Animation showing the behaviour of water-ice observed in the neck region of Comet 67P/Churyumov-Gerasimenko between 1 August 2014 and 10 February 2015 by Rosetta’s VIRTIS instrument, when the comet-Sun separation decreased from 542 million km to 352 million km..
The blue regions indicate the presence of ice in the uppermost surface layer; red shows no ice; and grey indicates portions of the comet that were in shadow.
The animation shows the ice abundance at each time during the comet's 12.4 hour day, such that each data point represents the average, for a particular hour of the comet day, over the entire time period August-February.
Full details: http://blogs.esa.int/rosetta/2015/09/...
- ESA/Rosetta/VIRTIS/INAF-IAPS/OBS DE PARIS-LESIA/DLR; VIRTIS data projection on shape model by A. Zinzi (ASDC)