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The nucleus and coma of 67P/Churyumov-Gerasimenko: highlights of the Rosetta-VIRTIS results

Capaccioni, F. and Filacchione, G. and Erard, S. and Arnold, Gabriele and Bockelee-Morvan, D. and De Sanctis, M.C. and Leyrat, C. and Tosi, F. and Schmitt, B. and Quirico, E. and Capria, M. T. and Ciarnello, M. and Raponi, A. and Kührt, E. and Piccioni, G. and Palomba, E. and Drossart, P. and Cerroni, P. and McCord, Thomas B. and Barucci, Antonella (2015) The nucleus and coma of 67P/Churyumov-Gerasimenko: highlights of the Rosetta-VIRTIS results. In: Geophysical Research Abstracts, 17, p. 12375. EGU General Assembly 2015, 12. April - 17. April 2015, Vienna, Austria.

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Official URL: http://meetingorganizer.copernicus.org/EGU2015/EGU2015-12375.pdf

Abstract

This paper will describe the major results obtained so far during the prelanding and initial escort phases (July 2014–February 2015) by the VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) dual channel spectrometer onboard Rosetta. The scientific goals of the VIRTIS instrument are related to the study of the nucleus surface composition and of its temperature and to the study of the gaseous and dust components of the coma. These are achieved by studying the reflected and emitted radiance of the comet in the spectral range 0.25-5.0 μm with a Mapping Spectrometer (VIRTIS-M) and a High Resolution Spectrometer (VIRTIS-H). The nucleus observations were performed with spatial resolution varying from the initial 500m down to 2.5m and have generated compositional maps of the illuminated areas. The nucleus integrated normal albedo has been calculated as 0.060 ± 0.003 at 0.55 μm, and reflectance spectra display distinct gradients in the VIS and IR regions (5-25 and 1.5-5 % kÅ-1 respectively). These results suggest a surface made of an association of carbon bearing species and opaque minerals such as sulfides. In addition a broad absorption feature in the 2.9-3.6μm range has been observed; this band is present across the entire illuminated surface and, its shape and width are compatible with absorptions due to non-volatile organic macromolecular materials, complex mixture of various types of C-H and/or O-H chemical groups. Ice rich regions of very limited extent, have also been observed. The surface temperature has been measured since the first distant observations of the nucleus in thermal emission. The highest surface temperature seen so far is 220K, which is an indication of a surface structure largely covered by a porous crust, mainly devoid of water ice. Water vapour and carbon dioxide molecules have been observed in the coma and their variability, as a function of altitude and geographic location has been studied. The molecules display an anti-correlated behaviour in their spatial distribution, which could suggest either intrinsic differences in the nucleus composition or insolation induced variability, which most probably will imply seasonal changes.

Item URL in elib:https://elib.dlr.de/100898/
Document Type:Conference or Workshop Item (Speech)
Title:The nucleus and coma of 67P/Churyumov-Gerasimenko: highlights of the Rosetta-VIRTIS results
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Capaccioni, F.INAF-IASF, italyUNSPECIFIED
Filacchione, G.INAF-IASF, Rome, ItalyUNSPECIFIED
Erard, S.LESIAUNSPECIFIED
Arnold, GabrieleGabriele.Arnold (at) dlr.deUNSPECIFIED
Bockelee-Morvan, D.Observatoire de Paris, MeudonUNSPECIFIED
De Sanctis, M.C.Istituto Nazionale di Astrofisica, Rome, Italy.UNSPECIFIED
Leyrat, C.LESIAUNSPECIFIED
Tosi, F.INAF-IASF Istituto di Astrofisica Spaziale e Fisica Cosmica, Roma ItalyUNSPECIFIED
Schmitt, B.Grenoble Planetology LaboratoryUNSPECIFIED
Quirico, E.Laboratory of Planetology, CNRS Joseph Fourier UniversityUNSPECIFIED
Capria, M. T.Instituto di Astrofisica Spaziale e Fisica Cosmica, Roma, ItalyUNSPECIFIED
Ciarnello, M.INAF-IASF, ItalyUNSPECIFIED
Raponi, A.INAF-IASF, ItalyUNSPECIFIED
Kührt, E.ekkehard.kuehrt (at) dlr.deUNSPECIFIED
Piccioni, G.INAF-IASFUNSPECIFIED
Palomba, E.Institute for Interplanetary Space Physics - INAF, Rome, ItalyUNSPECIFIED
Drossart, P.Observatoire de Paris, Meudon, FranceUNSPECIFIED
Cerroni, P.INAF-IASF, Rome, ItalyUNSPECIFIED
McCord, Thomas B.Bear Fight Institute, Winthrop, WA, United States.UNSPECIFIED
Barucci, AntonellaObservatoire de Paris-Meudon, FranceUNSPECIFIED
Date:13 April 2015
Journal or Publication Title:Geophysical Research Abstracts
Refereed publication:No
Open Access:Yes
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Volume:17
Page Range:p. 12375
Status:Published
Keywords:VIRTIS, Rosetta, 67P
Event Title:EGU General Assembly 2015
Event Location:Vienna, Austria
Event Type:international Conference
Event Dates:12. April - 17. April 2015
Organizer:European Geosciences Union
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Space Science and Exploration
DLR - Research area:Raumfahrt
DLR - Program:R EW - Erforschung des Weltraums
DLR - Research theme (Project):R - Projekt ROSETTA Instrumente
Location: Berlin-Adlershof
Institutes and Institutions:Institute of Planetary Research > Leitungsbereich PF
Deposited By: Kappel, David
Deposited On:17 Dec 2015 08:48
Last Modified:31 Jul 2019 19:58

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