Large patches of water ice found on comet surface
Date: 16 November 2016
Satellite: Rosetta
Depicts: Comet 67P/Churyumov-Gerasimenko
Copyright: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; Reprinted with permission from S. Fornasier et al., Science 10.1126/science.aag2671 (2016)
At the end of April 2015, Rosetta's OSIRIS narrow angle camera detected two unusually large patches of water ice on Comet 67P/Churyumov-Gerasimenko, between the southern regions of Anhur and Bes.
The graphic shows the appearance of the two bright spots (indicated as A and B), which persisted for about 10 days before they completely disappeared.
The two ice-rich areas span some 30 m × 40 m each – larger than the size of an Olympic swimming pool – and are much larger than the many metre-sized patches of exposed water ice that had been previously spotted at the comet.
The two patches contain 20–30% of water ice mixed with darker material, forming a layer up to 30 cm thick of solid ice. The water ice patch indicated as A was likely lurking underneath the carbon dioxide ice sheet revealed by Rosetta's VIRTIS instrument about a month before.
This finding is part of a broader study on seasonal and daily colour variations on the surface of the comet based on OSIRIS images obtained throughout the course of the mission.
For more information see: Icy surprises at Rosetta's comet
