Water ice in Imhotep region - colour
On 3 July 2016, a dust plume was spotted streaming from Comet 67P/Churyumov–Gerasimenko (67P/C-G), the target of ESA's Rosetta mission. This image, taken by Rosetta's OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System), shows the appearance of the plume site at 21:26 UTC on 2 July 2016, about 10 hours before the outburst took place.
This view comprises three separate images from OSIRIS's Narrow Angle Camera, and combines observations gathered using the system's red (near-infrared), green, and blue channels (coloured red, orange, and blue respectively to create this false-colour composite). The patches of light blue seen in the frame indicate the presence and location of water ice. The outburst was located within the ice-filled depression near the large boulder towards the bottom of the frame.
The 3 July 2016 plume was especially useful from a scientific perspective. As well as observing both the site of the plume and the plume itself, Rosetta's trajectory took it through the ejected material, allowing instruments on the spacecraft to collect valuable in situ measurements. Analysis of these data indicates that some as-yet-undetermined source of subsurface energy helped to power the plume.
Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA