Gale Crater. False-colour mosaic image of Gale Crater (centre) on the surface of Mars. This crater is the exploration site of NASA's Curiosity rover. The colours in this image come from an image processing technique that identifies mineral differences in surface materials and displays them in false colours. Windblown dust appears pale pink and olivine-rich basalt looks purple. The bright pink on Gale's floor is due to a mix of basaltic sand and windblown dust. The blue at the summit of Gale's central mound, Mount Sharp, probably comes from local materials exposed there. The typical average Martian surface soil looks greyish-green. Scientists use false-colour images such as these to identify places of potential geologic interest. Imaged by the Thermal