Heat transport and ice sublimation in comets are interrelated processes reflecting properties acquired at the time of formation and during subsequent evolution. The Microwave Instrument on the Rosetta Orbiter (MIRO) acquired maps of the subsurface temperature of comet 67P/Churyumov-Gerasimenko, at 1.6 mm and 0.5 mm wavelengths, and spectra of water vapor. The total H2O production rate varied from 0.3 kg s(-1) in early June 2014 to 1.2 kg s(-1) in late August and showed periodic variations related to nucleus rotation and shape. Water outgassing was localized to the "neck" region of the comet. Subsurface temperatures showed seasonal and diurnal variations, which indicated that the submillimeter radiation originated at depths comparable to the diurnal thermal skin depth. A low thermal inertia (~10 to 50 J K(-1) m(-2) s(-0.5)), consistent with a thermally insulating powdered surface, is inferred.
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Geometric preprocessing for measurements of comet 67P acquired by Rosetta's Visible and InfraRed Thermal Imaging Spectrometer, Mapping channel (VIRTIS-M).
Rev Sci Instrum
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Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstr. 2, 12489 Berlin, Germany.
Comet 67P/Churyumov-Gerasimenko (hereafter 67P) was the primary target of ESA's Rosetta mission. Hyperspectral images acquired by the Mapping channel of the Visible and InfraRed Thermal Imaging Spectrometer aboard Rosetta can be used to derive physical and compositional surface properties by detailed spectrophotometric analyses. This calls for a precise spatial co-registration between measurements and geometry information.
View Article and Find Full Text PDFA nearly terrestrial D/H for comet 67P/Churyumov-Gerasimenko.
Sci Adv
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Laboratory for Astrophysics and Space Physics, University of Colorado, Boulder, CO 80303, USA.
Cometary comae are a mixture of gas and ice-covered dust. Processing on the surface and in the coma change the composition of ice on dust grains relative to that of the nucleus. As the ice on dust grains sublimates, the local coma composition changes.
View Article and Find Full Text PDFCorrection of instrument temperature dependence of detector responsivity for measurements of comet 67P acquired by Rosetta's Visible and InfraRed Thermal Imaging Spectrometer, Mapping channel (VIRTIS-M).
Rev Sci Instrum
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Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstr. 2, 12489 Berlin, Germany.
Article Synopsis
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Philos Trans A Math Phys Eng Sci
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Max-Planck-Institut für Kernphysik , Heidelberg, Germany.
The Ulysses spacecraft was launched in 1990 and, after a Jupiter swing-by in 1992, became the first interplanetary spacecraft orbiting the Sun on a highly inclined trajectory with an inclination of [Formula: see text]. The spacecraft was equipped with an impact ionization dust detector which provided 17 years of dust measurements in interplanetary space from 1990 to 2007. Cometary meteoroid streams (also referred to as trails) exist along the orbits of comets, forming fine structures of the interplanetary dust cloud.
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