ALBERT

Description: Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vincent, Jean-Baptiste -- Bodewits, Dennis -- Besse, Sebastien -- Sierks, Holger -- Barbieri, Cesare -- Lamy, Philippe -- Rodrigo, Rafael -- Koschny, Detlef -- Rickman, Hans -- Keller, Horst Uwe -- Agarwal, Jessica -- A'Hearn, Michael F -- Auger, Anne-Therese -- Barucci, M Antonella -- Bertaux, Jean-Loup -- Bertini, Ivano -- Capanna, Claire -- Cremonese, Gabriele -- Da Deppo, Vania -- Davidsson, Bjorn -- Debei, Stefano -- De Cecco, Mariolino -- El-Maarry, Mohamed Ramy -- Ferri, Francesca -- Fornasier, Sonia -- Fulle, Marco -- Gaskell, Robert -- Giacomini, Lorenza -- Groussin, Olivier -- Guilbert-Lepoutre, Aurelie -- Gutierrez-Marques, P -- Gutierrez, Pedro J -- Guttler, Carsten -- Hoekzema, Nick -- Hofner, Sebastian -- Hviid, Stubbe F -- Ip, Wing-Huen -- Jorda, Laurent -- Knollenberg, Jorg -- Kovacs, Gabor -- Kramm, Rainer -- Kuhrt, Ekkehard -- Kuppers, Michael -- La Forgia, Fiorangela -- Lara, Luisa M -- Lazzarin, Monica -- Lee, Vicky -- Leyrat, Cedric -- Lin, Zhong-Yi -- Lopez Moreno, Jose J -- Lowry, Stephen -- Magrin, Sara -- Maquet, Lucie -- Marchi, Simone -- Marzari, Francesco -- Massironi, Matteo -- Michalik, Harald -- Moissl, Richard -- Mottola, Stefano -- Naletto, Giampiero -- Oklay, Nilda -- Pajola, Maurizio -- Preusker, Frank -- Scholten, Frank -- Thomas, Nicolas -- Toth, Imre -- Tubiana, Cecilia -- England -- Nature. 2015 Jul 2;523(7558):63-6. doi: 10.1038/nature14564.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Gottingen, Germany. ; University of Maryland, Department of Astronomy, College Park, Maryland 20742-2421, USA. ; Scientific Support Office, European Space Research and Technology Centre/ESA, Keplerlaan 1, Postbus 299, 2201 AZ Noordwijk ZH, The Netherlands. ; University of Padova, Department of Physics and Astronomy, Vicolo dell'Osservatorio 3, 35122 Padova, Italy. ; Laboratoire d'Astrophysique de Marseille, UMR 7326, CNRS and Aix Marseille Universite, 13388 Marseille Cedex 13, France. ; 1] Centro de Astrobiologia, CSIC-INTA, 28850 Torrejon de Ardoz, Madrid, Spain [2] International Space Science Institute, Hallerstrasse 6, 3012 Bern, Switzerland. ; 1] Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden [2] PAS Space Research Center, Bartycka 18A, 00716 Warszawa, Poland. ; Institut fur Geophysik und extraterrestrische Physik (IGEP), Technische Universitat Braunschweig, Mendelssohnstrasse 3, 38106 Braunschweig, Germany. ; 1] University of Maryland, Department of Astronomy, College Park, Maryland 20742-2421, USA [2] Akademie der Wissenschaften zu Gottingen and Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Gottingen, Germany. ; LESIA-Observatoire de Paris, CNRS, Universite Pierre et Marie Curie, Universite Paris Diderot, 5 place Jules Janssen, 92195 Meudon, France. ; LATMOS, 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. ; INAF, Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy. ; CNR-IFN UOS Padova LUXOR, via Trasea 7, 35131 Padova, Italy. ; Centro de Astrobiologia, CSIC-INTA, 28850 Torrejon de Ardoz, Madrid, Spain. ; Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy. ; University of Trento, via Mesiano 77, 38100 Trento, Italy. ; Physikalisches Institut der Universitat Bern, Sidlerstrasse 5, 3012 Bern, Switzerland. ; INAF Osservatorio Astronomico, via Tiepolo 11, 34014 Trieste, Italy. ; Planetary Science Institute, Tucson, Arizona 85719, USA. ; Instituto de Astrofisica de Andalucia (CSIC), Glorieta de la Astronomia s/n, 18008 Granada, Spain. ; Deutsches Zentrum fur Luft- und Raumfahrt (DLR), Institut fur Planetenforschung, Rutherfordstrasse 2, 12489 Berlin, Germany. ; National Central University, Graduate Institute of Astronomy, 300 Chung-Da Rd, Chung-Li 32054, Taiwan. ; Operations Department, European Space Astronomy Centre/ESA, PO Box 78, 28691 Villanueva de la Canada, Madrid, Spain. ; The University of Kent, School of Physical Sciences, Canterbury, Kent CT2 7NZ, UK. ; University of Padova, Deptartment of Physics and Astronomy, via Marzolo 8, 35131 Padova, Italy. ; Solar System Exploration Research Virtual Institute, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, Colorado 80302, USA. ; Dipartimento di Geoscienze, University of Padova, via Giovanni Gradenigo 6, 35131 Padova, Italy. ; Institut fur Datentechnik und Kommunikationsnetze der Technische Universitat Braunschweig, Hans-Sommer-Strasse 66, 38106 Braunschweig, Germany. ; 1] Centro di Ateneo di Studi ed Attivita Spaziali "Giuseppe Colombo" (CISAS), University of Padova, via Venezia 15, 35131 Padova, Italy [2] CNR-IFN UOS Padova LUXOR, via Trasea 7, 35131 Padova, Italy [3] University of Padova, Department of Information Engineering, via Gradenigo 6/B, 35131 Padova, Italy. ; Konkoly Observatory of the Hungarian Academy of Sciences, PO Box 67, 1525 Budapest, Hungary.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26135448" target="_blank"〉PubMed〈/a〉

Description: The factors shaping cometary nuclei are still largely unknown, but could be the result of concurrent effects of evolutionary and primordial processes. The peculiar bilobed shape of comet 67P/Churyumov-Gerasimenko may be the result of the fusion of two objects that were once separate or the result of a localized excavation by outgassing at the interface between the two lobes. Here we report that the comet's major lobe is enveloped by a nearly continuous set of strata, up to 650 metres thick, which are independent of an analogous stratified envelope on the minor lobe. Gravity vectors computed for the two lobes separately are closer to perpendicular to the strata than those calculated for the entire nucleus and adjacent to the neck separating the two lobes. Therefore comet 67P/Churyumov-Gerasimenko is an accreted body of two distinct objects with 'onion-like' stratification, which formed before they merged. We conclude that gentle, low-velocity collisions occurred between two fully formed kilometre-sized cometesimals in the early stages of the Solar System. The notable structural similarities between the two lobes of comet 67P/Churyumov-Gerasimenko indicate that the early-forming cometesimals experienced similar primordial stratified accretion, even though they formed independently.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Massironi, Matteo -- Simioni, Emanuele -- Marzari, Francesco -- Cremonese, Gabriele -- Giacomini, Lorenza -- Pajola, Maurizio -- Jorda, Laurent -- Naletto, Giampiero -- Lowry, Stephen -- El-Maarry, Mohamed Ramy -- Preusker, Frank -- Scholten, Frank -- Sierks, Holger -- Barbieri, Cesare -- Lamy, Philippe -- Rodrigo, Rafael -- Koschny, Detlef -- Rickman, Hans -- Keller, Horst Uwe -- A'Hearn, Michael F -- Agarwal, Jessica -- Auger, Anne-Therese -- Barucci, M Antonella -- Bertaux, Jean-Loup -- Bertini, Ivano -- Besse, Sebastien -- Bodewits, Dennis -- Capanna, Claire -- Da Deppo, Vania -- Davidsson, Bjorn -- Debei, Stefano -- De Cecco, Mariolino -- Ferri, Francesca -- Fornasier, Sonia -- Fulle, Marco -- Gaskell, Robert -- Groussin, Olivier -- Gutierrez, Pedro J -- Guttler, Carsten -- Hviid, Stubbe F -- Ip, Wing-Huen -- Knollenberg, Jorg -- Kovacs, Gabor -- Kramm, Rainer -- Kuhrt, Ekkehard -- Kuppers, Michael -- La Forgia, Fiorangela -- Lara, Luisa M -- Lazzarin, Monica -- Lin, Zhong-Yi -- Lopez Moreno, Jose J -- Magrin, Sara -- Michalik, Harald -- Mottola, Stefano -- Oklay, Nilda -- Pommerol, Antoine -- Thomas, Nicolas -- Tubiana, Cecilia -- Vincent, Jean-Baptiste -- England -- Nature. 2015 Oct 15;526(7573):402-5. doi: 10.1038/nature15511. Epub 2015 Sep 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉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. ; CNR-IFN UOS Padova LUXOR, via Trasea 7, 35131 Padova, Italy. ; University of Padova, Department of Physics and Astronomy, Vicolo dell'Osservatorio 3, 35122 Padova, Italy. ; INAF, Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy. ; Aix Marseille Universite, CNRS, LAM (Laboratoire d'Astrophysique de Marseille), UMR 7326, 38 rue Frederic Joliot-Curie, 13388 Marseille, France. ; Department of Information Engineering, University of Padova, via Gradenigo 6/B, 35131 Padova, Italy. ; The University of Kent, School of Physical Sciences, Canterbury, Kent CT2 7NZ, UK. ; Physikalisches Institut der Universitat Bern, Sidlerstrasse 5, 3012 Bern, Switzerland. ; Deutsches Zentrum fur Luft- und Raumfahrt (DLR), Institut fur Planetenforschung, Rutherfordstrasse 2, 12489 Berlin, Germany. ; Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig Weg 3, 37077 Gottingen, Germany. ; Centro de Astrobiologia, CSIC-INTA, 28850 Torrejon de Ardoz, Madrid, Spain. ; International Space Science Institute, Hallerstrasse 6, 3012 Bern, Switzerland. ; Scientific Support Office, European Space Research and Technology Centre/ESA, Keplerlaan 1, Postbus 299, 2201 AZ Noordwijk ZH, The Netherlands. ; Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden. ; PAS Space Research Center, Bartycka 18A, 00716 Warszawa, Poland. ; Institut fur Geophysik und extraterrestrische Physik (IGEP), Technische Universitat Braunschweig, Mendelssohnstrasse 3, 38106 Braunschweig, Germany. ; University of Maryland, Department of Astronomy, College Park, Maryland 20742-2421, USA. ; Akademie der Wissenschaften zu Gottingen and Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig Weg 3, 37077 Gottingen, Germany. ; LESIA-Observatoire de Paris, CNRS, Universite Pierre et Marie Curie, Universite Paris Diderot, 5 place J. Janssen, 92195 Meudon, France. ; LATMOS, CNRS/UVSQ/IPSL, 11 boulevard d'Alembert, 78280 Guyancourt, France. ; Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy. ; University of Trento, Via Mesiano 77, 38100 Trento, Italy. ; INAF-Osservatorio Astronomico, Via Tiepolo 11, 34014 Trieste, Italy. ; Planetary Science Institute, Tucson, Arizona 85719, USA. ; Instituto de Astrofisica de Andalucia (CSIC), Glorieta de la Astronomia s/n, 18008 Granada, Spain. ; National Central University, Graduate Institute of Astronomy, 300 Chung-Da Road, Chung-Li 32054 Taiwan. ; Operations Department, European Space Astronomy Centre/ESA, PO Box 78, 28691 Villanueva de la Canada, Madrid, Spain. ; Institut fur Datentechnik und Kommunikationsnetze der TU Braunschweig, Hans-Sommer Strasse 66, 38106 Braunschweig, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26416730" target="_blank"〉PubMed〈/a〉

Description: On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of dust mass to gas mass in the ejecta was much larger than before impact; (iii) the new activity did not last more than a few days, and by 9 July the comet's behavior was indistinguishable from its pre-impact behavior; and (iv) there were interesting transient phenomena that may be correlated with cratering physics.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Meech, K J -- Ageorges, N -- A'Hearn, M F -- Arpigny, C -- Ates, A -- Aycock, J -- Bagnulo, S -- Bailey, J -- Barber, R -- Barrera, L -- Barrena, R -- Bauer, J M -- Belton, M J S -- Bensch, F -- Bhattacharya, B -- Biver, N -- Blake, G -- Bockelee-Morvan, D -- Boehnhardt, H -- Bonev, B P -- Bonev, T -- Buie, M W -- Burton, M G -- Butner, H M -- Cabanac, R -- Campbell, R -- Campins, H -- Capria, M T -- Carroll, T -- Chaffee, F -- Charnley, S B -- Cleis, R -- Coates, A -- Cochran, A -- Colom, P -- Conrad, A -- Coulson, I M -- Crovisier, J -- deBuizer, J -- Dekany, R -- de Leon, J -- Dello Russo, N -- Delsanti, A -- DiSanti, M -- Drummond, J -- Dundon, L -- Etzel, P B -- Farnham, T L -- Feldman, P -- Fernandez, Y R -- Filipovic, M D -- Fisher, S -- Fitzsimmons, A -- Fong, D -- Fugate, R -- Fujiwara, H -- Fujiyoshi, T -- Furusho, R -- Fuse, T -- Gibb, E -- Groussin, O -- Gulkis, S -- Gurwell, M -- Hadamcik, E -- Hainaut, O -- Harker, D -- Harrington, D -- Harwit, M -- Hasegawa, S -- Hergenrother, C W -- Hirst, P -- Hodapp, K -- Honda, M -- Howell, E S -- Hutsemekers, D -- Iono, D -- Ip, W-H -- Jackson, W -- Jehin, E -- Jiang, Z J -- Jones, G H -- Jones, P A -- Kadono, T -- Kamath, U W -- Kaufl, H U -- Kasuga, T -- Kawakita, H -- Kelley, M S -- Kerber, F -- Kidger, M -- Kinoshita, D -- Knight, M -- Lara, L -- Larson, S M -- Lederer, S -- Lee, C-F -- Levasseur-Regourd, A C -- Li, J Y -- Li, Q-S -- Licandro, J -- Lin, Z-Y -- Lisse, C M -- LoCurto, G -- Lovell, A J -- Lowry, S C -- Lyke, J -- Lynch, D -- Ma, J -- Magee-Sauer, K -- Maheswar, G -- Manfroid, J -- Marco, O -- Martin, P -- Melnick, G -- Miller, S -- Miyata, T -- Moriarty-Schieven, G H -- Moskovitz, N -- Mueller, B E A -- Mumma, M J -- Muneer, S -- Neufeld, D A -- Ootsubo, T -- Osip, D -- Pandea, S K -- Pantin, E -- Paterno-Mahler, R -- Patten, B -- Penprase, B E -- Peck, A -- Petitas, G -- Pinilla-Alonso, N -- Pittichova, J -- Pompei, E -- Prabhu, T P -- Qi, C -- Rao, R -- Rauer, H -- Reitsema, H -- Rodgers, S D -- Rodriguez, P -- Ruane, R -- Ruch, G -- Rujopakarn, W -- Sahu, D K -- Sako, S -- Sakon, I -- Samarasinha, N -- Sarkissian, J M -- Saviane, I -- Schirmer, M -- Schultz, P -- Schulz, R -- Seitzer, P -- Sekiguchi, T -- Selman, F -- Serra-Ricart, M -- Sharp, R -- Snell, R L -- Snodgrass, C -- Stallard, T -- Stecklein, G -- Sterken, C -- Stuwe, J A -- Sugita, S -- Sumner, M -- Suntzeff, N -- Swaters, R -- Takakuwa, S -- Takato, N -- Thomas-Osip, J -- Thompson, E -- Tokunaga, A T -- Tozzi, G P -- Tran, H -- Troy, M -- Trujillo, C -- Van Cleve, J -- Vasundhara, R -- Vazquez, R -- Vilas, F -- Villanueva, G -- von Braun, K -- Vora, P -- Wainscoat, R J -- Walsh, K -- Watanabe, J -- Weaver, H A -- Weaver, W -- Weiler, M -- Weissman, P R -- Welsh, W F -- Wilner, D -- Wolk, S -- Womack, M -- Wooden, D -- Woodney, L M -- Woodward, C -- Wu, Z-Y -- Wu, J-H -- Yamashita, T -- Yang, B -- Yang, Y-B -- Yokogawa, S -- Zook, A C -- Zauderer, A -- Zhao, X -- Zhou, X -- Zucconi, J-M -- New York, N.Y. -- Science. 2005 Oct 14;310(5746):265-9. Epub 2005 Sep 8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute for Astronomy, University of Hawaii at Manoa, 2680 Woodlawn Drive, Honolulu, HI 96822, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16150977" target="_blank"〉PubMed〈/a〉

Description: The Magnetospheric Imaging Instrument (MIMI) onboard the Cassini spacecraft observed the saturnian magnetosphere from January 2004 until Saturn orbit insertion (SOI) on 1 July 2004. The MIMI sensors observed frequent energetic particle activity in interplanetary space for several months before SOI. When the imaging sensor was switched to its energetic neutral atom (ENA) operating mode on 20 February 2004, at approximately 10(3) times Saturn's radius RS (0.43 astronomical units), a weak but persistent signal was observed from the magnetosphere. About 10 days before SOI, the magnetosphere exhibited a day-night asymmetry that varied with an approximately 11-hour periodicity. Once Cassini entered the magnetosphere, in situ measurements showed high concentrations of H+, H2+, O+, OH+, and H2O+ and low concentrations of N+. The radial dependence of ion intensity profiles implies neutral gas densities sufficient to produce high loss rates of trapped ions from the middle and inner magnetosphere. ENA imaging has revealed a radiation belt that resides inward of the D ring and is probably the result of double charge exchange between the main radiation belt and the upper layers of Saturn's exosphere.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Krimigis, S M -- Mitchell, D G -- Hamilton, D C -- Krupp, N -- Livi, S -- Roelof, E C -- Dandouras, J -- Armstrong, T P -- Mauk, B H -- Paranicas, C -- Brandt, P C -- Bolton, S -- Cheng, A F -- Choo, T -- Gloeckler, G -- Hayes, J -- Hsieh, K C -- Ip, W-H -- Jaskulek, S -- Keath, E P -- Kirsch, E -- Kusterer, M -- Lagg, A -- Lanzerotti, L J -- Lavallee, D -- Manweiler, J -- McEntire, R W -- Rasmuss, W -- Saur, J -- Turner, F S -- Williams, D J -- Woch, J -- New York, N.Y. -- Science. 2005 Feb 25;307(5713):1270-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA. tom.krimigis@jhuapl.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15731445" target="_blank"〉PubMed〈/a〉

Description: The impact cratering process on a comet is controversial but holds the key for interpreting observations of the Deep Impact collision with comet 9P/Tempel 1. Mid-infrared data from the Cooled Mid-Infrared Camera and Spectrometer (COMICS) of the Subaru Telescope indicate that the large-scale dust plume ejected by the impact contained a large mass (approximately 10(6) kilograms) of dust and formed two wings approximately +/-45 degrees from the symmetric center, both consistent with gravity as the primary control on the impact and its immediate aftermath. The dust distribution in the inner part of the plume, however, is inconsistent with a pure gravity control and implies that evaporation and expansion of volatiles accelerated dust.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sugita, S -- Ootsubo, T -- Kadono, T -- Honda, M -- Sako, S -- Miyata, T -- Sakon, I -- Yamashita, T -- Kawakita, H -- Fujiwara, H -- Fujiyoshi, T -- Takato, N -- Fuse, T -- Watanabe, J -- Furusho, R -- Hasegawa, S -- Kasuga, T -- Sekiguchi, T -- Kinoshita, D -- Meech, K J -- Wooden, D H -- Ip, W H -- A'Hearn, M F -- New York, N.Y. -- Science. 2005 Oct 14;310(5746):274-8. Epub 2005 Sep 15.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Complexity Science and Engineering, University of Tokyo, Kashiwa, Chiba, Japan. sugita@k.u-tokyo.ac.jp〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16166476" target="_blank"〉PubMed〈/a〉

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〉