Temporal morphological changes in the Imhotep region of comet 67P/Churyumov-Gerasimenko

Abstract

We report on the first major temporal morphological changes observed on the surface of the nucleus of comet 67P/Churyumov-Gerasimenko, in the smooth terrains of the Imhotep region. We use images of the OSIRIS cameras onboard Rosetta to follow the temporal changes from 24 May 2015 to 11 July 2015. The morphological changes observed on the surface are visible in the form of roundish features, which are growing in size from a given location in a preferential direction, at a rate of 5.6 - 8.1$\times$10${}^{-5}$ m s${}^{-1}$ during the observational period. The location where changes started and the contours of the expanding features are bluer than the surroundings, suggesting the presence of ices (H${}_2$O and/or CO${}_2$) exposed on the surface. However, sublimation of ices alone is not sufficient to explain the observed expanding features. No significant variations in the dust activity pattern are observed during the period of changes.

4 pages, 3 figures; Letter for Astronomy and Astrophysics: accepted

References in corpus (2)

• Spectrophotometric properties of the nucleus of comet 67P/Churyumov-Gerasimenko from the OSIRIS instrument onboard the ROSETTA spacecraft
• Gravitational slopes, geomorphology, and material strengths of the nucleus of comet 67P/Churyumov-Gerasimenko from OSIRIS observations

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• Airfall on Comet 67P/Churyumov-Gerasimenko
• Sublimation of icy aggregates in the coma of comet 67P/Churyumov-Gerasimenko detected with the OSIRIS cameras onboard Rosetta
• The Effect of Cosmic Rays on Cometary Nuclei: I Dose deposition
• Surface evolution of the Anhur region on comet 67P from high-resolution OSIRIS images
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• Volatile exposures on the 67P/Churyumov-Gerasimenko nucleus
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• CO2-driven surface changes in the Hapi region on Comet 67P/Churyumov-Gerasimenko
• Evolution of pits at the surface of 67P/Churyumov-Gerasimenko
• ROSETTA/OSIRIS observations of the 67P nucleus during the April 2016 flyby: high-resolution spectrophotometry
• Ancient and present surface evolution processes in the Ash regionof comet 67P/Churyumov-Gerasimenko
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