Figure 7-14 Surface Features on Europa (a) This false-color Galileo image of Europa combining visible and infrared observations shows smooth plains of ice, mineral ridges deposited by upwelling water, and numerous fractures believed to be caused by tidal stresses. (b) This region of Europa’s surface shows the jumbled, stressed features common to the surface, as well as direct indications of liquid water activity underground. (c) Lenticulae attributed to rising warmed ice and debris travel up from the moon’s interior by convection, arriving at and then leaking out at the surface. The white domes are likely to be rising material that has not yet reached the surface. (d) A lava lamp in which warmed material rises through cooler liquid. The rising material in Europa is analogous to the rising motion of the blobs in a lava lamp, except that on Europa, the motion is through ice.