The subtle tints seen in this colour-composite image of the floor of Kibuye crater on Mars, in the region of Terra Sirenum, highlight the rich variety of mineralogical composition found in these rocks.
The image was taken by the Colour and Stereo Surface Imaging System (CaSSIS) onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter on 15 December 2018. Chloride salt and clay minerals have been identified here from orbit in the past by infrared spectrometers. CaSSIS colour-composite images processed like this one allow scientists to refine the mapping of Mars mineralogy at higher spatial scales. In this region, for example, there is strong evidence for sustained weathering of the rocks by water and possible ancient lakes.
Such colour-composite images illustrate the extraordinary sensitivity of CaSSIS to the mineralogical composition of the rocks.
The image is centred at 29.1°S/178.2°E.