ALBERT

Description: Ions were detected in the vicinity of Saturn's A ring by the Ion and Neutral Mass Spectrometer (INMS) instrument onboard the Cassini Orbiter during the spacecraft's passage over the rings. The INMS saw signatures of molecular and atomic oxygen ions and of protons, thus demonstrating the existence of an ionosphere associated with the A ring. A likely explanation for these ions is photoionization by solar ultraviolet radiation of neutral O2 molecules associated with a tenuous ring atmosphere. INMS neutral measurements made during the ring encounter are dominated by a background signal.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Waite, J H Jr -- Cravens, T E -- Ip, W-H -- Kasprzak, W T -- Luhmann, J G -- McNutt, R L -- Niemann, H B -- Yelle, R V -- Mueller-Wodarg, I -- Ledvina, S A -- Scherer, S -- New York, N.Y. -- Science. 2005 Feb 25;307(5713):1260-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Atmospheric, Oceanic, and Space Physics, University of Michigan, Ann Arbor, MI 48109, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15731442" target="_blank"〉PubMed〈/a〉

Description: The Cassini Ion Neutral Mass Spectrometer (INMS) has obtained the first in situ composition measurements of the neutral densities of molecular nitrogen, methane, molecular hydrogen, argon, and a host of stable carbon-nitrile compounds in Titan's upper atmosphere. INMS in situ mass spectrometry has also provided evidence for atmospheric waves in the upper atmosphere and the first direct measurements of isotopes of nitrogen, carbon, and argon, which reveal interesting clues about the evolution of the atmosphere. The bulk composition and thermal structure of the moon's upper atmosphere do not appear to have changed considerably since the Voyager 1 flyby.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Waite, J Hunter Jr -- Niemann, Hasso -- Yelle, Roger V -- Kasprzak, Wayne T -- Cravens, Thomas E -- Luhmann, Janet G -- McNutt, Ralph L -- Ip, Wing-Huen -- Gell, David -- De La Haye, Virginie -- Muller-Wordag, Ingo -- Magee, Brian -- Borggren, Nathan -- Ledvina, Steve -- Fletcher, Greg -- Walter, Erin -- Miller, Ryan -- Scherer, Stefan -- Thorpe, Rob -- Xu, Jing -- Block, Bruce -- Arnett, Ken -- New York, N.Y. -- Science. 2005 May 13;308(5724):982-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48109-2143, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15890873" target="_blank"〉PubMed〈/a〉

Description: The Cassini spacecraft passed within 168.2 kilometers of the surface above the southern hemisphere at 19:55:22 universal time coordinated on 14 July 2005 during its closest approach to Enceladus. Before and after this time, a substantial atmospheric plume and coma were observed, detectable in the Ion and Neutral Mass Spectrometer (INMS) data set out to a distance of over 4000 kilometers from Enceladus. INMS data indicate that the atmospheric plume and coma are dominated by water, with significant amounts of carbon dioxide, an unidentified species with a mass-to-charge ratio of 28 daltons (either carbon monoxide or molecular nitrogen), and methane. Trace quantities (〈1%) of acetylene and propane also appear to be present. Ammonia is present at a level that does not exceed 0.5%. The radial and angular distributions of the gas density near the closest approach, as well as other independent evidence, suggest a significant contribution to the plume from a source centered near the south polar cap, as distinct from a separately measured more uniform and possibly global source observed on the outbound leg of the flyby.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Waite, J Hunter Jr -- Combi, Michael R -- Ip, Wing-Huen -- Cravens, Thomas E -- McNutt, Ralph L Jr -- Kasprzak, Wayne -- Yelle, Roger -- Luhmann, Janet -- Niemann, Hasso -- Gell, David -- Magee, Brian -- Fletcher, Greg -- Lunine, Jonathan -- Tseng, Wei-Ling -- New York, N.Y. -- Science. 2006 Mar 10;311(5766):1419-22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48109, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16527970" target="_blank"〉PubMed〈/a〉

Description: The electrodynamic interaction of the dust and gas comae of comet Shoemaker-Levy 9 with the jovian magnetosphere was unique and different from the atmospheric effects. Early theoretical predictions of auroral-type processes on the comet magnetic field line and advanced modeling of the time-varying morphology of these lines allowed dedicated observations with the Hubble Space Telescope Wide Field Planetary Camera 2 and resulted in the detection of a bright auroral spot. In that respect, this observation of the surface signature of an externally triggered auroral process can be considered as a "magnetospheric active experiment" on Jupiter.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Prange, R -- Engle, I M -- Clarke, J T -- Dunlop, M -- Ballester, G E -- Ip, W H -- Maurice, S -- Trauger, J -- New York, N.Y. -- Science. 1995 Mar 3;267(5202):1317-20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut d'Astrophysique Spatiale, CNRS-Universite Paris XI, Orsay, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7871430" target="_blank"〉PubMed〈/a〉

Description: The European Space Agency's Rosetta mission encountered the main-belt asteroid (2867) Steins while on its way to rendezvous with comet 67P/Churyumov-Gerasimenko. Images taken with the OSIRIS (optical, spectroscopic, and infrared remote( )imaging system) cameras on board Rosetta show that Steins is an oblate body with an effective spherical diameter of 5.3 kilometers. Its surface does not show color variations. The morphology of Steins is dominated by linear faults and a large 2.1-kilometer-diameter crater near its south pole. Crater counts reveal a distinct lack of small craters. Steins is not solid rock but a rubble pile and has a conical appearance that is probably the result of reshaping due to Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) spin-up. The OSIRIS images constitute direct evidence for the YORP effect on a main-belt asteroid.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Keller, H U -- Barbieri, C -- Koschny, D -- Lamy, P -- Rickman, H -- Rodrigo, R -- Sierks, H -- A'Hearn, M F -- Angrilli, F -- Barucci, M A -- Bertaux, J-L -- Cremonese, G -- Da Deppo, V -- Davidsson, B -- De Cecco, M -- Debei, S -- Fornasier, S -- Fulle, M -- Groussin, O -- Gutierrez, P J -- Hviid, S F -- Ip, W-H -- Jorda, L -- Knollenberg, J -- Kramm, J R -- Kuhrt, E -- Kuppers, M -- Lara, L-M -- Lazzarin, M -- Lopez Moreno, J -- Marzari, F -- Michalik, H -- Naletto, G -- Sabau, L -- Thomas, N -- Wenzel, K-P -- Bertini, I -- Besse, S -- Ferri, F -- Kaasalainen, M -- Lowry, S -- Marchi, S -- Mottola, S -- Sabolo, W -- Schroder, S E -- Spjuth, S -- Vernazza, P -- New York, N.Y. -- Science. 2010 Jan 8;327(5962):190-3. doi: 10.1126/science.1179559.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany. keller@linmpi.mpg.de〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20056887" target="_blank"〉PubMed〈/a〉

Description: The Visible, InfraRed, and Thermal Imaging Spectrometer (VIRTIS) on Rosetta obtained hyperspectral images, spectral reflectance maps, and temperature maps of the asteroid 21 Lutetia. No absorption features, of either silicates or hydrated minerals, have been detected across the observed area in the spectral range from 0.4 to 3.5 micrometers. The surface temperature reaches a maximum value of 245 kelvin and correlates well with topographic features. The thermal inertia is in the range from 20 to 30 joules meter(-2) kelvin(-1) second(-0.5), comparable to a lunarlike powdery regolith. Spectral signatures of surface alteration, resulting from space weathering, seem to be missing. Lutetia is likely a remnant of the primordial planetesimal population, unaltered by differentiation processes and composed of chondritic materials of enstatitic or carbonaceous origin, dominated by iron-poor minerals that have not suffered aqueous alteration.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Coradini, A -- Capaccioni, F -- Erard, S -- Arnold, G -- De Sanctis, M C -- Filacchione, G -- Tosi, F -- Barucci, M A -- Capria, M T -- Ammannito, E -- Grassi, D -- Piccioni, G -- Giuppi, S -- Bellucci, G -- Benkhoff, J -- Bibring, J P -- Blanco, A -- Blecka, M -- Bockelee-Morvan, D -- Carraro, F -- Carlson, R -- Carsenty, U -- Cerroni, P -- Colangeli, L -- Combes, M -- Combi, M -- Crovisier, J -- Drossart, P -- Encrenaz, E T -- Federico, C -- Fink, U -- Fonti, S -- Giacomini, L -- Ip, W H -- Jaumann, R -- Kuehrt, E -- Langevin, Y -- Magni, G -- McCord, T -- Mennella, V -- Mottola, S -- Neukum, G -- Orofino, V -- Palumbo, P -- Schade, U -- Schmitt, B -- Taylor, F -- Tiphene, D -- Tozzi, G -- New York, N.Y. -- Science. 2011 Oct 28;334(6055):492-4. doi: 10.1126/science.1204062.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Istituto di Fisica dello Spazio Interplanetario, Istituto Nazionale di Astrofisica (INAF), 00133 Rome, Italy.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22034430" target="_blank"〉PubMed〈/a〉

Description: Images of comet 67P/Churyumov-Gerasimenko acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) imaging system onboard the European Space Agency's Rosetta spacecraft at scales of better than 0.8 meter per pixel show a wide variety of different structures and textures. The data show the importance of airfall, surface dust transport, mass wasting, and insolation weathering for cometary surface evolution, and they offer some support for subsurface fluidization models and mass loss through the ejection of large chunks of material.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Thomas, Nicolas -- Sierks, Holger -- Barbieri, Cesare -- Lamy, Philippe L -- Rodrigo, Rafael -- Rickman, Hans -- Koschny, Detlef -- Keller, Horst Uwe -- Agarwal, Jessica -- A'Hearn, Michael F -- Angrilli, Francesco -- Auger, Anne-Therese -- Barucci, M Antonella -- Bertaux, Jean-Loup -- Bertini, Ivano -- Besse, Sebastien -- Bodewits, Dennis -- Cremonese, Gabriele -- Da Deppo, Vania -- Davidsson, Bjorn -- De Cecco, Mariolino -- Debei, Stefano -- El-Maarry, Mohamed Ramy -- Ferri, Francesca -- Fornasier, Sonia -- Fulle, Marco -- Giacomini, Lorenza -- Groussin, Olivier -- Gutierrez, Pedro J -- Guttler, Carsten -- Hviid, Stubbe F -- Ip, Wing-Huen -- Jorda, Laurent -- Knollenberg, Jorg -- Kramm, J-Rainer -- Kuhrt, Ekkehard -- Kuppers, Michael -- La Forgia, Fiorangela -- Lara, Luisa M -- Lazzarin, Monica -- Lopez Moreno, Jose J -- Magrin, Sara -- Marchi, Simone -- Marzari, Francesco -- Massironi, Matteo -- Michalik, Harald -- Moissl, Richard -- Mottola, Stefano -- Naletto, Giampiero -- Oklay, Nilda -- Pajola, Maurizio -- Pommerol, Antoine -- Preusker, Frank -- Sabau, Lola -- Scholten, Frank -- Snodgrass, Colin -- Tubiana, Cecilia -- Vincent, Jean-Baptiste -- Wenzel, Klaus-Peter -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):aaa0440. doi: 10.1126/science.aaa0440.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Physikalisches Institut, Sidlerstrasse 5, University of Bern, 3012, Bern, Switzerland. nicolas.thomas@space.unibe.ch. ; Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg, 3, 37077, Gottingen, Germany. ; Department of Physics and Astronomy, University of Padova, Vicolo dell'Osservatorio 3, 35122 Padova, Italy. ; Laboratoire d'Astrophysique de Marseille, UMR 7326, CNRS, and Aix Marseille Universite, 38 Rue Frederic Joliot-Curie, 13388 Marseille Cedex 13, France. ; International Space Science Institute, Hallerstrasse 6, 3012 Bern, Switzerland, and Centro de Astrobiologia, Consejo Superior de Investigaciones Cientificas - Instituto Nacional de Tecnica Aeroespacial, 28850 Torrejon de Ardoz, Madrid, Spain. ; Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala, Sweden, and Polish Academy of Sciences Space Research Center, Bartycka 18A, PL-00716 Warszawa, Poland. ; Scientific Support Office, European Space Agency, 2201, Noordwijk, Netherlands. ; Institute for Geophysics and Extraterrestrial Physics, Technische Universitat Braunschweig, 38106, Braunschweig, Germany. Deutsches Zentrum fur Luft- und Raumfahrt (DLR), Institut fur Planetenforschung, Asteroiden und Kometen, Rutherfordstrasse 2, 12489 Berlin, Germany. ; Department of Astronomy, University of Maryland, College Park, MD 20742-2421, USA. ; Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy. ; Aix Marseille Universite, CNRS, Laboratoire d'Astrophysique de Marseille, UMR 7326, 38 rue Frederic Joliot-Curie, 13388 Marseille, France. ; Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris, CNRS, Universite Paris 06, Universite Paris-Diderot, 5 Place J. Janssen, 92195, Meudon, France. ; Laboratoire Atmospheres, Milieux, Observations Spatiales, CNRS/UVSQ/IPSL, 11 Boulevard d'Alembert, 78280, Guyancourt, France. ; Centro di Ateneo di Studi ed Attivita Spaziali, "Giuseppe Colombo" (CISAS), University of Padova, Via Venezia 15, 35131 Padova, Italy. ; Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy. ; CNR-IFN UOS Padova LUXOR, Via Trasea, 7, 35131 Padova, Italy. ; Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden. ; UNITN, Universita di Trento, Via Mesiano, 77, 38100 Trento, Italy. ; Physikalisches Institut, Sidlerstrasse 5, University of Bern, 3012, Bern, Switzerland. ; INAF, Osservatorio Astronomico, Via Tiepolo 11, 34014 Trieste, Italy. ; Dipartimento di Geoscienze, University of Padova, via G. Gradenigo 6, 35131 Padova, Italy. ; Instituto de Astrofisica de Andalucia (CSIC), c/ Glorieta de la Astronomia s/n, 18008 Granada, Spain. ; Deutsches Zentrum fur Luft- und Raumfahrt (DLR), Institut fur Planetenforschung, Asteroiden und Kometen, Rutherfordstrasse 2, 12489 Berlin, Germany. Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg, 3, 37077, Gottingen, Germany. ; National Central University, Graduate Institute of Astronomy, 300 Chung-Da Road, Chung-Li 32054, Taiwan. ; Laboratoire d'Astrophysique de Marseille, 38 Rue de Frederic Joliot-Curie, 13388 Marseille Cedex 13, France. ; Deutsches Zentrum fur Luft- und Raumfahrt (DLR), Institut fur Planetenforschung, Asteroiden und Kometen, Rutherfordstrasse 2, 12489 Berlin, Germany. ; Science Operations Department, European Space Astronomy Centre/European Space Agency, Post Office Box 78, 28691 Villanueva de la Canada, Madrid, Spain. ; Solar System Exploration Research Virtual Institute, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302, USA. ; Dipartimento di Geoscienze, University of Padova, via G. Gradenigo 6, 35131 Padova, Italy. Centro di Ateneo di Studi ed Attivita Spaziali, "Giuseppe Colombo" (CISAS), University of Padova, Via Venezia 15, 35131 Padova, Italy. ; Institut fur Datentechnik und Kommunikationsnetze der Technische Universitat Braunschweig, Hans-Sommer-Strasse 66, 38106 Braunschweig, Germany. ; University of Padova, Department of Information Engineering, Via Gradenigo 6/B, 35131 Padova, Italy. CNR-IFN UOS Padova LUXOR, Via Trasea, 7, 35131 Padova, Italy. Centro di Ateneo di Studi ed Attivita Spaziali, "Giuseppe Colombo" (CISAS), University of Padova, Via Venezia 15, 35131 Padova, Italy. ; Instituto Nacional de Tecnica Aeroespacial, Carretera de Ajalvir, 28850 Torrejon de Ardoz (Madrid), Spain. ; Planetary and Space Sciences, Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK. Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg, 3, 37077, Gottingen, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25613893" target="_blank"〉PubMed〈/a〉

Description: The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The very low reflectance of the nucleus (normal albedo of 0.060 +/- 0.003 at 0.55 micrometers), the spectral slopes in visible and infrared ranges (5 to 25 and 1.5 to 5% kA(-1)), and the broad absorption feature in the 2.9-to-3.6-micrometer range present across the entire illuminated surface are compatible with opaque minerals associated with nonvolatile organic macromolecular materials: a complex mixture of various types of carbon-hydrogen and/or oxygen-hydrogen chemical groups, with little contribution of nitrogen-hydrogen groups. In active areas, the changes in spectral slope and absorption feature width may suggest small amounts of water-ice. However, no ice-rich patches are observed, indicating a generally dehydrated nature for the surface currently illuminated by the Sun.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Capaccioni, F -- Coradini, A -- Filacchione, G -- Erard, S -- Arnold, G -- Drossart, P -- De Sanctis, M C -- Bockelee-Morvan, D -- Capria, M T -- Tosi, F -- Leyrat, C -- Schmitt, B -- Quirico, E -- Cerroni, P -- Mennella, V -- Raponi, A -- Ciarniello, M -- McCord, T -- Moroz, L -- Palomba, E -- Ammannito, E -- Barucci, M A -- Bellucci, G -- Benkhoff, J -- Bibring, J P -- Blanco, A -- Blecka, M -- Carlson, R -- Carsenty, U -- Colangeli, L -- Combes, M -- Combi, M -- Crovisier, J -- Encrenaz, T -- Federico, C -- Fink, U -- Fonti, S -- Ip, W H -- Irwin, P -- Jaumann, R -- Kuehrt, E -- Langevin, Y -- Magni, G -- Mottola, S -- Orofino, V -- Palumbo, P -- Piccioni, G -- Schade, U -- Taylor, F -- Tiphene, D -- Tozzi, G P -- Beck, P -- Biver, N -- Bonal, L -- Combe, J-Ph -- Despan, D -- Flamini, E -- Fornasier, S -- Frigeri, A -- Grassi, D -- Gudipati, M -- Longobardo, A -- Markus, K -- Merlin, F -- Orosei, R -- Rinaldi, G -- Stephan, K -- Cartacci, M -- Cicchetti, A -- Giuppi, S -- Hello, Y -- Henry, F -- Jacquinod, S -- Noschese, R -- Peter, G -- Politi, R -- Reess, J M -- Semery, A -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):aaa0628. doi: 10.1126/science.aaa0628.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Rome, Italy. fabrizio.capaccioni@iaps.inaf.it. ; Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Rome, Italy. ; Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris/CNRS/Universite Pierre et Marie Curie[acute accent over last letter in "Universite"]/Universite Paris-Diderot, Meudon, France. ; Institute for Planetary Research, Deutsches Zentrum fur Luft- und Raumfahrt (DLR), Berlin, Germany. ; Universite Grenoble Alpes, CNRS, Institut de Planetologie et d'Astrophysique de Grenoble, Grenoble, France. ; Osservatorio di Capodimonte, INAF, Napoli, Italy. ; Bear Fight Institute, Winthrop, WA 98862, USA. ; University of California, Los Angeles, Los Angeles, CA 90095, USA. ; European Space Agency (ESA), European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands. ; Institut d'Astrophysique Spatial, CNRS, Orsay, France. ; Dipartimento di Matematica e Fisica "Ennio De Giorgi," Universita del Salento, Italy. ; Space Research Centre, Polish Academy of Sciences, Warsaw, Poland. ; NASA Jet Propulsion Laboratory, Pasadena, CA 91109, USA. ; Space Physics Research Laboratory, The University of Michigan, Ann Arbor, MI 48109, USA. ; Universita di Perugia, Perugia, Italy. ; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA. ; National Central University, Taipei, Taiwan. ; Departement of Physics, Oxford University, Oxford, UK. ; Institute for Planetary Research, Deutsches Zentrum fur Luft- und Raumfahrt (DLR), Berlin, Germany. Free University of Berlin, Institute of Geosciences, Malteserstrasse 74-100, Building Haus A, 12249 Berlin, Germany. ; Universita "Parthenope," Napoli, Italy. ; Helmholtz-Zentrum Berlin fur Materialien und Energie, Berlin, Germany. ; Osservatorio Astrofisico di Arcetri, INAF, Firenze, Italy. ; Agenzia Spaziale Italiana, Rome, Italy. ; NASA Jet Propulsion Laboratory, Pasadena, CA 91109, USA. Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA. ; Istituto di Radioastronomia, INAF, Bologna, Italy. ; Institut fur Optische Sensorsysteme, DLR, Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25613895" target="_blank"〉PubMed〈/a〉

Description: Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of 〉3 astronomical units is predominantly from the neck, where jets have been seen consistently. The nucleus rotates about the principal axis of momentum. The surface morphology suggests that the removal of larger volumes of material, possibly via explosive release of subsurface pressure or via creation of overhangs by sublimation, may be a major mass loss process. The shape raises the question of whether the two lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sierks, Holger -- Barbieri, Cesare -- Lamy, Philippe L -- Rodrigo, Rafael -- Koschny, Detlef -- Rickman, Hans -- Keller, Horst Uwe -- Agarwal, Jessica -- A'Hearn, Michael F -- Angrilli, Francesco -- Auger, Anne-Therese -- Barucci, M Antonella -- Bertaux, Jean-Loup -- Bertini, Ivano -- Besse, Sebastien -- Bodewits, Dennis -- Capanna, Claire -- Cremonese, Gabriele -- Da Deppo, Vania -- Davidsson, Bjorn -- Debei, Stefano -- De Cecco, Mariolino -- Ferri, Francesca -- Fornasier, Sonia -- Fulle, Marco -- Gaskell, Robert -- Giacomini, Lorenza -- Groussin, Olivier -- Gutierrez-Marques, Pablo -- Gutierrez, Pedro J -- Guttler, Carsten -- Hoekzema, Nick -- Hviid, Stubbe F -- Ip, Wing-Huen -- Jorda, Laurent -- Knollenberg, Jorg -- Kovacs, Gabor -- Kramm, J Rainer -- Kuhrt, Ekkehard -- Kuppers, Michael -- La Forgia, Fiorangela -- Lara, Luisa M -- Lazzarin, Monica -- Leyrat, Cedric -- Lopez Moreno, Jose J -- Magrin, Sara -- Marchi, Simone -- Marzari, Francesco -- Massironi, Matteo -- Michalik, Harald -- Moissl, Richard -- Mottola, Stefano -- Naletto, Giampiero -- Oklay, Nilda -- Pajola, Maurizio -- Pertile, Marco -- Preusker, Frank -- Sabau, Lola -- Scholten, Frank -- Snodgrass, Colin -- Thomas, Nicolas -- Tubiana, Cecilia -- Vincent, Jean-Baptiste -- Wenzel, Klaus-Peter -- Zaccariotto, Mirco -- Patzold, Martin -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):aaa1044. doi: 10.1126/science.aaa1044.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max-Planck-Institut fur Sonnensystemforschung, 37077 Gottingen, Germany. sierks@mps.mpg.de. ; Department of Physics and Astronomy, University of Padova, 35122 Padova, Italy. ; Laboratoire d'Astrophysique de Marseille, UMR 7326, CNRS & Aix Marseille Universite, 13388 Marseille Cedex 13, France. ; Centro de Astrobiologia, CSIC-INTA,28850 Madrid, Spain. International Space Science Institute, 3012 Bern, Switzerland. ; Scientific Support Office, European Space Research and Technology Centre/ESA, 2201 AZ Noordwijk ZH, Netherlands. ; Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden. PAS Space Research Center, 00716 Warszawa, Poland. ; Institut fur Geophysik und extraterrestrische Physik, Technische Universitat Braunschweig, 38106 Braunschweig, Germany. Deutsches Zentrum fur Luft- und Raumfahrt, Institut fur Planetenforschung, 12489 Berlin, Germany. ; Max-Planck-Institut fur Sonnensystemforschung, 37077 Gottingen, Germany. ; Max-Planck-Institut fur Sonnensystemforschung, 37077 Gottingen, Germany. Department of Astronomy, University of Maryland, College Park, MD 20742, USA. Akademie der Wissenschaften zu Gottingen, 37077 Gottingen, Germany. ; Department of Industrial Engineering, University of Padova, 35131 Padova, Italy. ; Aix Marseille Universite, CNRS, Laboratoire d'Astrophysique de Marseille, UMR 7326, 13388 Marseille, France. ; LESIA-Observatoire de Paris, CNRS, Universite Pierre et Marie Curie, Universite Paris Diderot, 92195 Meudon, France. ; LATMOS, CNRS/UVSQ/IPSL, 78280 Guyancourt, France. ; Centro di Ateneo di Studi ed Attivita Spaziali "Giuseppe Colombo" (CISAS), University of Padova, 35131 Padova, Italy. ; Department of Astronomy, University of Maryland, College Park, MD 20742, USA. ; INAF, Osservatorio Astronomico di Padova, 35122 Padova, Italy. ; CNR-IFN UOS Padova LUXOR, 35131 Padova, Italy. ; Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden. ; University of Trento, 38100 Trento, Italy. ; INAF - Osservatorio Astronomico di Trieste, 34014 Trieste, Italy. ; Planetary Science Institute, Tucson, AZ 85719, USA. ; Instituto de Astrofisica de Andalucia (CSIC), c/ Glorieta de la AstronomIa s/n, 18008 Granada, Spain. ; Max-Planck-Institut fur Sonnensystemforschung, 37077 Gottingen, Germany. Deutsches Zentrum fur Luft- und Raumfahrt, Institut fur Planetenforschung, 12489 Berlin, Germany. ; Graduate Institute of Astronomy, National Central University, Chung-Li 32054, Taiwan. Space Science Institute, Macau University of Science and Technology, Macao, China. ; Deutsches Zentrum fur Luft- und Raumfahrt, Institut fur Planetenforschung, 12489 Berlin, Germany. ; Operations Department, European Space Astronomy Centre/ESA, 28691 Villanueva de la Canada, Madrid, Spain. ; Solar System Exploration Research, Virtual Institute, Southwest Research Institute, Boulder, CO 80302, USA. ; Centro di Ateneo di Studi ed Attivita Spaziali "Giuseppe Colombo" (CISAS), University of Padova, 35131 Padova, Italy. Dipartimento di Geoscienze, University of Padova, 35131 Padova, Italy. ; Institut fur Datentechnik und Kommunikationsnetze der TU Braunschweig, 38106 Braunschweig, Germany. ; Centro di Ateneo di Studi ed Attivita Spaziali "Giuseppe Colombo" (CISAS), University of Padova, 35131 Padova, Italy. CNR-IFN UOS Padova LUXOR, 35131 Padova, Italy. Department of Information Engineering, University of Padova, 35131 Padova, Italy. ; Department of Industrial Engineering, University of Padova, 35131 Padova, Italy. Centro di Ateneo di Studi ed Attivita Spaziali "Giuseppe Colombo" (CISAS), University of Padova, 35131 Padova, Italy. ; Instituto Nacional de Tecnica Aeroespacial, 28850 Torrejon de Ardoz, Madrid, Spain. ; Physikalisches Institut, University of Bern, 3012 Bern, Switzerland. Center for Space and Habitability, University of Bern, 3012 Bern, Switzerland. ; Rheinisches Institut fur Umweltforschung, Abteilung Planetenforschung, Universitat zu Koln, 50931 Koln, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25613897" target="_blank"〉PubMed〈/a〉

Description: Heat transport and ice sublimation in comets are interrelated processes reflecting properties acquired at the time of formation and during subsequent evolution. The Microwave Instrument on the Rosetta Orbiter (MIRO) acquired maps of the subsurface temperature of comet 67P/Churyumov-Gerasimenko, at 1.6 mm and 0.5 mm wavelengths, and spectra of water vapor. The total H2O production rate varied from 0.3 kg s(-1) in early June 2014 to 1.2 kg s(-1) in late August and showed periodic variations related to nucleus rotation and shape. Water outgassing was localized to the "neck" region of the comet. Subsurface temperatures showed seasonal and diurnal variations, which indicated that the submillimeter radiation originated at depths comparable to the diurnal thermal skin depth. A low thermal inertia (~10 to 50 J K(-1) m(-2) s(-0.5)), consistent with a thermally insulating powdered surface, is inferred.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gulkis, Samuel -- Allen, Mark -- von Allmen, Paul -- Beaudin, Gerard -- Biver, Nicolas -- Bockelee-Morvan, Dominique -- Choukroun, Mathieu -- Crovisier, Jacques -- Davidsson, Bjorn J R -- Encrenaz, Pierre -- Encrenaz, Therese -- Frerking, Margaret -- Hartogh, Paul -- Hofstadter, Mark -- Ip, Wing-Huen -- Janssen, Michael -- Jarchow, Christopher -- Keihm, Stephen -- Lee, Seungwon -- Lellouch, Emmanuel -- Leyrat, Cedric -- Rezac, Ladislav -- Schloerb, F Peter -- Spilker, Thomas -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):aaa0709. doi: 10.1126/science.aaa0709.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Jet Propulsion Laboratory/California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA. samuel.gulkis@jpl.nasa.gov. ; Jet Propulsion Laboratory/California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA. ; LERMA, Observatoire de Paris, PSL Research University, UPMC Universite Paris 06, CNRS, UMR8112, F-75014 Paris, France. ; LESIA-Observatoire de Paris, CNRS, UPMC, Universite Paris-Diderot, 5 place Jules Janssen, 92195 Meudon, France. ; Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala, Sweden. ; Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Gottingen, Germany. ; National Central University, Jhongli, Taoyuan City 32001, Taiwan. ; University of Massachusetts, 619 Lederle Graduate Research Tower, Amherst, MA 01003, USA. Jet Propulsion Laboratory/California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25613896" target="_blank"〉PubMed〈/a〉