Looking for the ice in the Imhotep and Anhur regions with MIRO/Rosetta
Abstract
After the arrival of the Rosetta spacecraft at the 67P/Churyumov-Gerasimenko comet in August 2014, and continuing until the end of mission in September 2016, the MIRO (Microwave Instrument for Rosetta Orbiter, performed broadband, continuum measurements at 188 GHz (1.6 mm wavelength) and 562 GHz (0.5 mm wavelength) of the nucleus and coma. The instrument measured the thermal emission from the close subsurface over a wide range of spatial resolutions (20 - 500 m) and emission angles.
One of the surprising results of the Rosetta mission is that although water ice was unequivocally detected in the coma its presence on the surface is limited. The presence of bright spots by the OSIRIS camera is indicative of its presence in some very limited areas and on boulders but the VIRTIS spectrometer has constrained to a maximum of 1% the surface water ice coverage. The thermal emission of the surface measured by MIRO when combined with a numerical thermal model of the subsurface of the nucleus allows us to constrain the subsurface properties including the water ice content in the first 10 cm. Therefore, MIRO is essential in locating the water ice in the top layers of the nucleus. We will present this method and use it on two regions: the illuminated and flat Imhotep region and the shadowed and rough Anhur region. In both these regions, temporary patches of water ice have been found on the surface and we will use MIRO data to search for evidence of additional presence of ice in the first 10 cm of the nucleus.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.P23G3518L
- Keywords:
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- 6008 Composition;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6017 Erosion and weathering;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6023 Comets: dust tails and trails;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6025 Interactions with solar wind plasma and fields;
- PLANETARY SCIENCES: COMETS AND SMALL BODIES