The Galileo SSI obtained this view of a boundary between bright and dark terrain at the southern border of Galileo Regio on Ganymede on May 7, 1997. A narrow (15-kilometer wide) band of fractured bright terrain runs from the upper left to lower right of this image. The dark terrain on either side of this band of bright terrain has been highly fractured in multiple directions by tectonic activity. The large bright circular feature in the upper right is probably an impact crater that has been topographically relaxed, perhaps indicating that the subsurface was warm in this region at some point in its history before the formation of the bright terrain.

NASA / JPL / OWW