During the far encounter phase of Voyager 1 in March 1979, Europa appeared smooth with little differences in elevation apparent on the surface. Broad zones of dark and light terrain were noted, as well as linear markings stretching a third of the way across the satellite.

Close-up views provided by Voyager 1 and 2 indicate that the light and dark colored lines are the dominant feature on this moon of Jupiter. These structures represent depressed and elevated areas on the satellite, although little differences in elevation have been noted. Only a few possible impact craters have been detected in Voyager images.