Journal ArticleDOI
In situ gas and ion measurements at comet Halley
Dieter Krankowsky,P. Lämmerzahl,I. Herrwerth,J. Woweries,Peter Eberhardt,U. Dolder,U. Herrmann,W. Schulte,J. J. Berthelier,J. M. Illiano,R. R. Hodges,J. H. Hoffman +11 more
Reads0
Chats0
TLDR
The Giotto space probe's neutral mass spectrometer experiment has determined the abundances and the chemical, elemental and isotopic compositions of gases and low energy ions in the coma of comet Halley.Abstract:
The Giotto space probe's neutral mass spectrometer experiment has determined the abundances and the chemical, elemental and isotopic compositions of gases and low energy ions in the coma of comet Halley. Preliminary results show water predominating, at about 80 percent by volume, with a density of 4.7 x 10 to the 7th molecules/cu cm at 1000 km and a photodestruction scale length of 39,000 km. Limits on the abundances of CO2, NH3 and CH4 relative to H2O are also obtained. An ion temperature change observation indicates a contact surface location at 47,000 + or - 200 km.read more
Citations
More filters
Journal ArticleDOI
Inventory of the volatiles on comet 67P/Churyumov-Gerasimenko from Rosetta/ROSINA
Léna Le Roy,Kathrin Altwegg,Hans Balsiger,Jean-Jacques Berthelier,André Bieler,Christelle Briois,Ursina Calmonte,Michael R. Combi,Johan De Keyser,Frederik Dhooghe,Björn Fiethe,Stephen A. Fuselier,Stephen A. Fuselier,Sébastien Gasc,Tamas I. Gombosi,Myrtha Hässig,Myrtha Hässig,Annette Jäckel,Martin Rubin,Chia-Yu Tzou +19 more
TL;DR: In this article, the double focus mass spectrometer (DFMS) of the ROSINA experiment on ESA's Rosetta mission was used to determine relative abundances of major and minor volatile species.
The composition of cometary volatiles
Abstract: The composition of cometary ices provides key information on the chemical and physical properties of the outer solar nebula where comets formed, 4.6 G.y. ago. This chapter summarizes our current knowledge of the volatile composition of cometary nuclei, based on spectroscopic observations and in situ measurements of parent molecules and noble gases in cometary comae. The processes that govern the excitation and emission of parent molecules in the radio, infrared (IR), and ultraviolet (UV) wavelength regions are reviewed. The techniques used to convert line or band fluxes into molecular production rates are described. More than two dozen parent molecules have been identified, and we describe how each is investigated. The spatial distribution of some of these molecules has been studied by in situ measurements, long-slit IR and UV spectroscopy, and millimeter wave mapping, including interferometry. The spatial distributions of CO, H2CO, and OCS differ from that expected during direct sublimation from the nucleus, which suggests that these species are produced, at least partly, from extended sources in the coma. Abundance determinations for parent molecules are reviewed, and the evidence for chemical diversity among comets is discussed.
Journal ArticleDOI
Molecular Nitrogen in Comet 67P/Churyumov-Gerasimenko Indicates a Low Formation Temperature
Martin Rubin,Kathrin Altwegg,Hans Balsiger,Akiva Bar-Nun,Jean-Jacques Berthelier,André Bieler,André Bieler,Peter Bochsler,C. Briois,Ursina Calmonte,Michael R. Combi,J. De Keyser,Frederik Dhooghe,Peter Eberhardt,B. Fiethe,Stephen A. Fuselier,Sébastien Gasc,Tamas I. Gombosi,Kirk C. Hansen,Myrtha Hässig,Myrtha Hässig,Annette Jäckel,E. Kopp,A. Korth,Léna Le Roy,Ulrich Mall,Bernard Marty,Olivier Mousis,T. C. Owen,Henri Rème,Henri Rème,Thierry Sémon,Chia-Yu Tzou,J. H. Waite,Peter Wurz +34 more
TL;DR: Direct measurements of N2 by instruments aboard the Rosetta spacecraft provide clues about the comet’s long history and depletion of molecular nitrogen at levels that are depleted compared to those in the primordial solar system suggests that the comet formed at low-temperature conditions below ~30 kelvin.
Journal ArticleDOI
Cyanogen jets in comet Halley
Michael F. A'Hearn,Susan Hoban,Peter V. Birch,Craig Bowers,Ralph Martin,Daniel A. Klinglesmith +5 more
TL;DR: In this paper, a CCD camera system at the Perth Observatory during the post-perihelion phase of Comet Halley was used to acquire the emission-band and continuum data of the comet.
Journal ArticleDOI
Imaging results from Dynamics Explorer 1
L. A. Frank,J. D. Craven +1 more
TL;DR: An overview of the most significant results from the global imaging instrumentation on board the earth-orbiting spacecraft Dynamics Explorer 1 is provided in this article, including the evolution of the auroral oval during substorms.
References
More filters
Journal ArticleDOI
The effects of the diffuse radiation fields due to multiple scattering and thermal reradiation by dust on the dynamics and thermodynamics of a dusty cometary atmosphere
M. L. Marconi,D. A. Mendis +1 more
TL;DR: In this paper, a self-consistent model of a dirty, clathrate cometary nucleus is extended to account for diffuse radiation fields caused by multiple scattering and thermal reradiation of the solar continuum by dust.
Journal ArticleDOI
On the Variability of Lyman-alpha With Solar-activity
Lucien Bossy,Marcel Nicolet +1 more