ALBERT

Description: The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brownlee, Don -- Tsou, Peter -- Aleon, Jerome -- Alexander, Conel M O'd -- Araki, Tohru -- Bajt, Sasa -- Baratta, Giuseppe A -- Bastien, Ron -- Bland, Phil -- Bleuet, Pierre -- Borg, Janet -- Bradley, John P -- Brearley, Adrian -- Brenker, F -- Brennan, Sean -- Bridges, John C -- Browning, Nigel D -- Brucato, John R -- Bullock, E -- Burchell, Mark J -- Busemann, Henner -- Butterworth, Anna -- Chaussidon, Marc -- Cheuvront, Allan -- Chi, Miaofang -- Cintala, Mark J -- Clark, B C -- Clemett, Simon J -- Cody, George -- Colangeli, Luigi -- Cooper, George -- Cordier, Patrick -- Daghlian, C -- Dai, Zurong -- D'Hendecourt, Louis -- Djouadi, Zahia -- Dominguez, Gerardo -- Duxbury, Tom -- Dworkin, Jason P -- Ebel, Denton S -- Economou, Thanasis E -- Fakra, Sirine -- Fairey, Sam A J -- Fallon, Stewart -- Ferrini, Gianluca -- Ferroir, T -- Fleckenstein, Holger -- Floss, Christine -- Flynn, George -- Franchi, Ian A -- Fries, Marc -- Gainsforth, Z -- Gallien, J-P -- Genge, Matt -- Gilles, Mary K -- Gillet, Philipe -- Gilmour, Jamie -- Glavin, Daniel P -- Gounelle, Matthieu -- Grady, Monica M -- Graham, Giles A -- Grant, P G -- Green, Simon F -- Grossemy, Faustine -- Grossman, Lawrence -- Grossman, Jeffrey N -- Guan, Yunbin -- Hagiya, Kenji -- Harvey, Ralph -- Heck, Philipp -- Herzog, Gregory F -- Hoppe, Peter -- Horz, Friedrich -- Huth, Joachim -- Hutcheon, Ian D -- Ignatyev, Konstantin -- Ishii, Hope -- Ito, Motoo -- Jacob, Damien -- Jacobsen, Chris -- Jacobsen, Stein -- Jones, Steven -- Joswiak, David -- Jurewicz, Amy -- Kearsley, Anton T -- Keller, Lindsay P -- Khodja, H -- Kilcoyne, A L David -- Kissel, Jochen -- Krot, Alexander -- Langenhorst, Falko -- Lanzirotti, Antonio -- Le, Loan -- Leshin, Laurie A -- Leitner, J -- Lemelle, L -- Leroux, Hugues -- Liu, Ming-Chang -- Luening, K -- Lyon, Ian -- Macpherson, Glen -- Marcus, Matthew A -- Marhas, Kuljeet -- Marty, Bernard -- Matrajt, Graciela -- McKeegan, Kevin -- Meibom, Anders -- Mennella, Vito -- Messenger, Keiko -- Messenger, Scott -- Mikouchi, Takashi -- Mostefaoui, Smail -- Nakamura, Tomoki -- Nakano, T -- Newville, M -- Nittler, Larry R -- Ohnishi, Ichiro -- Ohsumi, Kazumasa -- Okudaira, Kyoko -- Papanastassiou, Dimitri A -- Palma, Russ -- Palumbo, Maria E -- Pepin, Robert O -- Perkins, David -- Perronnet, Murielle -- Pianetta, P -- Rao, William -- Rietmeijer, Frans J M -- Robert, Francois -- Rost, D -- Rotundi, Alessandra -- Ryan, Robert -- Sandford, Scott A -- Schwandt, Craig S -- See, Thomas H -- Schlutter, Dennis -- Sheffield-Parker, J -- Simionovici, Alexandre -- Simon, Steven -- Sitnitsky, I -- Snead, Christopher J -- Spencer, Maegan K -- Stadermann, Frank J -- Steele, Andrew -- Stephan, Thomas -- Stroud, Rhonda -- Susini, Jean -- Sutton, S R -- Suzuki, Y -- Taheri, Mitra -- Taylor, Susan -- Teslich, Nick -- Tomeoka, Kazu -- Tomioka, Naotaka -- Toppani, Alice -- Trigo-Rodriguez, Josep M -- Troadec, David -- Tsuchiyama, Akira -- Tuzzolino, Anthony J -- Tyliszczak, Tolek -- Uesugi, K -- Velbel, Michael -- Vellenga, Joe -- Vicenzi, E -- Vincze, L -- Warren, Jack -- Weber, Iris -- Weisberg, Mike -- Westphal, Andrew J -- Wirick, Sue -- Wooden, Diane -- Wopenka, Brigitte -- Wozniakiewicz, Penelope -- Wright, Ian -- Yabuta, Hikaru -- Yano, Hajime -- Young, Edward D -- Zare, Richard N -- Zega, Thomas -- Ziegler, Karen -- Zimmerman, Laurent -- Zinner, Ernst -- Zolensky, Michael -- New York, N.Y. -- Science. 2006 Dec 15;314(5806):1711-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Astronomy, University of Washington, Seattle, WA 98195, USA. brownlee@astro.washington.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17170289" target="_blank"〉PubMed〈/a〉

Description: Organics found in comet 81P/Wild 2 samples show a heterogeneous and unequilibrated distribution in abundance and composition. Some organics are similar, but not identical, to those in interplanetary dust particles and carbonaceous meteorites. A class of aromatic-poor organic material is also present. The organics are rich in oxygen and nitrogen compared with meteoritic organics. Aromatic compounds are present, but the samples tend to be relatively poorer in aromatics than are meteorites and interplanetary dust particles. The presence of deuterium and nitrogen-15 excesses suggest that some organics have an interstellar/protostellar heritage. Although the variable extent of modification of these materials by impact capture is not yet fully constrained, a diverse suite of organic compounds is present and identifiable within the returned samples.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sandford, Scott A -- Aleon, Jerome -- Alexander, Conel M O'd -- Araki, Tohru -- Bajt, Sasa -- Baratta, Giuseppe A -- Borg, Janet -- Bradley, John P -- Brownlee, Donald E -- Brucato, John R -- Burchell, Mark J -- Busemann, Henner -- Butterworth, Anna -- Clemett, Simon J -- Cody, George -- Colangeli, Luigi -- Cooper, George -- D'Hendecourt, Louis -- Djouadi, Zahia -- Dworkin, Jason P -- Ferrini, Gianluca -- Fleckenstein, Holger -- Flynn, George J -- Franchi, Ian A -- Fries, Marc -- Gilles, Mary K -- Glavin, Daniel P -- Gounelle, Matthieu -- Grossemy, Faustine -- Jacobsen, Chris -- Keller, Lindsay P -- Kilcoyne, A L David -- Leitner, Jan -- Matrajt, Graciela -- Meibom, Anders -- Mennella, Vito -- Mostefaoui, Smail -- Nittler, Larry R -- Palumbo, Maria E -- Papanastassiou, Dimitri A -- Robert, Francois -- Rotundi, Alessandra -- Snead, Christopher J -- Spencer, Maegan K -- Stadermann, Frank J -- Steele, Andrew -- Stephan, Thomas -- Tsou, Peter -- Tyliszczak, Tolek -- Westphal, Andrew J -- Wirick, Sue -- Wopenka, Brigitte -- Yabuta, Hikaru -- Zare, Richard N -- Zolensky, Michael E -- New York, N.Y. -- Science. 2006 Dec 15;314(5806):1720-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Astrophysics Branch, NASA-Ames Research Center, Moffett Field, CA 94035, USA. ssandford@mail.arc.nasa.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17170291" target="_blank"〉PubMed〈/a〉

Description: Infrared spectra of material captured from comet 81P/Wild 2 by the Stardust spacecraft reveal indigenous aliphatic hydrocarbons similar to those in interplanetary dust particles thought to be derived from comets, but with longer chain lengths than those observed in the diffuse interstellar medium. Similarly, the Stardust samples contain abundant amorphous silicates in addition to crystalline silicates such as olivine and pyroxene. The presence of crystalline silicates in Wild 2 is consistent with mixing of solar system and interstellar matter. No hydrous silicates or carbonate minerals were detected, which suggests a lack of aqueous processing of Wild 2 dust.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Keller, Lindsay P -- Bajt, Sasa -- Baratta, Giuseppe A -- Borg, Janet -- Bradley, John P -- Brownlee, Don E -- Busemann, Henner -- Brucato, John R -- Burchell, Mark -- Colangeli, Luigi -- d'Hendecourt, Louis -- Djouadi, Zahia -- Ferrini, Gianluca -- Flynn, George -- Franchi, Ian A -- Fries, Marc -- Grady, Monica M -- Graham, Giles A -- Grossemy, Faustine -- Kearsley, Anton -- Matrajt, Graciela -- Nakamura-Messenger, Keiko -- Mennella, Vito -- Nittler, Larry -- Palumbo, Maria E -- Stadermann, Frank J -- Tsou, Peter -- Rotundi, Alessandra -- Sandford, Scott A -- Snead, Christopher -- Steele, Andrew -- Wooden, Diane -- Zolensky, Mike -- New York, N.Y. -- Science. 2006 Dec 15;314(5806):1728-31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Astromaterials Research and Exploration Science Directorate, Mail Code KR, NASA-Johnson Space Center, Houston, TX 77058, USA. lindsay.p.keller@nasa.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17170293" target="_blank"〉PubMed〈/a〉

Description: In this work, we applied infrared spectroscopy to investigate the spectral signature of the volcanic ash particles emitted during the 21–24 July 2001 eruption at Mount Etna, in Italy. We used a Bruker Equinox-55 Fourier transform infrared spectrometer in the range 7000–600 cm 1 (1.43–16.67 μm) and, for every collected spectrum, an image of the volcanic ash particles was recorded in the visible spectral range through the same microscope. These images were then analyzed by standard image analysis software in order to evaluate the main features of the particle: the length of the major and minor axes (Max and Min L), Feret diameter (FD), equivalent diameter (ED), and aspect ratio (AR). We measured transmission spectra in different conditions; spectra of one single particle (Single-Particle Measurement, SPM), spectra of a number of particles from two to ten (Multi-Particle Measurements type 1, MPM1) and of more than a hundred particles (Multi-Particle Measurements type 2, MPM2). For SPM,Max andMin L range between 5 and 24 μm and 3.5 and 15 μm, FD ranges between 5.5 and 25 μm, ED varies between 5 and 19 μm, and AR between 0.45 and 0.95. For MPM1 and MPM2, the mean values of Max and Min L are between 4–17 μm and 3–10 μm, FD and ED between 5 and 19 μm and 3.5 and 23 μm, and AR between 0.3 and 1. The optical depth spectra as a function of the wave number clearly show the presence of the Christiansen effect that produces high transmission at a given frequency in the infrared region (Christiansen frequency). We find that the effect depends on the particle size through a linear relation. Both the Christiansen effect and their relationship with the ash particle effective radius were compared with radiative transfer model simulations using different ash refractive indexes. The combined use of the linear relationship and the spectral position of the Christiansen frequency also indicated the possibility to characterize ash type. All these information can be used to improve the IR remote sensing volcanic ash quantitative estimations.

Description: Published

Description: 12207–12215

Description: 3V. Dinamiche e scenari eruttivi

Description: JCR Journal

Description: restricted