ALBERT

Description: Infrared observations of the coma of 67P/Churyumov–Gerasimenko were carried out from 2015 July to September, i.e. around perihelion (2015 August 13), with the high-resolution channel of the Visible and Infrared Thermal Imaging Spectrometer instrument onboard Rosetta . We present the analysis of fluorescence emission lines of H 2 O, CO 2 , 13 CO 2 , OCS, and CH 4 detected in limb sounding with the field of view at 2.7–5 km from the comet centre. Measurements are sampling outgassing from the illuminated Southern hemisphere, as revealed by H 2 O and CO 2 raster maps, which show anisotropic distributions, aligned along the projected rotation axis. An abrupt increase of water production is observed 6 d after perihelion. In the meantime, CO 2 , CH 4 , and OCS abundances relative to water increased by a factor of 2 to reach mean values of 32, 0.47, and 0.18 per cent, respectively, averaging post-perihelion data. We interpret these changes as resulting from the erosion of volatile-poor surface layers. Sustained dust ablation due to the sublimation of water ice maintained volatile-rich layers near the surface until at least the end of the considered period, as expected for low thermal inertia surface layers. The large abundance measured for CO 2 should be representative of the 67P nucleus original composition, and indicates that 67P is a CO 2 -rich comet. Comparison with abundance ratios measured in the Northern hemisphere shows that seasons play an important role in comet outgassing. The low CO 2 /H 2 O values measured above the illuminated Northern hemisphere are not original, but the result of the devolatilization of the uppermost layers.

Description: The Jovian moon, Europa, hosts a thin neutral gas atmosphere, which is tightly coupled to Jupiter's magnetosphere. Magnetospheric ions impacting the surface sputter off neutral atoms, which, upon ionization, carry currents that modify the magnetic field around the moon. The magnetic field in the plasma is also affected by Europa's induced magnetic field. In this paper we investigate the environment of Europa using our multifluid MHD model and focus on the effects introduced by both the magnetospheric and the pick-up ion populations. The model self-consistently derives the electron temperature that governs the electron impact ionization process, which is the major source of ionization in this environment. The resulting magnetic field is compared to measurements performed by the Galileo magnetometer, the bulk properties of the modeled thermal plasma population is compared to the Galileo PLS observations, and the modeled surface precipitation fluxes are compared to Galileo Ultraviolet Spectrometer observations. The model shows good agreement with the measured magnetic field and reproduces the basic features of the plasma interaction observed at the moon for both the E4 and the E26 flybys of the Galileo spacecraft. The simulation also produces perturbations asymmetric about the flow direction that account for observed asymmetries.

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: Molecular nitrogen (N2) is thought to have been the most abundant form of nitrogen in the protosolar nebula. It is the main N-bearing molecule in the atmospheres of Pluto and Triton and probably the main nitrogen reservoir from which the giant planets formed. Yet in comets, often considered the most primitive bodies in the solar system, N2 has not been detected. Here we report the direct in situ measurement of N2 in the Jupiter family comet 67P/Churyumov-Gerasimenko, made by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis mass spectrometer aboard the Rosetta spacecraft. A N2/CO ratio of (5.70 +/- 0.66) x 10(-3) (2sigma standard deviation of the sampled mean) corresponds to depletion by a factor of ~25.4 +/- 8.9 as compared to the protosolar value. This depletion suggests that cometary grains formed at low-temperature conditions below ~30 kelvin.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Rubin, M -- Altwegg, K -- Balsiger, H -- Bar-Nun, A -- Berthelier, J-J -- Bieler, A -- Bochsler, P -- Briois, C -- Calmonte, U -- Combi, M -- De Keyser, J -- Dhooghe, F -- Eberhardt, P -- Fiethe, B -- Fuselier, S A -- Gasc, S -- Gombosi, T I -- Hansen, K C -- Hassig, M -- Jackel, A -- Kopp, E -- Korth, A -- Le Roy, L -- Mall, U -- Marty, B -- Mousis, O -- Owen, T -- Reme, H -- Semon, T -- Tzou, C-Y -- Waite, J H -- Wurz, P -- New York, N.Y. -- Science. 2015 Apr 10;348(6231):232-5. doi: 10.1126/science.aaa6100. Epub 2015 Mar 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. martin.rubin@space.unibe.ch. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Center for Space and Habitability, University of Bern, Sidlerstrasse. 5, CH-3012 Bern, Switzerland. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. ; Department of Geoscience, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel. ; Laboratoire Atmospheres, Milieux, Observations Spatiales (LATMOS)/Institute Pierre Simon Laplace-CNRS-UPMC-UVSQ, 4 Avenue de Neptune F-94100, Saint-Maur, France. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA. ; Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), UMR 6115 CNRS-Universite d'Orleans, Orleans, France. ; Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA. ; Belgian Institute for Space Aeronomy, Belgisch Instituut voor Ruimte-Aeronomie-Institut d'Aeronomie Spatiale de Belgique (BIRA-IASB), Ringlaan 3, B-1180 Brussels, Belgium. ; Institute of Computer and Network Engineering, Technische Universitat Braunschweig, Hans-Sommer-Strasse 66, D-38106 Braunschweig, Germany. ; Department of Space Science, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Department of Space Science, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA. ; Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Gottingen, Germany. ; Center for Space and Habitability, University of Bern, Sidlerstrasse. 5, CH-3012 Bern, Switzerland. ; Centre de Recherches Petrographiques et Geochimiques (CRPG)-CNRS, Universite de Lorraine, 15 rue Notre Dame des Pauvres, Boite Postale 20, 54501 Vandoeuvre les Nancy, France. ; Aix Marseille Universite, CNRS, Laboratoire d'Astrophysique de Marseille UMR 7326, 13388, Marseille, France. ; Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA. ; Universite de Toulouse; UPS-OMP; Institut de Recherche en Astrophysique et Planetologie (IRAP), Toulouse, France. CNRS; IRAP; 9 Avenue du Colonel Roche, Boite Postale 44346, F-31028 Toulouse Cedex 4, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25791084" target="_blank"〉PubMed〈/a〉

Description: The Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements of martian thermosphere and ionosphere composition, structure, and variability at altitudes down to ~130 kilometers in the subsolar region. This altitude range contains the diffusively separated upper atmosphere just above the well-mixed atmosphere, the layer of peak extreme ultraviolet heating and primary reservoir for atmospheric escape. In situ measurements of the upper atmosphere reveal previously unmeasured populations of neutral and charged particles, the homopause altitude at approximately 130 kilometers, and an unexpected level of variability both on an orbit-to-orbit basis and within individual orbits. These observations help constrain volatile escape processes controlled by thermosphere and ionosphere structure and variability.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bougher, S -- Jakosky, B -- Halekas, J -- Grebowsky, J -- Luhmann, J -- Mahaffy, P -- Connerney, J -- Eparvier, F -- Ergun, R -- Larson, D -- McFadden, J -- Mitchell, D -- Schneider, N -- Zurek, R -- Mazelle, C -- Andersson, L -- Andrews, D -- Baird, D -- Baker, D N -- Bell, J M -- Benna, M -- Brain, D -- Chaffin, M -- Chamberlin, P -- Chaufray, J-Y -- Clarke, J -- Collinson, G -- Combi, M -- Crary, F -- Cravens, T -- Crismani, M -- Curry, S -- Curtis, D -- Deighan, J -- Delory, G -- Dewey, R -- DiBraccio, G -- Dong, C -- Dong, Y -- Dunn, P -- Elrod, M -- England, S -- Eriksson, A -- Espley, J -- Evans, S -- Fang, X -- Fillingim, M -- Fortier, K -- Fowler, C M -- Fox, J -- Groller, H -- Guzewich, S -- Hara, T -- Harada, Y -- Holsclaw, G -- Jain, S K -- Jolitz, R -- Leblanc, F -- Lee, C O -- Lee, Y -- Lefevre, F -- Lillis, R -- Livi, R -- Lo, D -- Ma, Y -- Mayyasi, M -- McClintock, W -- McEnulty, T -- Modolo, R -- Montmessin, F -- Morooka, M -- Nagy, A -- Olsen, K -- Peterson, W -- Rahmati, A -- Ruhunusiri, S -- Russell, C T -- Sakai, S -- Sauvaud, J-A -- Seki, K -- Steckiewicz, M -- Stevens, M -- Stewart, A I F -- Stiepen, A -- Stone, S -- Tenishev, V -- Thiemann, E -- Tolson, R -- Toublanc, D -- Vogt, M -- Weber, T -- Withers, P -- Woods, T -- Yelle, R -- New York, N.Y. -- Science. 2015 Nov 6;350(6261):aad0459. doi: 10.1126/science.aad0459.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉CLaSP Department, University of Michigan, Ann Arbor, MI, USA. bougher@umich.edu. ; Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA. ; Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA. ; NASA/Goddard Space Flight Center, Greenbelt, MD, USA. ; Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA. ; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA. ; CNRS/Institut de Recherche en Astrophysique et Planetologie, Toulouse, France. University Paul Sabatier, Toulouse, France. ; Swedish Institute of Space Physics, Kiruna, Sweden. ; NASA/Johnson Space Center, Houston, TX, USA. ; National Institute of Aerospace, Hampton, VA, USA. ; Laboratoire Atmospheres, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France. ; Department of Astronomy, Boston University, Boston, MA, USA. ; CLaSP Department, University of Michigan, Ann Arbor, MI, USA. ; Department of Physics and Astronomy, University of Kansas, Lawrence, KS, USA. ; Computational Physics, Springfield, VA, USA. ; Department of Physics, Wright State University, Fairborn, OH, USA. ; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA. ; Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Los Angeles, CA, USA. ; Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi, Japan. ; Naval Research Laboratory, Washington, DC, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26542579" target="_blank"〉PubMed〈/a〉

Description: Comets contain the best-preserved material from the beginning of our planetary system. Their nuclei and comae composition reveal clues about physical and chemical conditions during the early solar system when comets formed. ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) onboard the Rosetta spacecraft has measured the coma composition of comet 67P/Churyumov-Gerasimenko with well-sampled time resolution per rotation. Measurements were made over many comet rotation periods and a wide range of latitudes. These measurements show large fluctuations in composition in a heterogeneous coma that has diurnal and possibly seasonal variations in the major outgassing species: water, carbon monoxide, and carbon dioxide. These results indicate a complex coma-nucleus relationship where seasonal variations may be driven by temperature differences just below the comet surface.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hassig, M -- Altwegg, K -- Balsiger, H -- Bar-Nun, A -- Berthelier, J J -- Bieler, A -- Bochsler, P -- Briois, C -- Calmonte, U -- Combi, M -- De Keyser, J -- Eberhardt, P -- Fiethe, B -- Fuselier, S A -- Galand, M -- Gasc, S -- Gombosi, T I -- Hansen, K C -- Jackel, A -- Keller, H U -- Kopp, E -- Korth, A -- Kuhrt, E -- Le Roy, L -- Mall, U -- Marty, B -- Mousis, O -- Neefs, E -- Owen, T -- Reme, H -- Rubin, M -- Semon, T -- Tornow, C -- Tzou, C-Y -- Waite, J H -- Wurz, P -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):aaa0276. doi: 10.1126/science.aaa0276. Epub 2015 Jan 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, USA. myrtha.haessig@swri.org. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Center for Space and Habitability (CSH), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. ; Department of Geosciences, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel. ; Laboratoire Atmospheres, Milieux, Observations Spatiales (LATMOS), Institute Pierre Simon Laplace (IPSL), Centre national de recherche scientifique (CNRS), Universite Pierre et Marie Curie (UPMC), Universite de Versailles Saint-Quentin-en-Yvelines (UVSQ), BP 102, UPMC, 4 Place Jussieu, F-75252 Paris Cedex 05, France. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109, USA. ; Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), UMR 7328 CNRS - Universite d'Orleans, France. ; Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109, USA. ; Belgian Institute for Space Aeronomy (BIRA-IASB), Ringlaan 3, B-1180 Brussels, Belgium. Center for Plasma Astrophysics, KULeuven, Celestijnenlaan 200D, 3001 Heverlee, Belgium. ; Institute of Computer and Network Engineering (IDA), TU Braunschweig, Hans-Sommer-Strasse 66, D-38106 Braunschweig, Germany. ; Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, USA. ; Department of Physics, Imperial College London, Prince Consort Road, London SW7 2AZ, UK. ; Institute for Geophysics and Extraterrestrial Physics, Technische Universitat (TU) Braunschweig, 38106 Braunschweig, Germany. German Aerospace Center, Institute of Planetary Research, Asteroids and Comets, Rutherfordstrasse 2, 12489 Berlin, Germany. ; Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Gottingen, Germany. ; German Aerospace Center, Institute of Planetary Research, Asteroids and Comets, Rutherfordstrasse 2, 12489 Berlin, Germany. ; Center for Space and Habitability (CSH), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. ; Centre de Recherches Petrographiques et Geochimiques (CRPG), 15 Rue Notre Dame des Pauvres, BP 20, 54501 Vandoeuvre les Nancy, France. ; Aix Marseille Universite, CNRS, LAM (Laboratoire d'Astrophysique de Marseille), UMR 7326, 13388, Marseille, France. ; Engineering Division, BIRA-IASB, Ringlaan 3, B-1180 Brussels, Belgium. ; Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA. ; Universite de Toulouse, Universite Paul Sabathier (UPS), Observatoire de Midi-Pyrenees (OMP), Institut de Recherche en Astrophysique et Planetologie (IRAP), Toulouse, France. CNRS, IRAP, 9 Avenue du Colonel Roche, BP 44346, F-31028 Toulouse Cedex 4, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25613892" 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: Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jakosky, B M -- Grebowsky, J M -- Luhmann, J G -- Connerney, J -- Eparvier, F -- Ergun, R -- Halekas, J -- Larson, D -- Mahaffy, P -- McFadden, J -- Mitchell, D F -- Schneider, N -- Zurek, R -- Bougher, S -- Brain, D -- Ma, Y J -- Mazelle, C -- Andersson, L -- Andrews, D -- Baird, D -- Baker, D -- Bell, J M -- Benna, M -- Chaffin, M -- Chamberlin, P -- Chaufray, Y-Y -- Clarke, J -- Collinson, G -- Combi, M -- Crary, F -- Cravens, T -- Crismani, M -- Curry, S -- Curtis, D -- Deighan, J -- Delory, G -- Dewey, R -- DiBraccio, G -- Dong, C -- Dong, Y -- Dunn, P -- Elrod, M -- England, S -- Eriksson, A -- Espley, J -- Evans, S -- Fang, X -- Fillingim, M -- Fortier, K -- Fowler, C M -- Fox, J -- Groller, H -- Guzewich, S -- Hara, T -- Harada, Y -- Holsclaw, G -- Jain, S K -- Jolitz, R -- Leblanc, F -- Lee, C O -- Lee, Y -- Lefevre, F -- Lillis, R -- Livi, R -- Lo, D -- Mayyasi, M -- McClintock, W -- McEnulty, T -- Modolo, R -- Montmessin, F -- Morooka, M -- Nagy, A -- Olsen, K -- Peterson, W -- Rahmati, A -- Ruhunusiri, S -- Russell, C T -- Sakai, S -- Sauvaud, J-A -- Seki, K -- Steckiewicz, M -- Stevens, M -- Stewart, A I F -- Stiepen, A -- Stone, S -- Tenishev, V -- Thiemann, E -- Tolson, R -- Toublanc, D -- Vogt, M -- Weber, T -- Withers, P -- Woods, T -- Yelle, R -- New York, N.Y. -- Science. 2015 Nov 6;350(6261):aad0210. doi: 10.1126/science.aad0210.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉University of Colorado, Boulder, CO, USA. bruce.jakosky@lasp.colorado.edu. ; NASA/Goddard Space Flight Center, Greenbelt, MD, USA. ; University of California at Berkeley, Berkeley, CA, USA. ; University of Colorado, Boulder, CO, USA. ; University of Iowa, Iowa City, IA, USA. ; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA. ; University of Michigan, Ann Arbor, MI, USA. ; University of California at Los Angeles, Los Angeles, CA, USA. ; CNRS-Institut de Recherche en Astrophysique et Planetologie (IRAP), Toulouse, France. University Paul Sabatier, Toulouse, France. ; Swedish Institute of Space Physics, Uppsala, Sweden. ; NASA/Johnson Space Center, Houston, TX, USA. ; National Institute of Aerospace, Hampton, VA, USA. ; Laboratoire atmospheres, milieux et observations spatiales (LATMOS)-CNRS, Paris, France. ; Boston University, Boston, MA, USA. ; University of Kansas, Lawrence, KS, USA. ; Computational Physics, Inc., Boulder, CO, USA. ; Wright State University, Dayton, OH, USA. ; University of Arizona, Tucson, AZ, USA. ; Nagoya University, Nagoya, Japan. ; Naval Research Laboratory, Washington, DC, USA. ; North Carolina State University, Raleigh, NC, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26542576" target="_blank"〉PubMed〈/a〉

Description: The provenance of water and organic compounds on Earth and other terrestrial planets has been discussed for a long time without reaching a consensus. One of the best means to distinguish between different scenarios is by determining the deuterium-to-hydrogen (D/H) ratios in the reservoirs for comets and Earth's oceans. Here, we report the direct in situ measurement of the D/H ratio in the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA mass spectrometer aboard the European Space Agency's Rosetta spacecraft, which is found to be (5.3 +/- 0.7) x 10(-4)-that is, approximately three times the terrestrial value. Previous cometary measurements and our new finding suggest a wide range of D/H ratios in the water within Jupiter family objects and preclude the idea that this reservoir is solely composed of Earth ocean-like water.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Altwegg, K -- Balsiger, H -- Bar-Nun, A -- Berthelier, J J -- Bieler, A -- Bochsler, P -- Briois, C -- Calmonte, U -- Combi, M -- De Keyser, J -- Eberhardt, P -- Fiethe, B -- Fuselier, S -- Gasc, S -- Gombosi, T I -- Hansen, K C -- Hassig, M -- Jackel, A -- Kopp, E -- Korth, A -- LeRoy, L -- Mall, U -- Marty, B -- Mousis, O -- Neefs, E -- Owen, T -- Reme, H -- Rubin, M -- Semon, T -- Tzou, C-Y -- Waite, H -- Wurz, P -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):1261952. doi: 10.1126/science.1261952. Epub 2014 Dec 10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. altwegg@space.unibe.ch. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. ; Department of Geosciences, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel. ; Laboratoire Atmospheres, Milieux, Observations Spatiales (LATMOS), 4 Avenue de Neptune, F-94100 Saint-Maur, France. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA. ; Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), UMR 6115 CNRS-Universite d'Orleans, France. ; Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI 48109, USA. ; Space Physics Division, Belgisch Instituut voor Ruimte-Aeronomie (BIRA)-Institut d'Aeronomie Spatiale de Belgique (IASB), Ringlaan 3, B-1180 Brussels, Belgium. ; Institute of Computer and Network Engineering (IDA), Technicsche Universitat Braunschweig, Hans-Sommer-Strasse 66, D-38106 Braunschweig, Germany. ; Department of Space Science, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA. ; Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. Department of Space Science, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA. ; Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Gottingen, Germany. ; Centre de Recherches Petrographiques et Geochimiques, Centre de Recherches Petrographiques et Geochimiques (CRPG)-CNRS, Universite de Lorraine, 15 rue Notre Dame des Pauvres, BP 20, 54501 Vandoeuvre les Nancy, France. ; Universite de Franche-Comte, Institut Univers, Transport, Interfaces, Nanostructures, Atmosphere et Environnement, Molecules (UTINAM), CNRS/Institut National des Sciences de l'Univers (INSU), UMR 6213 Besancon Cedex, France. ; Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA. ; Universite de Toulouse, Universite Paul Sabatier (UPS)-Observatoire Midi-Pyrenees (OMP), Institut de Recherche en Astrophysique et Planetologie (IRAP), Toulouse, France. CNRS, IRAP, 9 Avenue du Colonel Roche, BP 44346, F-31028 Toulouse cedex 4, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25501976" target="_blank"〉PubMed〈/a〉

Description: Although water vapour is the main species observed in the coma of comet 67P/Churyumov-Gerasimenko and water is the major constituent of cometary nuclei, limited evidence for exposed water-ice regions on the surface of the nucleus has been found so far. The absence of large regions of exposed water ice seems a common finding on the surfaces of many of the comets observed so far. The nucleus of 67P/Churyumov-Gerasimenko appears to be fairly uniformly coated with dark, dehydrated, refractory and organic-rich material. Here we report the identification at infrared wavelengths of water ice on two debris falls in the Imhotep region of the nucleus. The ice has been exposed on the walls of elevated structures and at the base of the walls. A quantitative derivation of the abundance of ice in these regions indicates the presence of millimetre-sized pure water-ice grains, considerably larger than in all previous observations. Although micrometre-sized water-ice grains are the usual result of vapour recondensation in ice-free layers, the occurrence of millimetre-sized grains of pure ice as observed in the Imhotep debris falls is best explained by grain growth by vapour diffusion in ice-rich layers, or by sintering. As a consequence of these processes, the nucleus can develop an extended and complex coating in which the outer dehydrated crust is superimposed on layers enriched in water ice. The stratigraphy observed on 67P/Churyumov-Gerasimenko is therefore the result of evolutionary processes affecting the uppermost metres of the nucleus and does not necessarily require a global layering to have occurred at the time of the comet's formation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Filacchione, G -- De Sanctis, M C -- Capaccioni, F -- Raponi, A -- Tosi, F -- Ciarniello, M -- Cerroni, P -- Piccioni, G -- Capria, M T -- Palomba, E -- Bellucci, G -- Erard, S -- Bockelee-Morvan, D -- Leyrat, C -- Arnold, G -- Barucci, M A -- Fulchignoni, M -- Schmitt, B -- Quirico, E -- Jaumann, R -- Stephan, K -- Longobardo, A -- Mennella, V -- Migliorini, A -- Ammannito, E -- Benkhoff, J -- Bibring, J P -- Blanco, A -- Blecka, M I -- Carlson, R -- Carsenty, U -- Colangeli, L -- Combes, M -- Combi, M -- Crovisier, J -- Drossart, P -- Encrenaz, T -- Federico, C -- Fink, U -- Fonti, S -- Ip, W H -- Irwin, P -- Kuehrt, E -- Langevin, Y -- Magni, G -- McCord, T -- Moroz, L -- Mottola, S -- Orofino, V -- Schade, U -- Taylor, F -- Tiphene, D -- Tozzi, G P -- Beck, P -- Biver, N -- Bonal, L -- Combe, J-Ph -- Despan, D -- Flamini, E -- Formisano, M -- Fornasier, S -- Frigeri, A -- Grassi, D -- Gudipati, M S -- Kappel, D -- Mancarella, F -- Markus, K -- Merlin, F -- Orosei, R -- Rinaldi, G -- Cartacci, M -- Cicchetti, A -- Giuppi, S -- Hello, Y -- Henry, F -- Jacquinod, S -- Reess, J M -- Noschese, R -- Politi, R -- Peter, G -- England -- Nature. 2016 Jan 21;529(7586):368-72. doi: 10.1038/nature16190. Epub 2016 Jan 13.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉INAF-IAPS, Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy. ; LESIA, Observatoire de Paris/CNRS/UPMC/Universite Paris-Diderot, Meudon, France. ; Institute for Planetary Research, DLR, Berlin, Germany. ; Universite Grenoble Alpes, CNRS, IPAG, Grenoble, France. ; INAF-Osservatorio di Capodimonte, Napoli, Italy. ; UCLA, Los Angeles, California, USA. ; European Space Agency-ESTEC, Noordwijk, The Netherlands. ; Institut d'Astrophysique Spatial CNRS, Orsay, France. ; Dipartimento di Matematica e Fisica "Ennio De Giorgi", Universita del Salento, Lecce, Italy. ; Space Research Centre, Polish Academy of Sciences, Warsaw, Poland. ; NASA JPL, Pasadena, California, USA. ; Space Physics Research Laboratory, The University of Michigan, Michigan, Ann Arbor, USA. ; Universita di Perugia, Perugia, Italy. ; Lunar Planetary Laboratory, University of Arizona, Tucson, Arizona, USA. ; National Central University, Taipei, Taiwan. ; Department of Physics, Oxford University, Oxford, UK. ; Bear Fight Institute, Winthrop, Washington, USA. ; Helmholtz-Zentrum Berlin fur Materialien und Energie, Berlin, Germany. ; INAF-Osservatorio Astrofisico di Arcetri, Firenze, Italy. ; Agenzia Spaziale Italiana, Rome, Italy. ; Istituto di Radioastronomia-INAF, Bologna, Italy. ; Institute of Optical Sensor Systems, DLR, Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26760209" target="_blank"〉PubMed〈/a〉