These two Galileo images of Europa's trailing hemisphere show the satellite in natural (left) and false colors. The false-color view at right (comprised of violet, green, and infrared images) highlights color differences in the moon's water-ice crust. Dark brown areas represent rocky material, bright bluish plains in the polar areas are possibly coarse-grained ice (dark blue) and fine-grained ice (light blue). Long, dark lines are fractures in the crust, some of which are more than 1,850 miles (3,000 kilometers) long.