ALBERT

Description: Analysis of Hubble Space Telescope (HST) images of comet Hale-Bopp (C/1995 O1) suggests that the effective diameter of the nucleus is between 27 to 42 kilometers, which is at least three times larger than that of comet P/Halley. The International Ultraviolet Explorer and HST spectra showed emissions from OH (a tracer of H2O) and CS (a tracer of CS2) starting in April 1996, and from the CO Cameron system (which primarily traces CO2) starting in June 1996. The variation of the H2O production rate with heliocentric distance was consistent with sublimation of an icy body near its subsolar point. The heliocentric variation in the production rates of CS2 and dust was different from that of H2O, which implies that H2O sublimation did not control the CS2 or dust production during these observations.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Weaver, H A -- Feldman, P D -- A'Hearn, M F -- Arpigny, C -- Brandt, J C -- Festou, M C -- Haken, M -- McPhate, J B -- Stern, S A -- Tozzi, G P -- New York, N.Y. -- Science. 1997 Mar 28;275(5308):1900-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9072959" target="_blank"〉PubMed〈/a〉

Description: Deep Impact collided with comet Tempel 1, excavating a crater controlled by gravity. The comet's outer layer is composed of 1- to 100-micrometer fine particles with negligible strength (〈65 pascals). Local gravitational field and average nucleus density (600 kilograms per cubic meter) are estimated from ejecta fallback. Initial ejecta were hot (〉1000 kelvins). A large increase in organic material occurred during and after the event, with smaller changes in carbon dioxide relative to water. On approach, the spacecraft observed frequent natural outbursts, a mean radius of 3.0 +/- 0.1 kilometers, smooth and rough terrain, scarps, and impact craters. A thermal map indicates a surface in equilibrium with sunlight.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉A'Hearn, M F -- Belton, M J S -- Delamere, W A -- Kissel, J -- Klaasen, K P -- McFadden, L A -- Meech, K J -- Melosh, H J -- Schultz, P H -- Sunshine, J M -- Thomas, P C -- Veverka, J -- Yeomans, D K -- Baca, M W -- Busko, I -- Crockett, C J -- Collins, S M -- Desnoyer, M -- Eberhardy, C A -- Ernst, C M -- Farnham, T L -- Feaga, L -- Groussin, O -- Hampton, D -- Ipatov, S I -- Li, J-Y -- Lindler, D -- Lisse, C M -- Mastrodemos, N -- Owen, W M Jr -- Richardson, J E -- Wellnitz, D D -- White, R L -- New York, N.Y. -- Science. 2005 Oct 14;310(5746):258-64. Epub 2005 Sep 8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉University of Maryland, College Park, MD 20742, USA. ma@astro.umd.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16150978" 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 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: We report the direct detection of solid water ice deposits exposed on the surface of comet 9P/Tempel 1, as observed by the Deep Impact mission. Three anomalously colored areas are shown to include water ice on the basis of their near-infrared spectra, which include diagnostic water ice absorptions at wavelengths of 1.5 and 2.0 micrometers. These absorptions are well modeled as a mixture of nearby non-ice regions and 3 to 6% water ice particles 10 to 50 micrometers in diameter. These particle sizes are larger than those ejected during the impact experiment, which suggests that the surface deposits are loose aggregates. The total area of exposed water ice is substantially less than that required to support the observed ambient outgassing from the comet, which likely has additional source regions below the surface.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sunshine, J M -- A'Hearn, M F -- Groussin, O -- Li, J-Y -- Belton, M J S -- Delamere, W A -- Kissel, J -- Klaasen, K P -- McFadden, L A -- Meech, K J -- Melosh, H J -- Schultz, P H -- Thomas, P C -- Veverka, J -- Yeomans, D K -- Busko, I C -- Desnoyer, M -- Farnham, T L -- Feaga, L M -- Hampton, D L -- Lindler, D J -- Lisse, C M -- Wellnitz, D D -- New York, N.Y. -- Science. 2006 Mar 10;311(5766):1453-5. Epub 2006 Feb 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Science Applications International Corporation (SAIC), Chantilly, VA 20151, USA. sunshinej@saic.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16456037" target="_blank"〉PubMed〈/a〉