite habitable, and more.

    But the answers to such questions are preceded by long years of planning, development, problem-solving and strategising.

    Late in 2017, 20 scientists from Japan, India, France, Germany and the USA – each with a special area of expertise – came together at a workshop run by the Earth-Life Science Institute (ELSI) at Giri’s Tokyo campus. There, they discussed the current progress and enticing possibilities of life-detection technologies.

    In particular, the boffins debated which ones should be a priority for research and development for missions within the local solar system – in other words, which instruments will be most feasible to out onto a space probe and send off to Mars or Enceladus during the next couple of decades.

    Of course, the planets and moons in the solar system are an extremely limited sample of the number of potentially habitable worlds in the universe, but understanding our own backyard will be key in interpreting data from far-flung exoplanets.

    So, according to these astrobiology experts, what’s the future plan for alien detection?

    The first step of any space mission is to study the planet or satellite from afar to determine whether it is habitable. Luckily, an array of next-generation telescopes is currently being built, from the ultra-sensitive James Webb Space Telescope, slated for launch in 2021, to the gargantuan Extremely Large Telescope in Chile, which will turn its 39-metre eye to the sky in 2024. The authors point out that observatories such as these will vastly expand our theoretical knowledge of planet habitability.

    NASA/ESA/CSA Webb Telescope annotated

    ESO/E-ELT,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).

    Just because a world is deemed habitable doesn’t mean life will be found all over it, though. It may exist only in limited geographical niches. To reach these inaccessible sites, the paper argues that we will require “agile robotic probes that are robust, able to seamlessly communicate with orbiters and deep space communications networks, be operationally semi-autonomous, have high-performance energy supplies, and are sterilisable to avoid forward contamination”.

    But according to Elizabeth Tasker, associate professor at the Japan Aerospace Exploration Agency (JAXA), who was not involved in the study, getting there is only half the struggle.

    “In fact, it’s the most tractable half because we can picture the problems we will face,” she says.

    The second, more pressing issue is how to recognise life unlike anything we know on Earth.

    As Tasker explains: “We only have Earth life to compare to and this is the result of huge evolutionary history on a planet whose complex past is unlikely to be replicated closely. That’s a lot of baggage to separate out.”

    According to the paper, the way forward is to equip missions with a suite of life-detection instruments that don’t look for life as we know it, but are instead able to identify the kinds of features that make organisms function.

    The authors outline a huge variety of exciting technologies that could be used for this purpose, including spectroscopy techniques (to analyse potential biological materials), quantum tunnelling [Nature Nanotechnology
    ] (to find DNA, RNA, peptides, and other small molecules), and fluorescence microscopy [ https://www.hou.usra.edu/meetings/lpsc2014/pdf/2744.pdf ](to identify the presence of cell membranes).

    They also nominate different forms of gas chromatography (to spot amino acids and sugars formed by living organisms, plus checking to see if molecules are “homochiral” [Space Science Reviews] (a suspected biosignature) using microfluidic devices and microscopes.

    High-resolution, miniaturised mass spectrometers would also be helpful, characterising biopolymers, which are created by living organisms, and measuring the elemental composition of objects to aid isotopic dating.

    Giri and colleagues also stress that exciting developments in machine learning, artificial intelligence, and pattern recognition will be useful in determining whether chemical samples are biological in origin.

    Interestingly, researchers are also developing technologies that may allow the detection of life in more unconventional places. On Earth, for example, cryotubes were recently used [International Journal of Systematic and Evolutionary Microbiology] to discover several new species of bacteria in the upper atmosphere.

    The scientists also discuss how certain technologies – such as high-powered synchrotron radiation and magnetic field facilities – are not yet compact enough to fly to other planets, and so samples must continue to be brought back for analysis.

    Several sample-and-return missions are currently underway, including JAXA’s Martian Moons exploration mission to Phobos, Hayabusa-2 to asteroid Ryugu, and NASA’s OSIRIS-rex to asteroid Bennu. What we learn from handling the organic-rich extraterrestrial materials brought back from these trips will be invaluable.

    JAXA MMX spacecraft

    JAXA/Hayabusa 2 Credit: JAXA/Akihiro Ikeshita

    NASA OSIRIS-REx Spacecraft

    What we learn from handling the organic-rich extraterrestrial materials brought back from these trips will be invaluable.

    The predictions and recommendations put forward by Giri and colleagues are the first steps in getting these technologies discussed in panel reviews, included in decadal surveys, and eventually funded.

    They complement several similar efforts, including a report prepared by US National Academies of Science, Engineering and Medicine (NASEM), calling for an expansion of the range of possible ET indicators, and a US-led exploration of how the next generation of radio telescopes will be utilised by SETI.

    Perhaps most importantly, these papers all highlight the need for collaborative work between scientists across disciplines.

    “A successful detection of life will need astrophysicists and geologists to examine possible environments on other planets, engineers and physicists to design the missions and instruments that can collect data, and chemists and biologists to determine how to classify life,” JAXA’s Tasker says.

    “But maybe that is appropriate: finding out what life really is and where it can flourish is the story of everyone on Earth. It should take all of us to unravel.”

    See the full article here .


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  • richardmitnick 9:36 am on March 12, 2018 Permalink | Reply
    Tags: , Astrochemistry, , , , Carbon-based molecules are a by-product of red giants, Circumstellar envelopes, , , , ,   

    From University of Hawaii Manoa via COSMOS: “Complex organic compounds from dying stars could be life precursors” 

    U Hawaii

    University of Hawaii Manoa

    COSMOS

    12 March 2018
    Richard A. Lovett

    Lab experiments reveal carbon-based molecules are a by-product of red giants.

    1
    A red giant star – the font, perhaps, of life… QAI Publishing/UIG via Getty Images

    Laboratory experiments designed to recreate conditions around carbon-rich red giant stars have revealed that startlingly complex organic compounds can form in the “circumstellar envelopes” created by stellar winds blowing off from them.

    The carbon is present because nuclear reactions in these dying stars have progressed to the point that much of their initial complement of hydrogen and helium has been converted into heavier elements such as carbon.

    “There is a lot of carbon in these circumstellar envelopes,” says Ralf Kaiser, a physical chemist at the University of Hawaii at Manoa, US.

    In research published in the journal Nature Astronomy, a team led by Kaiser used a high-temperature chemical reactor to simulate conditions inside these circumstellar envelopes.

    The goal, he says, is to demonstrate how complex compounds can be assembled a couple of carbon atoms at a time at temperatures of up to about 1200 degrees Celsius. Previous research found that a host of organic chemicals can indeed be formed, but the new study pushed the process farther, demonstrating that it is possible to create chemicals at least as complex as pyrene, a 16-carbon compound with a structure like four fused benzene rings.

    So far, pyrene is the most complex molecule constructed in this manner, but Kaiser thinks that it might be just the beginning. “We hope when we do further experiments that this can be extended,” he says.

    What this means, he explains, is that circumstellar envelopes might be able to create molecules with 60 or 70 carbons, or even nanoparticle-sized sheets of graphene, a material composed of a larger array of fused rings.

    Such materials, he says, can act as building blocks on which other molecules, such as water, methane, methanol, carbon monoxide, and ammonia can condense as they move away from the star and cool to temperatures as low as minu-263 degrees Celsius. When the resulting chemical stew is exposed to ionising radiation either from nearby sources or galactic cosmic rays, Kaiser says, they can form sugars, amino acids, and dipeptides.

    “These are molecules relevant to the origins of life,” he adds.

    Billions of years ago, such organic-rich particles may have found their way into asteroids that then rained down onto the primordial Earth, endowing us with the precursors for life.

    Pyrene is a member of a family of compounds called polycyclic aromatic hydrocarbons (PAHs), the simplest of which is naphthalene, the primary ingredient of mothballs. Simple PAHs have already been detected in space, but the holy grail, Kaiser says, will be if more complex ones, such as pyrene, are found by NASA’s OSIRIS-REx mission, now en route to asteroid 101955 Bennu, from which it is expected to send back a sample in 2023.

    NASA OSIRIS-REx Spacecraft

    “We do not know what this mission will find,” Kaiser says. But, “if they find carbonaceous materials such as PAHs, then our experiments say how this organic matter can be formed.”

    Humberto Campins, a planetary scientist from Central Florida University, Orlando, Florida, and member of the OSIRIS REx science team, agrees. Studying the chemical makeup of asteroids, he says, doesn’t just tell us about the composition of our own early solar system, but can also reveal information about “pre-solar” compounds.

    “One of the beauties of sample return missions is that the latest analytical techniques for chemical, mineralogical, and isotopic composition can be applied to very small components of the sample, such as pre-solar grains or molecules,” he says.

    “We know that the dust from these kinds of stars gets incorporated into meteorites, so they are absolutely contributing to the compounds that would be present within Bennu,” adds Chris Bennett, also of the University of Central Florida (and a former student of Kaiser’s, although he was not part of the present study team).

    Chris McKay, an astrobiologist at NASA Ames Research Centre in Moffett Field, California, adds that the paper supports the notion that that the universe contains a large amount of carbon in the form of organic molecules. “[That’s] not a new result,” he says, “but [it is] further support for this key idea in astrobiology.”

    Kaiser adds that the finding demonstrates the value of interdisciplinary studies.

    “Most of the scientists dealing with PAHs [in space] are astronomers,” he says. “They are excellent spectroscopists, but by nature, astronomy sometimes lacks fundamental knowledge about chemistry.”

    Laboratory studies are necessary to turn theories for how complex chemicals can form in space from “hand-waving” into something more definitive, he says.

    But the interdisciplinary impact goes beyond astronomy. Pyrene and other PAHs are common pollutants that can be incorporated into dangerous soot particles created by internal combustion engines and other industrial processes.

    Lessons from astrochemistry about how they can be formed, he says, says Kaiser, can therefore have the very practical side effect of helping us develop less-polluting automobile engines.

    See the full article here .

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  • richardmitnick 6:42 pm on December 11, 2015 Permalink | Reply
    Tags: Astrochemistry, , ,   

    From SA: “The Hunt for Alien Molecules” 

    Scientific American

    Scientific American

    December 11, 2015
    Clara Moskowitz

    Astrochemists are discovering many compounds in the cosmos that cannot exist on Earth

    1
    Horsehead nebula.Credit: NASA/Hubble

    Something strange was hiding in the Horsehead. The nebula, named for its stallionlike silhouette, is a towering cloud of dust and gas 1,500 light-years from Earth where new stars are continually born. It is one of the most recognizable celestial objects, and scientists have studied it intensely. But in 2011 astronomers from the Institute of Millimeter Radioastronomy (IRAM) and elsewhere probed it again. With IRAM’s 30-meter telescope in the Spanish Sierra Nevada, they homed in on two portions of the horse’s mane in radio light.

    IRAM
    IRAM’s 30-meter telescope

    They weren’t interested in taking more pictures of the Horsehead; instead, they were after spectra—readings of the light broken down into their constituent wavelengths, which reveal the chemical makeup of the nebula. Displayed on screen, the data looked like blips on a heart monitor; each wiggle indicated that some molecule in the nebula had emitted light of a particular wavelength.

    Every molecule in the universe makes its own characteristic wiggles based on the orientation of the protons, neutrons and electrons within it. Most of the wiggles in the Horsehead data were easily attributable to common chemicals such as carbon monoxide, formaldehyde and neutral carbon. But there was also a small, unidentified line at 89.957 gigahertz. This was a mystery—a molecule completely unknown to science.

    Immediately after seeing the data Evelyne Roueff of Paris Observatory and other chemists on the team started theorizing about what kind of molecule might create the signal. They concluded that the unknown species had to be a linear molecule—a compound whose atoms are arrayed in a straight chain. Only a certain type of linear molecule would produce the spectral pattern the chemists were seeing. After working through lists of likely molecules, they hit on C3H+, propynylidynium. This molecular ion had never been seen before. In fact there was no proof it existed at all. If it could form, it would be highly unstable. On Earth it would almost immediately react with something else to transform into a more settled species. But in space, where the pressure is low and molecules rarely run into anything else to bond with, C3H+ might just be able to survive.

    2
    Astronomers observing the Horsehead nebula with a radio telescope in Spain saw the chemical signature of a mystery molecule. The telescope returned spectroscopic data—a line graph representing the intensity of light coming from the nebula across a range of wavelengths. Sharp rises in the light, such as the feature shown here, indicate the presence of a specific molecule whose chemical properties allow it to emit that particular wavelength of light. After much sleuthing researchers were able to determine that this unidentified line feature comes from the never-before-seen compound C3H+, which exists only in space.

    Roueff and her colleagues studied whether the Horsehead Nebula contained the right ingredients and conditions to form the molecule. In 2012 they published a paper in Astronomy & Astrophysics concluding that the wiggle they saw likely belonged to C3H+. “I was relatively confident myself,” Roueff says. “But it required about two to three years to convince everyone that we had the right identification.”

    At first, some skeptics contested the claim—if C3H+ had never been seen before, how could they be sure this was it? The clincher came last year, when researchers at the University of Cologne in Germany managed to create C3H+ very briefly in a laboratory. Not only did the feat prove that the molecule could exist, it also allowed scientists to measure the spectrum it produces when excited—the very same spectrum that showed up in the Horsehead. “It’s very rewarding to find a new molecule which we did not really think about before,” Roueff says. “When you are able to identify it through a chain of logic, it’s like being a detective.”

    One alien molecule down, many, many more to go. The Horsehead Nebula is no aberration. Almost everywhere in the universe astronomers look—if they peer closely enough—they see unidentified spectral lines. The compounds we humans are familiar with, the species responsible for the huge diversity of materials on this planet, are just a fraction of those nature has created. And finally, after decades of work developing theoretical models and computer simulation techniques, along with laboratory experiments to reproduce new molecules, astrochemists are putting names to many of those unidentified lines.

    Empty space

    As recently as the 1960s most scientists doubted molecules could exist in interstellar space at all—the radiation there was thought to be too harsh for anything much beyond atoms and a few basic free radicals to survive. In 1968 physicist Charles Townes of the University of California, Berkeley, decided to look for molecules in space anyway. “I got the feeling that most of the Berkeley astronomers thought my idea was a little wild,” Townes, a Nobel laureate who died earlier this year, recalled in a 2006 account for the Astronomical Society of the Pacific. But Townes forged ahead and built a new amplifier for the six-meter antenna at Hat Creek Radio Observatory in California, which revealed the presence of ammonia in the Sagittarius B2 cloud. “How easy, and how exciting!” he wrote. “The news media as well as scientists began buzzing us.”

    3
    In 1968 astronomers discovered ammonia in the Sagittarius B2 cloud.Credit: ESO

    In the years since astronomers have found more than 200 types of molecules floating in space. Many are quite different from the species seen on the ground. “We usually do chemistry based on the conditions we have on Earth,” says Ryan Fortenberry, an astrochemist at Georgia Southern University. “When we get away from that paradigm, the chemicals that can be created are unbounded. If you can dream of a molecule, no matter how bizarre, there is a finite probability that over the eons of time and the immensity of space it has existed somewhere.”

    Space is literally an alien environment. Temperatures can be much, much hotter than on Earth (such as in the atmosphere of a star) and much, much colder (in relatively empty interstellar space). Likewise, the pressures (extremely high or low) are far from terrestrial. Consequently molecules can form in space that would never emerge on our planet—and then they can stick around, even if they are highly reactive. “A molecule can go years and years before it bounces into another molecule in interstellar space,” says Timothy Lee, an astrophysicist at NASA Ames Research Center. “It might be in a region where there’s no radiation, so even if it’s not that stable, it can exist for a long time.”

    These space molecules, once identified, could teach us a lot. Some of them might prove beneficial if scientists can create them in laboratories and learn to exploit their properties. Other molecules may help explain the origins of the organic compounds that gave rise to life on Earth. And all of them stand to expand the bounds of what is possible for chemistry in the universe.

    Game-changing telescopes

    In the past decade, as powerful new telescopes capable of observing faint spectral lines have come online, the search for alien molecules has accelerated. “It’s actually a heyday for astrochemistry right now,” says Susanna Widicus Weaver who leads an astrochemistry group at Emory University. The data available now, she says, are a huge improvement from just a decade ago when she completed her doctorate. NASA’s high-altitude Stratospheric Observatory for Infrared Astronomy (SOFIA), mounted on the side of a Boeing 747SP, began observing in infrared and microwave light in 2010 and the European Space Agency’s Herschel Space Observatory launched into orbit in 2009 to target the same wavelengths.

    NASA SOFIA
    ESO SOFI
    NASA/SOFIA

    ESA Herschel
    ESA/Herschel

    3
    The Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.Credit: NRAO

    The real game-changer, however, is the multinational Atacama Large Millimeter/submillimeter Array (ALMA), a constellation of 66 radio dishes inaugurated in 2013. At an altitude of about 5,200 meters on the Chajnantor Plateau, a Mars-like red expanse in Chile’s Atacama Desert, the driest place in the world, ALMA’s matching antennas swivel in unison as observers collect light from cosmic objects. Extremely dark and clear skies nearly devoid of image-blurring moisture give the telescope unprecedented sensitivity and precision in wavelengths from infrared to radio. ALMA creates both a visual picture and a spectrum for every pixel of its images, producing tens of thousands of spectral lines in every field of view it observes. “It’s amazing and it’s overwhelming at the same time,” Widicus Weaver says. “These data sets are so big that they often have to mail them to scientists on flash drives because they can’t download them.” The flood of data is providing a wealth of new spectral lines for astrochemists to mine. But like unidentified fingerprints at a crime scene, these lines are useless to scientists unless they can determine which molecules created them.

    Finding a link

    To match molecules to these lines, scientists can go in a few directions. As in the case of C3H+, astrochemists might start with theory, using clues from the spectrum to guess what molecule might be behind it. A technique called ab initio quantum chemistry (ab initio is Latin for “from the beginning”) allows scientists to start from pure quantum mechanics—the theory that describes the behavior of subatomic particles—to calculate a molecule’s properties based on the motions of the protons, neutrons and electrons in the atoms that comprise it. On a supercomputer, scientists can run repeated simulations of a molecule, each time slightly adjusting its structure and the arrangement of its particles, and watch the results to find the optimal geometry of a compound. “With quantum chemistry we’re not limited by what we can synthesize,” Fortenberry says. “We’re limited by the size of the molecules. We need large amounts of computational power to do the calculations.”

    Researchers can also look for hard evidence of new molecules by creating them in a laboratory and directly measuring their spectral features. A common technique is to start with a chamber of gas and run a current of electricity through it. An electron in the current might collide with a molecule of gas and break its chemical bond, giving rise to something new. Researchers keep the gas at very low pressure so that any chemicals that arise have a chance to hang out for a few moments before running into another molecule and reacting. Scientists will then shine various wavelengths of light through the chamber to measure the spectrum of whatever is inside. “You can get to the point where you’ve produced in the lab the same molecule that’s occurring in space but you don’t necessarily know what the molecule is,” says Michael McCarthy, a physicist at the Harvard–Smithsonian Center for Astrophysics. “So then you have to try to infer the elemental composition from a combination of different laboratory experiments with different samples.”

    In 2006 McCarthy and his colleagues created the negatively charged molecule C6H– and measured its spectrum. Soon afterward they found the same spectral features in the interstellar Taurus Molecular Cloud around 430 light-years away. Previous searches for negative molecules in space had come up empty, so many scientists doubted whether they existed in significant numbers. “It led us to a whole set of discoveries in which we were able to detect related molecules in the lab and then in space,” McCarthy says. The team has now found C6H– in more than a dozen cosmic sources.

    4
    The Taurus Molecular Cloud as seen by the APEX (Atacama Pathfinder Experiment) telescope in Chile. Credit: ESO/APEX (MPIfR/ESO/OSO)/A. Hacar et al./Digitized Sky Survey 2. Acknowledgment: Davide De Martin

    ESO APEX
    APEX

    And in the 1980s scientists trying to make new chemicals produced the molecule argonium (36ArH+), a strange compound not normally found on Earth that combines hydrogen with the generally inert gas argon. In 2013 astronomers found argonium in space, first in the Crab Nebula and later in a distant galaxy via ALMA observations.

    6
    This is a mosaic image, one of the largest ever taken by NASA’s Hubble Space Telescope of the Crab Nebula, a six-light-year-wide expanding remnant of a star’s supernova explosion. Japanese and Chinese astronomers recorded this violent event nearly 1,000 years ago in 1054, as did, almost certainly, Native Americans

    NASA Hubble Telescope
    NASA/ESA Hubble

    Compounds based on noble gases form only under very specific circumstances; scientists think that in space, high-energy charged particles called cosmic rays slam into argon and knock electrons loose, enabling it to bond with hydrogen. For this reason, if scientists see argonium in a region of space, they can surmise that the place is flooded with cosmic rays. “It’s a very specific indictor of these circumstances which actually are very important in space,” says Holger Müller of the University of Cologne, leader of the team behind the ALMA discovery.

    A new world of molecules

    Many of the molecules lurking in stars and nebulae are foreign in the extreme. To ask what they would look or feel like if you could hold them in your hand is nonsensical, because you could never hold them—they would react immediately. If you did manage to make contact with them, they would almost certainly prove toxic and carcinogenic. Oddly, however, scientists have a rough idea of what some alien molecules would smell like: Many detected so far belong to a class of compounds called aromatics, which are derived from benzene (C6H6) and were originally named for their strong odors.

    Some new compounds reveal surprising atomic structures and share charge between atoms in unforeseen ways. Sometimes they challenge current theories of molecular bonding. A recent example is the molecule SiCSi, discovered in 2015 in a dying star, which is made of two silicon atoms and one carbon atom that are bonded in an unexpected way. The resulting molecule is somewhat floppy and produces a spectrum different from what simple theoretical models predict.

    And space molecules may help answer one of the universe’s most fundamental questions: How did life get started? Scientists do not know if amino acids, the building blocks of life, first arose on Earth or in space (and were then delivered to our planet by comets and meteorites). “The big question is, do they form in molecular clouds as a star is forming,” asks Widicus Weaver, “or do they form once you have a planet or some other chunk of rock where chemistry can occur on the surface?” The answer will determine whether it is likely that amino acids are plentiful in the universe and available to possibly seed life on the myriad exoplanets out there or whether the chemistry that sparked us was isolated to our own planetary cradle. Astrochemists have already spotted signs of amino acids in space as well as sequences of molecules that might have given rise to them.

    5
    Buckyballs, conglomerations of 60 carbon atoms, were first created in labs on Earth and later discovered in space. Credit: NASA/JPL-Caltech

    Finally, perhaps some rare species could prove useful if they can be created in great enough quantity and kept under controlled conditions. “The great hope of astrochemistry is that we can find molecules that have completely new properties and we can apply those to problems here on Earth,” Fortenberry says. An example is the soccer ball–shaped molecules buckyballs. These large conglomerations of 60 carbon atoms first showed up in a laboratory in 1985 (and won their discoverers a Nobel Prize). Almost a decade later astronomers saw spectral features in interstellar gas that looked consistent with positively charged versions of buckyballs, and the connection was confirmed this July when researchers matched those features to the spectrum of buckyballs created under spacelike conditions in the lab. “This molecule is now all over the galaxy and all over the universe,” says buckyball co-discoverer Harold Kroto, now a chemistry professor at The Florida State University. Lately buckyballs have turned out to be not just a quirk found in space but a practical tool for nanotechnology, useful for strengthening materials, improving solar cells and even in pharmaceuticals.

    At this point astrochemists are still testing the shallow waters in the great sea of molecules out there in space. The finds they have already turned up are a reminder that our own small corner of the cosmos is just that—an insignificant, and not necessarily representative, sample of what is possible. Perhaps the species we are familiar with on Earth are in fact the exotic ones, and the buckyballs, the Horsehead Nebula C3H+ and others still unknown are the ordinary stuff of the universe.

    See the full article here .

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