The ratio of light passing through the 750 nm (red) filter relative to the 550 nm (green) filter from the HRI (left) and MRI (right) instruments. The dark band around the limb of the comet in the MRI image is an artifact of registering the images (the space craft was moving so fast, that images taken a few seconds apart present slightly different faces to the camera. It is not possible to align two images exactly). The darkest areas on the nucleus, the three regions toward the top of the nucleus, are the regions where water ice was found and reported by Sunshine et al. 2006. The blue color palette is arbitrarily chosen and does not represent the color of the nucleus.
Photo Credit: NASA/UM/Jianyang Li
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