On 3 July 2016, a plume was spotted on Comet 67P/Churyumov-Gerasimenko, from inside the ice-filled depression close to the large boulder near the bottom of this image. This plume was especially useful from a scientific point of view. As well as observing the site of the plume and the plume itself, the Rosetta Mission’s trajectory took it through the ejected material, allowing the spacecraft to collect valuable measurements. Analysis of these data indicates that some as-yet-undetermined source of subsurface energy helped to power the plume. This image is a false-colour composite, where the pale blue patches highlight the presence and location of water-ice. See http://www.esa.int/spaceinimages/Images/2017/10/Water_ice_in_Imhotep_region
