Europas surface Coloured Galileo spacecraft image of the surface of Europa one of the four Galilean moons of Jupiter The image has been processed to enhance the surfaces colour differ ences ice contaminated with rocky material is red or brown finegrained ice is light blue ice with coarse grains is dark blue The brown lines are cracks in the icy crust which have been filled by material coming up from beneath These fractures can be more than kilometres km long Image made by combining observations by Galileos Solid State Imaging camera at wavelengths of and nanometres The image area is about xkm