Montage of four images taken by Rosetta's navigation camera (NAVCAM) on 7 September 2014 at a distance of 51 km from comet 67P/Churyumov-Gerasimenko. The four images were taken in sequence as a 2×2 raster over a short period, meaning that there is some motion of the spacecraft and rotation of the comet between the images. The images have been cleaned to remove the more obvious bad 'pixel pairs' and cosmic ray artefacts, intensities have been scaled, and the montage has been cropped to remove most of the black space around the comet. For more details, see the Rosetta blog post : CometWatch 7 September