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  • richardmitnick 1:01 pm on October 3, 2017 Permalink | Reply
    Tags: , , , , Comet 67P/Churyumov–Gerasimenko, , ,   

    From ESA: “Biomarker found in space complicates search for life on exoplanets” 

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    European Space Agency

    1
    Comet 67P/Churyumov–Gerasimenko. No image credit.

    A molecule once thought to be a useful marker for life as we know it has been discovered around a young star and at a comet for the first time, suggesting these ingredients are inherited during the planet-forming phase.

    The discovery of methyl chloride was made by the ground-based Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, and by ESA’s Rosetta spacecraft following Comet 67P/Churyumov–Gerasimenko. It is the simplest member of a class of molecules known as organohalogens, which contain halogens, such as chlorine or fluorine, bonded with carbon.

    Methyl chloride is well known on Earth as being used in industry. It is also produced naturally by biological and geological activity: it is the most abundant organohalogen in Earth’s atmosphere, with up to three megatonnes produced a year, primarily from biological processes.

    As such, it had been identified as a possible ‘biomarker’ in the search for life at exoplanets. This has been called into question, however, now it is seen in environments not derived from living organisms, and instead as a raw ingredient from which planets could eventually form.

    This is also the first time an organohalogen has been detected in space, indicating that halogen- and carbon-centred chemistries are more intertwined than previously thought.

    The ALMA observations were made towards the young star IRAS 16293-2422, a low-mass binary system in the Rho Ophiuchi star-forming region about 400 light-years from Earth.

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

    The system was already known to have a wealth of organic molecules distributed around it, but ALMA now makes it possible to zoom in to scales equivalent to the outer planets in our own Solar System, making it an ideal target for comparative studies with comets.

    Because comets are believed to preserve the chemical composition of the Sun’s birth cloud, and in order to better understand the formation pathways of organic molecules, the detection of the molecule in the young star system triggered a search in the extensive data collected by ESA’s Rosetta spacecraft during its 2014–16 mission at Comet 67P/Churyumov–Gerasimenko.

    Because comets are believed to preserve the chemical composition of the Sun’s birth cloud, and in order to better understand the formation pathways of organic molecules, the detection of the molecule in the young star system triggered a search in the extensive data collected by ESA’s Rosetta spacecraft during its 2014–16 mission at Comet 67P/Churyumov–Gerasimenko.

    ESA/Rosetta spacecraft

    “We found it but it is very elusive, one of the ‘chameleons’ of our molecule zoo, only present during short times when we observed a lot of chlorine,” says Kathrin Altwegg, principal investigator of the ROSINA instrument that made the comet detection.

    ESA Rosetta ROSINA

    The measurements were made in May 2015, when the comet was approaching its closest point to the Sun along its elliptical orbit, near to the orbit of Mars, and was very active, releasing a lot of gas and dust as the Sun warmed its icy surface. The methyl chloride was identified in the measurements when the hydrogen chloride signal was at its highest.

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    Delivering ingredients to Earth. Released 02/10/2017. Copyright ESA

    Our Solar System condensed from a cloud of gas and dust over 4.6 billion years ago. As the newborn planets settled in their orbits, gravitational perturbations are thought to have disrupted swarms of comets into the inner Solar System, impacting the rocky planets. As well as inheriting ingredients during the planet-forming process itself, comets are also believed to have delivered some of the basic ingredients for life to Earth, leading to life as we know it today.

    Moreover, the methyl chloride was found in comparable abundances in both the young star system and the comet. Rocky planets like Earth could directly inherit these ingredients during the planet-building phase, but comets could also act as a vessel to deliver them through the high rate of impacts occurring in the early years of a forming solar system.

    “The dual detection of an organohalogen in a star-forming region and at a comet indicates that these chemicals will likely be part of the ‘primordial soup’ on the young Earth and newly formed rocky exoplanets,” says Edith Fayolle, lead author of the study published in Nature Astronomy. “Understanding this initial chemistry on planets is an important step toward the origins of life.”

    It is also a crucial aspect for the search for life outside our Solar System, but the apparent prevalence of organohalogens in space calls into question their use as a biomarker when interpreting possible future detections of the molecule in the atmospheres of rocky exoplanets.

    “The combined study takes detections of key biological molecules to a new level, with the exciting possibility that they predate the formation of our Solar System as we know it today,” comments Matt Taylor, ESA’s Rosetta project scientist.

    “The complementary results provide an important context for our Rosetta data and for the wider implications of Solar System formation, and especially how we might interpret observations of extrasolar systems.”

    Notes for Editors

    Protostellar and cometary detections of organohalogens, by E. Fayolle et al. is published in Nature Astronomy, 2 October 2017.

    The ALMA data were part of the Protostellar Interferometric Line Survey (PILS). The aim of the survey is to chart the chemical complexity of IRAS 16293-2422 by imaging the full wavelength range covered by ALMA on very small scales, equivalent to the size of our Solar System.

    ALMA is an international astronomy facility, and a partnership between the European Southern Observatory, the US National Science Foundation and the National Institutes of Natural Sciences of Japan in collaboration with the Republic of Chile. More about ALMA partners.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 7:29 am on September 13, 2017 Permalink | Reply
    Tags: , , , Comet 67P/Churyumov–Gerasimenko, , Does organic material in comets predate our solar system?, ,   

    From EarthSky: “Does organic material in comets predate our solar system?” 

    1

    EarthSky

    September 13, 2017
    Deborah Byrd

    “If cometary organic molecules were indeed produced in interstellar space—and if they played a role in the emergence of life on our planet—might they not also have seeded life on many other planets of our galaxy?”

    1
    Comet 67P/Churyumov-Gerasimenko as seen by ESA’s Rosetta spacecraft.

    On September 4, 2017, researchers in Paris announced the results of their study of the organic compounds – combinations of carbon, hydrogen, nitrogen, and oxygen – in comet 67P Churyumov-Gerasimenko. This is the comet studied up-close and in detail by ESA’s Rosetta spacecraft for two years, beginning in August 2014.

    ESA/Rosetta spacecraft

    The sorts of organic molecules found in this comet and others have long been proposed by scientists as possible building blocks for life on Earth. Published in late August in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society, the French researchers advance the theory that this organic matter has its origin in interstellar space and predates the birth of our solar system.

    The Rosetta mission found a large amount of organic material in the nucleus of the comet, which some people simply 67P and others call Chury for Klim Ivanovich Churyumov, one of its discovers. The Rosetta mission found that organic matter made up 40% (by mass) of the nucleus of the comet. According to researchers Jean-Loup Bertaux and Rosine Lallement, not only were the organic molecules were produced in interstellar space, well before the formation of the solar system, but also other astronomers are already very familiar with the source of this matter. Their statement explained:

    “For 70 years, scientists have known that analysis of stellar spectra indicates unknown absorptions, throughout interstellar space, at specific wavelengths called the diffuse interstellar bands (DIBs). DIBs are attributed to complex organic molecules that American astrophysicist Theodore Snow believes may constitute the largest known reservoir of organic matter in the universe.

    This interstellar organic material is usually found in the same proportions. However, very dense clouds of matter like presolar nebulae are exceptions. In the middle of these nebulae, where matter is even denser, DIB absorptions plateau or even drop. This is because the organic molecules responsible for DIBs clump together there. The clumped matter absorbs less radiation than when it floated freely in space.

    Such primitive nebulae end up contracting to form a solar system like our own, with planets . . . and comets. The Rosetta mission taught us that comet nuclei form by gentle accretion of grains progressively greater in size. First, small particles stick together to form larger grains. These in turn combine to form still larger chunks, and so on, until we have a comet nucleus a few kilometers wide.

    Thus, the organic molecules that formerly populated the primitive nebulae—and that are responsible for DIBs—were probably not destroyed, but instead incorporated into the grains making up cometary nuclei. And there they have remained for 4.6 billion years. A sample-return mission would allow laboratory analysis of cometary organic material and finally reveal the identity of the mysterious interstellar matter underlying observed patterns in stellar spectra.

    If cometary organic molecules were indeed produced in interstellar space—and if they played a role in the emergence of life on our planet, as scientists believe today—might they not also have seeded life on many other planets of our galaxy?”

    Bottom line: French researchers advance the theory that the organic matter found in comets – possible building blocks for earthly life – has its origin in interstellar space and predates the birth of our solar system.

    See the full article here .

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  • richardmitnick 1:22 pm on September 6, 2017 Permalink | Reply
    Tags: , Comet 67P/Churyumov–Gerasimenko, DIBs-diffuse interstellar bands (DIBs),   

    From CNRS: “Does the organic material of comets predate our Solar System?” 

    CNRS bloc

    Centre Nationnal de la Recherche Scientifique [The National Center for Scientific Research]

    4 September 2017
    Contacts:
    CNRS researcher
    Jean-Loup Bertaux
    jean-loup.bertaux@latmos.ipsl.fr

    Paris Observatory researcher
    Rosine Lallement
    rosine.lallement@obspm.fr

    CNRS press officer
    Julien Guillaume l
    (+33) (0)1 44 96 46 35 / 51 51 l
    julien.guillaume@cnrs-dir.fr

    The Rosetta space probe discovered a large amount of organic material in the nucleus of comet “Chury.” In an article published by MNRAS on August 31, 2017, two French researchers advance the theory that this matter has its origin in interstellar space and predates the birth of the Solar System.

    ESA/Rosetta spacecraft

    1
    67P Churyumov-Gerasimenko, a.k.a. Chury

    The ESA’s Rosetta mission, which ended in September 2016, found that organic matter made up 40% (by mass) of the nucleus of comet 67P Churyumov-Gerasimenko, a.k.a. Chury. Organic compounds, combining carbon, hydrogen, nitrogen, and oxygen, are building blocks of life on Earth. Yet, according to Jean-Loup Bertaux and Rosine Lallement—from Laboratoire Atmosphères, Milieux, Observations Spatiales (CNRS / UPMC / Université de Versailles Saint-Quentin-en-Yvelines) and the Galaxies, Étoiles, Physique et Instrumentation department of the Paris Observatory (Observatoire de Paris / CNRS / Université Paris Diderot), respectively—these organic molecules were produced in interstellar space, well before the formation of the solar system. Bertaux and Lallement further assert that astronomers are already very familiar with the source of this matter.

    For 70 years, scientists have known that analysis of stellar spectra indicates unknown absorptions, throughout interstellar space, at specific wavelengths called the diffuse interstellar bands (DIBs). DIBs are attributed to complex organic molecules that American astrophysicist Theodore Snow believes may constitute the largest known reservoir of organic matter in the universe. This interstellar organic material is usually found in the same proportions. However, very dense clouds of matter like presolar nebulae are exceptions. In the middle of these nebulae, where matter is even denser, DIB absorptions plateau or even drop. This is because the organic molecules responsible for DIBs clump together there. The clumped matter absorbs less radiation than when it floated freely in space.

    Such primitive nebulae end up contracting to form a solar system like our own, with planets . . . and comets. The Rosetta mission taught us that comet nuclei form by gentle accretion of grains progressively greater in size. First, small particles stick together to form larger grains. These in turn combine to form still larger chunks, and so on, until we have a comet nucleus a few kilometers wide.

    Thus, the organic molecules that formerly populated the primitive nebulae—and that are responsible for DIBs—were probably not destroyed, but instead incorporated into the grains making up cometary nuclei. And there they have remained for 4.6 billion years. A sample-return mission would allow laboratory analysis of cometary organic material and finally reveal the identity of the mysterious interstellar matter underlying observed patterns in stellar spectra.

    If cometary organic molecules were indeed produced in interstellar space—and if they played a role in the emergence of life on our planet, as scientists believe today—might they not also have seeded life on many other planets of our galaxy?

    See the full article here .

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    CNRS encourages collaboration between specialists from different disciplines in particular with the university thus opening up new fields of enquiry to meet social and economic needs. CNRS has developed interdisciplinary programs which bring together various CNRS departments as well as other research institutions and industry.

    Interdisciplinary research is undertaken in the following domains:

    Life and its social implications
    Information, communication and knowledge
    Environment, energy and sustainable development
    Nanosciences, nanotechnologies, materials
    Astroparticles: from particles to the Universe

     
  • richardmitnick 5:03 am on June 17, 2017 Permalink | Reply
    Tags: , , , Comet 67P/Churyumov–Gerasimenko, , , Noble gas xenon, Rosetta finds comet connection to Earth's atmosphere   

    From ESA: “Rosetta finds comet connection to Earth’s atmosphere” 

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    European Space Agency

    08 June 2017

    Bernard Marty
    CRPG-CNRS, Université de Lorraine
    Vandoeuvre-les-Nancy Cedex, France
    bmarty@crpg.cnrs-nancy.fr
    +33 383 59 42 22

    Kathrin Altwegg
    Universität Bern
    Switzerland
    altwegg@space.unibe.ch
    +41 31 6314420

    Matt Taylor
    ESA Rosetta Project Scientist
    Directorate of Science
    European Space Agency
    mtaylor@cosmos.esa.int
    +31 71 565 8009

    The challenging detection, by ESA’s Rosetta mission, of several isotopes of the noble gas xenon at Comet 67P/Churyumov-Gerasimenko has established the first quantitative link between comets and the atmosphere of Earth. The blend of xenon found at the comet closely resembles U-xenon, the primordial mixture that scientists believe was brought to Earth during the early stages of Solar System formation. These measurements suggest that comets contributed about one fifth the amount of xenon in Earth’s ancient atmosphere.

    2
    Comet 67P/Churyumov-Gerasimenko on 15 May 2016. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

    Xenon – a colourless, odourless gas which makes up less than one billionth of the volume of Earth’s atmosphere – might hold the key to answer a long-standing question about comets: did they contribute to the delivery of material to our planet when the Solar System was taking shape, some 4.6 billion years ago? And if so, by how much?

    The noble gas xenon is formed in a variety of stellar processes, from the late phases of low- and intermediate-mass stars to supernova explosions and even neutron star mergers. Each of these phenomena gives rise to different isotopes of the element [1]. As a noble gas, xenon does not interact with other chemical species, and is therefore an important tracer of the material from which the Sun and planets originated, which in turns derives from earlier generations of stars.

    “Xenon is the heaviest stable noble gas and perhaps the most important because of its many isotopes that originate in different stellar processes: each one provides an additional piece of information about our cosmic origins,” says Bernard Marty from CRPG-CNRS and Université de Lorraine, France. Bernard is the lead author of a paper reporting Rosetta’s discovery of xenon at Comet 67P/C-G, which is published today in Science[2].

    Xenon across the Solar System

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    The blend of isotopes of the noble gas xenon detected by ESA’s Rosetta mission at Comet 67P/Churyumov-Gerasimenko, compared with the mixture of xenon measured in other regions of the Solar System. All abundances are normalised with respect to the abundance observed in the solar wind, the flow of charged particles streaming from the Sun (shown as a yellow line).
    The blend of xenon measured in chondrite meteorites that came from asteroids (grey line) is quite similar to that found in the solar wind, while the one present in the atmosphere of our planet (blue line) contains a higher abundance of heavier isotopes with respect to the lighter ones.
    However, the latter is a result of lighter elements escaping more easily from Earth’s gravitational pull and being lost to space in greater amounts. By correcting the atmospheric composition of xenon for this runaway effect, scientists in the 1970s calculated the composition of the primordial mixture of this noble gas, known as U-xenon, that was once present on Earth. This U-xenon contained a similar mix of light isotopes to that of asteroids and the solar wind, but included significantly smaller amounts of the heavier isotopes.
    Observations from Rosetta revealed that the blend of xenon at Comet 67P/C-G (black data points and line) contains larger amounts of light isotopes than heavy ones, and so it is quite different from the average mixture found in the Solar System. A comparison with the on-board calibration sample (blue data points) confirmed that the xenon detected at the comet is also different from the current mix in the Earth’s atmosphere.

    By contrast, the composition of xenon detected at the comet seems to be closer to the composition that scientists think was present in the early atmosphere of Earth.
    Rosetta’s measurements of xenon at Comet 67P/C-G suggest that comets contributed about one fifth the amount of xenon in Earth’s ancient atmosphere. They also indicate that the protosolar cloud from which the Sun, planets, and small bodies were born was a rather inhomogeneous place in terms of its chemical composition.

    It is because of this special ‘fingerprint’ that scientists have been using xenon to investigate the composition of the early Solar System, which provides important clues to constrain its formation. Over the past decades, they sampled the relative abundances of its various isotopes at different locations: in the atmosphere of Earth and Mars, in meteorites deriving from asteroids, at Jupiter, and in the solar wind – the flow of charged particles streaming from the Sun.

    The blend of xenon present in the atmosphere of our planet contains a higher abundance of heavier isotopes with respect to the lighter ones; however, this is a result of lighter elements escaping more easily from Earth’s gravitational pull and being lost to space in greater amounts. By correcting the atmospheric composition of xenon for this runaway effect, scientists in the 1970s calculated the composition of the primordial mixture of this noble gas, known as U-xenon, that was once present on Earth.

    This U-xenon contained a similar mix of light isotopes to that of asteroids and the solar wind, but included significantly smaller amounts of the heavier isotopes.

    “For these reasons, we have long suspected that xenon in the early atmosphere of Earth could have a different origin from the average blend of this noble gas found in the Solar System,” says Bernard.

    One of the explanations is that Solar System xenon derives directly from the protosolar cloud, a mass of gas and dust that gave rise to the Sun and planets, while the xenon found in the Earth’s atmosphere was delivered at a later stage by comets, which in turn might have formed from a different mix of material.

    With ESA’s Rosetta mission visiting Comet 67P/Churyumov-Gerasimenko, an icy fossil of the early Solar System, scientists could finally gather the long-sought data to test this hypothesis.

    “Searching for xenon at the comet was one of the most crucial and challenging measurements we performed with Rosetta,” says Kathrin Altwegg from the University of Bern, Switzerland, principal investigator of ROSINA, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, which was used for this study.

    Xenon is very diffuse in the comet’s thin atmosphere, so the navigation team had to fly Rosetta very close – 5 km to 8 km from the surface of the nucleus – for a period of three weeks so that ROSINA could obtain a significant detection of all the relevant isotopes.

    Flying so close to the comet was extremely challenging because of the large amount of dust that was lifting off the surface at the time, which could confuse the star trackers that were used to orient the spacecraft.

    Eventually, the Rosetta team decided to perform this operation in the second half of May 2016. This period was chosen as a compromise so that enough time would have passed after the comet’s perihelion, in August 2015, for the dust activity to be less intense, but not too much for the atmosphere to be excessively thin and the presence of xenon hard to detect.

    As a result of the observations, ROSINA identified seven isotopes of xenon, as well as several isotopes of another noble gas, krypton; these brought to three the inventory of noble gases found at Rosetta’s comet, following the discovery of argon from measurements performed in late 2014.

    “These measurements required a long stretch of dedicated time solely for ROSINA, and it would have been very disappointing if we hadn’t detected xenon at Comet 67P/C-G, so I’m really glad that we succeeded in detecting so many isotopes,” adds Kathrin.

    Further analysis of the data revealed that the blend of xenon at Comet 67P/C-G, which contains larger amounts of light isotopes than heavy ones, is quite different from the average mixture found in the Solar System. A comparison with the on-board calibration sample confirmed that the xenon detected at the comet is also different from the current mix in the Earth’s atmosphere.

    A link between xenon at Rosetta’s comet and on Earth

    4
    Date: 08 June 2017
    Satellite: Rosetta
    Copyright: Data from B. Marty et al., 2017 and references therein
    The composition of isotopes of the noble gas xenon in the primordial composition, known as U-xenon, that scientists think was present in the early atmosphere of Earth (shown as blue data points and line). This U-xenon contained a similar mix of light isotopes to that of the solar wind (yellow line), but included significantly smaller amounts of the heavier isotopes.
    The blend of xenon detected by ESA’s Rosetta mission at Comet 67P/Churyumov-Gerasimenko seems to be closer to U-xenon than to the average composition found in the solar wind. This is the first discovery of a candidate for the hypothesised U-xenon.
    Scientists think that the primordial xenon delivered to our planet could derive from a combination of impacting comets and asteroids (grey data points and line), to which comets contributed about 22 percent. This combination also takes into account the excess of one particular isotope of xenon, 129Xe, which is observed in Earth’s atmosphere (black data point).
    Rosetta’s measurements of xenon at Comet 67P/C-G suggest that comets contributed about one fifth the amount of xenon in Earth’s ancient atmosphere. They also indicate that the protosolar cloud from which the Sun, planets, and small bodies were born was a rather inhomogeneous place in terms of its chemical composition.

    By contrast, the composition of xenon detected at the comet seems to be closer to the composition that scientists think was present in the early atmosphere of Earth.

    “This is a very exciting result because it is the first discovery of a candidate for the hypothesised U-xenon,” explains Bernard.

    “There are some discrepancies between the two compositions, which indicate that the primordial xenon delivered to our planet could derive from a combination of impacting comets and asteroids.”

    In particular, Bernard and his colleagues were able to establish the first quantitative link between comets and our planet’s gaseous shroud: based on the Rosetta measurements at Comet 67P/C-G, 22 percent of the xenon once present in Earth’s atmosphere could originate from comets – the rest being delivered by asteroids.

    This result is not in contradiction with the isotopic measurements of water at Rosetta’s comet, which were significantly different to that found on Earth. In fact, given the trace amounts of xenon in Earth’s atmosphere and the much larger amount of water in the oceans, comets could have contributed to atmospheric xenon without having a significant impact on the composition of water in the oceans.

    The contribution inferred from the xenon measurements, instead, agrees with the possibility that comets have been significant carriers of pre-biotic material – such as phosphorus and the amino acid glycine, which were also detected by Rosetta at the comet – that was crucial to the emergence of life on Earth.

    Finally, the difference between the blend of xenon found at the comet – which was incorporated in the nucleus at the time of its formation – and the xenon observed across the Solar System indicates that the protosolar cloud from which the Sun, planets, and small bodies were born was a rather inhomogeneous place in terms of its chemical composition.

    “This conclusion is in accord with previous measurements performed by Rosetta, including the unexpected detections of molecular oxygen (O2) and di-sulphur (S2), and the high deuterium-to-hydrogen ratio observed in the comet water,” adds Kathrin.

    Additional evidence for the inhomogeneous nature of the protosolar cloud came also from anther study based on ROSINA observations, published in May in Astronomy & Astrophysics, which revealed that the mixture of silicon isotopes seen at the comet is different from what is measured elsewhere in the Solar System.

    “As we anticipated last year, now that mission operations are over, the teams can focus on the science,” says Matt Taylor, Rosetta Project Scientist at ESA.

    “The detailed analysis performed in this work, based on specially designed operations, addresses one of the mission’s key scientific goals: to find quantitative clues linking back to the formation and early evolution of our planet and Solar System.”
    Notes

    [1] The lightest isotopes of xenon (124Xe and 126Xe) are produced during supernova explosions; intermediate-mass isotopes (127Xe, 128Xe, 129Xe, 130Xe, 131Xe and 132Xe) are produced during the Asymptotic Giant Branch phase of evolved low- and intermediate-mass stars; the heaviest isotopes (134Xe and 136Xe) are produced during the merger of neutron stars.

    [2] The discovery of xenon by Rosetta at Comet 67P/Churyumov-Gerasimenko was announced during a Royal Society meeting in London, UK, and on the ESA Rosetta blog in June 2016, shortly after the scientists had made the detection. This is the first peer-reviewed study based on those measurements.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 10:21 am on December 18, 2016 Permalink | Reply
    Tags: , , Comet 67P/Churyumov–Gerasimenko, ,   

    From ESA via Daily Minor Planet: “How Comets are Born” 

    ESA Space For Europe Banner

    European Space Agency

    minor-planet-center

    Minor Planet Center

    28 July 2016
    Markus Bauer








    ESA Science and Robotic Exploration Communication Officer









    Tel: +31 71 565 6799









    Mob: +31 61 594 3 954









    Email: markus.bauer@esa.int

    Bjorn Davidsson
    Email: bjorn.davidsson@jpl.nasa.gov

    Matt Taylor
    ESA Rosetta Project Scientist
    Email: matt.taylor@esa.int

    1
    Comet 67P/Churyumov–Gerasimenko, ESA Rosetta

    ESA/Rosetta spacecraft
    ESA/Rosetta spacecraft

    Detailed analysis of data collected by Rosetta show that comets are the ancient leftovers of early Solar System formation, and not younger fragments resulting from subsequent collisions between other, larger bodies.

    Understanding how and when objects like Comet 67P/Churyumov–Gerasimenko took shape is of utmost importance in determining how exactly they can be used to interpret the formation and early evolution of our Solar System.

    A new study addressing this question led by Björn Davidsson of the Jet Propulsion Laboratory, California Institute of Technology in Pasadena (USA), has been published in Astronomy & Astrophysics.

    If comets are primordial, then they could help reveal the properties of the solar nebula from which the Sun, planets and small bodies condensed 4.6 billion years ago, and the processes that transformed our planetary system into the architecture we see today.

    The alternative hypothesis is that they are younger fragments resulting from collisions between older ‘parent’ bodies such as icy trans-Neptunian objects (TNOs). They would then provide insight into the interior of such larger bodies, the collisions that disrupted them, and the process of building new bodies from the remains of older ones.

    “Either way, comets have been witness to important Solar System evolution events, and this is why we have made these detailed measurements with Rosetta – along with observations of other comets – to find out which scenario is more likely,” says Matt Taylor, ESA’s Rosetta project scientist.

    During its two-year sojourn at Comet 67P/Churyumov–Gerasimenko, Rosetta has revealed a picture of the comet as a low-density, high-porosity, double-lobed body with extensive layering, suggesting that the lobes accumulated material over time before they merged.

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    Profile of a primordial comet
    Released 28/07/2016 4:00 pm
    Copyright Centre: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0; Insets: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; Fornasier et al. (2015); ESA/Rosetta/MPS for COSIMA Team MPS/CSNSM/UNIBW/TUORLA/IWF/IAS/ESA/BUW/MPE/LPC2E/LCM/FMI/UTU/LISA/UOFC/vH&S; Langevin et al. (2016)

    Evidence that Comet 67P/Churyumov–Gerasimenko is composed of ancient material preserved from the formation of the early Solar System and that came together under low speed. The evidence collected by Rosetta lies in the comet’s structural properties, the gases detected leaving the nucleus, and observations of surface features.

    Earlier work showed that the head and body were originally separate objects, but the collision that merged them must have been at low speed in order not to destroy both of them. The fact that both parts have similar layering also tells us that they must have undergone similar evolutionary histories and that survival rates against catastrophic collision must have been high for a significant period of time.

    Merging events may also have happened on smaller scales. For example, three spherical ‘caps’ have been identified in the Bastet region on the small comet lobe, and suggestions are that they are remnants of smaller cometesimals that are still partially preserved today.

    At even smaller scales of just a few metres across, there are the so-called ‘goosebumps’ and ‘clod’ features, rough textures observed in numerous pits and exposed cliff walls in various locations on the comet.

    While it is possible that this morphology might arise from fracturing alone, it is actually thought to represent an intrinsic ‘lumpiness’ of the comet’s constituents. That is, these ‘goosebumps’ could be showing the typical size of the smallest cometesimals that accumulated and merged to build up the comet, made visible again today through erosion due to sunlight.

    According to theory, the speeds at which cometesimals collide and merge change during the growth process, with a peak when the lumps have sizes of a few metres. For this reason, metre-sized structures are expected to be the most compact and resilient, and it is particularly interesting that the comet material appears lumpy on that particular size scale.

    Further lines of evidence include spectral analysis of the comet’s composition showing that the surface has experienced little or no in situ alteration by liquid water, and analysis of the gases ejected from sublimating ices buried deeper within the surface, which finds the comet to be rich in supervolatiles such as carbon monoxide, oxygen, nitrogen and argon.

    3
    How are comets born? No image credit.

    These observations imply that comets formed in extremely cold conditions and did not experience significant thermal processing during most of their lifetimes. Instead, to explain the low temperatures, survival of certain ices and retention of supervolatiles, they must have accumulated slowly over a significant time period.

    “While larger TNOs in the outer reaches of the Solar System appear to have been heated by short-lived radioactive substances, comets don’t seem to show similar signs of thermal processing. We had to resolve this paradox by taking a detailed look at the time line of our current Solar System models, and consider new ideas,” says Björn.

    Björn and colleagues propose that the larger members of the TNO population formed rapidly within the first one million years of the solar nebula, aided by turbulent gas streams that rapidly accelerated their growth to sizes of up to 400 km.

    Around three million years into the Solar System’s history, gas had disappeared from the solar nebula, only leaving solid material behind. Then, over a much longer period of around 400 million years, the already massive TNOs slowly accreted further material and underwent compaction into layers, their ices melting and refreezing, for example. Some TNOs even grew into Pluto or Triton-sized objects.

    Comets took a different path. After the rapid initial growth phase of the TNOs, leftover grains and ‘pebbles’ of icy material in the cold, outer parts of the solar nebula started to come together at low velocity, yielding comets roughly 5 km in size by the time gas has disappeared from the solar nebula. The low speeds at which the material accumulated led to objects with fragile nuclei with high porosity and low density.

    This slow growth also allowed comets to preserve some of the oldest, volatile-rich material from the solar nebula, since they were able to release the energy generated by radioactive decay inside them without heating up too much.

    The larger TNOs played a further role in the evolution of comets. By ‘stirring’ the cometary orbits, additional material was accreted at somewhat higher speed over the next 25 million years, forming the outer layers of comets. The stirring also made it possible for the few kilometre-sized objects in size to bump gently into each other, leading to the bi-lobed nature of some observed comets.

    “Comets do not appear to display the characteristics expected for collisional rubble piles, which result from the smash-up of large objects like TNOs. Rather, we think they grew gently in the shadow of the TNOs, surviving essentially undamaged for 4.6 billion years,” concludes Björn.

    “Our new model explains what we see in Rosetta’s detailed observations of its comet, and what had been hinted at by previous comet flyby missions.”

    “Comets really are the treasure-troves of the Solar System,” adds Matt.

    “They give us unparalleled insight into the processes that were important in the planetary construction yard at these early times and how they relate to the Solar System architecture that we see today.”

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 8:02 am on December 4, 2016 Permalink | Reply
    Tags: Comet 67P/Churyumov–Gerasimenko, , ,   

    From SPACE.com: “Sun Storm May Have Caused Flare-Up of Rosetta’s Comet” 

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    SPACE.com

    December 2, 2016
    Nola Taylor Redd

    1
    The ESA/NASA Solar and Heliospheric Observatory spacecraft captured this image of a coronal mass ejection erupting on the sun on Sept. 30, 2015.
    Credit: ESA/NASA/SOHO

    ESA/NASA SOHO
    ESA/NASA SOHO

    Material from the sun may have caused Comet 67P/Churyumov-Gerasimenko to flare up nearly 100 times brighter than average in some parts of the visual spectrum, new research reports.

    At about the same time that charged solar particles slammed into Comet 67P, the European Space Agency’s (ESA) Rosetta spacecraft observed that the icy wanderer dramatically brightened. Initially, scientists assumed that unusual effect came from jets of material within the comet. However, newly released observations of 67P suggest that a burst of charged particles from the sun, known as a coronal mass ejection (CME), could have caused the change.

    “The [brightening] was characterized by a substantial increase in the hydrogen, carbon and oxygen emission lines that increased by roughly 100 times their average brightness on the night of Oct. 5 and 6, 2015,” John Noonan told Space.com. Noonan, who just completed his undergraduate degree at the University of Colorado at Boulder, presented the research at the Division for Planetary Sciences meeting in Pasadena, California, in October.

    After reading a report of a CME that hit 67P at the same time, Noonan realized that the increased emissions from water, carbon dioxide and molecular oxygen observed by Rosetta’s R-Alice instrument could all be explained by the collision of the comet with material jettisoned from the sun.

    “This doesn’t yet rule out that an outburst could have happened, but it looks possible that all of the emissions could have been caused by the CME impact,” Noonan said.

    2
    A simulation reveals how the plasma of the solar wind should interact with Comet 67P/C-G. Credit: Modelling and simulation: Technische Universität Braunschweig and Deutsches Zentrum für Luft- und Raumfahrt; Visualisation: Zuse-Institut Berlin

    Colliding particles

    Rosetta entered orbit around Comet 67P in August 2014, making detailed observations until the probe deliberately crashed into the icy body at the end of its mission in September 2016.

    So Rosetta was tagging along when Comet 67P made its closest pass to the sun in August 2015. (Such “perihelion passages” occur once every 6.45 years — the time it takes the icy object to circle the sun.)

    As 67P neared the sun, newly warmed jets began to release gas from the surface, building up the cloud of debris around the nucleus known as the coma. Jets continued to spout throughout Rosetta’s observations as different regions of the comet rotated into sunlight. Such spouts were initially credited with the extreme brightening that took place in October 2015.

    In addition to warming the comet, the sun also interacted with it through its solar wind, the constant rush of charged particles streaming into space in all directions. Occasionally, the sun also blows off the collections of plasma and charged particles known as CMEs. When CMEs collide with Earth, they can interact with the planet’s magnetic field to create dazzling auroral displays; this interaction can also damage power grids and satellites.

    Niklas Edberg, a scientist on the Rosetta Plasma Consortium Ion and Electron Spectrometer instrument on the spacecraft, and his colleagues recently reported that RPC/IES observed a CME impact on Rosetta at the same time as the bizarre brightening. The ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft detected the CME as it left the sun on Sept. 30, 2015.

    According to Edberg, the CME compressed the plasma material around the comet. Because Rosetta was orbiting within the coma, the probe hadn’t sampled any material streaming from the solar wind since the previous April, and wasn’t expected to do so for several more months. When the CME slammed into the comet, however, the coma was compressed and Rosetta briefly tasted part of the solar wind once again.

    “This suggests that the plasma environment had been compressed significantly, such that the solar wind ions could briefly reach the detector, and provides further evidence that these signatures in the cometary plasma environment are indeed caused by a solar wind event, such as a CME,” Edberg and his team wrote in their study, which was published in the journal Monthly Notices of the Royal Astronomical Society in September 2016.

    Forces at play

    For Noonan, the realization that a CME had impacted the comet at the same time of its unusual brightening had an illuminating effect.

    “I read this [Edberg et al.] paper and realized that the substantial increase in electron density could account for the increased emissions from the coma that R-Alice observed, and set about testing what the density of the coma’s water, carbon dioxide and molecular oxygen components would have to be to match what we saw,” Noonan said.

    Charged particles from the CME may have excited cometary material, causing it to release photons, he added. Some of the observed changes could be created only by interacting electrons, causing what Noonan called “unique fingerprints” that let the scientists know electrons were impacting the material. Of special importance was the transition of oxygen line in the spectra, a change that can only be caused by electrons.

    “During the course of the CME, we saw this line increase in strength by roughly hundredfold,” Noonan said.

    The charged particles were unlikely to have come from the solar wind, which Noonan said would be blocked from ever penetrating this deep.

    While CMEs have been observed around other comets, they have only been viewed remotely. From such great distances, only large-scale changes in the comets’ comas and tails could be observed, Edberg said. Over the course of its two-year mission at Comet 67P, Rosetta’s close orbit allowed it to observe other CMEs interacting with the comet, but Noonan said none were as noticeable as the event of Oct. 5-6, 2015.

    “Prior to Rosetta, these electron impact emissions had never been observed around a comet, and it was these emissions that gave away that the CME might be a factor in causing them,” Noonan said.

    He cautioned that it isn’t a given that the influx of charged particles caused the bizarre brightening, which still could be caused by the jets of material.

    “At this point, we are still working to understand exactly what was the cause to see if it was the CME, and outburst, or both, that caused the emission,” Noonan said.

    Given the timing of the impact, however, it is unlikely that the flare-up was the result of gas released by jets alone.

    “There are more forces at play than just a higher density of gas,” Noonan said.

    See the full article here .

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  • richardmitnick 12:23 pm on November 7, 2016 Permalink | Reply
    Tags: , , Comet 67P/Churyumov–Gerasimenko, , , Thirty comet chemical 'fingerprints' identified from Earth   

    From COSMOS: “Thirty comet chemical ‘fingerprints’ identified from Earth” 

    Cosmos Magazine bloc

    COSMOS

    07 November 2016
    Belinda Smith

    1
    A false-colour image of the long-period Comet Hale-Bopp. An enormous dust jet emanates northwards of the nucleus. ESO

    The European Space Agency’s Rosetta probe’s decade-long mission told us more about Comet 67P/Churyumov-Gerasimenko than we could have ever discovered from Earth.

    ESA/Rosetta spacecraft
    ESA/Rosetta spacecraft

    2
    Comet 67P by Rosetta’s OSIRIS narrow-angle camera on 3 August 2014. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

    But it turns out we can pick out aspects of a comet’s chemical fingerprint without leaving the planet – and those “dirty snowballs” are quite the diverse bunch.

    Planetary scientists from the US and Japan, led by Johns Hopkins University’s Neil Dello Russo, examined the chemicals in 30 comets, focusing on the coma – the hazy halo of material around the solid nucleus – and tail of each.

    Writing in Icarus, they found each comet had its unique chemistry – but those that whiz around the sun more often tend to have lower levels of the most volatile substances.

    “When NASA or [the European Space Agency] sends a mission to a comet, we can learn a tremendous amount of detail on that specific comet,” Dello Russo says.

    His work, he adds, puts those findings into a larger chemical context: “We can help answer where an individual comet fits into the population of comets.”

    Comets are thought to be largely unchanged clumps of rock and ice leftover from the formation of the solar system 4.6 billion years ago. Knowing where and how comets formed, evolved and were stored can give insights into the solar system’s youth.

    The solar system has two main comet storage reservoirs.

    Just beyond Neptune is the Kuiper belt – a region thought to contain mainly icy bodies such as comets. It’s a disc roughly 30 to 50 astronomical units away (where one astronomical unit is the distance between the sun and Earth).

    But far beyond that is the Oort cloud, a vast spherical shell icy bodies – such as comets – that surrounds the sun between 2,000 and 50,000 astronomical units away.

    Sometimes, a comet makes the journey towards the sun, loops around and whizzes back out again.

    Those with a round trip of more than 200 years are called long-period comets; if the journey is made in less than 200 years, it’s in the short-period group. (Comet 67P/Churyumov-Gerasimenko, which skirts around the sun every 6.5 years, is a short-period comet, while the long-period Comet Hale-Bopp takes more than 2,500 years.)

    Uncovering the chemical composition of these primordial bodies has only recently been made possible with advances in infrared detection methods.

    Seeing comets in the visible part of the spectrum is pretty, but it’s the infrared that unveils their chemistry.

    Different infrared wavelengths correspond to different molecules – particularly symmetric hydrocarbons such as methane.

    As volatiles sublime (transition from solid to gas) they form the coma and tail, giving planetary scientists a proxy for the chemical composition of the frozen nucleus.

    So from 1997 to 2013, Dello Russo and colleagues gathered data from four Earth-based telescopes on molecules such as methane, formaldehyde, ammonia and carbon monoxide from 21 Oort cloud comets and nine Kuiper belt comets.

    While each comet had its own chemical fingerprint, they noticed short-period comets were relatively depleted in the most volatile molecules measured: acetylene, ethane, methane and carbon monoxide.

    It may seem logical that short-period comets, with more passes close to the sun, would have fewer volatiles. But previous work shows no correlation between those molecules and number of orbits.

    So Della Russo and colleagues conclude that the comets were “built” with less of those chemicals in the first place – or were kept in conditions that enabled those molecules to react into different ones more easily.

    One of the next steps, the researchers suggest, is to check out levels of these “parent” and “daughter” molecules.

    See the full article here .

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  • richardmitnick 3:44 pm on October 28, 2015 Permalink | Reply
    Tags: , , Comet 67P/Churyumov–Gerasimenko, , O2   

    From ESA: “First detection of molecular oxygen at a comet” 

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    European Space Agency

    28 October 2015
    Markus Bauer








    ESA Science and Robotic Exploration Communication Officer









    Tel: +31 71 565 6799









    Mob: +31 61 594 3 954









    Email: markus.bauer@esa.int

    Kathrin Altwegg

    Principal investigator for ROSINA

    University of Bern, Switzerland

    Email: kathrin.altwegg@space.unibe.ch

    Andre Bieler
    University of Michigan
    Email: abieler@umich.edu

    Ewine van Dishoeck
    Leiden Observatory, University of Leiden, the Netherlands
    Email: ewine@strw.leidenuniv.nl

    Matt Taylor
    ESA Rosetta Project Scientist
    Email: matt.taylor@esa.int

    1
    Rosetta’s detection of molecular oxygen Released 28/10/2015

    ESA’s Rosetta spacecraft has made the first in situ detection of oxygen molecules outgassing from a comet, a surprising observation that suggests they were incorporated into the comet during its formation.

    Rosetta has been studying Comet 67P/Churyumov–Gerasimenko for over a year and has detected an abundance of different gases pouring from its nucleus. Water vapour, carbon monoxide and carbon dioxide are the most prolific, with a rich array of other nitrogen-, sulphur- and carbon-bearing species, and even noble gases also recorded.

    2
    Comet 67P/Churyumov–Gerasimenko

    ESA Rosetta spacecraft
    Rosetta

    4
    Rosetta’s Philae Lander

    Oxygen is the third most abundant element in the Universe, but the simplest molecular version of the gas, O2, has proven surprisingly hard to track down, even in star-forming clouds, because it is highly reactive and readily breaks apart to bind with other atoms and molecules.

    For example, oxygen atoms can combine with hydrogen atoms on cold dust grains to form water, or a free oxygen split from O2 by ultraviolet radiation can recombine with an O2 molecule to form ozone (O3).

    Despite its detection on the icy moons of Jupiter and Saturn, O2 had been missing in the inventory of volatile species associated with comets until now.

    “We weren’t really expecting to detect O2 at the comet – and in such high abundance – because it is so chemically reactive, so it was quite a surprise,” says Kathrin Altwegg of the University of Bern, and principal investigator of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument, ROSINA.

    ESA Rosetta ROSINA
    ROSINA

    “It’s also unanticipated because there aren’t very many examples of the detection of interstellar O2. And thus, even though it must have been incorporated into the comet during its formation, this is not so easily explained by current Solar System formation models.”

    The team analysed more than 3000 samples collected around the comet between September 2014 and March 2015 to identify the O2. They determined an abundance of 1–10% relative to H2O, with an average value of 3.80 ± 0.85%, an order of magnitude higher than predicted by models describing the chemistry in molecular clouds.

    The amount of molecular oxygen detected showed a strong relationship to the amount of water measured at any given time, suggesting that their origin on the nucleus and release mechanism are linked. By contrast, the amount of O2 seen was poorly correlated with carbon monoxide and molecular nitrogen, even though they have a similar volatility to O2. In addition, no ozone was detected.

    Over the six-month study period, Rosetta was inbound towards the Sun along its orbit, and orbiting as close as 10–30 km from the nucleus. Despite the decreasing distance to the Sun, the O2/H2O ratio remained constant over time, and it also did not change with Rosetta’s longitude or latitude over the comet.

    In more detail, the O2/H2O ratio was seen to decrease for high H2O abundances, an observation that might be influenced by surface water ice produced in the observed daily sublimation–condensation process.

    The team explored the possibilities to explain the presence and consistently high abundance of O2 and its relationship to water, as well as the lack of ozone, by first considering photolysis and radiolysis of water ice over a range of timescales.

    In photolysis, photons break bonds between molecules, whereas radiolysis involves more energetic photons or fast electrons and ions depositing energy into ice and ionising molecules – a process observed on icy moons in the outer Solar System, and in Saturn’s rings. Either process can, in principle, lead to the formation and liberation of molecular oxygen.

    Radiolysis will have operated over the billions of years that the comet spent in the Kuiper Belt and led to the build-up of O2 to a few metres depth.

    5
    Known objects in the Kuiper belt beyond the orbit of Neptune. (Scale in AU; epoch as of January 2015.)

    But these top layers must all have been removed in the time since the comet moved into its inner Solar System orbit, ruling this out as the source of the O2 seen today.

    More recent generation of O2 via radiolysis and photolysis by solar wind particles and UV photons should only have occurred in the top few micrometres of the comet.

    “But if this was the primary source of the O2 then we would have expected to see a decrease in the O2/H2O ratio as this layer was removed during the six-month timespan of our observations,” says Andre Bieler of the University of Michigan and lead author of the paper describing the new results in the journal Nature this week.

    “The instantaneous generation of O2 also seems unlikely, as that should lead to variable O2 ratios under different illumination conditions. Instead, it seems more likely that primordial O2 was somehow incorporated into the comet’s ices during its formation, and is being released with the water vapour today.”

    In one scenario, gaseous O2 would first be incorporated into water ice in the early protosolar nebula stage of our Solar System. Chemical models of protoplanetary discs predict that high abundances of gaseous O2 could be available in the comet forming zone, but rapid cooling from temperatures above –173ºC to less than –243ºC would be required to form water ice with O2 trapped on dust grains. The grains would then have to be incorporated into the comet without being chemically altered.

    “Other possibilities include the Solar System being formed in an unusually warm part of a dense molecular cloud, at temperatures of 10–20ºC above the –263ºC or so typically expected for such clouds,” says Ewine van Dishoeck of Leiden Observatory in the Netherlands, co-author of the paper.

    “This is still consistent with estimates for the comet formation conditions in the outer solar nebula, and also with previous findings at Rosetta’s comet regarding the low abundance of N2.”

    Alternatively, radiolysis of icy dust grains could have taken place prior to the comet’s accretion into a larger body. In this case, the O2 would remain trapped in the voids of the water ice on the grains while the hydrogen diffused out, preventing the reformation of O2 to water, and resulting in an increased and stable level of O2 in the solid ice.

    Incorporation of such icy grains into the nucleus could explain the observed strong correlation with H2O observed at the comet today.

    “Regardless of how it was made, the O2 was also somehow protected during the accretion stage of the comet: this must have happened gently to avoid the O2 being destroyed by further chemical reactions,” adds Kathrin.

    “This is an intriguing result for studies both within and beyond the comet community, with possible implications for our models of Solar System evolution,” says Matt Taylor, ESA’s Rosetta project scientist.

    Abundant molecular oxygen in the coma of 67P/Churyumov–Gerasimenko, by A. Bieler et al is published in the 29 October 2015 issue of the journal Nature.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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