Sökning: onr:"swepub:oai:DiVA.org:ri-6800" > Comet 67P/Churyumov...
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000 | 05434naa a2200553 4500 | |
001 | oai:DiVA.org:ri-6800 | |
003 | SwePub | |
008 | 160908s2015 | |||||||||||000 ||eng| | |
024 | 7 | a https://urn.kb.se/resolve?urn=urn:nbn:se:ri:diva-68002 URI |
024 | 7 | a https://doi.org/10.1038/nature141592 DOI |
040 | a (SwePub)ri | |
041 | a engb eng | |
042 | 9 SwePub | |
072 | 7 | a ref2 swepub-contenttype |
072 | 7 | a art2 swepub-publicationtype |
100 | 1 | a Schulz, Ritau ESA European Space Agency, The Netherlands4 aut |
245 | 1 0 | a Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years |
264 | c 2015-01-26 | |
264 | 1 | b Springer Science and Business Media LLC,c 2015 |
338 | a print2 rdacarrier | |
520 | a Comets are composed of dust and frozen gases. The ices are mixed with the refractory material either as an icy conglomerate, or as an aggregate of pre-solar grains (grains that existed prior to the formation of the Solar System), mantled by an ice layer. The presence of water-ice grains in periodic comets is now well established. Modelling of infrared spectra obtained about ten kilometres from the nucleus of comet Hartley 2 suggests that larger dust particles are being physically decoupled from fine-grained water-ice particles that may be aggregates, which supports the icy-conglomerate model. It is known that comets build up crusts of dust that are subsequently shed as they approach perihelion. Micrometre-sized interplanetary dust particles collected in the Earth's stratosphere and certain micrometeorites are assumed to be of cometary origin. Here we report that grains collected from the Jupiter-family comet 67P/Churyumov-Gerasimenko come from a dusty crust that quenches the material outflow activity at the comet surface. The larger grains (exceeding 50 micrometres across) are fluffy (with porosity over 50 per cent), and many shattered when collected on the target plate, suggesting that they are agglomerates of entities in the size range of interplanetary dust particles. Their surfaces are generally rich in sodium, which explains the high sodium abundance in cometary meteoroids. The particles collected to date therefore probably represent parent material of interplanetary dust particles. This argues against comet dust being composed of a silicate core mantled by organic refractory material and then by a mixture of water-dominated ices. At its previous recurrence (orbital period 6.5 years), the comet's dust production doubled when it was between 2.7 and 2.5 astronomical units from the Sun, indicating that this was when the nucleus shed its mantle. Once the mantle is shed, unprocessed material starts to supply the developing coma, radically changing its dust component, which then also contains icy grains, as detected during encounters with other comets closer to the Sun. | |
700 | 1 | a Hilchenbach, Martinu Max Planck Institute for Solar System Research, Germany4 aut |
700 | 1 | a Langevin, Yvesu CNRS, France; University of Paris-Sud, France4 aut |
700 | 1 | a Kissel, Jochenu Max Planck Institute for Solar System Research, Germany4 aut |
700 | 1 | a Silén, Johanu Finnish Meteorological Institute, Finland4 aut |
700 | 1 | a Briois, Christelleu CNRS, France; University of Orléans, France4 aut |
700 | 1 | a Engrand, Cécileu CNRS, France; University of Paris-Sud, France4 aut |
700 | 1 | a Hornung, Klausu Universität der Bundeswehr, Germany4 aut |
700 | 1 | a Baklouti, Doniau CNRS, France; University of Paris-Sud, France4 aut |
700 | 1 | a Bardyn, Anaïsu CNRS, France; University of Orléans, France; LISA Laboratoire Interuniversitaire des Systèmes Atmosphériques, France4 aut |
700 | 1 | a Cottin, Hervéu LISA Laboratoire Interuniversitaire des Systèmes Atmosphériques, France4 aut |
700 | 1 | a Fischer, Henningu Max Planck Institute for Solar System Research, Germany4 aut |
700 | 1 | a Fray, Nicolasu LISA Laboratoire Interuniversitaire des Systèmes Atmosphériques, France4 aut |
700 | 1 | a Godard, Marieu CNRS, France; University of Paris-Sud, France4 aut |
700 | 1 | a Lehto, Harry J.u University of Turku, Finland4 aut |
700 | 1 | a Le Roy, Lénau University of Bern, Switzerland4 aut |
700 | 1 | a Merouane, Sihaneu Max Planck Institute for Solar System Research, Germany4 aut |
700 | 1 | a Orthous-Daunay, François Régisu CNRS, France; Université Grenoble Alpes, France4 aut |
700 | 1 | a Paquette, John A.u Max Planck Institute for Solar System Research, Germany4 aut |
700 | 1 | a Rynö, Jouniu Finnish Meteorological Institute, Finland4 aut |
700 | 1 | a Siljeström, Sandrau RISE,SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf)4 aut0 (Swepub:ri)SandraSi@ri.se |
700 | 1 | a Stenzel, Oliveru Max Planck Institute for Solar System Research, Germany4 aut |
700 | 1 | a Thirkell, Laurentu CNRS, France; University of Orléans, France4 aut |
700 | 1 | a Varmuza, Kurtu Vienna University of Technology, Austria4 aut |
700 | 1 | a Zaprudin, Borisu University of Turku, Finland4 aut |
710 | 2 | a ESA European Space Agency, The Netherlandsb Max Planck Institute for Solar System Research, Germany4 org |
773 | 0 | t Natured : Springer Science and Business Media LLCg 518:7538, s. 216-218q 518:7538<216-218x 0028-0836x 1476-4687 |
856 | 4 8 | u https://urn.kb.se/resolve?urn=urn:nbn:se:ri:diva-6800 |
856 | 4 8 | u https://doi.org/10.1038/nature14159 |
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